ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • 1
    Digitale Medien
    Digitale Medien
    Assessment of soil erosion in a small agricultural basin of the St. Lawrence River watershed (1999)
    Springer
    Hydrobiologia 410 (1999), S. 263-268 
    Details
    ISSN: 1573-5117
    Schlagwort(e): erosion ; 137Cs ; nonpoint pollution ; ecosystems ; mapping ; St. Lawrence watershed
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In the last decades, the conservation of soil and water resources has become a major environmental concern worldwide. The authors used an anthropogenic radiotracer (137Cs) to assess the magnitude and the spatial distribution of soil movement in a 80 ha agricultural watershed located in Southeastern Québec (Canada). This project is part of a larger one aimed at increasing our understanding of erosive processes, in order to minimize their impacts on soil resources and downstream hydrosystems. Using this technique, it was possible to establish a budget and a map of soil redistribution. The results could help farm operators to implement a resource conservation strategy. It was also possible to assess the environmental impact of this soil movement, by estimating the magnitude of the net output of sediment from the studied watershed. This was estimated at an average of 237 tons per year, over a period of some 33 years. The output represents 93% of the total soil displacement within the watershed boundaries. Although slightly higher, these results are consistent with those obtained, over a time period limited to 2 years, by water quality monitoring at the watershed outlet and by model simulation. This intensive study, involving more than 500 sampling points for 137Cs, has yielded valuable information on the assessment and the spatial representation of erosive processes. Such information is needed to improve the management of watersheds and can help identify the areas most at risk and establish priorities for corrective actions. In this way, nonpoint pollution of downstream hydrosystems may be controlled more efficiently.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003802602613
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    facet.materialart.
    Unbekannt
    Apparent fertilizer nitrogen recovery and residual soil nitrate under continuous potato cropping: Effect of N fertilization rate and timing (2008)
    Canadian Science Publishing
    Details
    Publikationsdatum: 2008-11-01
    Beschreibung: Adequate nitrogen (N) fertilization is crucial to optimize yield and quality of potato and also to minimize N environmental losses. Effects of rates and timing of N fertilizer on residual soil nitrate (RSN) [NO3-N, 0-0.7 m], soil solution nitrate (SWN) concentrations and apparent fertilizer nitrogen recovery (Nrec) by potato (Solanum tuberosum L.) tubers were evaluated from 1999 to 2001. Two sites representative of the management zones (MZ) previously delineated by apparent soil electrical conductivity and differing in soil water availability were selected. The MZ differed primarily with depth to a clayey substratum, with average values of 1.06 m and 1.34 m in the shallow MZ (SMZ) and in the deep MZ (DMZ), respectively. At each site, a trial with 21 treatments including five rates of ammonium nitrate (0–200 kg N ha-1 in 1999; 0–240 kg N ha-1 in 2000 and 2001) was conducted. Each N rate was applied according to five application timings (100, 75, 50, 25 or 0% of N applied at planting with the remainder at hilling). The effects of N rates and timing on Nrec, RSN and SWN sometimes differed between sites. The Nrec was less responsive to N rates and timing in the SMZ site compared with the DMZ site. Application of the same rate of fertilizer N generally resulted in higher values of RSN at harvest in the SMZ site compared with the DMZ site. Measured SWN was higher in the DMZ than in the SMZ on several occasions in 1999 and 2001, indicating greater nitrate (NO3) leaching in the DMZ site compared with the SMZ site. Different site-specific N management regimes could thus be used at the two sites to improve N use efficiency and to limit the risk of NO3 leaching. However, the temporal variability in the measured parameters, influenced mainly by climatic conditions, was greater than the spatial N variability and this emphasizes the fact that a dynamic model of the N status based on the soil and/or the plant is a prerequisite to help growers to adjust the N fertilizer application within fields and seasons. Key words: Solanum tuberosum, apparent soil electrical conductivity, suction lysimeter
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 3
    facet.materialart.
