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  • phosphorus  (681)
  • Springer  (681)
  • Oxford University Press
  • American Chemical Society (ACS)
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  • 1
    Digitale Medien
    Digitale Medien
    Ni–Zn–P alloy deposition from sulfate bath: inhibitory effect of zinc (1999)
    Springer
    Journal of applied electrochemistry 29 (1999), S. 1171-1176 
    Details
    ISSN: 1572-8838
    Schlagwort(e): alloys ; cyclic voltammetry ; electrodeposition ; electroless deposition ; nickel ; phosphorus ; zinc
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: Abstract Electroless Ni–Zn–P alloy deposition from a sulphate bath, containing sodium hypophosphite as reducer, was investigated. To increase the plating rate, the deposition parameters were optimized. The effect of process parameters (T, pH and [Zn2+]) on the plating rate and deposit composition was examined and it was found that the presence of zinc in the bath has an inhibitory effect on the alloy deposition. As a consequence, the percentage of zinc in the electroless Ni–Zn–P alloys never reaches high values. Using cyclic voltammetry the electrodeposition mechanism of Ni–Zn–P alloys was investigated. It was observed that the zinc deposition inhibits the nickel discharge and, as a consequence, its catalytic activity on hypophosphite oxidation. It was also found that increase in temperature or pH leads to the deposition of nickel rich alloys.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003426904395
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  • 2
    Digitale Medien
    Digitale Medien
    Structure of (meso-5,10,15,20-tetraphenylporphyrinato) dichlorophosphorus(V) chloride, [P(tpp)Cl2]+Cl− (1995)
    Springer
    Journal of chemical crystallography 25 (1995), S. 231-235 
    Details
    ISSN: 1572-8854
    Schlagwort(e): Octahedral ; phosphorus ; chloride
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The title compound [P(tpp)Cl2]+Cl− crystallizes in the space group P21/n witha=10.701(2),b=24.860(2),c=14.799(2), β=94.24(2)°,Z=4. The phosphorus atom has an octahedral coordination geometry formed by the four nitrogen atoms (Np) of the porphyrinato group and the two chloride ions. The average phosphorus-chloride distance is 2.150(1) Å, with phosphorus situated 0.006 Å below the porphyrin ring.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01665175
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  • 3
    Digitale Medien
    Digitale Medien
    Electrochemical characterization of Fe-Ni-P alloy electrodeposition (1997)
    Springer
    Journal of applied electrochemistry 27 (1997), S. 1198-1206 
    Details
    ISSN: 1572-8838
    Schlagwort(e): alloy ; amorphous ; anomalous ; hydrogen ; iron ; nickel ; phosphorus ; plating
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: Abstract In this study we have investigated the electrodeposition of amorphous iron–nickel–phosphorus alloys from a sulfate electrolyte. Fe-Ni alloys are known to exhibit an ’anomalous‘ type of plating behaviour in which deposition of the less noble metal is favoured. We have found that the codeposition of phosphorus from hypophosphite in the electrolyte led to a reversal to a ’normal‘ behaviour. This reversal was due both to the suppression of iron and enhancement of nickel partial currents. The overall deposition process is dominated by the hydrogen evolution reaction. This is exacerbated by the low pH needed to codeposit sufficient phosphorus to achieve an amorphous structure.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1018475718629
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  • 4
    Digitale Medien
    Digitale Medien
    Microstructural characterization and corrosion resistance of Ni–Zn–P alloys electrolessly deposited from a sulphate bath (1999)
    Springer
    Journal of applied electrochemistry 29 (1999), S. 637-645 
    Details
    ISSN: 1572-8838
    Schlagwort(e): alloys ; electroless ; microstructure ; morphology ; nickel ; phosphorus ; zinc
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: Abstract Electroless Ni–Zn–P alloy coatings were obtained on an iron substrate from a sulfate bath at various pH values. The effects of changes in bath pH on alloy composition, morphology, microstructure and corrosion resistance were studied. Scanning electron microscopy was performed to observe the morphological change of the deposits with bath pH. Coating crystallinity was investigated by grazing incidence asymmetric Bragg X-ray diffraction and transmission electron microscopy. A transition from an amorphous to polycrystalline structure was observed on increasing the bath alkalinity, and thus decreasing the phosphorus content of the alloys. A single crystalline phase corresponding to face-centred-cubic nickel was identified in the alloys obtained from a strong alkaline solution. An increase in zinc percentage up to 23% in the deposits does not change the f.c.c. nickel crystalline structure. Corrosion potential and polarization resistance measurements indicated that the corrosion resistance of electroless Ni–Zn–P alloys depends strongly on the microstructure and chemical composition. The deposits obtained at pH 9.0–9.5 and with 11.4–12.5% zinc and 11.8–11.2% phosphorous exhibited the best corrosion resistance.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1026441403282
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  • 5
    Digitale Medien
    Digitale Medien
    Surface acid property and its relation to SCR activity of phosphorus added to commercial V2O5(WO3)/TiO2 catalyst (1998)
    Springer
    Catalysis letters 53 (1998), S. 65-71 
    Details
    ISSN: 1572-879X
    Schlagwort(e): selective catalytic reduction ; nitric oxide reduction ; phosphorus ; acid property
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract To examine the influence of phosphorus on the commercial V2O5(WO3)/TiO2 SCR catalyst, measurements were carried out by means of infrared and Raman spectroscopy, XPS, and NO reduction measurement as a function of phosphorus loading. Phosphorus added to the catalyst was found to disperse well over the catalyst without a significant agglomeration up to 5 wt% P2O5 addition. The number of the hydroxyl groups bonded to the vanadium and titanium species decreased readily with increasing amount of phosphorus. Correspondingly, the hydroxyl groups bonded to the phosphorus species were formed. NH3 adsorbed on both hydroxyl groups bonded to vanadium and phosphorus as ammonium ions, implying that the P–OH groups formed are also responsible for the Brønsted acidity. The NO reduction activity was found to be decreased with increasing amount of phosphorus; however, the influence of phosphorus was relatively small irrespective of the large amount of phosphorus addition. The deactivation might be caused by the change in the nature of the surface hydroxyl groups as Brønsted acid sites. Phosphorus species might partially wrap the surface V=O and W=O groups, which might also contribute to the deactivation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1019020931117
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  • 6
    Digitale Medien
    Digitale Medien
    The ecosystem of a mesotrophic lake-II. Interactions among nutrient load, river flow, and epilimnion depth (1991)
    Springer
    Aquatic sciences 53 (1991), S. 263-272 
    Details
    ISSN: 1420-9055
    Schlagwort(e): Lake ecosystem ; chl-a ; phosphorus ; nitrogen ; river flow ; thermocline ; simulation model ; multiple regression
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The management variables which primarily affect phytoplankton biomass (as chl-a) in Lake Mjøsa, Norway, are total phosphorus loading (TP) and the timing and volume of water through flow (by active storage reservoirs). The response of the lake to changes in these factors is studied using a simulation model of the lake ecosystem. Chl-a responses from both observed data and the simulated results are extracted by multiple regression. Results show that decreasing TP load decreases chl-a, but less at low TP levels (〈 10 mg TP · m−3). There is also a certain time period for peak river flow which gives the least yield of chl-a per unit TP. This time period occurs in early summer (i.e., around June 10) if the total phosphorus load is low, and later if the load is high. Both observations and simulation results show that a high water flow increases chl-a at low epilimnion depths (〈 15 m), but that the same high water flow decreases chl-a when epilmnion is deep.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00877062
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  • 7
    Digitale Medien
    Digitale Medien
    The short term response to eutrophication abatement (1990)
    Springer
    Aquatic sciences 52 (1990), S. 199-220 
    Details
    ISSN: 1420-9055
    Schlagwort(e): Eutrophication ; lake management ; phosphorus ; ecosystem ; chlorophyll-a ; mathematical modelling
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We compare results of a new model for predicting the short term inter annual changes in chlorophyll-a (chl-a) in lakes after reductions in total phosphorus (TP) to predictions made by least squares regression models. In the new method, slopes of chl-a/TP graphs (both axes in mg · m−3) are depicted in frequency diagrams and used to extract information on the expected, short term chl-a/TP response. The short term response for nine shallow (〈 10 m deep) and nutrient rich lakes to changes in TP was found to be: Chl-a = 0.49 · TP + 17.3, and for nine deep, P-limited lakes: Chl-a = 0.08 · TP + 3.5. If the TP-reduction is known to be greater than 10 mg · m−3, the expected slope increases to 0.58 for shallow lakes and to 0.26 for deep lakes. The slope, 0.58, is 8% lower than the slope for the long term response calculated by regression for the shallow lakes. For deep lakes the slope, 0.26, is 2 to 3 times higher than that calculated by regression, indicating that reductions in TP for deep lakes give greater effects than least squares regression equations suggest. We have also calculated the reduction in TP which will give about 80% probability that a reduction in chl-a will be observed next year. For shallow, P-limited lakes this reduction is about 30 mg · m−3 (5% of average initial in-lake TP concentration), and for deep lakes about 14 mg · m−3 (35% of average initial in-lake TP concentration).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00877280
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  • 8
    Digitale Medien
    Digitale Medien
    Vertical mixing in Überlinger See, western part of Lake Constance (1990)
    Springer
    Aquatic sciences 52 (1990), S. 256-268 
    Details
    ISSN: 1420-9055
    Schlagwort(e): Vertical mixing ; stratification ; phosphorus ; Lake Constance
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Depth variable vertical eddy diffusion coefficients for heat (K z) were calculated from continuously measured temperature profiles in Überlinger See (western part of Lake Constance). The temperatures were averaged over vertical intervals of 10 m yielding 14 discrete values (maximum depth of Überlinger See: 147 m). A linear fit from 10 June to 29 September 1987 was used to smooth the significant temperature fluctuations caused by internal seiches of Lake Constance. Assuming horizontal homogeneity for the smoothed data the Gradient-Flux-Method was applied to compute vertical diffusion coefficientsK z at different depths using the depth variable volumes and surfaces of the 14 layers. The resulting mean diffusion coefficients for the period from June to September are 0.04 cm2/s near the thermocline and up to 0.8 cm2/s in deeper strata (accuracy: ± 50%). It is shown that horizontal mixing between Überlinger See and Obersee (main lake) alters the computation ofK z by less than 50%. A relationship betweenK z and stability (Brunt-Väisälä) frequencyN is found which corresponds well to the theory of internal wave induced turbulence. Combining the diffusion coefficients with measured phosphorus profiles, a phosphorus flux from the hypolimnion to the epilimnion of (0.7 ± 0.4) mg P m−2 d−1 was calculated, corresponding to about 20% of the average external loading per area of Lake Constance in 1986.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00877283
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  • 9
    Digitale Medien
    Digitale Medien
    Measurement of total dissolved phosphorus in small volumes of iron rich interstitial water (1992)
    Springer
    Aquatic sciences 54 (1992), S. 1-9 
    Details
    ISSN: 1420-9055
    Schlagwort(e): Sediment ; interstitial water ; phosphorus ; iron ; persulfate digestion
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract It is shown that sorption of orthophosphate to iron compounds, formed during persulfate digestion, can cause a significant underestimation of total dissolved phosphorus in interstitial waters rich in iron and poor in phosphorus. Labelling the samples with carrier free32PO4 before digestion allows to correct for these losses.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00877261
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  • 10
    Digitale Medien
    Digitale Medien
    Effects of repeated manure and fertilizer phosphorus additions on soil phosphorus dynamics under a soybean-wheat rotation (1999)
    Springer
    Biology and fertility of soils 28 (1999), S. 150-155 
    Details
    ISSN: 1432-0789
    Schlagwort(e): Key words Phosphorus dynamics ; Olsen ; phosphorus ; Soil phosphorus fractions ; Manure ; Soybean-wheat rotation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract  Soil P availability and efficiency of applied P may be improved through an understanding of soil P dynamics in relation to management practices in a cropping system. Our objectives in this study were to evaluate changes in plant-available (Olsen) P and in different inorganic P (Pi) and organic P (P0) fractions in soil as related to repeated additions of manure and fertilizer P under a soybean-wheat rotation. A field experiment on a Typic Haplustert was conducted from 1992 to 1995 wherein the annual treatments included four rates of fertilizer P (0, 11, 22 and 44 kg ha–1 applied to both soybean and wheat) in the absence and presence of 16 t ha–1 of manure (applied to soybean only). With regular application of fertilizer P to each crop the level of Olsen P increased significantly and linearly through the years in both manured and unmanured plots. The mean P balance required to raise Olsen P by 1 mg kg–1 was 17.9 kg ha–1 of fertilizer P in unmanured plots and 5.6 kg ha–1 of manure plus fertilizer P in manured plots. The relative sizes of labile [NaHCO3-extractable Pi (NaHCO3-Pi) and NaHCO3-extractable P0 (NaHCO3-P0)], moderately labile [NaOH-extractable Pi (NaOH-Pi) and NaOH-extractable P0 (NaOH-P0)] and stable [HCl-extractable P (HCl-P) and H2SO4/H2O2-extractable P (resisual-P)] P pools were in a 1 : 2.9 : 7.6 ratio. Application of fertilizer P and manure significantly increased NaHCO3-Pi and -P0 and NaOH-Pi, and -P0 fractions and also total P. However, HCl-P and residual-P were not affected. The changes in NaHCO3-Pi, NaOH-Pi and NaOH-P0 fractions were significantly correlated with the apparent P balance and were thought to represent biologically dynamic soil P and act as major sources and sinks of plant-available P.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003740050477
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  • 11
    Digitale Medien
    Digitale Medien
    Determination of P/Al ratio in phosphorus-doped aluminium oxide thin films by XRF, RBS and FTIR (1995)
    Springer
    Microchimica acta 119 (1995), S. 13-22 
    Details
    ISSN: 1436-5073
    Schlagwort(e): aluminium oxide ; phosphorus ; XRF ; RBS ; FTIR
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Phosphorus-doped aluminium oxide thin films were deposited in a flow-type ALE reactor from AlCl3, H2O and from either P2O5 or trimethyl-phosphate. Structural information of the films was obtained from Fourier transform infrared (FTIR) spectra. Rutherford backscattering spectroscopy (RBS) was used to quantitatively determine the composition of the films. The P/Al intensity ratios calculated from X-ray fluorescence (XRF) results were in a linear relation with the P/Al concentration ratios calculated from RBS results. For comparison, the intensity ratios of the phosphorus peak (P=O) at about 1250 cm−1 and the aluminium peak (Al-O) at about 950 cm−1 were determined from the IR absorption spectra. The calibration of FTIR peak intensities was done by plotting the intensity ratios of phosphorus and aluminium peaks against the P/Al concentration ratios measured by RBS. FTIR gave also a linear calibration curve with RBS but the method is less suitable for routine analysis of P/Al ratio than XRF.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01244850
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  • 12
    Digitale Medien
    Digitale Medien
    Determination of phosphorus, sulfur and chlorine in high-purity aluminium (1990)
    Springer
    Microchimica acta 101 (1990), S. 273-279 
    Details
    ISSN: 1436-5073
    Schlagwort(e): aluminium analysis ; phosphorus ; sulfur ; chlorine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Multi-step procedures for the determination of phosphorus, sulfur and chlorine are described and tested against established methods and on reference materials. Phosphorus is separated as hydrogen phosphide, extracted as phosphomolybdic acid, reduced to molydenum blue and measured photometrically (detection limit 0.05 μg/g). Sulfur is separated after reduction as hydrogen sulfide or by means of pyrohydrolysis and measured by ICP-OES (detection limit 0.1 μg/g). Chloride can be measured by ion chromatography after pyrohydrolytic separation (detection limit 0.1 μg/g). The determination of sulfur was also successfully tested on copper and steel samples.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01244179
