Library

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
    Immobilization of nitrogen from urea and plant residues in a ferrallitic soil: Laboratory experiments and study by size-fractionation (1991)
    Springer
    Biology and fertility of soils 12 (1991), S. 182-188 
    Details
    ISSN: 1432-0789
    Keywords: Nitrogen ; urea ; crop residues ; particle-size fractionation ; ferrallitic soil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary The fate of N when incorporated in a ferrallitic soil was investigated during a 3-month incubation, using either 15N-labelled urea or 15N-labelled crop residues (sugarcane roots and leaves). The organic matter was characterized by particle-size fractionation. The urea-derived organic 15N was mainly found in the clay-sized fractions and was ascribed to biological activity. The plant-derived 15N was observed both in the sand-sized and in the clay-sized fractions; the former pool was ascribed to the persistence of crops residues, the latter to biological immobilization. The relative proportions of organic 15N recovered in the various clay fractions (coarse, fine, and very fine) were similar, irrespective of the nature of the added 15N. The very fine clay fraction (F〈0.05 μm) showed the highest isotopic excess, and thus gave rise to the highest turnover rate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00337199
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Influences of organic fertilization and solarization in a greenhouse on particle-size fractions of a Mediterranean sandy soil (2000)
    Springer
    Biology and fertility of soils 32 (2000), S. 449-457 
    Details
    ISSN: 1432-0789
    Keywords: Keywords Soil organic matter ; Particle-size fractions ; Organic fertilization ; Solarization ; Mediterranean sandy soil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  The effects of a composted organic amendment and solarization on the organic matter (OM) of a sandy soil were determined by means of particle-size fractionation and analysis of carbon and nitrogen contents. After 2 years, total soil carbon increased under organic fertilization but did not significantly change with solarization. As a consequence of the climatic conditions in the greenhouse, the carbon concentrations (g kg–1 fraction) of the particle-size fractions were lower than those found for temperate soils and closer to those for tropical soils. The carbon amounts (g kg–1 soil) and carbon:nitrogen ratios, which were highest in fractions 〉200 μm, reflected the short-term influence of the industrially processed organic amendment, rich in composted coarse plant debris. In contrast, the characteristics of the OM associated with each fraction were not significantly affected by solarization. In comparison with other coarse-textured temperate or tropical soils, carbon concentrations in fine silt (2–20 μm) and clay (0–2 μm) fractions were very low. This suggests a "greenhouse effect", together with a high rate of carbon mineralization affecting fine silt and clay fractions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003740000275
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Effect of a legume cover crop (Mucuna pruriens var. utilis) on soil carbon in an Ultisol under maize cultivation in southern Benin (2004)
    Oxford, UK : Blackwell Publishing Ltd
    Soil use and management 20 (2004), S. 0 
    Details
    ISSN: 1475-2743
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract. Long term fallow is no longer possible in densely populated tropical areas, but legume cover crops can help maintain soil fertility. Our work aimed to study changes in soil carbon in a sandy loam Ultisol in Benin, which involved a 12-year experiment on three maize cropping systems under manual tillage: traditional no-input cultivation (T), mineral fertilized cultivation (NPK), and association with Mucuna pruriens (M). The origin of soil carbon was also determined through the natural abundance of soil and biomass 13C. In T, NPK and M changes in soil carbon at 0–40 cm were −0.2, +0.2 and +1.3 t C ha−1 yr−1, with residue carbon amounting to 3.5, 6.4 and 10.0 t C ha−1 yr−1, respectively. After 12 years of experimentation, carbon originating from maize in litter-plus-soil (0–40 cm) represented less than 4% of both total carbon and overall maize residue carbon. In contrast, carbon originating from mucuna in litter-plus-soil represented more than 50% of both total carbon and overall mucuna residue carbon in M, possibly due to accelerated mineralization of native soil carbon (priming effect) and slow mulch decomposition. Carbon originating from weeds in litter-plus-soil represented c. 10% of both total carbon and overall weed residue carbon in T and NPK. Thus mucuna mulch was very effective in promoting carbon sequestration in the soil studied.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1475-2743.2004.tb00363.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Carbon cycling and sequestration opportunities in South America: the case of Brazil (2004)
    Oxford, UK : Blackwell Publishing Ltd
    Soil use and management 20 (2004), S. 0 
    Details
    ISSN: 1475-2743
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract. A carbon emission inventory of the Brazilian agricultural sector was used to compare greenhouse gas emissions with estimated carbon offsets promoted by two main changes in agricultural management: the replacement of conventional tillage by no-tillage and the cessation of annual burning in sugar cane production. Using the IPCC revised 1996 guidelines for national greenhouse gas inventories, we estimate that 12.65 Mt C are emitted annually from agricultural land in Brazil. Ongoing conversion of conventionally tilled land to no-tillage currently accumulates 9 Mt C yr−1. Industrial by-products like alcohol and bagasse from sugar cane processing substitute fossil fuel for transportation and power generation offsetting 10 and 8 Mt C yr−1, respectively. An additional opportunity for 0.53 Mt C yr−1 sequestration is presented by avoiding burning before harvesting of sugar cane. These data show that there could be almost full compensation between sources and sinks/offsets in the agricultural carbon cycle. There is a great opportunity to achieve this mitigation benefit because the adoption of new technologies is increasing rapidly.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1475-2743.2004.tb00365.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    La matiére organique soluble à l'eau chaude et la stabilityé de l'agrégation. Aspects méthodologiques et application à des sols ferrallitiques du Congo (1997)