    Unbekannt
    EFFECTS OF PHOSPHATE ADDITIONS ON THE CHARGE PROPERTIES OF A PODZOLIC B HORIZON (1982)
    Canadian Science Publishing
    Details
    Publikationsdatum: 1982-08-01
    Beschreibung: The Podzolic B horizon of the Calder series sampled in Quebec was incubated at field capacity for 2 yr in the presence of various amounts of P (0–1500 ppm). Total and available P measured after incubation ranged from 179 to 1627 ppm and from 26 to 489 ppm, respectively, following the different P additions. Charge properties were determined using 1 N NH4OAc at pH 4.8 and 7.0, potentiometric titration and ion adsorption techniques. The CEC of the sample measured at pH 4.8 varied from 7.2 to 11.4 meq/100 g, while at pH 7.0 it ranged from 9.1 to 16.3 meq/100 g following the 0- to 1500-ppm P additions. This increase in negative charges was attributed to the progressive lowering of the pHzpc (from 4.30 to 3.35 in NaCl) determined by potentiometric titrations of the P-treated samples and as a result of specific P adsorption. Ion adsorption in 0.01 N NaCl showed a gradual increase in Na+ adsorbed as a function of pH and amount of P added while an opposite trend was observed for Cl− as a function of pH. P added did not seem to change the amount of Cl− adsorbed or compete for adsorption sites; this would rather demonstrate the specificity of these sites for anion adsorption.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 4
    facet.materialart.
    Unbekannt
    Effet à long terme d'apports d'engrais minéraux et de fumier sur les teneurs en C et en N des fractions densimétriques et des agrégats du loam limoneux Le Bras (1997)
    Canadian Science Publishing
    Details
    Publikationsdatum: 1997-08-01
    Beschreibung: Long-term mineral fertilizer applications could reduce organic matter (OM) levels in soil if coupled with crop rotations with low organic residues inputs. The main objective of this study was to evaluate the C and N contents in whole soil, in densimetric OM fractions and in different aggregate size fractions of a Le Bras silt loam (Humic Gleysol). The treatments were arranged in a split-plot design, with dairy cattle manure applied at 0 and 20 Mgha−1 as the main factor. The subplots consisted of six fertilizer treatments (NK, PK, NP, NPK, NPKMg and the unfertilized check). The four year rotation included silage corn, (Zea mays L.) silage corn, wheat (Triticum Aestivum L.) and barley (Hordeum vulgaris L.). Contrary to mineral fertilizer, long-term manure applications significantly increased the C content in whole soil and also in the light and heavy fractions of OM (Fl and Fd). Mineral fertilizer significantly increased the C and N contents only in Fl. Moreover, manure application also increased the weight of the 5–8 mm aggregate size fraction and the C and N content in the 5–8 mm, 2–5 mm, 1–2 mm and 0,25–1 mm aggregate size fractions, compared to mineral fertilizer alone. In manured plots, soil C biomass, microbial respiration (CO2) and N mineralization (NO3) levels increased by 30% compared with mineral fertilizer treatments. Results of this study demonstrate the important effect of manure applications on C and N enrichment in soil and also on soil macroaggregation and biological activity. To maintain optimal C and N levels in soil and to favour soil macroaggregation, long-term mineral fertilizer application should be combined with crops in rotations which ensure high organic residues returns to soils. Key words: Macroaggregation, microbial biomass, N mineralization, long-term, light fraction, heavy fraction
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 5
    facet.materialart.
    Unbekannt
    EFFET DU MODELAGE DES CHAMPS SUR L’HETEROGENEITE DES SOLS ET LES RENDEMENTS EN MAIS-GRAIN (1981)
    Canadian Science Publishing
    Details
    Publikationsdatum: 1981-05-01
    Beschreibung: Rounding of the lands in a field involves changes in the surface horizons. The thickness of Ap horizons at various sites in corn fields varied from 15 to 41 cm. In these horizons, the organic matter content that ranged between 10 and 250 t/ha influenced the real density of the particles, the bulk density of soils with similar texture, and also the shape of the water retention curves at tensions from 0 to 1.5 MPa. Maximum available water in the Ap horizons between 33.3 kPa and 1.5 MPa varied from 0.5 to 4 cm H2O. Yield differences reached 74% while the standard deviations were generally lower than 15%. Higher yields were observed at higher, intermediate and lower sites of the fields. The differences in the yield were not entirely accounted for by the variations in the chemical and physical properties of the soils.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 6
    facet.materialart.