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  • 13
    Digitale Medien
    Digitale Medien
    Extraction inductively coupled plasma-optical emission spectrometry (ICP-OES) determination of traces of phosphorus in tungsten (1989)
    Springer
    Microchimica acta 99 (1989), S. 399-412 
    Details
    ISSN: 1436-5073
    Schlagwort(e): phosphorus ; tungsten ; preconcentration ; ICP-OES
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract A method for the separation and preconcentration of traces of phosphorus from tungsten was developed. Solid phase extraction of the phosphovanadomolybdate complex performed on a micro-column was applied. Phosphorus was determined by optical emission spectroscopy (OES) with inductively coupled plasma (ICP) excitation. A limit of detection of 0.4 μg/g P with respect to the solid phase is obtained. By directly coupling the extraction/elution step to the ICP instrument a detection limit of 0.06 μg/g P in W was achieved. Besides, the complexity of spectral evaluation in ICP-OES determinations of traces in spectralline-rich matrices is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01244696
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  • 14
    Digitale Medien
    Digitale Medien
    Elemental analysis of organic phosphorus compounds X. Schöniger-flask method for phosphorus (1986)
    Springer
    Microchimica acta 88 (1986), S. 245-247 
    Details
    ISSN: 1436-5073
    Schlagwort(e): Schöniger-flask method ; phosphorus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract By use of a fused-silica hook for holding the sample packet in a Schöniger combustion flask, even difficultly combustible phosphorus compounds can be completely decomposed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01196617
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  • 15
    Digitale Medien
    Digitale Medien
    The determination of phosphonate base scale inhibitors in brines by plasma spectrometry (1992)
    Springer
    Microchimica acta 109 (1992), S. 201-209 
    Details
    ISSN: 1436-5073
    Schlagwort(e): phosphonate base scale inhibitor ; brine ; direct current plasma ; inductively coupled plasma atomic emission spectrometry ; phosphorus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract The determination of phosphonate base scale inhibitors in brines by direct current plasma (DCP) and inductively coupled plasma atomic emission spectrometry (ICP-AES) is described. The first method is based on a direct nebulization of the brine samples and plasma using the phosphorus line at 213.618 nm. The second method involves extraction of phosphorus as phospho-antimonyl molybdate complex into methylisobutyl ketone (MIBK) phase and analysis of the extract for molybdenum using the Mo 313.260 nm line. Comparison between the proposed methods and an established recommended method [1] shows excellent agreement between the results in addition to the sensitivity and ease of automation provided by AES.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01242475
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  • 16
    Digitale Medien
    Digitale Medien
    Historical changes in sediments of Pyramid Lake, Nevada, USA: consequences of changes in the water balance of a terminal desert lake (1994)
    Springer
    Journal of paleolimnology 12 (1994), S. 87-101 
    Details
    ISSN: 1573-0417
    Schlagwort(e): Great Basin ; climatic variations ; productivity ; organic matter ; nitrogen ; phosphorus ; hardwater lake
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie
    Notizen: Abstract Sediment cores from the shallow and deep basins of Pyramid Lake, Nevada, revealed variations in composition with depth reflecting changes in lake level, river inflow, and lake productivity. Recent sediments from the period of historical record indicate: (1) CaCO3 and organic content of sediment in the shallow basin decrease at lower lake level, (2) CaCO3 content of deep basin sediments increases when lake level decreases rapidly, and (3) the inorganic P content of sediments increases with decreasing lake volume. Variations in sediment composition also indicate several periods for which productivity in Pyramid Lake may have been elevated over the past 1000 years. Our data provide strong evidence for increased productivity during the first half of the 20th Century, although the typical pattern for cultural eutrophication was not observed. The organic content of sediments also suggests periods of increased productivity in the lake prior to the discovery and development of the region by white settlers. Indeed, a broad peak in organic fractions during the 1800's originates as an increase starting around 1600. However, periods of changing organic content of sediments also correspond to periods when inflow to the lake was probably at extremes (e.g. drought or flood) indicating that fluctuations in river inflow may be an important factor affecting sediment composition in Pyramid Lake.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00678089
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  • 17
    Digitale Medien
    Digitale Medien
    An expanded weighted-averaging model for inferring past total phosphorus concentrations from diatom assemblages in eutrophic British Columbia (Canada) lakes (1995)
    Springer
    Journal of paleolimnology 14 (1995), S. 49-67 
    Details
    ISSN: 1573-0417
    Schlagwort(e): diatoms ; eutrophication ; lake management ; paleolimnology ; British Columbia ; lakes ; phosphorus ; training sets
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie
    Notizen: Abstract Eighteen lakes were added to a published training set of 46 British Columbia (BC) lakes in order to expand the original range of total phosphorus (TP) concentrations. Canonical correspondence analysis (CCA) was used to analyze the relationship between diatom assemblages and environmental variables. Specific conductivity and [TP] each explained significant (P≤0.05) directions of variance in the distribution of the diatoms. The relationship between diatom assemblages and [TP] was sufficiently strong to warrant the development of a weighted-averaging (WA) regression and calibration model that can be used to infer past trophic status from fossil diatom assemblages. The relationship between observed and inferred [TP] was not improved by the addition of more eutrophic lakes, however the [TP] range and the number of taxa used in the transfer function are now superior to the original model. Diatom species assemblages changed very little in lakes with TP concentrations greater than 85 µg 1−1, so we document the development of a model containing lakes with TP≤85 µg 1−1. The updated model uses 59 training lakes and covers a range of species optima from 6 to 41.9 µg 1−1 TP, and a total of 150 diatom taxa. The updated inference model provided a more realistic reconstruction of the anthropogenic history of a highly eutrophic BC lake. The model can now be used to infer past nutrient conditions in other BC lakes in order to assess changes in trophic status.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00682593
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  • 18
    Digitale Medien
    Digitale Medien
    Variability of diatom-inferred phosphorus profiles in a small lake basin and its implications for histories of lake eutrophication (1998)
    Springer
    Journal of paleolimnology 20 (1998), S. 47-55 
    Details
    ISSN: 1573-0417
    Schlagwort(e): diatoms ; spatial variability ; canonical correspondence analysis ; lake eutrophication ; transfer functions ; phosphorus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie
    Notizen: Abstract Diatom analyses were undertaken of sediment cores covering a range of water depths in a small eutrophic lake (Lough Augher, Co. Tyrone, N. Ireland). The significance of between-core variability in diatom relative frequency stratigraphy was assessed by Canonical Correspondence Analysis (CCA) where the ordination axes were constrained to external environmental variables (sediment depth, core location coordinates, water depth, effective fetch, distance-from-shore and distance-from-inflow). After the removal of the effect of sediment age by partialling it out, the resultant first two axes from the partial-CCA were significantly correlated with water depth and distance-from-shore, indicating non-uniform diatom stratigraphies across the lake. Despite this variability, all cores show the same succession of species and, therefore, record the eutrophication of the lake. Diatom-inferred total phosphorus (DI-TP) was inferred for six cores using weighted averaging regression and calibration. Apart from considerable differences of DI-TP in surficial sediment samples, there was good between-core repeatability of DI-TP profiles. These data support the use of DI-TP for establishing background nutrient concentrations for lakes, and associated implications for lake restoration schemes using single cores. Comparisons of DI-TP profiles and total diatom accumulation rate data for the individual cores indicate that diatom production peaked prior to the maximum TP concentrations in the lake.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1007923813511
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  • 19
    Digitale Medien
    Digitale Medien
    Stable isotope (δ13C and δ15N) signatures of sedimented organic matter as indicators of historic lake trophic state (1999)
    Springer
    Journal of paleolimnology 22 (1999), S. 205-221 
    Details
    ISSN: 1573-0417
    Schlagwort(e): carbon isotopes ; diatoms ; lake management ; nitrogen isotopes ; phosphorus ; radium-226 ; sediments ; trophic state
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie
    Notizen: Abstract We explored the use of carbon and nitrogen isotopes (δ13C and δ15N) in sedimented organic matter (OM) as proxy indicators of trophic state change in Florida lakes. Stable isotope data from four 210Pb-dated sediment cores were compared stratigraphically with established proxies for historical trophic state (diatom-inferred limnetic total phosphorus, sediment C/N ratio) and indicators of cultural disturbance (sediment total P and 226Ra activity). Diatom-based limnetic total P inferences indicate a transition from oligo-mesotrophy to meso-eutrophy in Clear Lake, and from eutrophy to hypereutrophy in Lakes Parker, Hollingsworth and Griffin. In cores from all four lakes, the carbon isotopic signature of accumulated OM generally tracks trophic state inferences and cultural impact assessments based on other variables. Oldest sediments in the records yield lower diatom-inferred total limnetic P concentrations and display relatively low δ13C values. In the Clear, Hollingsworth and Parker records, diatom-inferred nutrient concentrations increase after ca. AD 1900, and are associated stratigraphically with higher δ13C values in sediment OM. In the Lake Griffin core, both proxies display slight increases before ~1900, but highest values occur over the last ~100 years. As Lakes Clear, Hollingsworth and Parker became increasingly nutrient-enriched over the past century, the δ15N of sedimented organic matter decreased. This reflects, in part, the increasing relative contribution of nitrogen-fixing cyanobacteria to sedimented organic matter as primary productivity increased in these waterbodies. The Lake Griffin core displays a narrow range of both δ13C and δ15N values. Despite the complexity of carbon and nitrogen cycles in lakes, stratigraphic agreement between diatom-inferred changes in limnetic total P and the stable isotope signatures of sedimented OM suggests that δ13C and δ15N reflect shifts in historic lake trophic state.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008078222806
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  • 20
    Digitale Medien
    Digitale Medien
    Calibration of diatoms along a nutrient gradient in Florida Everglades Water Conservation Area-2A, USA (1999)
    Springer
    Journal of paleolimnology 22 (1999), S. 413-437 
    Details
    ISSN: 1573-0417
    Schlagwort(e): diatoms ; Everglades ; phosphorus ; wetland ; calibration ; multivariate ; Florida
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie
    Notizen: Abstract The relationship between diatom taxa preserved in surface soils and environmental variables at 31 sites in Water Conservation Area 2A (WCA-2A) of the Florida Everglades was explored using multivariate analyses. Surface soils were collected along a phosphorus (P) gradient and analyzed for diatoms, total P, % nitrogen (N), %carbon (C), calcium (Ca), and biogenic silica (BSi). Phosphorus varied from 315-1781 μg g-1, and was not found to be correlated with the other geochemical variables. Canonical correspondence analysis (CCA) was used to examine which environmental variables correlated most closely with the distributions in diatom taxa. Canonical correspondence analysis with forward selection, constrained and partial CCA, and Monte Carlo permutation tests of significance show the most significant changes in diatom assemblages along the P gradient (p 〈 0.01), with additional species differences correlated with soil C, N, Ca, and BSi. Weighted-averaging (WA) regression and calibration models of diatom assemblages to P and BSi were developed. The diatom-based inference model for soil [P] had a high apparent r2 (0.86) with RMSEboot = 218 μg g-1. Indicator diatom species identified by assessing species WA optima and WA tolerance to [P], such as Nitzschia amphibia and N. palea for high [P] (~1300-1400 μ g-1) and Achnanthes minutissima var. scotica and Mastogloia smithii for low [P] (~400-600 μg g-1), may be useful as monitoring tools for eutrophication in WCA-2A as well as other areas of the Everglades. Diatom assemblages analyzed by cluster analysis were related to location within WCA-2A, and dominant taxa within clusters are discussed in relation to the geochemical variables measured as well as hydrology and pH. Diversity of diatom assemblages and a ‘Disturbance Index’ based on diatom data are discussed in relation to the historically P-limited Everglades ecosystem. Diatom assemblages should be very useful for reconstructions of [P] through time in the Florida Everglades, provided diatoms are well preserved in soil cores.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008049224045
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  • 21
    Digitale Medien
    Digitale Medien
    Modern and historic accumulation rates of phosphorus in Lake Okeechobee, Florida (1998)
    Springer
    Journal of paleolimnology 20 (1998), S. 31-46 
    Details
    ISSN: 1573-0417
    Schlagwort(e): phosphorus ; Lake Okeechobee ; lead-210 dating ; eutrophication ; phosphorus loading
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie
    Notizen: Abstract Phosphorus accumulation rates in depositional zone sediments of Lake Okeechobee were determined in 11 mud-zone cores and two peat-zone cores dated by 210Pb. Although difficulties were encountered in interpreting 210Pb data from some sites, reliable dating of sediments from the mud zone of this shallow lake is possible. Sediment accumulation rates in this zone have increased during the present century by an average of about twofold, and accumulation of organic sediments in the lake during pre-settlement times apparently was much slower than during the past century. Concentrations of all forms of sedimentary P but especially nonapatite inorganic-P and organic-P also have increased since pre-settlement times and especially since about 1940. Annual P accumulation rates in the lake's sediments have increased about fourfold during the 1900s, with most of the increase occurring in the past 40–50 years. The recent accumulation rate of sedimentary P (past ~ 10 years) agrees within a factor of 1.5 with the net retention of P in the lake calculated from published input-output mass balances.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1007939714301
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  • 22
    Digitale Medien
    Digitale Medien
    Fertilizer regime and changes in the phosphate and potash status of a silty marine clay soil during 25 years (1980)
    Springer
    Nutrient cycling in agroecosystems 1 (1980), S. 95-101 
    Details
    ISSN: 1573-0867
    Schlagwort(e): soil fertility ; phosphorus ; potassium ; green manure ; crop rotation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Changes in the soil phosphorus and potassium status on three farming systems in the Northeast Polder during 25 years are related to the fertilizer regime over this period. The changes in the nutrient status of the soil are reflected in fertilizer policy. High rates of phosphate dressings markedly increased the phosphate status of the soil and built up a reserve of phosphate. In contrast, the potassium status decreased by about half, because only potatoes in the rotation were dressed with potassium. Methods of fertilization are discussed and suggestions are made with regard to possible improvements.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01073181
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  • 23
    Digitale Medien
    Digitale Medien
    The variation of element contents in triticale during vegetative growth (1987)
    Springer
    Nutrient cycling in agroecosystems 13 (1987), S. 155-159 
    Details
    ISSN: 1573-0867
    Schlagwort(e): triticale ; contents of nitrogen ; phosphorus ; potassium ; calcium ; magnesium ; trace elements ; heavy metals ; stage of growth
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Es wurden die Schwankungen in den Konzentration von N, P, K, Ca, Mg, Fe, Mn, Zn, Cu, B, Ba, Be, Bi, Sn, Sr, Sb, Ti, Te, V, Se, As und Hg in Triticale unter Feldbedingungen untersucht. Von der Bestockung bis zur Vollreife wurden alle 10 Tage von je 0.5 m2 pro Parzelle Pflanzenproben genommen. In allgemeinen haben die Konzentrationen von Frühjar bis zur Ernte abgenommen. Der elementengehalt in Triticale war demjenigen der übrigen Getreidearten verschieden, aber der Trend der Änderungen war ähnlich.
