ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Temporal and spatial variability in soil nutrient status of a former beach plain (1990)
    Springer
    Plant and soil 127 (1990), S. 1-12 
    Details
    ISSN: 1573-5036
    Keywords: ammonium ; labile organic P ; nitrate ; N mineralization ; phosphorus ; Plantago major L. ssp. pleiosperma ; soil nutrient availability ; soil nutrient pools ; spatial variation ; temporal variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract As part of a research project on the variation in life-history characteristics within a population of Plantago major L. ssp. pleiosperma, seasonal and spatial variability in the availability of macronutrients (N, P, and K) were examined on a small scale in the 0–25 cm soil depth at a primary beach plain site, embanked since 1966. On the basis of distinct differences, among other things, in plant biomass, an a priori division into three different types of microhabitat occurring in a mosaic distribution pattern was made: an overall low-lying area (subsite 1) with slightly elevated patches of 0.5 to 1.5 m in diameter (subsite 2) and rather large patches, 20 to 40 m in diameter, of sea buckthorn shrubs, with small and relatively open spots (subsite 3) in the transitional zone from lower area into scrub. All three subsite types were studied within a total area of approximately 2000 m2. Three methods of analysis were applied: an inventory survey (sampling once at the start of the growing season), an analysis of the seasonal variation (sampling at approximately monthly intervals during the period April-November), and an assessment of nitrogen mineralization potentials in the laboratory (sampling once at the beginning of the growing season). All three procedures clearly demonstrated the occurrence of differences in the availability of nutrients over very short distances, i.e. a pronounced spatial variability among subsites. Particularly the availability of N and P appeared to have increased at the subsites 2 and 3, when compared to subsite 1. This small-scale differentiation in soil properties has occurred in an essentially homogeneous parent material (e.g. in texture and carbonate content) over a period of about 20 years. Besides a spatial variability, statistically significant temporal fluctuations were observed in the availability of N, P, and K. Relative fluctuations of mineral N (as indicated by the range/mean ratio) were especially large at the subsites 2 and 3.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00010831
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Nitrification in Dutch heathland soils (1990)
    Springer
    Plant and soil 127 (1990), S. 179-192 
    Details
    ISSN: 1573-5036
    Keywords: acid soils ; ammonium ; Calluna vulgaris ; Deschampsia flexuosa ; Erica tetralix ; heathland ecosystems ; labile organic P ; Molinia caerulea ; nitrogen mineralization ; nitrate ; nitrification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A survey was conducted over a range of 17 Dutch heathland locations, subdivided into 41 sites dominated by either dwarf-shrubs (Calluna vulgaris or Erica tetralix) or grass species (Deschampsia flexuosa or Molinia caerulea). Among the habitats of the dominant plant species relatively little differences in general soil properties were observed. The P status of Deschampsia sites was relatively high as well as the NO3 −-N concentrations in the 0–10 cm layer (FH included) at the grass-dominated sites. At sites with a dead or degenerating dwarf-shrub vegetation, NH4 +-N concentrations reached very high levels. Net production of nitrate was observed during incubation of intact 0–10 cm soil cores (FH-layer included) in the laboratory for all sites, even though in some instances, particularly at Calluna and Erica sites, no nitrate was initially measured. Generally, a higher nitrification rate was found for the grass-dominated sites, and for Deschampsia in particular. The net production of nitrate was highly significantly correlated with net N mineralization, being a reasonable predictor of nitrification in a simple regression model (R2=0.47; P〈0.001). Net nitrification was also significantly correlated with the NO3 −-N initially present at the start of the growing season (R=0.65; P〈0.001) and with the labile organic P content of the soil (R=0.65; P〈0.001). By including initial NO3 −-N and labile organic P, together with net N mineralization and pH, in a multiple regression model, net nitrate production could be predicted with a much higher precision (R2=0.75; P〈0.001). Although apparent nitrification was not significantly correlated with pH, the latter contributed significantly to the multiple regression equation for the prediction of the former. The influence of the labile organic P pool may act via its positive correlation with microbial biomass, thus more or less reflecting the potential mineralization/nitrifying capacity of a particular site.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00014424
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Soil nitrogen transformations and nitrate utilization by Deschampsia flexuosa (L.) Trin. at two contrasting heathland sites (1995)
    Springer
    Plant and soil 176 (1995), S. 81-93 
    Details
    ISSN: 1573-5036