    Oxford, UK : Blackwell Publishing Ltd
    European journal of soil science 48 (1997), S. 0 
    Details
    ISSN: 1365-2389
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: La stabilityé de la structure des horizons de surface et de profondeur de sols ferrallitiques du Congo est étudiée en fonction du mode de gestion des terres et de la teneur en carbone organique total des échantillons. Le rôle du carbone soluble à l'eau chaude dans l'agrégation est appréciéà partir de deux approches expérimentales, impliquant des extractions après chauffage en étuve ou en autoclave. Pour ce faire, des comparaisons sont faites entre les taux des macroagrégats stables (〉200 pm) à l'eau froide et à l'eau chaude. Les résultats indiquent que les situations culturales étudiées induisent des variations significatives des teneurs en carbone total. Le taux des macroagégats stables à l'eau froide est très fortement corrélé aux teneurs en carbone total et en carbone solubiliséà l'eau chaude. Toutefois, les taux des macroagrégats stables obtenus avant et après extraction du carbone à l'eau chaude ne sont pas significativement différents, ce qui peut remettre en question les résultats sur la fonction agrégeante des matières organiques solubles, déduits des seules approches statistiques.Hot-water soluble organic matter and aggregate stability. Methodological aspects and application to ferrallitic soils of the Congo〈section xml:id="abs1-2"〉〈title type="main"〉SummaryThe structural stability of surface and deeper horizons of ferrallitic soils of the Congo was studied in relation to the land use and the total organic carbon content of the samples. The role of hot-water soluble carbon in aggregation was assessed with two experimental approaches, one by heating in an oven and the other in an autoclave under pressure. The proportion of aggregates (〉 200 μm) stable in cold water were compared with that of macroaggregates stable in hot water. Cropping situation sunder study induced significant variations in total carbon content. Aggregate stability was highly correlated with both soluble and total carbon contents. However, amounts of water-stable aggregates obtained before and after solubilization of organic matter in hot water were not significantly different. This result would infirm the supposed aggregating role of soluble organic matter, inferred from statistical data only.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2389.1997.tb00544.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Pseudopotential investigations on indium, tin and antimony compounds
    Amsterdam : Elsevier
    Journal of Molecular Structure: THEOCHEM 209 (1990), S. 313-331 
    Details
    ISSN: 0166-1280
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0166-1280(90)80085-3
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Time course of the pharmacological response to beta-lactam antibiotics in vitro and in vivo (1984)
    Springer
    European journal of clinical microbiology & infectious diseases 3 (1984), S. 592-597 
    Details
    ISSN: 1435-4373
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Experimental examples of different beta-lactam-organism combinations in vitro and in vivo are presented to demonstrate that a rationale for dosage regimens of antibiotics should not be based solely on pharmacokinetic parameters. The time course of the pharmacological response (onset and speed of bacterial killing) and the presence or absence of a postantibiotic effect must also be considered. Such pertinent information can be derived from in vitro studies such as time-kill curves and regrowth curves of bacteria obtained at and after short exposure of the target organisms to various concentrations of the drug.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02013630
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Carbon Sequestration and Turnover in Semiarid Savannas and Dry Forest (1998)
    Springer
    Climatic change 40 (1998), S. 105-117 
    Details
    ISSN: 1573-1480
    Keywords: C-sequestration ; mitigation ; semiarid tropics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Data on carbon and biomass budgets under different land use in tropical savannas and some dry forests are reviewed. Global data show wide ranges of biomass carbon stocks (20-150 Mg C ha-1), net primary production (2-15 Mg C ha-1y-1) and litter production (2-10 Mg C ha-1y-1) for the semiarid tropics. Although ranges for soil carbon are also wide, an average figure for the top 20 cm is probably 10 g C kg-1, or about 25 Mg C ha-1. In order to arrive at a better understanding of C budgets and their controls, two regional reviews are presented for NE Brazil and W. Africa. In NE Brazil approximately 40% of the lands have "near-climax" native vegetation. Less than 10% of the area is planted annually, but about 3-4 times that area is affected by shifting cultivation which has an average cycle of 5 y arable use followed by 20 y or more recovery. Standing biomass of native caatinga shows nearly the full global range with 2-50 Mg C ha-1. Litter fall around 1-2 Mg C ha-1y-1 is partly decomposed and partly consumed by animals, resulting in low average soil C levels near 8 g kg-1, or 20 Mg C ha-1. Under cultivation, C sequestration is decreased, and soils lose approximately half their C stocks before being abandoned. In W. Africa between 50-70% of the land is under a management regime with minimal C returns to the soils. Overgrazing and over-exploitation for fuel wood has resulted in land degradation. Short fallow periods on cultivated lands have caused serious declines in soil C stocks. Both C sequestration and stocks are therefore lower in W. Africa than in NE Brazil. Improvements in the C sequestration in these semi arid regions depend on an increase in crop production under suitable rotations, improved fallow and animal husbandry, and a limitation on biomnass burning. Use of fertilizer is required for improved productivities but socioeconomic constraints largely prevent such improvements, resulting in a very limited scope for changes in soil C management.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005342932178
    Library Location Call Number Volume/Issue/Year 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...