    Notizen: Abstract The variation of N, P, K, Ca, Mg, Fe, Mn, Zn, Cu, B, Ba, Be, Bi, Sn, Sr, Sb, Ti, Te, V, Se, As and Hg concentrations was studied under field conditions in triticale. The samples were collected every 10 days from tillering to full ripening stage using plant material from 0.5 m2 per plot. The concentrations generally decreased from early growth to harvest. The elemental concentrations in triticale differed from the other cereals, but the variation's trend was similar.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01064828
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  • 24
    Digitale Medien
    Digitale Medien
    Effect of nitrogen, phosphorus and soil and crop residues management practices on maize (Zea mays L.) yield in ultisol of eastern Cameroon (1987)
    Springer
    Nutrient cycling in agroecosystems 14 (1987), S. 135-142 
    Details
    ISSN: 1573-0867
    Schlagwort(e): nitrogen ; phosphorus ; soil and crop residues management practices ; maize yield ; Plinthudult ; Cameroon
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The shortening of fallow period in several areas in tropical Africa has reduced soil fertility and exposed soils to erosion and run-off. Fertilizer application and crop conservation practices are needeed to sustain high crop yield and to conserve the natural resource base for upland crop production in the continent. Field trials were carried out to evaluate the effect of fertilizer application and soil and crop residues management practices on yield of maize (Zea mays L.) planted on a Plinthudult soil at Bertoua, Eastern Cameroon. Maize yields increased significantly with nitrogen and phosphorus fertilizer application. Under the rainfall pattern prevailing in the area, the amount of nitrogen required for maximum yield was higher in the second season. On the other hand, the amount of phosphorus required for maximum yield appeared to decrease with time. The burning of crop residues and weeds prior to planting together with no-till practive gave higher yield of maize than other soil and crop residues management practices.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01066606
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  • 25
    Digitale Medien
    Digitale Medien
    Africa — how much fertilizer needed: Case study of Sierra Leone (1988)
    Springer
    Nutrient cycling in agroecosystems 17 (1988), S. 101-118 
    Details
    ISSN: 1573-0867
    Schlagwort(e): Nitrogen ; phosphorus ; potassium ; organic matter ; fallow ; forecasting ; fertilizer requirement ; Sierra Leone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The quantities of nitrogen, phosphorus and potassium supplied by an ‘average’ African soil cleared from bush fallow, assuming no losses, were approximated. Values ranged from 23 to 120 Kg N ha−1, 1.8 to 12 Kg P ha−1, 47 to 187 Kg K ha−1, depending on type of fallow, length of fallow, drainage and extent of depletion of native supplies. Additional amounts of 4 to 5 Kg N ha−1, 4 to 6 Kg P ha−1 and 14 to 20 Kg K ha−1 are obtained from the ash. Using crop nutrient removal data and approximate efficiencies of native and fertilizer N, P and K, fertilizer requirements at the reconnaissance level were estimated for selected target yields. For newly cleared uplands at cropping/fallow ratio of 2:7, N fertilizer requirements for cassava (30 t ha−1), maize (4 t ha−1), and sweet potato (16 t ha−1), were 138, 98, 42 kg ha−1 respectively. Wetland rice (4 t ha−1) required 55 kg N ha−1. Corresponding P fertilizer requirements for cassava, maize, sweet potato, upland rice (1.5 t ha−1) and ground-nut (1 t ha−1) were 190, 80, 30, 30 and 16 kg P ha−1 respectively. Wetland rice required 83 kg P ha−1. Substantial residual values of applied P are to be expected. Cassava required 60 kg ha−1 of K on newly cleared land. In soils of lowered nutrient status higher N, P, and K fertilizer requirements were indicated for all crops. Land use data from Sierra Leone were used to illustrate how the total quantities of N, P and K fertilizers in a country in the forest zone of Africa can be approximated. Fertilizer needs in Sierra Leone were in decreasing order P 〉 N ≫ K. N, P and K requirements were estimated to be 10,000 t, 20,000 t and 4,000 t respectively. The nutrient balance sheet method described in this paper is a useful tool to estimate the order of magnitude of fertilizer requirement at selected target yields for countries in Africa.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01050271
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  • 26
    Digitale Medien
    Digitale Medien
    Fertilizer requirement of rice-wheat and maize-wheat rotations on coarse-textured soils amended with farmyard manure (1988)
    Springer
    Nutrient cycling in agroecosystems 17 (1988), S. 153-164 
    Details
    ISSN: 1573-0867
    Schlagwort(e): farmyard manure ; maize ; nitrogen ; phosphorus ; rice ; wheat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Field experiments with rice-wheat rotation were conducted during five consecutive years on a coarse-textured low organic matter soil. By amending the soil with 12t FYM ha−1, the yield of wetland rice in the absence of fertilizers was increased by 32 per cent. Application of 80 kg N ha−1 as urea could increase the grain yield of rice equivalent to 120 kg N ha−1 on the unamended soil. Although the soil under test was low in Olsen's P, rice did not respond to the application of phosphorus on both amended and unamended soils. For producing equivalent grain yield, fertilizer requirement of maize grown on soils amended with 6 and 12 t FYM ha−1 could be reduced, respectively to 50 and 25 per cent of the dose recommended for unamended soil (120 kg N + 26.2 kg P + 25 kg K ha−1). Grain yield of wheat grown after rice on soils amended with FYM was significantly higher than that obtained on unamended soil. In contrast, grain yield of wheat which followed maize did not differ significantly on amended or unamended soils.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01050276
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  • 27
    Digitale Medien
    Digitale Medien
    Phosphorus management of a rice-wheat cropping system (1989)
    Springer
    Nutrient cycling in agroecosystems 20 (1989), S. 27-32 
    Details
    ISSN: 1573-0867
    Schlagwort(e): Cropping system ; phosphorus ; rice ; wheat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract A long term field experiment was conducted on a sandy loam soil from 1983 to 1987 to determine how to best apply phosphorus fertilizer in a rice-wheat cropping system. The treatments included 9 combinations of phosphorus application either to both rice and wheat or to rice or wheat alone. Direct application of phosphorus at 13 kg/ha to both the crops resulted in significantly higher total productivity of the rice-wheat cropping system as compared with 26 kg P/ha applied either to rice or wheat alone. Phosphorus at 13 kg/ha for rice and 26 kg/ha for wheat was as efficient as 13 kg P/ha for rice and 13 kg P/ha for wheat. The higher rate of P (26 kg/ha) applied to both rice and wheat resulted a decline in the total productivity. The residual effects of phosphorus applied to either rice or wheat were significant to the succeeding crop but was inferior to its direct application. Phosphorus increased the leaf area index, chlorophyll content of leaves, and interception of more photosynthetically active radiation (PAR) which resulted in increased grain yield of rice and wheat. Phosphorus status of the surface soil declined markedly, in the absence of P application from 15.4 to 6.4 kg P/ha. Phosphorus applied at 26 kg P/ha to both the crops resulted a build up of the available P status of soil. Phosphorus application at 13 kg/ha to both rice and wheat maintained the phosphorus status of the soil at original level.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01055398
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  • 28
    Digitale Medien
    Digitale Medien
    Hydrology of the Peel-Harvey estuary catchment (1993)
    Springer
    Nutrient cycling in agroecosystems 36 (1993), S. 127-133 
    Details
    ISSN: 1573-0867
    Schlagwort(e): hydrology ; water balance ; phosphorus ; Streamflow ; Peel-Harvey
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract This paper discusses the land types, hydrologic characteristics and processes, and the major modification of these, in relation to mechanisms and magnitude of phosphorus losses to drains and riverine systems which discharge to the Peel-Harvey estuary. About 75% of the coastal plain part of the catchment is cleared of native vegetation and used for dryland, dairy and beef grazing. There are small areas devoted to irrigated pasture and commercial horticulture. Seventy-five percent of the soils of the catchment are sandy surfaced with a poor capacity to retain phosphorus. Though the area is flat, catchment water yields are high because of a large winter rainfall excess and low soil storage capacity. Drainage schemes have been constructed in much of the catchment to remove excess water quickly. This was required initially to allow agricultural expansion and is now important for protecting a growing infrastructure which serves the most populous region of Western Australia.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00747583
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  • 29
    Digitale Medien
    Digitale Medien
    Phosphorus and mycorrhizal interaction on uptake of P and trace elements by maize (1989)
    Springer
    Nutrient cycling in agroecosystems 21 (1989), S. 19-22 
    Details
    ISSN: 1573-0867
    Schlagwort(e): VAM fungi ; phosphorus ; molybdenum ; interaction ; maize
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Vesicular arbuscular mycorrhizal fungi (VAM) when applied to soils can result in marked increases in plant growth and P uptake. Application of molybdenum can also result in a synergistic interaction with phosphorus, with reslutant increases in plant dry matter production. The current investigation was designed to evaluate P X Mo X VAM interactions on yield and P uptake of sweet corn (Zea mays L.) The experiment was conducted in the greenhouse using soils from Missouri and Jamaica (West Indies) which were very low in available soil P. Corn was grown in pots amended with P and VAM, with and without Mo. Colonizing Jamaican soil amended with P withGlomus etunicatum increased shoot dry matter weights significantly. Greatest P uptake occured in treatments receiving the highest application of P and mycorrhizal inoculation. There was a significant difference between the two soils with respect to treatment effects on micronutrient accumulation of the test crop. The decreases in Cu, Zn, Mn, and Mo concentration of corn leaves between control and the treated pots, is attributed to dry matter dilution effect. The results indicated that mycorrhizal inoculation increased the dry matter significantly in Jamaican soil amended with P, however not in Missouri soil.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01054731
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  • 30
    Digitale Medien
    Digitale Medien
    Environmental impact of fertilizing soils by using sewage and animal wastes (1994)
    Springer
    Nutrient cycling in agroecosystems 37 (1994), S. 1-22 
    Details
    ISSN: 1573-0867
    Schlagwort(e): animal slurries and manures ; applications to soils ; carbon- ; nitrogen- ; phosphorus ; contamination ; crop production ; dissemination ; hazardous organics ; heavy metals ; inputs ; macro- and micronutrients ; pathogens ; sewage sludges ; survival- ; transfer- ; transport and adsorption rates in soils
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The European Community is producing annually about 300 × 106 tons of sewage sludges as well as about 150, 950,160 and 200 tons of domestic, agricultural, industrial and other wastes (street litter, dead leaves etc.). About 20–25% of the German sewage sludges, which contain in average about 3.8,1.6, 0.4, 0.6, 5.3% DM−1 N, P, K, Mg and Ca, 202, 5, 131, 349, 53, 3 and 1446 mg kg−1 DM Pb, Cd, Cr, Cu, Ni, Hg, Zn as well as ca. 37 and 5 mg kg−1 Dm polychlorinated hydrocarbons and biphenyls, are recycled annually as fertilizer. In addition environmental impacts on the arable land of Germany may derive from 76,19.2, 64.7, 33.6, 7.8 and 0.1 kg ha−1 a−1 of N, P, K, Ca, Mg and Cu added as animal manures. Besides heavy metals and hazardous organics pathogens are disseminated with organic wastes. Crop production and soil fertility generally profit from the considerable amounts of plant nutrients and carbon in sewage sludges, animal slurries and manures, but the physicochemical soil properties, the composition of microbial, faunal and plant communities as well as the metabolic processes in the soil-, rhizo- and phyllosphere are changed by organic manuring. Consequences for the soil carbon-, nitrogen-and phosphorus-cycle are discussed. Impacts of heavy metals and hazardous organics on the soil biomass and its habitat as well as on transport mechanisms and surival times of disseminated pathogens in soils are reviewed with emphasis on the German situation. A proposal for future strategies (landscape recycling) is made.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00750669
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  • 31
    Digitale Medien
    Digitale Medien
    Results and experiences from fertilization experiments in The Netherlands (1991)
    Springer
    Nutrient cycling in agroecosystems 27 (1991), S. 107-111 
    Details
    ISSN: 1573-0867
    Schlagwort(e): Liming ; phosphorus ; heathland ; copper ; fertilization ; forest
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Forest fertilization in the Netherlands has played an important role in the phase of afforestation of former heathlands. Research started in the early fifties, but results were not applied in practical forestry. A review is presented on forest fertilization in practice, and on the main results of the activities of De Dorschkamp on NPK fertilization, liming and micronutrients application. Attention is paid to problems which have developed during the past ten years.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01048613
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  • 32
    Digitale Medien
    Digitale Medien
    Share of agriculture in nitrogen and phosphorus emissions into the surface waters of Western Europe against the background of their eutrophication (1990)
    Springer
    Nutrient cycling in agroecosystems 26 (1990), S. 253-269 
    Details
    ISSN: 1573-0867
    Schlagwort(e): Nitrogen ; phosphorus ; sulphur ; nutrient balances ; surface waters ; North Sea ; Baltic Sea ; eutrophication ; hypertrophication ; primary production
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Dissolved inorganic nitrogen and phosphorus, their relationship to each other (DIN/DIP) as predisposing (nutrient) factors, as well as prevailing weather as a triggering factor all work together to induce the primary production and hence the eutrophication (hypertrophication) process in surface waters. Sulfate likewise is a decisive predisposing factor influencing the eutrophication process by reducing N availability but increasing P availability and thus acting towards an N limitation of the primary production. This is one of the reasons why marine (coastal) waters and estuaries often exhibit N limitation with respect to primary production, while freshwater ecosystems often tend to exhibit P limitation. Within the N and P balance of agriculture of some countries of Western Europe (Netherlands, Denmark, Switzerland, FRG, UK and Sweden for N, resp. Netherlands, FRG and GDR for P) more the level than the efficiency of the N and P applications indicates the extent of the nutrient surplus. Despite 59–73% N utilization in plant production, the rate of 13–23% for agriculture as a whole equals to the 12–21% efficiency of N use in animal production. The varying N surplus in agriculture in the separate countries of 124 to 465 kg N ha−1 a−1 is determined almost exclusively by the level of the N application and not by its efficiency. The situation is similar for P: In spite of P utilization in plant production of 59–76%, P utilization in total agriculture is only 11–38%, or comparable to the P efficiency within animal production of 10–34%. The differing P excess balance of 55 to 88 kg P2O5 ha−1 a−1 is influenced by the level of the P application. The N and P efficacy of total agriculture hence is determined almost completely by that of animal production, since 83–95% (N basis) and 76–94% (P basis) of the total plant production (on top of the nationally varying levels of N and P use via imported feeds) are fed to animals — with the low N and P utilization cited above. Agriculture's share of the N and P emissions into surface water of several countries/regions in Western Europe (FRG, Netherlands, Italy, Denmark, Switzerland, Norway) ranges from 37 to 82% resp. 27 to 38%. Its share in the flus into the North Sea catchment basin will be about 60% for N and 25% for P related only to the anthropogenic material carried by the rivers. Agriculture's share in the atmospheric N emissions into the North and Baltic Seas can be estimated at about 65% or 55%, resp. while the remaining approx. 35% or 45%, resp. are traceable primarily to anthropogenic burning processes. For agriculture the priority lies in limiting N emissions into surface water caused by leaching, erosion and NH3 emissions, and reducing P emissions mainly through soil conservation (protection against erosion) and water protection. As regards N this means a demand for comprehensive protection of groundwater and atmosphere differentiated according to the potential for losses or the risk of losses on a site, also outside the protection zones. As regards P only those areas can be included in the demand for reduction of emissions that are actually threatened by erosion or surface runoff. Plenty of short-term and long-term measures are available to agriculture to reduce N and P emissions. Especially the long-range measures (such as creating nutrient balances on farms and fields, the integration of animal and plant production, maintaining maximum livestock densities according to the ability of areas to absorb nutrients, altered feeding programs in animal nutrition, changes in livestock keeping (slurry→deep litter), increasing the internal and external recycling of N and P) are capable of bringing about a satisfactory degree of success within the next 20 to 30 years.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01048764
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  • 33
    Digitale Medien
    Digitale Medien
    Land application of poultry litter and water quality in Oklahoma, U.S.A. (1994)
    Springer
    Nutrient cycling in agroecosystems 40 (1994), S. 165-173 
    Details
    ISSN: 1573-0867
    Schlagwort(e): Animal manure ; eutrophication ; ground water ; nitrogen ; phosphorus ; surface runoff
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract With the rapid growth of the poultry industry in Oklahoma, U.S.A., more litter is applied to farm land. Thus, information is required on the impact of applications on regional soil and water resources. The effect of soil and poultry litter management on nitrogen (N) and phosphorus (P) loss in runoff and subsurface flow from four 16 m2 plots (Ruston fine sandy loam, 6 to 8% slope) was investigated under natural rainfall. Plots under Bermudagrass (Cynodon dactylon) received 11 Mg litter ha−1, which amounts to contributions of approximately 410 kg N and 140 kg P ha−1 yr−1. In spring, litter was broadcast on 3 of the plots; the upper half of one and total area of the other two. One of the total-area broadcast plots was tilled to 6 cm, the other remained as no till. The fourth plot served as a control. Relative to the control, litter application increased mean concentrations of total N and total P in runoff during the 16-week study for no-till (15.4 and 5.8 mg L−1) and tilled treatments (16.7 and 6.1 mg L−1). However, values for the half-area application (5.6 and 2.0 mg L−1) were similar to the control (5.7 and 1.3 mg L−1). Interflow (subsurface lateral flow at 70 cm depth) P was not affected by litter application; however, nitrate-N concentrations increased from 0.6 (control) to 2.9 mg L−1 (no till). In all cases, 〈 2 % litter N and P was lost in runoff and interflow, maintaining acceptable water quality concentrations. Although litter increased grass yield (8518 kg ha−1) compared to the control (3501 kg ha−1), yields were not affected by litter management. An 8-fold increase in the plant available P content of surface soil indicates long-term litter management and application rates will be critical to the environmentally sound use of this nutrient resource.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00750462
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  • 34
    Digitale Medien
    Digitale Medien
    Future directions for agricultural phosphorus research (1995)
    Springer
    Nutrient cycling in agroecosystems 41 (1995), S. 167-178 
    Details
    ISSN: 1573-0867
    Schlagwort(e): phosphorus ; workshop ; environment ; review
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract A workshop was held in 1990 in Muscle Shoals, Alabama to discuss current and future research on phosphorus in agriculture. Twenty four presentations were given in areas ranging from basic to applied research. For five of the research areas presented at the workshop, this paper presents a literature review, a review of presentations at the workshop, and a discussion of future research ideas.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00748306
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  • 35
    Digitale Medien
    Digitale Medien
    Coordinated phosphorus research within a network of six European institutions (1995)
    Springer
    Nutrient cycling in agroecosystems 43 (1995), S. 109-115 
    Details
    ISSN: 1573-0867
    Schlagwort(e): phosphorus ; European network ; maintenance fertilization ; fixation capacity ; comparison of methods