    Keywords: acidic soils ; ammonium ; Deschampsia flexuosa (L.) Trin. ; nitrate ; nitrification ; N-mineralization ; NRA ; seasonal variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Two Dutch heathland sites Hoorneboeg (HB) and Ede, dominated by Deschampsia flexuosa and differing in nitrate production, were sampled for an entire growing season. A large number of soil and plant parameters were monitored in an attempt to assess the contribution of nitrate in the N supply and its assimilation by Deschampsia. Average NO3 − and NH4 + concentrations (mg kg−1) in the top 10-cm depth were 0.03 and 2.2, respectively, for HB, and 2.1 and 6.7, respectively, for Ede. Laboratory incubations of intact cores and experiments with FH-layer suspensions showed significantly higher mineralization and nitrification rates for the Ede site during most of the season. Nitrification was largely controlled by the rate of net N-mineralization, which in turn was highly affected by soil moisture. Nitrate production was virtually zero at HB and accounted for 25% of the net N-mineralization at Ede. Shoot chemical composition showed no essential differences for the two sites, but mean in vivo (current) foliar NRA was almost 2-fold higher at Ede than at HB, indicating some utilization of nitrate at the former location. At the HB site with essentially no nitrate production, however, enzyme activities were clearly higher than ‘basal’ constitutive levels in NH4 +-fed plants. Apparently, shoot NRA at the HB site became positively affected by factors other than nitrate availability and/or showed disproportional increases in response to atmospheric nitrate inputs. Root NRA displayed the same low basal level at the two sites. Nitrate fertilization (100 kg N ha−1) yielded maximally induced foliar NRAs similar to levels found in hydroponic nitrate plants. Although no accumulation of free NO3 − was observed in shoots from fertilized plots, increases in foliar concentrations of both organic N and carboxylates clearly indicated nitrate assimilation. Root NRA showed no response to nitrate addition. It is concluded that current NRA measurements in Deschampsia at heathland sites are of limited value only, especially when interpreted ‘in isolation’. A combined approach, using concurrently conducted soil and plant analyses, will allow the extent of nitrate utilization in the field to be best characterized.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00017678
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Ionic balance, proton efflux, nitrate reductase activity and growth ofHippophaë rhamnoides L. ssp.rhamnoides as influenced by combined-N nutrition or N2 fixation (1987)
    Springer
    Plant and soil 103 (1987), S. 169-183 
    Details
    ISSN: 1573-5036
    Keywords: ammonium ; Hippophaë rhamnoides ; hydroxyl-ion efflux ; ionic balance ; ion uptake ; nitrogen fixation ; nitrate ; nitrate reductase activity ; proton efflux ; rhizosphere pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Growth of 2-month-old nonnodulatedHippophaë rhamnoides seedlings supplied with combined N was compared with that of nodulated seedlings grown on zero N. Plant growth was significantly better with combined N than with N2 fixation and, although not statistically significant for individual harvests, tended to be highest in the presence of NH 4 + , a mixture of NH 4 + and NO 3 − producing the highest yields. Growth was severely reduced when solely dependent on N2 fixation and, unlike the combined-N plants, shoot to root ratios had only slightly increased after an initial decrease. An apparently insufficient nodule mass (nodule weight ratio 〈5 per cent) during the greater part of the experimental period is suggested as the main cause of the growth reduction in N2-fixing plants. Thein vivo nitrate reductase activity (NRA) of NO 3 − dependent plants was almost entirely located in the roots. However, when grown with a combination of NO 3 − and NH 4 + , root NRA was decreased by approximately 85 per cent.H. rhamnoides demonstrated in the mixed supply a strong preference for uptake of N as NH 4 + , NO 3 − contributing only for approximately 20 per cent to the total N assimilation. Specific rates of N acquisition and ion uptake were generally highest in NO 3 − +NH 4 + plants. The generation of organic anions per unit total plant dry weight was approximately 40 per cent less in the NH 4 + plants than in the NO 3 − plants. Measured extrusions of H+ or OH− (HCO 3 − ) were generally in good agreement with calculated values on the basis of plant composition, and the acidity generated with N2 fixation amounted to 0.45–0.55 meq H+. (mmol Norg)−1. Without acidity control and in the presence of NH 4 + , specific rates of ion uptake and carboxylate generation were strongly depressed and growth was reduced by 30–35 per cent. Growth of nonnodulatedH. rhamnoides plants ceased at the lower pH limit of 3.1–3.2 and deterioration set in; in the case of N2-fixing plants the nutrient solution pH stabilized at a value of 3.8–3.9 without any apparent adverse effects upon plant performance. The chemical composition of experimental and field-growing plants is being compared and some comments are made on the nitrogen supply characteristics of their natural sites.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02370386
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...