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
Filter
  • 15N isotope dilution  (2)
  • 15N-labelled crop residues  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Nitrogen immobilization and mineralization during initial decomposition of 15N-labelled pea and barley residues (1996)
    Springer
    Biology and fertility of soils 24 (1996), S. 39-44 
    Details
    ISSN: 1432-0789
    Keywords: Key words Immobilization ; Mineralization ; 15N-labelled crop residues ; Residue quality ; Soil microbial biomass
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The immobilization and mineralization of N following plant residue incorporation were studied in a sandy loam soil using 15N-labelled field pea (Pisum sativum L.) and spring barley (Hordeum vulgare L.) straw. Both crop residues caused a net immobilization of soil-derived inorganic N during the complete incubation period of 84 days. The maximum rate of N immobilization was found to 12 and 18 mg soil-derived N g–1 added C after incorporation of pea and barley residues, respectively. After 7 days of incubation, 21% of the pea and 17% of the barley residue N were assimilated by the soil microbial biomass. A comparison of the 15N enrichments of the soil organic N and the newly formed biomass N pools indicated that either residue N may have been assimilated directly by the microbial biomass without entering the soil inorganic N pool or the biomass had a higher preference for mineralized ammonium than for soil-derived nitrate already present in the soil. In the barley residue treatment, the microbial biomass N was apparently stabilized to a higher degree than the biomass N in the pea residue treatment, which declined during the incubation period. This was probably due to N-deficiency delaying the decomposition of the barley residue. The net mineralization of residue-derived N was 2% in the barley and 22% in the pea residue treatment after 84 days of incubation. The results demonstrated that even if crop residues have a relative low C/N ratio (15), transient immobilization of soil N in the microbial biomass may contribute to improved conservation of soil N sources.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01420218
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Nitrogen immobilization and mineralization during initial decomposition of15N-labelled pea and barley residues (1997)
    Springer
    Biology and fertility of soils 24 (1997), S. 39-44 
    Details
    ISSN: 1432-0789
    Keywords: Immobilization ; Mineralization ; 15N-labelled crop residues ; Residue quality ; Soil microbial biomass
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The immobilization and mineralization of N following plant residue incorporation were studied in a sandy loam soil using15N-labelled field pea (Pisum sativum L.) and spring barley (Hordeum vulgare L.) straw. Both crop residues caused a net immobilization of soil-derived inorganic N during the complete incubation period of 84 days. The maximum rate of N immobilization was found to 12 and 18 mg soil-derived N g−1 added C after incorporation of pea and barley residues, respectively. After 7 days of incubation, 21% of the pea and 17% of the barley residue N were assimilated by the soil microbial biomass. A comparison of the15N enrichments of the soil organic N and the newly formed biomass N pools indicated that either residue N may have been assimilated directly by the microbial biomass without entering the soil inorganic N pool or the biomass had a higher preference for mineralized ammonium than for soil-derived nitrate already present in the soil. In the barley residue treatment, the microbial biomass N was apparently stabilized to a higher degree than the biomass N in the pea residue treatment, which declined during the incubation period. This was probably due to N-deficiency delaying the decomposition of the barley residue. The net mineralization of residue-derived N was 2% in the barley and 22% in the pea residue treatment after 84 days of incubation. The results demonstrated that even if crop residues have a relative low C/N ratio (15), transient immobilization of soil N in the microbial biomass may contribute to improved conservation of soil N sources.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01420218
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Seasonal patterns of growth and nitrogen fixation in field-grown pea (1987)
    Springer
    Plant and soil 101 (1987), S. 29-37 
    Details
    ISSN: 1573-5036
    Keywords: assimilate partitioning ; growth analysis ; leaf area ; nitrate ; nitrogen fixation ; 15N isotope dilution ; pea ; Pisum sativum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The seasonal patterns of growth and symbiotic N2 fixation under field conditions were studied by growth analysis and use of15N-labelled fertilizer in a determinate pea cultivar (Pisum sativum L.) grown for harvest at the dry seed stage. The patterns of fertilizer N-uptake were almost identical in pea and barley (the non-fixing reference crop), but more fertilizer-N was recovered in barley than in pea. The estimated rate of N2 fixation in pea gradually increased during the pre-flowering and flowering growth stages and reached a maximum of 10 kg N fixed per ha per day nine to ten weeks after seedling emergence. This was the time of early pod-development (flat pod growth stage) and also the time for maximum crop growth rate and maximum green leaf area index. A steep drop in N2 fixation rate occurred during the following week. This drop was simultaneous with lodging of the crop, pod-filling (round pod growth stage) and the initiation of mobilization of nitrogen from vegetative organs. The application of fertilizer-N inhibited the rate of N2 fixation only during that period of growth, when the main part of fertilizer-N was taken up and shortly after. Total accumulation of fixed nitrogen was estimated to be 244, 238 and 213 kg N ha−1 in pea supplied with nil, 25 or 50 kg NO 3 − −N ha−1, respectively. About one-fourth of total N2 fixation was carried out during preflowering, one fourth during the two weeks of flowering and the remainder during post-flowering. About 55% of the amount of N present in pods at maturity was estimated to be derived from mobilization of N from vegetative organs. “Starter” N (25 or 50 kg NO 3 − −N ha−1) did not significantly influence either dry matter and nitrogen accumulation or the development of leaf area. Neither root length and root biomass determined 8 weeks after seedling emergence nor the yield of seed dry matter and nitrogen at maturity were influenced by fertilizer application.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02371027
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Symbiotic N2-fixation by the cover crop Pueraria phaseoloides as influenced by litter mineralization (1995)
    Springer
    Plant and soil 177 (1995), S. 1-10 
    Details
    ISSN: 1573-5036
    Keywords: cross-labeling ; litter mineralization ; 15N isotope dilution ; Pueraria phaseoloides ; symbiotic N2-fixation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The perennial legume Pueraria phaseoloides is widely used as a cover crop in rubber and oil palm plantations. However, very little knowledge exists on the effect of litter mineralization from P. phaseoloides on its symbiotic N2-fixation. The contribution from symbiotic N2-fixation (Ndfa) and litter N (Ndfl) to total plant N in P. phaseoloides was determined in a pot experiment using a 15N cross-labeling technique. For determination of N2-fixation the non-fixing plant Axonopus compressus was used as a reference. The experiment was carried out in a growth chamber during 9 weeks with a sandy soil and 4 rates of ground litter (C/N=16,2.8% N). P. phaseoloides plants supplied with the highest amount of litter produced 26% more dry matter and fixed 23% more N than plants grown in soil with no litter application, but the percentage of Ndfa decreased slightly, but significantly, from 87 to 84%. The litter N uptake was directly proportional to the rate of application and constituted 10% of total plant N at the highest application rate. Additionally, a positive correlation was found between litter N uptake and the amount of fixed N2. The total recovery of litter N in plants averaged 26% at harvest (shoot + root) and was not affected by the quantity added. A parallel incubation experiment also showed that, as an average of all litter levels, 26% of the litter N was present in the inorganic N pool. The amounts of fertilizer and soil N taken up by plants decreased with litter application, probably due to microbial immobilization and denitrification. It is concluded that, within the litter levels studied, litter mineralization will result in a higher amount of N2-fixed by P. phaseoloides.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00010332
    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...