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract After three years of a research network project on mineral phosphorus fertilization including five experimental fields located in Europe the first results are discussed. Crop response was very significant to TSP application in the alluvial calcareous polder soil of Netherlands, and in the brown silty acid soil of Scotland, both having a low level of P availability and a high fixation capacity. In the alluvial sandy loam on chalk in England, a response was observed to the first fertilization level equal to the previous crop export of phosphorus. In the brown sandy-silty soil on sand in Germany the highest rate of TSP led to a response in the third year. No effect on the final yields was observed in the brown silt loam of Belgium characterised by a textural B horizon with a high P fixation capacity. The critical values for phosphorus fertilization are discussed as the amount of P needed to maintain a target value of soil phosphorus. Concerning the supply of the different soils, no balance was reached in the Dutch and Scottish soils, a steady state was reached in the English soil with the return of the previous crop removal and the critical value for P was lower than the return of the previous crop export in the German and Belgian soils. According to the eight methods of P determination compared in the network, the P contents in the plow layer were raised in the soils of Netherlands, England and Scotland. They remained at the same level or fluctuated depending on the soil testing methods in Germany and in Belgium. High correlations exist between the different methods used in routine analysis, except for the calcium cloride and calcium acetate lactate method. Annual fluctuations in the soil P were detected at different depths depending on analytical methods and need further research.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00747689
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  • 36
    Digitale Medien
    Digitale Medien
    Plant biomass and fruit yield induction by Ti(IV) in P-stressed pepper crops (1995)
    Springer
    Nutrient cycling in agroecosystems 43 (1995), S. 131-136 
    Details
    ISSN: 1573-0867
    Schlagwort(e): phosphorus ; titanium ; fertilizer efficiency ; plant nutrition
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract To study the titanium effect on P nutrition, a greenhouse experiment withCapsicum annuum L., cv. Bunejo plants growing under differential P fertilization was conducted. All the plants were grown under identical conditions and they only differred in the P fertilization and in Ti supply. Plant biomass production of the Ti-untreated plants was affected by the diminution of the P-feed, but the plants growing under the lowest P supply did not showed any deficiency symptom during the crop cycle. All the Ti-treated plots showed a significative increase of the plant biomass against their corresponding untreated references. The biomass enhancement was mainly caused by the increase of the fruit yield with an absolute enhancement of 62% in the plants growing under the lowest P feed, and of 45% in the plants with a complete P support.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00747692
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  • 37
    Digitale Medien
    Digitale Medien
    Phosphate enrichment in the sandy loam soils of West-Flanders, Belgium (1995)
    Springer
    Nutrient cycling in agroecosystems 43 (1995), S. 209-215 
    Details
    ISSN: 1573-0867
    Schlagwort(e): phosphorus ; saturation ; inventory ; leaching ; eutrophication
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The last three decades, pig breeding has evolved towards a specialised, large scaled, land independent bio-industry in the province of West-Flanders. Subsequently, in certain regions, very high amounts of liquid pig manure are produced each year. This pig slurry is used as a fertilizer at a rate which very often exceeds normal agricultural practices. Because of the nonequilibrium between the phosphorus crop requirements and the P-inputs, phosphates accumulate in the soil. However, the phosphate sorption capacity of a soil is limited. Once the sorption capacity is exceeded, phosphates will start leaching through the soil profile. Since, during winter, in these areas, the groundwater table is situated at a depth of less than 1.0 m, phosphate breakthrough might take place. In the sandy loam soil region (± 1000 km2) of the province, an inventory of the P status of the soil was made. The region was sampled according to a regular grid with 2 km intervals. At random, some sample points were only 500 m apart. This resulted in a total of 296 samplings. In view of fertilizer recommendations, lactate extractable P of the plough layer (0-30 cm) was determined. A maximum value of 101 mg P 100 g−1 of air dry soil, a minimum value of 6 mg P 100 g−1 and a median value of 31 mg P 100 g−1 were found, indicating that for half of the spots monitored, the P status of the soil is high to very high. An oxalate extraction was done to investigate the phosphate saturation of the soil profile (0-90 cm). Based on a critical phosphate saturation degree of 30%, more than half of the soil profiles are phosphate saturated. Phosphate leaching at a rate higher than 0.1 mg ortho-P 1−1 at a depth of 90 cm can be expected. Therefore, a restriction of the P fertilization should be highly recommended. The geostatistical processing of the data using block kriging resulted in a spatial continuous estimate of the phosphate saturation degree. A good agreement was found between the pig density and the phosphate saturation degree of the soil profile.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00747704
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  • 38
    Digitale Medien
    Digitale Medien
    Response of ensete (Ensete ventricosum W.) to mineral fertilizers in southwest Ethiopia (1994)
    Springer
    Nutrient cycling in agroecosystems 37 (1994), S. 107-113 
    Details
    ISSN: 1573-0867
    Schlagwort(e): Ensete ventricosum ; fertilizer response ; nitrogen ; phosphorus ; potassium ; sulphur ; starch
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Ensete (Ensete ventricosum W. Cheesm.) is a root crop which stores starch in the root and in the lower part of the stem. It is grown in the southwest of Ethiopia and due to its drought resistance, it is of outstanding importance for the supply of food to the local population. Until now virtually nothing is known about the response of Ensete to fertilizer application. Field trials carried out on three representative soils in Ethiopia showed that Ensete biomass yields were increased significantly on all three soils by nitrogen and phosphorus application. Potassium had only marginal effect on biomass growth but favourably influenced starch production. Sulfate application had no major impact on growth and starch yield. The yield response was well related to the level of available nutrients in the soil, as determined by electroultrafiltration (EUF). Leaf analysis provided preliminary evidence that optimum levels of N, P, and K may be 3.8%, 0.3%, and 4.8%, respectively.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00748551
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  • 39
    Digitale Medien
    Digitale Medien
    Estimating nutrient surplus and nutrient use efficiency from farm characteristics (1995)
    Springer
    Nutrient cycling in agroecosystems 45 (1995), S. 221-233 
    Details
    ISSN: 1573-0867
    Schlagwort(e): fertilizer recovery ; modelling ; nitrogen ; nutrient efficiency ; nutrient surplus ; phosphorus ; Poland
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Research on nutrient losses from agricultural systems should try to relate these losses to farm characteristics. This was done for private farms in two districts in Poland. Using data from a farm survey, nutrient surpluses and Nutrient Use Efficiency (NUE, defined as the ratio of outgoing and incoming nutrients) were calculated for nitrogen and phosphorus. Both nutrient surplus and NUE are relatively high. A model was developed to estimate surpluses and NUE from farm characteristics like location, farm size, fertilizer application level, animal density, grass production and sugar beet or potato area. The results of the model are satisfying for nutrient surplus (R2=0.9) and nitrogen NUE (R2=0.4). Estimation of phosphorus NUE was not satisfactory. High surpluses are associated with high fertilizer applications, high animal density and high grass production while an increasing share of sugar beets leads to lower surpluses. A high nitrogen NUE is associated with low fertilizer applications, low animal density and little grass production, and with a high sugar beet area share. Results suggest that, with exception of sugar beet, fertilizer recovery in Poland is very low. Sugar beet, however, combines high fertilizer applications with low surpluses and high NUE. The outcome of the model can be used in the design of environmental policies. The paper ends with some remarks on the type of measures that can be taken, and the effects these will have on private farms in Poland.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00748593
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  • 40
    Digitale Medien
    Digitale Medien
    Influence of co-granulated nutrients and granule size on plant responses to elemental sulfur in compound fertilizers (1996)
    Springer
    Nutrient cycling in agroecosystems 46 (1996), S. 81-90 
    Details
    ISSN: 1573-0867
    Schlagwort(e): elemental sulfur ; granule size ; nitrogen ; phosphorus ; potassium ; S oxidation ; sulfur fertilizers
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Experiments were undertaken to determine the effect of granule size and nutrients in granulated compound fertilizers fortified with finely divided elemental sulfur (So) on the rate of So oxidation. In one experiment, So was banded together with or apart from triple superphosphate (TSP) while in two others, So was granulated with nutrient and inert carriers. A fourth experiment examined response to S in an So-fortified TSP from a range of granule sizes. Response and, in some cases, So recovery (using 35S labels) by test crops (maize, wheat, upland rice) was measured. In all experiments, P mixed with So increased plant growth and S recovery above treatments in which P and So were physically separated. There was however, no effect of distance of separation on S recovery. In one experiment, N as urea and N and P as diammonium phosphate (DAP) were also found to enhance response to So although to a lesser degree than P alone. These observations were attributed to a nutritional requirement of So-oxidizing microorganisms for P and N. Granulation of So with carriers also influenced oxidation rate, as inferred from the fertilizer S recovery. For a given So concentration, the effect was inversely proportional to the mean diameter of granules. It is shown that this relationship can be explained if one assumes that So particles in granules collapse into a fixed number of aggregates per granule irrespective of granule size when the soluble nutrient carrier dissolves and diffuses away from the point of application.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00210226
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  • 41
    Digitale Medien
    Digitale Medien
    Fertilizer inputs, nutrient balance and soil nutrient supplying power in intensive, irrigated rice system. III. Phosphorus (1996)
    Springer
    Nutrient cycling in agroecosystems 46 (1996), S. 111-125 
    Details
    ISSN: 1573-0867
    Schlagwort(e): long-term experiments ; phosphorus ; rice ; nutrient balance ; phosphorus uptake ; fertilizer P response ; soil testing ; ion-exchange resin ; phosphorus supplying capacity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Data from long-term experiments at 11 sites in Asia with a wide range of nutrient input treatments and yield levels were used to quantify crop P requirements of rice (Oryza sativa L.) and the P balance in intensive, irrigated rice systems. Uptake of 1.8–4.2 kg P was required to produce one ton of grain yield. Physiological P use efficiency varied between 220 to 900 kg grain kg P-1. Without added P, there was a net loss of 7 to 8 kg P ha-1 per crop; with added P there was a net gain of 4 to 5 kg P ha-1 per crop. Phosphorus adsorption kinetics on mixed-bed ion-exchange resin capsules provided an integrative measure of soil P status, P diffusion, and acid-induced P solubilization. The resin capsule was a sensitive tool to characterize buildup or depletion of soil P as a result of different P balances. Both Olsen-P and the resin capsule were suitable methods to predict P uptake of tropical lowland rice. It is hypothesized that both methods measure a similar soil P pool which is soluble under alkaline, aerobic conditions but transformed into acid-soluble P froms as a result of submergence and reduction. Present recommendations for P fertilizer use on rice of 20–25 kg P ha-1 are adequate to maintain yields of 5–6 t ha-1, but sustaining higher yields of 7–8 t ha-1 will require farm-specific management strategies based on knowledge of the long-term P balance and soil P-supplying capacity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00704311
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  • 42
    Digitale Medien
    Digitale Medien
    Characterization of soil-fertilizer P reaction products and their evaluation as sources of P for gram (Cicer arietinum L.) (1996)
    Springer
    Nutrient cycling in agroecosystems 46 (1996), S. 71-79 
    Details
    ISSN: 1573-0867
    Schlagwort(e): ammonium poly-phosphate ; diammonium orthophosphate ; fertilizer reaction ; gram ; Indian soils ; phosphorus ; P uptake ; single superphosphate ; triple superphosphate ; yield
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Laboratory studies on the characterization of soil-fertilizer P reaction products were carried out by reacting three-soils occurring in a toposequence in the plateau region of Bihar (India) with saturated solutions of diammonium orthophosphate (DAP), triple superphosphate (TSP) and ammonium polyphosphate (APP) for 1 hour and 24 hours. The reaction products (precipitates) formed in the solutions after 120 days of incubation were isolated and identified through X-ray diffraction technique. Results indicate the formation of Brushite [CaHPO4 · 2H2O, Strengite (FePO4 · 2H2O), Variscite (AIPO4 · 2H2O) and Fe4(P2O7)3 as major soil-fertilizer P reaction products in these soils with ortho-and polyphosphates as source of phosphorus. Pot cultures were used to evaluate the relative efficiency of reaction products (Struvite, Brushite, Variscite and Strengite), orthophosphates (DAP and SSP) and polyphosphate (APP) as sources of P for gram (Cicer arietinum L.) in a typical acid soil. Results indicate significant response of gram to different sources and level of added P. The dry weight and P uptake at 0, 6 and 12 mg P kg-1 soil were 0.406, 0.519 and 0.609 (g pot-1); and 0.289, 0.428 and 0.575 (mg P pot-1), respectively. Among the sources , struvite proved to be superior or equally effective as APP, DAP or SSP as sources of P for gram. Uptake of P also varied significantly with different P sources and levels of P application. Strengite was least effective in enhancing yield and P uptake by the crop.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00210225
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  • 43
    Digitale Medien
    Digitale Medien
    Comparison of resin beads and resin membranes for extracting soil phosphate (1995)
    Springer
    Nutrient cycling in agroecosystems 44 (1995), S. 1-8 
    Details
    ISSN: 1573-0867
    Schlagwort(e): aerobic incubation ; cation-anion-exchange resin ; phosphorus ; resin beads ; resin membranes ; suspension incubation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Six Portuguese soils of varying P sorption capacity were incubated aerobically at 30° C without and with added P in order to give 0.1.mg P L−1 in the soil solution. Two methods of measuring extractable P were compared: (i) mixed-bed cation-anion-resin beads in bags and (ii) a simpler method with anion-resin membrane only. The bag method extracted about twice and 1.5 times as much as the strip method, respectively, without and with added P. The relationships were much closer after one extraction for 2 hours (r = 0.982, p 〈 0.01) instead of the cumulative extraction of 24 hours (r = 0.635,p 〉 0.05.). P recovery after incubation was inversely related to some soil properties as organic matter, buffer capacity, selective dissolution Al forms (Alox and Ald) and P sorption. It is suggested that the simpler resin membrane method is more adequate to assess P for many studies of P reaction with soil. A simpler incubation method was tried, consisting of incubation as a soil suspension in water at a high temperature (50° C). The results suggested that this method gave similar results to aerobic incubation, with the advantage that there was no need to measure the required and final water contents of incubated soil.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00750686
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  • 44
    Digitale Medien
    Digitale Medien
    Effects of temperature on nutrient release from slow-release fertilizers (1996)
    Springer
    Nutrient cycling in agroecosystems 46 (1996), S. 179-187 
    Details
    ISSN: 1573-0867
    Schlagwort(e): electrical conductivity ; leaching ; nitrogen ; pH ; phosphorus ; potassium ; release pattern ; slow-release fertilizers ; temperature
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract We studied the effect of temperature on the release of N, P, and K from slow-release fertilizers (SRF). The study was conducted in micro-lysimeters filled with moist peat medium. Increasing the temperature from 4 to 12°C slightly increased N release from three different slow-release N (SRN) carriers with different particle sizes and coating thicknesses. At 21°C the rate of release was significantly different than the other two temperatures. Urea formaldehyde (UF), sulphur coated urea (SCU) and coated calcium nitrate (CCN), incubated in sphagnum moss peat, released between 3 and 20% of the applied N in six weeks. For eight synthetic and organic NPK carriers, the release pattern was similar to UF and SCU. However, the leaching losses of N from the NPK fertilizers were up to twenty times more than for the SRN products. Except for Osmocote® and Duna, which released 30–40% of the applied N as mineral-N within six weeks, all other slow-release and slowly mineralized NPK carriers acted like readily water-soluble compound NPK. Temperature did not affect the nutrient release from NPK fertilizers.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00420552
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  • 45
    Digitale Medien
    Digitale Medien
    Leaching of nitrogen and phosphorus from rural areas to surface waters in the Netherlands (1998)
    Springer
    Nutrient cycling in agroecosystems 50 (1998), S. 321-324 
    Details
    ISSN: 1573-0867
    Schlagwort(e): nutrient modelling ; leaching ; nitrogen ; phosphorus ; schematization
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract In context of preparing the Fourth National Policy Document on Water Management in the Netherlands effects of different scenarios of fertilizer management on nitrogen (N) and phosphorus (P) leaching from rural areas into Dutch surface waters were analyzed. The manuscript offers insight into the model instrument that is used to simulate the different scenarios. Main parts of the modelinstrument are: a procedure to schematize the Netherlands in horizontal areal units, field scale mechanistic models for water and nutrient behaviour in the soil and an empirical model for fertilizer additions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009773202654
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  • 46
    Digitale Medien
    Digitale Medien
    Changes in fertilizer and manurial practices during 1960–1990: implications for N and P inputs to the Ythan catchment, N.E. Scotland (1998)
    Springer
    Nutrient cycling in agroecosystems 52 (1998), S. 19-29 
    Details
    ISSN: 1573-0867
    Schlagwort(e): agriculture ; catchment ; fertilizer ; historical ; manure ; nitrate ; phosphorus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract A suggested increase in the growth of macrophytic algae within the Ythan estuary (N.E. Scotland) over recent years has been linked to the increased amounts of nitrogen in the form of NO3–N entering the estuary from the river. The increased NO3 concentration in the river has been associated with recent changes in farming practices in this predominantly agricultural catchment. Terrestrially derived phosphorus is also considered to contribute increasingly to eutrophication of fresh waters. Historical agricultural census data together with appropriate surveys of fertilizer practice were used to calculate the total quantities of fertilizer and manure derived N and P applied annually over the wholeYthan catchment during the period 1960 – 1990. While the total agricultural land area has remained similar, significant changes in cropping practice have occurred. In particular, a greater proportion of land is given to autumn sown crops while the area of grassland has declined. These changes in farming practice are associated with differences in both the total amounts and timing of fertilizer applied. The use of inorganic N in the catchment has trebled since 1960 and is currently approximately 6400 tonnes (104 kg N/ha). The use of P has decreased by more than a quarter to 1274 tonnes (21 kg P/ha) over a similar time period. There has been no obvious change in total quantity of N and P derived from animal manures, estimated to be 44 and 11 kg per ha, respectively, when averaged over the area of agricultural land. Cattle and sheep numbers have remained relatively constant and together account for approximately 80% of the manure N and 70% of the manure P produced annually. However, poultry have declined by 70% since 1960 while pig numbers have increased six-fold. The average annual application rate of manure derived N over the whole catchment (44 kg/ha) is considerably below that proposed at the farm scale in the EC Nitrate Directive (210–170 kg/ha). However, on a local scale difficulties may arise for large manure producing concerns such as dairy or pig units.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009787618943