    Unbekannt
    FACTEURS QUI INFLUENCENT LA TENEUR DE LA MATIERE ORGANIQUE ET LES PROPRIETES D'ECHANGE CATIONIQUE DES HORIZONS Ap DES SOLS DE GRANDE CULTURE DU QUEBEC (1976)
    Canadian Science Publishing
    Details
    Publikationsdatum: 1976-08-01
    Beschreibung: The objectives of this work were (1) to determine the relation existing between the organic matter contents of Ap horizons and their respective soil Orders, (Gleysolic and Podzolic), texture, pH and geographic locations in the different thermal regions of Quebec and (2) to determine the role of organic matter and soil texture on the cation exchange properties of the same Ap horizons coming from soils used for forage crops in Quebec. The cation-exchange capacity (CEC), the exchangeable bases and acidity were determined by using 1 N NH4OAC – pH 7. The results showed a variation in the carbon content ranging from 1.4 to 6.9%. The heat units accumulated in each region and the clay contents were correlated with the percentage of carbon and nitrogen. Soil pH and soil Orders (Gleysolic vs. Podzolic) did not seem to affect the organic matter content. The cation-exchange capacity (CEC) ranged from 10.6 to 42.6 meq/100 g soil; 40% of this was attributable to carbon and 32% to clay contents. Simple and multiple regression equations showed that carbon was correlated with the exchangeable acidity, while clay was related to the exchangeable bases. The CEC of organic matter and clay were respectively 161 ± 45 meq/100 g organic matter and 29 ± 6 meq/100 g clay. These values, lower than for Western Canada, reflected the nature of the organic matter that is less developed in Eastern Canada than in the Chernozemic soils; they also showed the effect of the predominant illite mineral found in the clay fractions compared to montmorillonite in Western Canada.
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 7
    facet.materialart.
    Unbekannt
    Impact of potato-cereal rotations and slurry applications on nitrate leaching and nitrogen balance in sandy soils (2002)
    Canadian Science Publishing
    Details
    Publikationsdatum: 2002-11-01
    Beschreibung: Groundwater quality is at risk when high levels of N fertilizers are used on sandy soils. A monitoring program was initiated in the summer of 1995, to quantify nitrate leaching in sandy soils used for potato production near Quebec city, Canada. Three drainable lysimeters were installed in each of five fields, for a total of 15 lysimeters. During a 5-yr monitoring period, crop N uptake, mineral and organic N fertilizers use, nitrate concentrations and fluxes from drainage water at 1-m soil depth were assessed under potato, cereal and hay crops. In one field, a clover and timothy sod that received low mineral N fertilizer inputs generated the lowest annual nitrate leaching losses ranging from 7 to 20 kg NO3-N ha-1. High nitrate leaching losses (116 ± 40 kg N ha-1) were measured under potato crops receiving high mineral N fertilizer inputs. Cereals, including barley and wheat receiving moderate mineral N fertilizer inputs and in some instance N from pig slurry, dairy cow manure or paper mill sludge, also generated high nitrate leaching losses (88 ± 45 kg N ha-1). Only sod and oat crops generated annual flux averaged nitrate concentrations lower than 10 mg NO3-N L-1, the accepted standard for drinking water, while higher concentrations, ranging from 13 to 52 mg NO3-N L-1, were recorded under barley, wheat and potato crops receiving moderate to high amounts of mineral N fertilizer. Nitrate flux concentrations were moderate during the cropping season (May-August), highest in fall (September-December) and lowest in the winter-early spring period (January-April). After 5 yr of survey, use of pig slurry and paper mill sludge in potato-cereal crop rotations (51 to 192 kg N ha-1 annually) with mineral N fertilizers (103 to 119 kg N ha-1 annually) resulted in nitrate leaching losses (87 to 132 kg N ha-1 annually), at least 20 kg N ha-1 more than N exported by crop at harvest. More than 60% of N applied as pig slurry seemed to be unaccounted for in the partial N balance that included crop N uptake and nitrate leaching, suggesting that important losses probably occurred through ammonia volatilization, denitrification, or N immobilization in soil organic matter and crop residues. Key words: Barley, lysimeter, nitrate leaching, nitrogen balance, pig slurry, potato
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 8
    facet.materialart.
