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
Filter
  • N recovery  (1)
  • N-mineralization  (1)
  • Nitrogen balance  (1)
  • 2000-2004  (3)
  • 1
    Electronic Resource
    Electronic Resource
    Transformations and recovery of residue and fertilizer nitrogen-15 in a sandy Lixisol of West Africa (2000)
    Springer
    Biology and fertility of soils 31 (2000), S. 261-269 
    Details
    ISSN: 1432-0789
    Keywords: Key words Cover crops ; Mixed residues ; Microbial biomass ; N-mineralization ; Soil organic matter fractions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  The fate of 15N-labeled plant residues from different cover-cropping systems and labeled inorganic N fertilizer in the organic, soil mineral, microbial biomass and soil organic matter (SOM) particle-size fractions was investigated in a sandy Lixisol. Plant residues were from mucuna (legume), lablab (legume), imperata (grass), maize (cereal) and mixtures of mucuna or lablab with imperata or maize, applied as a surface mulch. Inorganic N fertilizer was applied as 15N-(NH4)2SO4 at two rates (21 and 42 mg N kg–1 soil). Total N release from mucuna or lablab residues was 2–3 times higher than from the other residues, whereas imperata immobilized N throughout the study period. In contrast, 15N was mineralized from all the plant residues irrespective of the mineralization–immobilization pattern observed for total N. After 168 days, 69% of soil mineral N in mucuna- or lablab-mulched soils was derived from the added residues, representing 4–8% of residue N, whereas 9–30% of inorganic N was derived from imperata, maize and the mixed residues. At the end of the study, 4–19% of microbial biomass N was derived from the added residue/fertilizer-N, accounting for 1–3% of added residue-N. Averaged across treatments, particulate SOM fractions accounted for less than 1% of the total soil by weight but contained 20% of total soil C and 8% of soil N. Soils amended with mucuna or lablab incorporated more N in the 250–2000 μm SOM pool, whereas soil amended with imperata or the mixed residues incorporated similar proportions of labeled N in the 250–2000 μm and 53–250 μm fractions. In contrast, in soils receiving the maize or inorganic fertilizer-N treatments, higher proportions of labeled N were incorporated into the 53–250 μm than the 250–2000 μm fractions. The relationship between these differences in residue/fertilizer-N partitioning into different SOM particle-size fractions and soil productivity is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003740050655
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Response of Mucuna pruriens to symbiotic nitrogen fixation by rhizobia following inoculation in farmers' fields in the derived savanna of Benin (2000)
    Springer
    Biology and fertility of soils 30 (2000), S. 558-565 
    Details
    ISSN: 1432-0789
    Keywords: Key words Arbuscular mycorrhizal fungi ; Mucuna pruriens ; Nitrogen balance ; Relay cropping ; Indigenous rhizobial populations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract  Leguminous cover crops such as Mucuna pruriens (mucuna) have the potential to contribute to soil N and increase the yields of subsequent or associated cereal crops through symbiotic N fixation. It has often been assumed that mucuna will freely nodulate, fix N2 and therefore contribute to soil N. However, results of recent work have indicated mucuna's failure to nodulate in some farmers' fields in the derived savanna in Benin. One of the management practices that can help to improve mucuna establishment and growth is the use of rhizobial inocula to ensure compatibility between the symbiotic partners. Experiments were conducted in 1995 and 1996 on 15 farmers' fields located in three different villages (Eglimé, Zouzouvou and Tchi) in the derived savanna in Benin. The aim was to determine the response of mucuna to inoculation and examine the factors affecting it when grown in relay cropping with maize. The actual amount of N2 fixed by mucuna in the farmers' fields at 20 weeks after planting (WAP) averaged 60 kg N ha–1 (range: 41–76 kg N ha–1) representing 55% (range: 49–58%) of the plant total N. The result suggested that mucuna in these farmers' fields could not meet its total N demand for growth and seed production only by N2 fixation. It was estimated that after grain removal mucuna led to a net N contribution ranging from –37 to 30 kg N ha–1. Shoot dry weight at 20 WAP varied between 1.5 and 8.7 t ha–1 and N accumulation ranged from 22 to 193 kg N ha–1. Inoculation increased shoot dry matter by an average of 28% above the uninoculated treatments, but the increase depended on the field, location and year. For the combinations of inoculated treatments and farmers' fields, the response frequency was higher in Eglimé and Tchi than in Zouzouvou. The response to inoculated treatments was dependent on the field and inversely related to the numbers of rhizobia in the soil. Soil rhizobial populations ranged from 0 to 〉188 cells g–1 soil, and response to inoculation often occurred when numbers of indigenous rhizobia were 〈5 cells g–1 soil. In two farmers' fields at Zouzouvou where extractable P was below 10 μg g–1 soil, mucuna did not respond to rhizobial inoculation despite a higher population of rhizobia. Significant relationships between mycorrhizal colonization, growth and nodulation of mucuna were observed, and inoculated plants with rhizobia had a higher rate of colonization by arbuscular mycorrhizal fungi (%AMF) than uninoculated ones. Therefore, it was shown that mucuna will establish and fix N2 effectively in those fields where farmer's management practices such as good crop rotation and rhizobial inoculation allow a build up of AMF spores that might lead to a high degree of AMF infection and alleviate P deficiency.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003740050036
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Nitrogen contributions from decomposing cover crop residues to maize in a tropical derived savanna (2000)
    Springer
    Nutrient cycling in agroecosystems 57 (2000), S. 131-140 
    Details
    ISSN: 1573-0867
    Keywords: herbaceous legumes ; imperata ; N recovery ; residue quality ; N-synchronization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In cover cropping systems in the tropics with herbaceous legumes, plant residues are expected to supply nitrogen (N) to non-legume crops during decomposition. Field experiments were carried out to (i) determine the effects of residue quality on decomposition and N release patterns of selected plants in cover cropping systems, (ii) relate the pattern of residue N release to N uptake by maize in cover cropping systems. To study decomposition, litter bags were used and monitored over two maize growing seasons. The residues studied were mucuna (Mucuna pruriens (L.) DC. var. utilis (Wright) Bruck), lablab (Lablab purpureus (L.) Sweet), and leaves and rhizomes of imperata (Imperata cylindrica (L.) Raueschel). Mucuna and lablab decomposed rapidly losing more than 60% of their dry weight within 28 days. In contrast, imperata decomposed slowly with only 25% of its dry matter lost in 56 days. At 28 days, mucuna had released 154 kg N ha-1 in in-situ mulch systems and 87 kg N ha-1 in live- mulch systems representing more than 50% of its N. More than 64% of N in lablab was released within 28 days amounting to 21 to 174 kg N ha-1. Imperata rhizomes mineralized 4 to 14 kg N ha-1 within 14 days, and subsequently immobilized N until 112 days whereas imperata leaves immobilized N throughout the study period. Decomposition and N release rates from the plant residues were most strongly correlated with the (lignin+polyphenol)/N ratio, N content, lignin/N ratio, polyphenol/N ratio, C/N ratio and lignin content of the residues. Relative to the controls, herbaceous legume residues increased maize dry matter yield and N uptake during the two cropping seasons. At 84 days, the maize crop had utilized 13 to 63 kg N ha-1from mucuna representing 13 to 36% of N released, whereas 16 to 25% of N released from mucuna was recovered by the maize crop at 168 days. The first maize crop recovered 9 to 62 kg N ha-1 or 28 to 35% of N released from lablab. However, at 168 days, N uptake by maize in antecedent live-mulched lablab was 32% higher than the quantity of N released, whereas imperata residues generally, resulted in net reduction of maize N uptake.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009846203062
    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...