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  • 47
    Digitale Medien
    Digitale Medien
    Controlling soil water content in fertiliser dissolution experiments (1999)
    Springer
    Nutrient cycling in agroecosystems 55 (1999), S. 7-14 
    Details
    ISSN: 1573-0867
    Schlagwort(e): fertiliser formulation ; nutrients ; phosphorus ; relative humidity ; soil moisture
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Phosphorus lost in runoff from agricultural land leads to the enrichment of surface waters and contributes to algal blooms. Fertilisers are one source of this P. To compare the water available P of different fertiliser formulations in the laboratory it is necessary to control environmental conditions, temperature, relative humidity and soil water content, prior to simulating rainfall. Two chambers were designed in which relative humidity and soil water content were controlled using salt solutions. An initial design comprising a sealed chamber with three layers of soil samples over a salt bath was found to be inferior to a single layer design. The changes in water content of soil samples were used to test the single layer chamber in a constant temperature environment (15 °C) using a saturated KCl solution (90% relative humidity). Based on the final soil water content of the samples, the spatial variation within the chamber was within tolerable limits. The single layer chamber was used for a simulation experiment comparing the water available P of two commercial fertilisers. Using a saturated resorcinol solution (95% relative humidity) soil samples were equilibrated at 15 °C for 21 days, fertiliser added, and the water available P measured up to 600 h after fertiliser application. The results indicate that the amount of water available P was related to the fertiliser compound and exponentially related to the time since fertiliser application. It was concluded that the single layer chamber is suitable for controlling relative humidity and soil water content in trials such as these where the water available P of fertilisers are being compared.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009816716466
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  • 48
    Digitale Medien
    Digitale Medien
    Transfers of phosphorus within three dairy farming systems receiving varying inputs in feeds and fertilizers (1999)
    Springer
    Nutrient cycling in agroecosystems 55 (1999), S. 63-75 
    Details
    ISSN: 1573-0867
    Schlagwort(e): dairy systems ; feeds ; fertilizers ; phosphorus ; P surplus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Inputs of phosphorus (P) above requirements for production on dairy farms lead to surplus P with increased risk of P transfer in land run-off to surface waters causing eutrophication. The impact of reducing surplus P inputs in purchased feeds and fertilizers on milk and forage production was investigated in a comparison of three dairy farm systems on chalkland soils in southern England over a 3-year period. In accordance with current commercial practice, no attempt was made to regulate P inputs in system 1, which accumulated an average annual surplus of 23 kg P ha-1. Progressive reductions in purchased feed and/or fertilizer inputs into systems 2 and 3 decreased surplus P to 17 and 3 kg ha-1, respectively, without apparently limiting either milk or herbage dry matter production. The estimated reduction in faecal P output from system 3 cows fed a low P diet compared to system 1 cows fed a high P diet was 26%. Milk P concentrations significantly (P 〈0.001) increased in systems 2 and 3 which included maize in the diet. Output of P in milk and meat products, as a proportion of the total dietary P inputs, increased from 28% in system 1 to 36% in system 3. Surplus P was greatest in continuous maize fields receiving both dairy manure and starter P fertilizer. Withholding P fertilizer in system 3 did not reduce P offtake in cut herbage on soils of moderate P fertility. Total annual losses of P in storm run-off and leaching were no greater than annual inputs of P from the atmosphere (0.5 kg ha-1). The results indicate there is scope to reduce surplus P on commercial dairy farms without sacrificing production targets at least in the short term. Purchased feeds are the largest of the P inputs on intensive dairy farms, yet these are rarely quantified on commercial holdings.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009860915462
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  • 49
    Digitale Medien
    Digitale Medien
    Applications of poultry litter and triple superphosphate fertilizer to a sandy soil: effects on soil phosphorus status and profile distribution (1999)
    Springer
    Nutrient cycling in agroecosystems 54 (1999), S. 233-242 
    Details
    ISSN: 1573-0867
    Schlagwort(e): leaching ; phosphorus ; poultry litter ; soil
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract To determine P loadings, added through poultry litter, sufficient to cause downward movement of P from the cultivated layer of a sandy soil, six rates of poultry litter were applied annually for four years to a site in central England. (total loading 0 – 1119 kg P ha-1). A single extra plot also received an extra 1000 kg ha-1 as triple superphosphate (TSP; total loading 2119 kg P ha-1) and three other treatments received 200 – 800 kg ha-1 P as TSP only. Annual soil sampling in 30-cm increments to 1.5-m depth provided information on P build-up in the topsoil and P movement to depth. There were strong linear trends between P balance (P applied – P removed in crops) and total P, Olsen bicarbonate extractable P and water-soluble P in the topsoil. Phosphorus from TSP and poultry litter fell on the same regression lines, suggesting that both would be equally effective as fertilizer sources. We calculated that 100 kg ha-1 surplus total P would increase the Olsen extractable P content by c. 6 mg kg-1 and the water-soluble P by c. 5 mg kg-1. Thus, relatively large amounts of P would need to be applied to raise soil P status. We found some evidence of P movement into the soil layers immediately below cultivation depth. However, neither soil sampling nor soil solution extracted through Teflon water samplers showed evidence of movement into the deep subsoil (1 m) despite large P loadings.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009744706679
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  • 50
    Digitale Medien
    Digitale Medien
    Inorganic phosphorus and manure effects on bahiagrass production on a Spodosol (1999)
    Springer
    Nutrient cycling in agroecosystems 54 (1999), S. 259-266 
    Details
    ISSN: 1573-0867
    Schlagwort(e): bahiagrass ; manure ; pasture fertilization ; phosphorus ; phosphorus cycling ; Spodosol
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Bahiagrass (Paspalum notatum Flugge) pasture fertilization recommendations have traditionally been based upon clipping studies. Inclusion of P from manure, not originally considered when P recommendations were developed for pastures, may minimize the need for P fertilization without reducing bahiagrass production or P uptake. The objective of this research was to determine if manure contributes greatly to the P crop nutrient requirement. A 2-year field study utilized a factorial arrangement of 0 and 6.9 Mg air-dried manure ha-1 with 0, 17, 34, 51, and 68 kg inorganic P ha-1 from triple superphosphate to evaluate bahiagrass yield, root distribution, and P uptake response on a Myakka fine sand (sandy, siliceous, hyperthermic Aeric Alaquod). Because air-dried manure was used in the field study, a greenhouse study was employed to confirm that there were no differences in bahiagrass yield or P uptake from either air-dried or fresh cattle (Bos spp.) manure sources. There were no manure or manure by P interaction effects on yield or P uptake of bahiagrass indicating that manure source did not effect grass production in the greenhouse. In the field study, bahiagrass roots were distributed into the Bh horizon, and the Bh horizon had at least four times more Mehlich-1 extractable P than that of the Ap horizon. This horizon was most likely acting as a main source for P-uptake by the grass. This observation was further confirmed by no yield response to levels of inorganic P application in 1989. A linear-response-and-plateau (R2=0.196) relationship with a critical point of 15.4 kg P ha-1 was found in 1990. Bahiagrass yield and P uptake were not dependent on P fertilization, either from manure or inorganic P, due to the availability of P from the Bh horizon.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009831011649
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  • 51
    Digitale Medien
    Digitale Medien
    Effect of P fertilizer on alleviating chloride toxicity in wheat (1985)
    Springer
    Nutrient cycling in agroecosystems 6 (1985), S. 171-176 
    Details
    ISSN: 1573-0867
    Schlagwort(e): Chloride ; phosphorus ; salinity ; wheat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract A pot study with four levels each P (control, 6.5, 13.0, 19.5 mg kg−1) and Cl− in irrigation water (control, 30, 60, 90me l−1) was carried out to test Cl− and P interaction on wheat. It has been found that optimum P nutrition alleviates the toxic effect of excess Cl−. Highest P rate resulted in a significant yield increase upto a Cl− level of 60me l−1. Cl− depressed P content in the plant only at a Cl− level of 90me l−1, while P rates had no major impact on the Cl− concentration in the plant. Lower Cl− concentration at higher P rates are rather a dilution effect than an antagonistic one. With optimum P supply higher Cl− contents in the plants were tolerated than with a low P supply.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01051011
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  • 52
    Digitale Medien
    Digitale Medien
    Tracking phosphorus patterns in mango (Mangifera indica L) and possible relations to floral induction (1985)
    Springer
    Nutrient cycling in agroecosystems 6 (1985), S. 225-234 
    Details
    ISSN: 1573-0867
    Schlagwort(e): bark ; floral induction ; leaves ; mango ; phosphorus ; shoots ; stems
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Phosphorus concentration was tracked in four types of mango shoots. The mean phosphorus concentration was highest in laterals existing on shoots which had either flowered or fruited in the preceding season, followed by young flush arising in July, laterals existing on shoots which did not flower or fruit in the preceding season and shoots which did not flower or fruit in the preceding season and having further extension of growth. A higher percentage of floral induction was noted in the laterals on shoots which had either flowered or fruited in the preceding season. The study clearly showed the association of availability of phosphorus with floral induction.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01048797
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  • 53
    Digitale Medien
    Digitale Medien
    Response of two okra (Abelmoschus esculentus L. Moench) varieties to fertilizers: Yield and yield components as influenced by nitrogen and phosphorus application (1985)
    Springer
    Nutrient cycling in agroecosystems 6 (1985), S. 257-267 
    Details
    ISSN: 1573-0867
    Schlagwort(e): nitrogen ; okra (Abelmoschus esculentus L. Moench) ; phosphorus ; yield ; yield components
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The response of two okra (Abelmoschus esculentus L. Moench) varieties (‘White velvet’ and ‘NHAE 47-4’) to fertilization in northern Nigeria was examined using four rates of nitrogen (0, 25, 50 and 100 kg ha−1) and three rates of phosphorus (0, 13 and 26 kg ha−1). Nitrogen application significantly increased green pod yield, pod diameter, number of fruits per plant, number of seeds per pod and pod weight. Application of phosphorus also significantly increased green pod yield, pod number and number of seeds per pod. The two varieties responded to nitrogen application differentially with respect to green pod yield. For optimum green pod yield of ‘White velvet’ 35 kg N ha−1 is suggested while for variety ‘NHAE 47-4’, N fertilization can be increased to 70 kg ha−1. There was no differential response of varieties to phosphorus fertilization for green pod yield; however, the application of 13 kg ha−1 enhanced the performance of both varieties.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01048799
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  • 54
    Digitale Medien
    Digitale Medien
    A conceptual model for initial and residual responses to phosphorus fertilizers (1985)
    Springer
    Nutrient cycling in agroecosystems 6 (1985), S. 131-138 
    Details
    ISSN: 1573-0867
    Schlagwort(e): modelling ; phosphorus ; residual value
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract A model is formulated to describe the amount of effective phosphorus in soil. For a source that is immediately fully effective only three parameters are required — the amount of effective phosphorus initially present, the proportion of phosphorus remaining effective after each year, and a parameter which determines the lower limit for the amount of effective phosphorus. An extension of the model to sources that release their phosphorus slowly requires one further parameter — the fraction of such phosphorus released each year. The effective phosphorus in soil is then related to yield using the Mitscherlich equation. The model gave a good description of the growth response ofStylosanthes humilis to superphosphate and calcined Christmas Island C-grade phosphate (CCICP) over three years on a red earth at Katherine, N.T. Furthermore, it enabled a quantitative assessment to be made of the residual value of the CCICP that was not achieved in an earlier analysis of the data.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01051007
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  • 55
    Digitale Medien
    Digitale Medien
    Fertilizer and liming value of lime-treated sewage sludge (1986)
    Springer
    Nutrient cycling in agroecosystems 8 (1986), S. 313-328 
    Details
    ISSN: 1573-0867
    Schlagwort(e): fertilizers ; lime ; lucerne ; nitrogen ; phosphorus ; sewage sludge
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract A field experiment was conducted with lucerne on a strongly acidic and phosphorus deficient soil to determine the liming and phosphorus and nitrogen fertilizer value of an undigested, lime-treated sewage sludge. The results are presented in terms of calculated combinations of lime, nitrogen and phosphorus fertilizer required to obtain the same lucerne yield (or soil pH or extractable phosphorus level) as achieved with 5 or 10 t ha−1 of dried sludge. The sludge was a good source of lime, phosphorus and nitrogen. The sludge phosphorus was 49% as effective as the fertilizer phosphorus in raising extractable phosphorus in the soil to the level required for crop growth. The calcium carbonate of the sludge raised soil pH more effectively than agricultural lime, probably because of finer particle size in the former. It was not possible to achieve the yield obtained with 25 t ha−1 of sludge with combinations of agricultural lime, and nitrogen and phosphorus fertilizers at high rates of application. This was attributed to the effects of the sludge on improving soil physical properties.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01048634
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  • 56
    Digitale Medien
    Digitale Medien
    Comparisons of the fertilizing and liming properties of lime-treated sewage sludge with its incinerated ash (1986)
    Springer
    Nutrient cycling in agroecosystems 9 (1986), S. 187-197 
    Details
    ISSN: 1573-0867
    Schlagwort(e): lime ; lucerne ; nitrogen ; phosphorus ; ryecorn ; ryegrass ; sewage sludge ; sewage ash
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Two field experiments were conducted to compare the fertilizing and liming properties of dried lime-treated sewage sludge with its incineration product (ash). One experiment used a mixture of ryecorn and ryegrass on a relatively fertile soil and the other lucerne on a strongly acidic and phosphorus deficient soil. The first harvest of the ryecorn-ryegrass experiment showed small but significant linear responses in dry matter yield to both ash and sludge. Ash applications did not affect foliage nitrogen and phosphorus concentrations, or uptakes, but sludge applications increased these significantly. Sludge also increased the concentrations of K, S, Mg, Cu and Zn but ash only increased the concentrations of S and Mg. At the second harvest (ryegrass) 5 t ha−1 of sludge increased dry matter yield and foliage nitrogen and phosphorus concentrations whereas ash had no effect. Levels of phosphorus extracted from the soil were increased by both amendments but the sludge was much more effective than the ash. Both ash and sludge raised soil pH. In the lucerne experiment comparisons between sludge and ash were calculated from response surfaces fitted to the data which showed marked increased in soil pH and dry matter yield. Sludge markedly increased extractable phosphorus whereas ash had no effect. The sludge was 22% as effective as ash in raising soil pH to 6.5. The amounts of ash required to obtain the same yield as 10 t ha−1 of sludge were 5.78, 12.78 and 6.39 t ha−1 respectively for three successive harvests. These results and those for foliage concentrations of nitrogen and phosphorus were also ascribed to the much greater availability of the sludge phosphorus than the ash phosphorus, and the presence of nitrogen in the sludge but not in the ash.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01050345
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  • 57
    Digitale Medien
    Digitale Medien
    Fertilization of tropical rice: A case study on Bangkok plain (1986)
    Springer
    Nutrient cycling in agroecosystems 10 (1986), S. 97-112 
    Details
    ISSN: 1573-0867
    Schlagwort(e): fertilizer ; nitrogen ; phosphorus ; plant analysis ; nutritional status
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract This study consisted of a survey on the nutritional status of rice plants in relation to nutrient application and yield in 70 farmers' fields in four provinces of Bangkok plain during the 1977 wet season. In addition a series of fertilizer experiments were carried out on rice experimental stations in the same provinces to study yield response to N and P fertilization and to develop a fertilizer recommendation system based on plant analysis. The average grain yield in the survey was 3.2 t ha−1 and the early (high yielding varieties), medium (local) and late maturity (local) types yielded 3.3, 2.8 and 3.0 t ha−1, respectively. The average amount of fertilizers applied to these maturity types were 33, 15 and 7 kg N ha−1 and 15, 8 and 6 kg P ha−1, respectively. Regression analysis indicated only a slight correlation between yield and any level of fertilizer application. On experimental stations yields over 6 t ha−1 were obtained with applications of N over 100 kg ha−1 and P over 22 kg ha−1. Evaluation of nutritional status of plants based on plant analysis showed that in all provinces there were strong and widespread nutrient deficiences primarily of N and secondarily of P, and possibly of some other nutrients. Fertilizer application based on plant analysis gave high yield responses. It was concluded that the major constraints of yield on Bangkok plain are too low fertilizer application especially of N, and unbalanced fertilization of N and P.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01074365
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  • 58
    Digitale Medien
    Digitale Medien
    Mathematical algorithm for effective phosphorus determination in a rice based cropping system (1988)
    Springer
    Nutrient cycling in agroecosystems 18 (1988), S. 57-61 
    Details
    ISSN: 1573-0867
    Schlagwort(e): Cropping system ; modelling ; phosphorus ; residual value ; rice based ; sources of P
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract A mathematical model similar to the one suggested by Probert [3] is used to calculate effective phosphorus in two rice crops followed by green gram. The effective phosphorus values are then related to dry matter yield, grain yield and phosphorus uptake in the three crops using linear and Mitscherlich equations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01064178
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  • 59
    Digitale Medien
    Digitale Medien
    Fertilization of millet cv. Souna III in Senegal: dry matter production and nutrient uptake (1993)
    Springer
    Nutrient cycling in agroecosystems 35 (1993), S. 217-226 
    Details
    ISSN: 1573-0867
    Schlagwort(e): calcium ; dry matter distribution ; fertilizer ; harvest index ; magnesium ; manure ; millet ; nitrogen ; nutrient uptake ; phosphorus ; potassium ; Senegal
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract In a fertilizer and manure experiment, millet was grown under four treatments (no fertilizer or manure, farmyard manure, chemical fertilizer, and both). Grain yield and total aboveground biomass production of the unfertilized plot were relatively high. The observed differences in total dry matter production must be attributed to differences in nutrient availability, as amount of rainfall and its distribution were favourable. Results show only small differences in distribution of dry matter among the various plant organs between the best and the non-fertilized treatments. Nutrient supply from natural sources, defined as crop content of N, P, and K at maturity without fertilizer application, amounted to 104, 16 and 103 kg ha−1, respectively, which are very high values. Total uptake of calcium and magnesium is related to that of potassium, as the combined content of these three elements is linearly related to total aboveground biomass production. Minimum removal of nitrogen and phosphorus per ton grain dry matter amounts to 29 and 4kg, respectively, and 9 kg potassium per ton total aboveground dry matter. A possible double function of phosphorus as element of structural biomass and for maintenance of electro-neutrality is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00750640