    Unbekannt
    Mixed papermill residues affect yield, nutritive value and nutrient use of a grass-alfalfa sward (2001)
    Canadian Science Publishing
    Details
    Publikationsdatum: 2001-02-01
    Beschreibung: Mixed papermill residues (MPR) can improve soil quality, but their impact on forage yield and quality is not well documented. Three MPRwere applied to mixed grass-alfalfa (Medicago sativa L.) sward in 1997 and 1998 at near 100, 200 and 400 kg N ha-1 and were compared to calcic ammonium nitrate (CAN) at 0, 50, 100 and 200 kg N ha-1 on a Bedford clay loam (Humic Gleysol). The MPR and CAN induced a significant linear increase in forage DM yield and relative yield (RY). The sward response to MPR addition in 1997 was related to the MPR C:NH4+ ratio. MPR and CAN increased the forage NDF concentration in 1998, but there was no effect in 1997. Nitrogen concentration in forage tissues was increased by MPR and CANinputs in 1997, but was decreased in 1998. In all treatments, NO3− tended to accumulate in forage tissues when the N nutrition index (INN) exceeded the optimum level. Forage nutritive value from the MPR was comparable to CAN.The results of this study suggest that MPR can be an efficient N source for grass-alfalfa swards on fine-textured soils. Key words: Acid detergent fiber, forage, grass, Medicago sativa L., mineral fertilizer, neutral detergent fiber, papermill residues
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 9
    facet.materialart.
    Unbekannt
    Quantification of soil redistribution and sediment budget in a Canadian watershed from fallout caesium-137 (137Cs) data (2002)
    Canadian Science Publishing
    Details
    Publikationsdatum: 2002-11-01
    Beschreibung: The intensification and specialization of agriculture that took place in the past decades have resulted in soil and water degradation in several areas of eastern Canada. Most studies on soil erosion in Quebec have been conducted at the experimental plot scale. Although this approach generates precise data, extrapolation at the field or watershed scale is difficult. In this study, caesium-137 (137Cs) was used to investigate the spatial extent and severity of soil erosion for an 80-ha watershed in Southeastern Quebec (cultivated area = 75 ha). Soil samples were collected based on a 25 (30 m grid and revealed soil redistribution rates ranging from -20 to +12 Mg ha-1 yr-1. From radiocaesium measurements, it was estimated that the experimental watershed experienced an average loss of 3.0 Mg ha-1 yr-1 with net sediment export of 2.8 Mg ha-1 yr-1 and a sediment delivery ratio of 93%. Snowmelt erosion is believed to have played an important role in the soil redistribution in this small watershed. Changing sampling strategy was tested (50 x 60 m and 100 x 120 m grid rather than 25 x 30 m) and only minor changes were noticed on soil erosion and sediment production estimates, when samples corresponding to the 50 x 60 m grid were used. Key words: Caesium-137 (137Cs), watershed, water erosion, snowmelt erosion, sampling strategy
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 10
    facet.materialart.
    Unbekannt
    Limed sewage sludge effects on nutrient status and metal fractions in acidic soils (1999)
    Canadian Science Publishing
    Details
    Publikationsdatum: 1999-02-01
    Beschreibung: The potential impacts of limed sludge on nutrient and heavy metal bioavailability must be studied for their safe use on acidic soils. The objective of this study was to assess the impact of limed sludges on six acidic soils from eastern Canada. CaCO3 and raw sewage sludges (RSS) stabilized with either CaO (CaO + S) or cement kiln dust (CKD + S) were added to soils in amount necessary to reach pH 6.5 and the mixtures were then incubated for 64 d. CaO + S treatments were the most efficient to neutralize soil acidity. After 10 d of incubation, the Sr-citrate extractable P was significantly increased by the CaO + S treatment in low P sorption soils. The extractable K, Zn and Cu contents were also slightly increased by CaO + S compared to CaCO3 whereas CKD + S resulted in an excessive soil exchangeable K content. After 64 d, labile Al content was decreased by all liming amendments. RSS and CaO + S tended to increase labile Cu and Mn contents. The RSS increased NaOH-extractable Cu but the treatments had no significant effects on the labile and stable forms of heavy metals. A combination of CaO + CKD to stabilize sewage sludge would be more suitable to provide appropriate levels of P and K without resulting in large increases in extractable heavy metal contents. Key words: pH, extractable P and K, cement kiln dust, Al and Mn toxicity, Cu fractions, water-soluble metals
    Print ISSN: 0008-4271
    Digitale ISSN: 1918-1841
    Thema: Geologie und Paläontologie , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Publiziert von Canadian Science Publishing
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...