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  • 60
    Digitale Medien
    Digitale Medien
    Fertilizers and eutrophication in southwestern Australia: Setting the scene (1993)
    Springer
    Nutrient cycling in agroecosystems 36 (1993), S. 95-103 
    Details
    ISSN: 1573-0867
    Schlagwort(e): eutrophication ; phosphorus ; fertilizer ; Peel-Harvey estuary ; algal blooms
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract An excess of plant nutrients has caused serious eutrophication in aquatic ecosystems of southwestern Australia manifested by excessive growth and accumulation of green and bluegreen algae. Phosphorus is generally the limiting nutrient for algal growth and phosphatic fertilizers applied to nutrient-deficient, leaching, sandy soils are the main source of P, supplemented by rural industry point sources. Nitrogen is the limiting nutrient in marine embayments with little drainage from the land. Measures to reduce the load of P delivered to drainage include basing fertilizer application rates on soil testing for P and the use of less soluble P fertilizers. Catchment management plans are being implemented with community involvement to reduce P loads and maintain agricultural production. This introductory paper reviews the history of eutrophication in southwestern Australia and of studies into its causes, principally in the large Peel-Harvey estuary. It briefly summarises other papers in this special issue concerned with different aspects of the problem: how to fertilize the land without causing eutrophication.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00747579
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  • 61
    Digitale Medien
    Digitale Medien
    Phosphorus retention and release from sandy soils of the Peel-Harvey catchment (1993)
    Springer
    Nutrient cycling in agroecosystems 36 (1993), S. 115-122 
    Details
    ISSN: 1573-0867
    Schlagwort(e): phosphorus ; retention ; release ; sandy soils
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract In order to manage phosphorus (P) losses from soils to waterbodies, knowledge of the mechanisms through which P is retained or released from the soil is essential. Sandy soils of the Peel-Harvey catchment (Western Australia) were subjected to a range of environmental and management factors in the laboratory and field in order to gain an understanding of the mechanisms that affect the magnitude of P losses. Sandy soils accumulated P, despite having little sorption capacity, and this accumulation could be monitored by measuring an acid-extractable fraction. The potential, short-term P loss could be estimated by determination of water-soluble soil solution P prior to winter rains. An annual cycle of the change in arbitrarily defined soil-P pools is discussed in relation to environmental and management factors. Laboratory experiments indicated that P rundown and potential annual P loss in the absence of P fertilizers could be estimated using bicarbonate extractable P. Phosphorus losses were decreased by the application of fertilizers with a low content of water-soluble P. The low ability of sandy soils of the Peel-Harvey coastal catchment to retain P, when compared to other Western Australian soils, is because of low contents of clay minerals and iron and aluminium hydrous oxides.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00747581
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  • 62
    Digitale Medien
    Digitale Medien
    The effect of level of nitrogen nutrition upon mineral content and removal in grasses and wheat (1990)
    Springer
    Nutrient cycling in agroecosystems 26 (1990), S. 229-235 
    Details
    ISSN: 1573-0867
    Schlagwort(e): Grass ; wheat ; nitrogen nutrition ; dilution curve ; mineral content ; mineral removal ; phosphorus ; potassium
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The important effect of nitrogen in changing the patterns of mineral content and mineral removal is analysed for grass swards and wheat. Different models are proposed; accumulated dry matter developed throughout a growing period is shown to be an excellent reference for assessing the evolution of the plant mineral content and the mineral removal the growing crop. Applications in diagnosing mineral nutrition status and optimising fertilizer use are proposed and discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01048760
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  • 63
    Digitale Medien
    Digitale Medien
    Effects of nitrogen and phosphorus fertilizers on unshaded Amazon cocoa in Nigeria (1982)
    Springer
    Nutrient cycling in agroecosystems 3 (1982), S. 13-16 
    Details
    ISSN: 1573-0867
    Schlagwort(e): cocoa ; nitrogen ; phosphorus ; soil analysis ; Nigeria
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract No extensive investigation on the effect of fertilizers on Amazon cocoa variety (Theobroma cacao L.) has been performed in Nigeria. Therefore eight fertilizer treatments involving nitrogen and phosphorus, replicated six times at four locations across southern Nigeria, were established in 1973. The four N levels (N0, N1, N2, N3) involved were 0, 80, 160 and 240 kg ha−1 y−1, and the two P levels (P0, P1) were 0 and 67 kg ha−1 y−1. Results of the first 5 years of fertilizer application are reported. Response to P was observed at all locations, and the response was statistically significant at 2 of the locations. There was no response to the application of nitrogen. The data suggest, however, that there is only a response to phosphorus when nitrogen is applied.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01063405
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  • 64
    Digitale Medien
    Digitale Medien
    The interpretation of Olsen extractable P values in relation to recommendations for the fertilizer requirements of crops (1992)
    Springer
    Nutrient cycling in agroecosystems 32 (1992), S. 223-227 
    Details
    ISSN: 1573-0867
    Schlagwort(e): Soil testing ; phosphorus ; relative yield
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract A greenhouse experiment, with Okra (Abelmoschus esculentus L.) as the test crop, was conducted on twenty-one soils ranging in Olsen's extractable phosphorus from 1.8 to 15.5µg Pg−1 soil. The experiment was conducted at Punjab Agricultural University, Ludhiana, India. The soils were nonsaline with pH ranging from 7.7 to 8.6. A critical level of 2.55µg Pg−1 soil was predicted by Cate and Nelson's (1971) statistical procedure. Because of a wide range in relative yields, this value did not accurately predict response to applied P. An approach to compute minimum response to applied fertilizer, which is likely to be obtained at a particular Olsen P level, has been presented. It involves calculation of lower 60 percent confidence limits for relative yield and fitting loge-linear regression to the transformed data. The regression was tested on a published data set and was found to hold well.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01048784
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  • 65
    Digitale Medien
    Digitale Medien
    Two post thinning fertilizer trials inPinus radiata in New South Wales, Australia (1992)
    Springer
    Nutrient cycling in agroecosystems 32 (1992), S. 259-267 
    Details
    ISSN: 1573-0867
    Schlagwort(e): Nitrogen ; phosphorus ; timber increment ; fertilization ; Pinus radiata
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Two trials inPinus radiata growing on different sites in N.S.W. allowed consideration of fertilizer applications after 2nd or 3rd thinning. The trials included factorial applications of N and P at a single thinning intensity plus a further treatment which allowed assessment of different thinning intensities. The most significant growth responses were obtained by application of N and P in combination. The largest response (additional productivity compared with the unfertilized control) occurred 4 years after application and after 7 years there was no additional absolute response for either of the two sites. The largest fertilizer response was 70 m3 ha−1 over 7 years on one site and 36 m3 ha−1 on the other, indicating differences in absolute responses between sites. It was concluded that in planning treatments the most responsive sites near the end of the rotation should be selected to maximise economic returns. Foliage analyses indicated differences between sites at the commencement of the study. It was concluded that either a single year of foliage analyses at study commencement is of value, or sampling every year of the study should be used to analyse responses, but a single year of analysis during or at the end of the study would not be of value.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01050363
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  • 66
    Digitale Medien
    Digitale Medien
    Effect of phosphate on the sorption, desorption and plant-availability of selenium in soil (1994)
    Springer
    Nutrient cycling in agroecosystems 39 (1994), S. 189-197 
    Details
    ISSN: 1573-0867
    Schlagwort(e): interaction ; isotopic exchange ; phosphorus ; plant-availability ; selenium ; soil
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Phosphate, applied at 5µg P cm−3, decreased selenite sorption by from 30–70% in three soils studied. Both maximum sorption (Xm) and the binding-energy of sorption as indicated by the binding-energy related constant (k) or the molar free energy (ΔG) of the sorption reaction derived from the Langmuir equation were considerably decreased. On the other hand, phosphate sorption was decreased by increasing concentration of selenite from 0.2µg Se cm−3 to 1.0µg Se cm−3 in the initial solution. The competitive sorption of phosphate with selenite was likely the main mechanism involved in the P-Se interactions. The competitively sorbed selenite exhibited much larger desorption in 0.01M CaCl2 solution, more readily extractable to 0.5M NaHCO3 and significantly higher isotopic exchangeability compared to that sorbed without the competing anion. Results from pot trial using ryegrass indicated that phosphate application increased more efficiently the plant-availability of applied fertilizer Se than that of indegeneous Se in soil.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00750246
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  • 67
    Digitale Medien
    Digitale Medien
    The value of poultry manure for wetland rice grown in rotation with wheat (1996)
    Springer
    Nutrient cycling in agroecosystems 47 (1996), S. 243-250 
    Details
    ISSN: 1573-0867
    Schlagwort(e): fertilizer value ; nitrogen ; phosphorus ; poultry manure ; urea ; wetland rice
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Poultry manure applied alone or in combination with urea at different N levels was evaluated as a N source for wetland rice grown in a Fatehpur loamy sand soil. Residual effects were studied on wheat which followed rice every year during the three cropping cycles. In the first year, poultry manure did not perform better than urea but by the third year, when applied in quantities sufficient to supply 120 and 180 kg N ha−1, it produced significantly more rice grain yield than the same rates of N as urea. Poultry manure sustained the grain yield of rice during the three years while the yield decreased with urea. Apparent N recovery by rice decreased from 45 to 28% during 1987 to 1989 in the case of urea, but it remained almost the same (35, 33 and 37%) for poultry manure. Thus, urea N values of poultry manure calculated from yield or N uptake data following two different approaches averaged 80, 112 and 127% in 1987, 1988 and 1989, respectively. Poultry manure and urea applied in 1:1 ratio on N basis produced yields in between the yields from the two sources applied alone. After three cycles of rice-wheat rotation, the organic matter in the soil increased with the amount of manure applied to a plot. Olsen available P increased in soils amended with poultry manure. A residual effect of poultry manure applied to rice to supply 120 or 180 kg N ha−1 was observed in the wheat which followed rice and it was equivalent to 40 kg N ha−1 plus some P applied directly to wheat.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01986279
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  • 68
    Digitale Medien
    Digitale Medien
    Balanced pasture fertilization in the Basque Country: I. Phosphorus and potassium budgets on dairy farms (1996)
    Springer
    Nutrient cycling in agroecosystems 47 (1996), S. 261-269 
    Details
    ISSN: 1573-0867
    Schlagwort(e): pasture fertilization ; phosphorus ; potassium ; nutrient budget ; nutrient efficiency
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Dairy farming is the main agricultural activity of the Basque Country. A dairy farm is characterized as a system with soils and crops, forage, cattle and manure as main components, and in such a system, nutrient cycling is very important to maintain soil fertility and optimize forage production. To quantify nutrient transfers in the cycle, a simple system was developed and has been applied to seventeen farms to examine its ability to achieve a balanced P and K fertilization. These farms have provided data on inputs (fertilizer, feeds, concentrates), pasture and manure management, and outputs (milk production), and soil samples have been taken from farm pastures. Phosphorus and K in excreta and uneaten pasture is used with a relatively high efficiency as suggested by the relatively high efficiency of P and K utilization by the pasture that usually ranges from 70 to 90%. Concentrate feeding (3000 kg cow−1 yr−1) represents one of the main P and K inputs in Basque Country dairy farms, averaging 26 and 66 kg ha−1, respectively. Besides, release of K in the soil through slow liberation from non-exchangeable sites was estimated as 30 kg ha−1. Thus, a high efficiency in excreta recycling would diminish substantially P and K mineral fertilizer needs. Farm nutrient budgets appear to be a convenient tool for determining nutrient shortages and surpluses at farm level, and thus they are considered as a first step to support a better management of maintenance fertilization of permanent pastures.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01986281
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  • 69
    Digitale Medien
    Digitale Medien
    Evaluation of two unusual high analysis compounds as fertilizers, including possible slow release features (1987)
    Springer
    Nutrient cycling in agroecosystems 11 (1987), S. 25-41 
    Details
    ISSN: 1573-0867
    Schlagwort(e): fertilizer ; high analysis nutrient compounds ; nitrogen ; phosphorus ; Rhodes grass ; slow-release ; sulphur ; Townsville stylo
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The fertilizer potential of two unusual N-P compounds with cage structures was evaluated in pot experiments where plants were repetitively cut over 400 days. One of the compounds, hexamethyl-hexaaza-tetraphosphaadamantane (APA), having 41.6% P and 28.2% N, showed high fertilizer capability. After more than 400 days, dry matter yield of Rhodes grass given APA was 83–102% of that given conventional N-P sources, and yield of Townsville stylo 60–70%. Curves for N and P uptakes over time were of sigmoidal form, with the steepest parts between days 40 and 120, suggesting a slow-release feature. However growth was depressed up to day 40, presumably by some toxic factor associated with the decomposition of the APA. This toxicity was avoided if some conventional fertilizer was applied with the APA. The other compound, the tetrasulphide of APA (APAS) had only limited fertilizer potential. Plants did absorb P and S at least from this compound, but Townsville stylo yield was only 32–38% of that with conventional fertilizers, and Rhodes grass yield not much greater than from control pots. The possible slow-release feature, and the toxic effect, did not occur with APAS.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01049562
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  • 70
    Digitale Medien
    Digitale Medien
    Zinc and phosphorus interaction in a wheat-maize cropping system (1987)
    Springer
    Nutrient cycling in agroecosystems 13 (1987), S. 77-86 
    Details
    ISSN: 1573-0867
    Schlagwort(e): zinc ; phosphorus ; interactions ; limed ; unlimed
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract To study the interaction effect of Zn and P in a wheat-maize cropping system, a field experiment was conducted at the H.P. Agricultural University Research Station, Palampur (India). Zinc was applied as ZnSO4·7H2O at the rate of 0, 20 and 40 kg per ha and P as superphosphate at the rate of 0, 60 and 120 kg per ha. The direct Zn-P interaction effect was investigated on wheat (S—308) and its residual effect on maize (early composite). Added Zn did not increase the grain and straw yield of wheat when P was not applied, but when P was applied, 20 kg per ha added Zn responded significantly. Contrary to this, in maize, only 20 kg per ha added Zn responded significantly when P was not applied, but when P was applied, even 40 kg per ha Zn increased the grain and straw yield of maize. The grain and straw yield of wheat and maize were higher under limed than under unlimed conditions. The concentration of Zn increased with the application of Zn and decreased with the application of P. The concentration of Zn was comparatively higher in grain than in straw of wheat and maize. The P concentration in wheat and maize plants decreased with the increasing levels of applied Zn. The concentrations of Zn were lower under limed than under unlimed condition, whereas the reverse was true for P concentrations. The respective absorption of Zn and P in wheat was 9.7 and 7.3 per cent upto tillering, 47.9 and 49.4 per cent between tillering and flowering, and 42.3 and 43.3 per cent between flowering and maturity. The corresponding absorption of Zn and P in maize was 11.7 and 9.4, 59.9 and 52.1, and 29.3 and 38.5 per cent before booting stage, between booting and tasseling stage and between tasseling and maturity stage, respectively. At maturity, about 53.1 and 13.0 per cent of the Zn and P taken up were retained by wheat straw and 46.9 and 87.0 per cent by wheat grain. The respective values for Zn and P in maize straw and grain were 66.8 and 30.3 and 33.2 and 69.7 per cent. When more Zn was applied, less Zn was translocated to grains; when more P was added, more Zn was translocated to grains. The effects of P and Zn on P distribution at maturity were opposite to that of Zn distribution.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01049804
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  • 71
    Digitale Medien
    Digitale Medien
    Nitrogen fertilizer use in rainfed agriculture (1984)
    Springer
    Nutrient cycling in agroecosystems 5 (1984), S. 371-382 
    Details
    ISSN: 1573-0867
    Schlagwort(e): nitrogen ; phosphorus ; dry areas ; apparent recovery fraction ; fertilizer management
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Agronomic efficiency (AE) is defined as the increase in economic yield of a crop per unit fertilizer applied. Components of AE are physiological efficiency and apparent recovery fraction. The latter can be further separated into uptake efficiency and availability index. Ways to increase the nitrogen fertilizer use efficiency in rainfed agriculture through fertilizer management are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01049117
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  • 72
    Digitale Medien
    Digitale Medien
    The effect of ionic strength on soil P reactions is negligible (1995)
    Springer
    Nutrient cycling in agroecosystems 45 (1995), S. 193-197 
    Details
    ISSN: 1573-0867
    Schlagwort(e): cation activity ; phosphorus ; potassium chloride ; soil solution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The electrolyte concentration of the soil solution affects the availability of some nutrients in the soil, especially of P, but it is not know at what salt concentration the reactions start to be significantly affected and their magnitude. This study was carried out to evaluate the effect of rates of potassium chloride (KCl) on some soil parameters that determine supplying of P, K, Ca, Mg, and Al in an unlimed acid soil. Increasing rates of KCl (from zero up to 2000 mg K kg−1) were applied to soil samples fertilized with 360 mg P kg−1. Solution (Cli) and exchangeable (Csi) forms of P, Ca, Mg, K, and Al were determined in the treated soil samples after 30-days of incubation; cation activity in solution and their selectivity coefficients were then calculated. Addition of KCl at rates equal to or above 500 mg K kg−1 caused a large relative increase on P in the soil solution (Pli) but a small and insignificant increase on the absolute value of Pli. All forms of soil K increased with increases on K applied, and buffer power for K varied according to the range of soil K. At all KCl rates, K displaced Ca, Mg, and Al from the solid phase to the soil solution, but had no effect on the extractable values. The relative preference of cations for the adsorption sites increased with increase on cation valency, and only those selectivity coefficients involving K were affected by K applied.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00748589
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  • 73
    Digitale Medien
    Digitale Medien
    Modelling nutrient flux and interspecies root competition in agroforestry interplantings (1989)
    Springer
    Agroforestry systems 8 (1989), S. 257-265 
    Details
    ISSN: 1572-9680
    Schlagwort(e): Nitrogen ; phosphorus ; potassium ; rooting density ; root biomass
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Nutrient competition between interplanted species is investigated using mechanistic modelling. Though tree and crop plant roots may occupy the same soil volume, nutrient competition is seen to be dependent on soil supply mechanisms. Model simulations illustrate the effects of nutrient diffusion rate, mobility/soil interaction, root diameter, soil moisture content, and rooting density on nutrient concentration gradients governing uptake adjacent to plant roots. These factors, unique for each nutrient and soil, combine to determine the potential for competition in agroforestry plantings. Nutrient competition is most likely for the more mobile nutrients and mechanistic modelling can be used to select tree and crop species with superior rooting and physiological characteristics for interplantings to better manage below-ground competition.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00129653
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  • 74
    Digitale Medien
    Digitale Medien
    Nutrient flows and land use change in a rural catchment: a modelling approach (2000)
    Springer
    Landscape ecology 15 (2000), S. 187-199 
    Details
    ISSN: 1572-9761
    Schlagwort(e): BOD5 ; catchment ; empirical model ; land use change ; land use scenarios ; nitrogen ; phosphorus ; runoff ; SO4
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Due largely to unprecedented land-use changes in the Porijõgi River catchment (southern Estonia) losses of nutrients and organic matter have decreased significantly. During the period 1987–1997 abandoned lands increased from 1.7 to 10.5% and arable lands decreased from 41.8 to 23.9%. At the same time, the runoff of total-N, total-P, SO4 and organic matter (after BOD5) decreased from 25.9 to 5.1, 0.32 to 0.13, 78 to 48, and 7.4 to 3.5 kg ha−1 yr−1, respectively. The most significant decreases occurred in agricultural subcatchments while the changes were insignificant in the forested upper course catchment. A simple empirical model which incorporates land-use pattern, fertilization intensity, soil parameters and water discharge accurately described the variations of total-N and total-P runoff in both the whole catchment and its agricultural subcatchments (R 2 varies from 0.95–0.99 for N to 0.49–0.93 for P). In small agricultural subcatchments the rate of fertilization is found the most important factor for nitrogen runoff, whereas in larger mosaic watersheds land use pattern plays the main role. Seven alternative scenarios compiled on the base of the empirical model allow to forecast potential nitrogen and phosphorus losses from the catchment. This information can be used in further landscape and regional planning of the whole region.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008181811552
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  • 75
    Digitale Medien
    Digitale Medien
    Distribution and fluxes as macrodetritus of phosphorus in red mangroves, Sepetiba Bay, Brazil (1998)
    Springer
    Mangroves and salt marshes 2 (1998), S. 37-42 
    Details
    ISSN: 1572-977X
    Schlagwort(e): mangrove ; phosphorus ; distribution ; dynamics ; exportation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The distribution and dynamics of phosphorus have been studied in the mangroves of Sepetiba Bay, Brazil. Leaf fall contributes 3.0 kg P ha=1yr=1to the sediment. The total above ground biomass of the R. mangle stand was about 65.3 t ha=1, the P accumulation was 3.9 kg P ha=1where 63% of the total P-biomass was accumulated in the leaves. The biomass of below ground roots was about 8.2 tha=1 and accumulated 16% of total P-biomass. Sediment contained 452 kg P ha=1 where P combined with calcium (P-Ca) was the main fraction (260 kg ha=1). The annual flux of P as litter fall was small (〈 1%) compared to total P in the sediment reservoir. The annual export of P by macrodetritus corresponds to 0.05% of the total sediment reservoir.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009950708155
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  • 76
    Digitale Medien
    Digitale Medien
    Aboveground nitrogen and phosphorus use by five plantation-grown trees with different leaf longevities (1991)
    Springer
    Biodegradation 14 (1991), S. 167-191 
    Details
    ISSN: 1572-9729
    Schlagwort(e): leaf longevity ; nitrogen ; nutrient use efficiency ; phosphorus ; requirement ; retranslocation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Energietechnik , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract Aboveground nitrogen (N) and phosphorus (P) requirement, retranslocation and use efficiency were determined for 28-year-old red oak (Quercus rubra L.), European larch (Larix decidua Miller), white pine (Pinus strobes L.), red pine (Pinus resinosa Ait.) and Norway spruce (Picea abies (L) Karst.) plantations on a similar soil in southwestern Wisconsin. Annual aboveground N and P requirements (kg/ha/yr) totaled 126 and 13 for red oak, 86 and 9 for European larch, 80 and 9 for white pine, 38 and 6 for red pine, and 81 and 13 for Norway spruce, respectively. Nitrogen and P retranslocation from current foliage ranged from 81 and 72%, respectively, for European larch, whereas red pine retranslocated the smallest amount of N (13%) and Norway spruce retranslocated the smallest amount of P (18%). In three evergreen species, uptake accounted for 72 to 74% of annual N requirement whereas for two deciduous species retranslocation accounted for 76 to 77% of the annual N requirement. Nitrogen and P use (ANPP/uptake) was more efficient in deciduous species than evergreen species. The results from this common garden experiment demonstrate that differences in N and P cycling among species may result from intrinsic characteristics (e.g. leaf longevity) rather than environmental conditions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00000806
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  • 77
    Digitale Medien
    Digitale Medien
    Seasonal dynamics of a cyanobacteria-dominated microbial community in surface sediments of a shallow, eutrophic lake (1989)
    Springer
    Aquatic sciences 51 (1989), S. 153-178 
    Details
    ISSN: 1420-9055
    Schlagwort(e): sediments ; cyanobacteria ; Microcystis ; bacterial biomass ; bacterial production ; phosphorus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The seasonal variation of microbial biomass and activity in the surface sediments (0–10 cm) of the shallow, eutrophic Lake Vallentunasjön was followed during one year. “Overwintering”Microcystis colonies dominated the microbial community during all seasons, constituting 60–90% of the total microbial biomass. Expressed on an areal basis, the benthic biomass was, throughout the year, larger than or similar to the planktonic biomass during the peak of the summer bloom, indicating an ability of the colonies to survive in the sediments for extended periods. Abundance of “other”, non-photosynthetic bacteria varied in the range 3.0–15.5 · 1010 cells g−1 d. w. over the year with minimum values in summer and maximum values in autumn in connection with the sedimentation of theMicrocystis bloom. A substantial part of the non-photosynthetic bacteria, up to circa 40%, was associated with the mucilage of healthyMicrocystis colonies. Bacterial production (3H-thymidine incorporation) appeared to be strongly temperature dependent and less influenced by the seasonal sedimentation pattern. Our data indicate an increasing proportion of non-growing cells in autumn and winter. Biomass-bound phosphorus constituted a significant portion, circa 10%, of the phosphorus content in Lake Vallentunasjön sediments. This pool has normally been overlooked in studies on phosphorus dynamics in lake sediments. Different mechanisms whereby organic phosphorus can be released from the sediments are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00879300
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  • 78
    Digitale Medien
    Digitale Medien
    Effect of snow and soil frost melting on the concentrations of suspended solids and phosphorus in two rural watersheds in Western Finland (1989)
    Springer
    Aquatic sciences 51 (1989), S. 211-223 
    Details
    ISSN: 1420-9055
    Schlagwort(e): Particles ; phosphorus ; watersheds ; snow ; frost ; soil
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Hydrological processes are known to have a considerable effect on nutrient transport from agricultural land to watercourses. In cold temperate regions peak discharges are caused not only by storm conditions but also by melting of snow and frost. The objective of this work was to investigate the effects of snow and frost melt on concentrations of phosphorus and suspended solids. The samples were taken using flowweighted automatic sampling techniques from two agricultural drainage basins. During the beginning of the snowmelt period the concentration of suspended solids was rather low by comparison with the total phosphorus concentration and the discharge. The different behaviour compared with the relationships found during storm conditions was probably caused by continuous extraction of the soil surface by low ionic concentration melt water, and to some extent by leaching from plant residues. The gradual decrease of total phosphorus concentration during the frost thawing period could be attributed to the gradually increasing proportion of the subsurface and ground water discharge in the runoff.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00877743
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  • 79
    Digitale Medien
    Digitale Medien
    Nutrient-chlorophyll trajectories across trophic gradients (1992)
    Springer
    Aquatic sciences 54 (1992), S. 58-76 
    Details
    ISSN: 1420-9055
    Schlagwort(e): Eutrophication ; lake management ; phosphorus ; nitrogen ; chlorophyll-a ; slope estimator
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We estimate the response of chl-a (mg · m−3) to changes in concentrations of total phosphorus (TP) by calculating the slopeS = Δchl-a/ΔTP in chl-a =f(TP) graphs. Results show that in years where algae are P-limited oligotrophic lakes respond less (median slope 0.21) to changes in nutrient concentrations than eutrophic lakes, (median slope 0.31) and these again less than hypereutrophic lakes, (median slope 1.02). We find no saturation value for the slope within the TP range considered (6–480 mg · m−3). Chl-a in eutrophic lakes responds more frequently to non-nutrient factors than oligotrophic and hypereutrophic lakes. Results obtained by replacing TP with a new nutrient parameter, TP′ = 0.056 · TP · IN0.226, in which inorganic nitrogen, IN, is factored in, suggest that nitrogen has an influence on chl-a in oligotrophic lakes. Blue-green algae respond less to changes in TP than other algal species, e.g., diatoms.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00877264
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  • 80
    Digitale Medien
    Digitale Medien
    Possibilities and limitations of lake restoration: Conclusions for Lake Lugano (1992)
    Springer
    Aquatic sciences 54 (1992), S. 381-390 
    Details
    ISSN: 1420-9055
    Schlagwort(e): Eutrophication ; phosphorus ; lake restoration ; internal restoration measures for lakes ; Swiss lakes ; Lake Lugano (Lago di Lugano)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In most lakes eutrophication is linked to an excessive input of phosphorus. Lake restoration by reduction of P-input (external measure) has led to a considerable drop of the P-concentration in all major Swiss lakes as well as in many other lakes. Internal restoration measures such as artificial mixing, drainage of hypolimnetic water, flushing, aeration, biomanipulation and others serve to improve and accelerate the response of a lake to external measures. For the case of Lago di Lugano, a simple two-box model is employed to demonstrate that a reduction of the P-input to about 25% of the present values is necessary to reach the “P-criterion” (P-concentration below 30 µg/l). Internal measures could possibly accelerate the extremely slow response of the northern basin.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00878149
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  • 81
    Digitale Medien
    Digitale Medien
    What controls levels of dissolved phosphate and ammonium in surface waters? (1993)
    Springer
    Aquatic sciences 55 (1993), S. 132-142 
    Details
    ISSN: 1420-9055
    Schlagwort(e): nitrogen ; phosphorus ; uptake ; regeneration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Dissolved inorganic nutrient pools are small relative to particulate pools, and dissolved pools turnover rapidly. It has been observed that pools change little from day to day on the sampling scales usually employed. A simple model is presented where uptake and regeneration rates balance to cause a local steady state concentration for dissolved inorganic nutrients. Enrichment and dilution perturbation experiments with lake water support the idea of steady state nutrient concentrations. Although inorganic nutrient concentrations are often controlled by biota, the absolute concentrations present tell little about the activity of that biota.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00877441
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  • 82
    Digitale Medien
    Digitale Medien
    Phosphorus and nitrogen limitation of algal biomass across trophic gradients (1994)
    Springer
    Aquatic sciences 56 (1994), S. 16-28 
    Details
    ISSN: 1420-9055
    Schlagwort(e): Chlorophyll-a ; phosphorus ; nitrogen ; lake ecosystem ; nutrient limitation ; regression analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Regression results based on data from 46 northern temperate lakes show that total phosphorus (TP) is the best predictor for phytoplankton (as chl-a) at lower trophic levels, TP 〈 200 mg · m−3. A regression including both TP and TN as regressors is the best predictor for lakes with TP 〉 200 mg · m−3. However, the good correlation is probably due to a high correlation between lake average chl-a (all years observed) and lake average TP and TN. Within single hypereutrophic lakes, TN alone is the best predictor. It was not possible to identify a medium trophic domain where TN and TP in combination was the best predictor for chl-a. The ratio TN:TP in the water decreases from about 40 to about 5 with increasing trophic level. Optimum TN:TP ratio for algal species with high abundance during late summer and autumn reflects this decreasing ratio, but within a lesser range, i.e., 20 to 5. In contrast, TN:TP ratios for species abundant during the early vernal period showed no, or an inverse, relation to the TN:TP ratio of the water.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00877432
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  • 83
    Digitale Medien
    Digitale Medien
    Distribution and sources of phosphorus in tidal river sediments in the Washington, DC, Area (1997)
    Springer
    Environmental geology 30 (1997), S. 224-230 
    Details
    ISSN: 1432-0495
    Schlagwort(e): Key words Sediment ; Washington ; DC ; Pollution ; phosphorus ; nutrients
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie
    Notizen: Abstract  Sediments in the rivers and basins around Washington, DC, have high concentrations of phosphorus, which, based on geographic distributions, is largely derived from urban runoff and municipal sewage. Dissolved-particulate phosphate exchange reactions and biological uptake of dissolved phosphorus from the water column may be an added source of phosphorus to the sediments. Concentrations of total sedimentary phosphorus ranged from 24 to 56 μm P/g-dw, and were highest in areas near combined sewer outfalls. As a part of this study, sedimentary phosphorus was fractionated into Fe-P, Ca-P, Al-P, and organic phases using a selective-sequential leaching procedure. The distribution of the phases in all sediments analyzed follow the order , Fe-P〉Ca-P〉Al-P. Spatial variations in the amounts of phosphorus in the different phases is related to the sources of phosphorus to the area. The proportions of occluded Al-P and organic P are 10–20% of the total P, respectively. This suggests that phosphorus from natural sources is small compared to anthropogenic inputs in this area. The high leachable Fe-P and Ca-P in these sediments might contribute a substantial amount of P to the water column under conditions of remobilization.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002540050150
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  • 84
    Digitale Medien
    Digitale Medien
    Contribution of nitrogen and phosphorus by precipitation in the drainage basin of the Santillana Reservoir (Madrid) (1994)
    Springer
    Environmental geology 23 (1994), S. 99-104 
    Details
    ISSN: 1432-0495
    Schlagwort(e): Nitrogen ; phosphorus ; Precipitation collector ; Nutrients rates
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie
    Notizen: Abstract The contribution of nitrogen and phosphorus due to precipitation constitutes the second most important route after superficial runoff. The sampling carried out during a two-year period by means of a precipitation collector allows us to determine the contribution of this route both qualitatively and quantitatively. Nitrogen is mainly supplied in an inorganic form, while phosphorus is principally supplied as orthophosphate. During the period of this study (March 1986–February 1988) it was found that in the Santillana Reservoir Watershed the level of nitrogen supplied by precipitation constitutes an average of 4.87% and the level of phosphorus constitutes 8.01%. The contribution of nitrogen varies in inverse ratio to precipitation and the contribution of phosphorus varies in direct ratio.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00766982
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  • 85
    Digitale Medien
    Digitale Medien
    Thermal Destruction of Polydimethyl-Siloxane on a Phosphorus-containing Silica Surface (2000)
    Springer
    Journal of thermal analysis and calorimetry 62 (2000), S. 335-344 
    Details
    ISSN: 1572-8943
    Schlagwort(e): phosphorus ; polydimethylsiloxane ; silica ; surface ; thermogravimetry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Thermogravimetry, differential thermal analysis, and IR spectroscopy were used to investigate the process of thermal destruction of adsorbed polydimethylsiloxane (PDMS) in air. The disperse adsorbents were pristine fumed silica and modified fumed silica whose surface contained oxygen compounds of phosphorus. It was shown that under the given experimental conditions the thermal destruction of PDMS on the fumed silica surface was accompanied by the complete transformation of the adsorbed PDMS to SiO2. In the case of phosphorus-containing silica, the thermal destruction proceeded in a different way. It was found that at 140–300°C depolymerization of the siloxane chains of a certain part of the adsorbed polymer took place with the concurrent removal of volatile products of the reaction. However, the remaining part of the adsorbed PDMS interacted with the modified silica surface to form chemisorbed dimethylsilyl structures. The thermal destruction of the chemisorbed fragments of PDMS in air was initiated at 400°C or above for both types of silica investigated.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1010184519492
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  • 86
    Digitale Medien
    Digitale Medien
    Oxidation behavior of sintered 434L ferritic stainless steel-Al2O3 composites with ternary additions (1985)
    Springer
    Oxidation of metals 23 (1985), S. 177-189 
    Details
    ISSN: 1573-4889
    Schlagwort(e): sintered ferritic stainless steel composite ; porosity ; transition metals ; phosphorus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau
    Notizen: Abstract The oxidation behavior of sintered ferritic stainless steel-Al2O3 composites, and composites with ternary additions such as titanium, niobium, or phosphorus, have been studied at 550°C in 1 atm oxygen up to 9 hr. It is found that α-SS-6 vol.% Al2O3 is most resistant to oxidation amongst all the compacts investigated. Amongst the ternary composites, niobium-containing compacts show better oxidation resistance compared to titanium or phosphorus-containing composites.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00659902
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  • 87
    Digitale Medien
    Digitale Medien
    XRD Investigations of the Phosphorus Effect on the Oxidation of TiAl Alloys by High-Resolution Methods (2000)
    Springer
    Oxidation of metals 54 (2000), S. 317-337 
    Details
    ISSN: 1573-4889
    Schlagwort(e): TiAl ; oxidation ; phosphorus ; microdiffraction ; doping ; rutile
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau
    Notizen: Abstract Recently it has been found that very small amounts (a few 100 ppm) of Padded to γ -titanium aluminide can significantly alter the oxidationbehavior between 973 and 1273 K. The mechanism responsible for this changeis, however, still not clear. In the present study, phosphorus wasincorporated into the surface of TiAl (containing 50 at.% Al) by ionimplantation and oxidation tests were carried out at 1173 K inair. Improvement of oxidation resistance is only temporary up to 100 hr forphosphorus-implanted TiAl. After 100 hr, the oxidation rate increases andbreakaway oxidation follows. XRD and EPMA showed that the breakawayoxidation is connected with massive nitride formation. Two different modelsare proposed which can explain the effect of phosphorus additions on theoxidation kinetics of TiAl during the protective stage within the first100 hr. The breakaway effect can be explained by penetration of air to themetal–oxide interface zone because of microcrack formation in theoxide scale, which was experimentally proved by acoustic-emission analysis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1004606513758
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  • 88
    Digitale Medien
    Digitale Medien
    Vanadium–molybdenum phosphates supported by TiO2 for ethane oxidation to acetic acid: a correlation between the local environment of vanadium and the reactivity (2000)
    Springer
    Topics in catalysis 11-12 (2000), S. 101-109 
    Details
    ISSN: 1572-9028
    Schlagwort(e): ethane ; vanadium ; molybdenum ; phosphorus ; titanium oxide ; acetic acid
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Different complementary physicochemical tools have been used to explain the improvement of the catalytic performances for ethane oxidation into acetic acid induced by the addition of molybdenum as phosphate to vanadium phosphate deposited on TiO2-anatase, at a coverage below the monolayer. Electron microscopy techniques have shown that the elements are dispersed on the support. Electron spin resonance, laser Raman and UV-visible spectroscopies have evidenced that the short range order around vanadium is modified by the presence of molybdenum. 51V NMR has shown that molybdenum favours the octahedral symmetry of vanadium. The acidic properties of the catalyst are improved by the adding effect of molybdenum and by the addition of water. This should explain a better desorption of acetic acid and the improvement of the corresponding yield. This confirms the importance of the atomic environment of vanadium-based oxides to control the mild oxidation of light alkanes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1027223208829
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  • 89
    Digitale Medien
    Digitale Medien
    Cost-Effective Nutrient Reductions to the Baltic Sea (1997)
    Springer
    Environmental and resource economics 10 (1997), S. 341-362 
    Details
    ISSN: 1573-1502
    Schlagwort(e): Baltic Sea ; eutrophication ; nitrogen ; phosphorus ; cost effective
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Energietechnik , Wirtschaftswissenschaften
    Notizen: Abstract Due to eutrophication caused by heavy loads of nitrogen and phosphorus, the biological conditions of the Baltic Sea have been disturbed: large sea bottom areas without any biological life, low stocks of cods, and toxic blue green algaes. It is recognized that the nitrogen and phosphorus loads to the Baltic Sea must be reduced by 50% in order to restore the sea. The main purpose of this paper is to calculate cost effective nitrogen and phosphorus reductions to the Baltic Sea from the nine countries surrounding the Baltic Sea. The results show a significant difference in minimum costs of decreasing nitrogen and phosphorus loads to the Sea: approximately 12 000 millions of SEK per year and 3 000 millions of SEK respectively for reductions by 50%. It is also shown that a change from a policy of cost-effective nutrient reductions to a policy where each country reduces the nutrient loads by 50% increase total costs for both nitrogen and phosphorus reductions by about 300%. The results are, however, sensitive to several of the underlying assumptions and should therefore be interpreted with much caution.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1026497515871
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  • 90
    Digitale Medien
    Digitale Medien
    Effects of ferulic acid, an allelopathic compound, on net P, K, and water uptake by cucumber seedlings in a split-root system (1990)
    Springer
    Journal of chemical ecology 16 (1990), S. 2429-2439 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Cucumis sativus ; ferulic acid ; split root ; phosphorus ; potassium ; water ; net uptake
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract Since distribution of allelopathic compounds in soils is highly variable, injurious effects by such compounds should be related to the frequency of contact with roots. Experiments were conducted to determine how P, K, and water uptake of cucumber seedlings were affected as the fraction of roots in contact with ferulic acid (FA) was increased. Seedlings were grown in Hoagland's nutrient solution for 14 days and then transferred to 0.5 mM CaSO4 solution for 24 hr before being placed into a split-root culture system. The containers in the system were filled with 0.5 mM concentrations of KH2PO4 and CaSO4 or 0.5 mM concentrations of KH2PO4, CaSO4, and ferulic acid (FA). Net uptake of P by seedlings (milligrams per seedling) decreased in a curvilinear (concave) manner as the fraction of the roots in contact with FA increased. Net uptake of K (milligrams per seedling) and water (milliliters per seedling) by seedlings decreased linearly as the fraction of the roots in contact with FA increased. Net uptake of P, K, and water by seedlings was reduced 57, 75, and 29%, respectively, when the whole root system was exposed to FA. Net P and K uptake of roots (milligrams per gram root fresh weight) not in contact with FA decreased in a linear and curvilinear (convex) manner, respectively, as the fraction of roots in contact with FA increased. Net P and K uptake of roots in contact with ferulic acid increased in a linear and curvilinear (convex) manner, respectively. Net water uptake of roots (milliliters per gram root fresh weight) not in contact with FA increased in a curvilinear (concave) manner as the frequency of the roots in contact with FA increased. Net water uptake of roots in contact with FA did not show a trend. Transpiration (milliliters per square centimeter) was reduced in a linear manner as the fraction of roots in contact with FA increased. A very slight compensation by roots not in contact with FA for roots in contact with FA was observed for net water uptake rates. No compensation for P and K uptake rates was observed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01017466
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  • 91
    Digitale Medien
    Digitale Medien
    Factors Regulating the Flux of Phosphate at the Sediment - Water Interface of a Subtropical Calcareous Lake: a Simulation Study with Intact Sediment Cores (1997)
    Springer
    Water, air & soil pollution 99 (1997), S. 401-409 
    Details
    ISSN: 1573-2932
    Schlagwort(e): phosphorus ; P flux ; microbial activity ; redox ; simulation ; Lake Kinneret ; sediment ; accumulative P release
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Energietechnik
    Notizen: Abstract Different factors which interactively control the flux of soluble reactive phosphorus (SRP) at the sediment-water interface (SWI) of Lake Kinneret were studied seasonally. The influence of pH, Eh and microbial activity on SRP flux at the SWI was investigated by manipulating the conditions in the overlying water of intact sediment cores. The calculated diffusive SRP flux out of the sediment was lower in cores sampled during winter and spring than during the period of amixis. Potential SRP release, as measured in the absence of microbial activity, was strongly enhanced upon the transition from oxic to anoxic conditions indicating P release from iron(III)-bound phosphorus. In spring and summer cores, an enhanced SRP flux from sediments at pH 7 in comparison to pH 8 indicated P release from carbonate-bound P which sedimented previously as result of high pH values during the algal spring bloom. Microbial uptake at the SWI was the most important sink for SRP and no net-flux occured under oxic conditions. The higher net-flux of P under anoxic conditions was linked to carbon limitation of the bacteria at the SWI.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1018335305539
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  • 92
    Digitale Medien
    Digitale Medien
    Bottom sediments in a humic lake with artificially increased calcium content: sink or source for phosphorus? (1997)
    Springer
    Water, air & soil pollution 99 (1997), S. 457-464 
    Details
    ISSN: 1573-2932
    Schlagwort(e): sediment ; phosphorus ; fractionation ; release ; humic lake
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Energietechnik
    Notizen: Abstract Lake Flosek (north-eastern part of Poland) is a small shallow and without outflow lake which has been limed in 1970. The concentration of Ca was increased from 3-4 mg L-1 to 17 mg L-1 in the water and from 0.2-0.3% dry weight to 0.9-1.7% dry weight in sediments (5 cm upper layer) due to CaCO3 addition to the lake. In the spring-summer seasons of 1992 and 1993, an experimental study was conducted in Lake Flosek to assess the capacity of bottom sediments to uptake and release mineral phosphorus. The rate of phosphorus exchange between sediments and near-bottom water was experimentally measured under conditions of high (100%), and of reduced (10%) oxygen saturation in near-bottom water. To determine the component of sediments responsible for the uptake of most phosphorus, the proportions of phosphorus forms in sediments were analysed. Sediments of Lake Flosek showed a slight tendency to release phosphates. The rate of this process was similar under high (100%) and low (10%) oxygen saturations ranging from - 0.161 to + 0.200 mg P m-2 d-1. This is much lower (by 1-2 orders of magnitude) than reported from other harmonic, non-humic lakes. In the total phosphorus pool, the highest content of phosphorus was found in the organic and residual phosphorus fractions (over 70% of the total phosphorus in sediments). The largest part of the readily extractable phosphorus was found in the fraction bound to Al and humic substances (41%). Both these fractions determine a weak exchange of phosphorus between sediments and water. No difference in P-release related to P-fraction compound was found in the cores taken from three sites in the lake.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1018395524195
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  • 93
    Digitale Medien
    Digitale Medien
    Sediment Accumulation of Nutrients (N, P) in the Eastern Gulf of Finland (Baltic Sea) (1997)
    Springer
    Water, air & soil pollution 99 (1997), S. 477-486 
    Details
    ISSN: 1573-2932
    Schlagwort(e): sediment ; nitrogen ; phosphorus ; organic matter ; cluster analysis ; Gulf of Finland ; estuaries
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Energietechnik
    Notizen: Abstract Dry weight (DW), ignition loss (IL) and concentrations of total nitrogen (TN) and total phosphorus (TP) of the sediment surface layer (0 to 10 cm, 1 cm slices) were analyzed from 20 sites in the eastern Gulf of Finland. The distance of the sampling sites from the mouth of the River Neva explained the nutrient concentrations of the sediments well, while the effect of water depth was negligible. The increase of TN and the decrease of TP along the transect from the river mouth towards the open Gulf were caused by the diminishing share of allochthonous material supplied from the River Neva. The mean TN concentration of the different accumulation areas was about 40 % higher in the sediment surface than in the deeper layer (9 to 10 cm). The corresponding difference for TP varied from 53 to 56 %. The results suggest considerable netflux of nutrients from sediment to water. The net sediment accumulation of nutrients were estimated as 6.0 g m-2 a-1 of N and 1.7 g m-2 a-1 of P corresponding 22 000 t a-1 of N and 6 100 t a-1 of P for the whole eastern Gulf.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1018399625103
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  • 94
    Digitale Medien
    Digitale Medien
    Benthic fluxes of dissolved inorganic carbon, nutrients and oxygen in the Gulf of Trieste (Northern Adriatic) (1997)
    Springer
    Water, air & soil pollution 99 (1997), S. 305-314 
    Details
    ISSN: 1573-2932
    Schlagwort(e): Adriatic Sea ; nutrients ; benthic fluxes ; carbon ; nitrogen ; silicon ; phosphorus ; budgets
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Energietechnik
    Notizen: Abstract Benthic fluxes of dissolved inorganic N, Si and P nutrients, alkalinity, dissolved inorganic C (DIC), and O2 from sediments in the Gulf of Trieste (northern Adriatic, Italy) were measured monthly in the period September 1995 – August 1996 using in situ incubated light benthic chambers. The highest efluxes of DIC, NH4 +, PO4 3−, Si(OH)4, and NO3 − influxes encountered in late summer — early autumn were the consequence of degradation of benthic microalgae, and in autumn mostly of sedimented phytoplankton. High NO3 − efflux was observed in spring. Only NH4 + and Si(OH)4 fluxes were significantly correlated with temperature. This correlation suggests that the rate of downward input and the quality and quantity of sedimentary organic matter (autochthonous and allochthonous) were superimposed on the temperature fluctuations. High DIC, NH4 + and Si(OH)4 effluxes observed in July 1996 were due to the late spring — early summer degradation of sedimentary organic matter produced by benthic microalgae, while the autumn phytoplankton bloom was quickly reflected in enhanced benthic fluxes due to higher temperature. Significant correlations between NH4 +, PO4 3− and Si(OH)4 fluxes suggested their parallel regeneration and utilization at the sediment-water interface. The nutrient fluxes were linked to O2 consumption, suggesting that aerobic oxidation processes were important at the sediment-water interface in the Gulf. The N, P and Si nutrients released from sediment pore waters are probably utilized in benthic microalgal and bottom-water primary production. This indicates that pelagic and benthic communities in the central part of the Gulf of Trieste function relatively independently of each other.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02406870
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  • 95
    Digitale Medien
    Digitale Medien
    Trophic modifications in Lake Como (N. Italy) caused by the zebra mussel (Dreissena polymorpha) (1997)
    Springer
    Water, air & soil pollution 99 (1997), S. 633-640 
    Details
    ISSN: 1573-2932
    Schlagwort(e): zebra mussel ; Dreissena polyrnorpha ; phosphorus ; trophic state ; recovery ; take Como
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Energietechnik
    Notizen: Abstract A large scale study on the western basin of Lake Como (N. Italy) was started in 1995 to examine the effects of the zebra mussel colonization which began in early '90. Our results have been related to '91–92 data (pre-Dreissena period), before the maximum colonization of zebra mussel. In spring and summer of the post-Dreissena period total phosphorus, P-PO4, nitrate and chlorophyll values decreased, while ammonium and tranparency increased at every sampling station. Zebra mussel does not modify the trophic state of this sub-basin but it plays an important role in nutrient cycling. The entire population can filter epilimnetic craters 2.1 times per year and can produce 2.9 × 104 t y of pseudofaeces which are transferred to sediments.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02406902
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  • 96
    Digitale Medien
    Digitale Medien
    Dry matter content and mineral composition of potatoes grown in Cyprus (1980)
    Springer
    Potato research 23 (1980), S. 371-375 
    Details
    ISSN: 1871-4528
    Schlagwort(e): nitrogen ; phosphorus ; potassium ; calcium ; sodium ; nitrate ; sulphate ; micronutrients
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary The specific gravity and dry matter content of 193 tuber samples (cultivars: Arran Banner, Spunta, Up-to-Date, Cara) from crops grown at Kokkinochoria, the major potato growing area of Cyprus, were related to each other as follows: Dry matter (%)=−269.59+268.24×specific gravity. This regression accounted for 82.4% of the variation; the fiducial limits (P〈0.05) for single determinations of specific gravity were±1.54 percentage units. The mineral contents of the tubers were similar to those reported in other countries.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02360677
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  • 97
    Digitale Medien
    Digitale Medien
    Rapid multiplication of potatoes in the warm tropics: rooting and establishment of cuttings (1990)
    Springer
    Potato research 33 (1990), S. 13-21 
    Details
    ISSN: 1871-4528
    Schlagwort(e): hormones ; media ; phosphorus ; rooting depth ; solar radiation ; temperature
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Summary To expand potato production in developing countries using cuttings as a source of good quality planting material, requires simple low cost methods to root and establish them. Experiments at a warm tropical site in the Philippines, to determine appropriate methods, showed that simple media ranging from fine sand to clay subsoil mixed with rice hulls enabled rooting which was not improved by hormones. Nitrogen rich media, such as volcanic soil or compost with additional P, were best for developing cuttings into strong transplants but there were no major differences in root and shoot development from cuttings differing in size and age. Tuberizations was favored by increasing the number of nodes buried in the media. Low solar radiation of 7 MJ/m2/day enabled high cutting survival up to root initiation, after which higher radiation supported larger root and shoot production.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02358126
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  • 98
    Digitale Medien
    Digitale Medien
    An EPR and molecular mechanics study of radical adducts of phosphonyl radicals with 2-hydroperfluoro-4-methyl-and 4,4-dimethyl-2-pentene (1992)
    Springer
    Russian chemical bulletin 41 (1992), S. 2008-2011 
    Details
    ISSN: 1573-9171
    Schlagwort(e): EPR ; radical ; fluorine ; conformation ; phosphorus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract EPR spectra of radical adducts of phosphonyl radicals with 2-hydroperfluoro-4-methyl- and 4,4-dimethyl-2-pentene have been studied. The molecular mechanics method has been used to determine the preferred conformation of the (CF3)2CF-CF-HCF3P(O)(OMe)2 radical. The eclipsed conformation of the C–P bond and 2p z -orbital of an unpaired electron is stabilized due to steric factor and hyperconjugation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00863364
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  • 99
    Digitale Medien
    Digitale Medien
    Impact of phosphorus availability on modelling phytoplankton dynamics (1986)
    Springer
    Aquatic ecology 20 (1986), S. 225-243 
    Details
    ISSN: 1573-5125
    Schlagwort(e): phosphorus ; bioavailability ; nutrient/phytoplankton modelling ; eutrophication
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Regulation of phosphorus loading is considered to be the primary method of eutrophication control for many lake systems. It is therefore necessary to have accurate estimates of the forms and bioavailability of all phosphorus sources in order to develop the most cost effective load control measures. Research at Clarkson University, aimed at improving the accuracy of estimates of the form and reactivity of phosphorus loadings to Lake Erie, has revealed a significant difference between the algal-availability of allochthonous and autochthonous particulate phosphorus. This paper presents the results of modifying an existing multi-nutrient phytoplankton model by separating allochthonous phosphorus into three forms: soluble reactive phosphorus (SRP) — immediately available for algal uptake; external ultimately-available phosphorus—not immediately available but converted to an available form at a specific rate; an external refractory phosphorus (ERP)—not available while in the water column. Comparisons between the original and modified models showed that the modified phosphorus dynamics proved to be a viable alternative to the concept of invoking an unexplained soluble phosphorus water column loss term, employed in the original model. The work also demonstrates that the distinction is significant for lakes receiving a significant portion of their external phosphorus load in a particulate (not immediately available) form and having a morphometry and hydrology such that this particulate phosphorus remains in the water column for longer than about two weeks.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02291165
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  • 100
    Digitale Medien
    Digitale Medien
    Retention of nutrients in river basins (1999)
    Springer
    Aquatic ecology 33 (1999), S. 29-40 
    Details
    ISSN: 1573-5125
    Schlagwort(e): denitrification ; nature restoration ; nitrogen ; phosphorus ; riparian areas ; sedimentation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In Denmark, as in many other European countries, the diffuse losses of nitrogen (N) and phosphorus (P) from the rural landscape are the major causes of surface water eutrophication and groundwater pollution. The export of total N and total P from the Gjern river basin amounted to 18.2 kg ha−1 and 0.63 kg P ha−1 during June 1994 to May 1995. Diffuse losses of N and P from agricultural areas were the main nutrient source in the river basin contributing 76% and 51%, respectively, of the total export. Investigations of nutrient cycling in the Gjern river basin have revealed the importance of permanent nutrient sinks (denitrification and overbank sedimentation) and temporary nutrient storage in watercourses. Temporary retention of N and P in the watercourses thus amounted to 7.2–16.1 g N m−2 yr−1 and 3.7–8.3 g P m−2 yr−1 during low-flow periods. Deposition of P on temporarily flooded riparian areas amounted from 0.16 to 6.50 g P m−2 during single irrigation and overbank flood events, whereas denitrification of nitrate amounted on average to 7.96 kg N yr−1 per running metre watercourse in a minerotrophic fen and 1.53 kg N yr−1 per linear metre watercourse in a wet meadow. On average, annual retention of N and P in 18 Danish shallow lakes amounted to 32.5 g N m−2 yr−1 and 0.30 g P m−2 yr−1, respectively, during the period 1989–1995. The results indicate that permanent nutrient sinks and temporary nutrient storage in river systems represent an important component of river basin nutrient budgets. Model estimates of the natural retention potential of the Gjern river basin revealed an increase from 38.8 to 81.4 tonnes yr−1 and that P-retention increased from −0.80 to 0.90 tonnes yr−1 following restoration of the water courses, riparian areas and a shallow lake. Catchment management measures such as nature restoration at the river basin scale can thus help to combat diffuse nutrient pollution.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1009947907811
    Standort Signatur Erwartet Verfügbarkeit
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