Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2006
Sammendrag
Lignin is a major plant litter compound. Due to its aromatic structure it is not easily decomposable by the soil microbial biomass and has for a long-time been considered to accumulate in soil. A recent study, however, indicated that lignin has a faster turnover than the bulk soil organic matter, suggesting that there is no long-term storage of the pristine lignin molecule in soil. Using a modelling approach we were able to show that more than 90 % of lignin deposited on the soil surface is transformed into non-lignin products. The aim of this study was to elucidate the forms of lignin derived carbon during a longterm laboratory incubation of 13C labelled lignin in soil. The conceptual approach included the extraction of lignin from a 13C labelled maize plant and its incubation under ideal conditions for 11 months. Our results show that the non-lignin products are mostly CO2, with few incorporation of lignin-derived carbon into the soil microbial biomass. We were able to detect a priming effect of soil organic matter induced by lignin addition. Analysis of the mineralisation kinetics suggested that the 13C labelled isolated lignin consisted of two compartments with different decomposition rates. One of the two compartments might be related to the presence of cellulose within the isolated lignin, which has been detected using 13C CPMAS NMR spectroscopy. Molecular analysis of lignin using chemolytical methods showed that lignin becomes more accessible to chemical attack in the course of incubation. Higher yields of lignin monomers were obtained after 4 month using cupric oxide oxidation as well as thioacidolysis. These results indicate that lignin degradation in soil can hardly be separated from cellulose decomposition
Forfattere
B. M. Dahal B. K. Sitaula R. M. Bajracharya K. Atreya Alhaji JengSammendrag
Soil and nutrient losses are a major threat to farmland productivity in Nepal. Thus, soil and nutrient losses were monitored and analyzed from two and three crop patterns per year in Ansikhola watershed. Erosion was monitored from multi-terraced garicultural plots consisting of 2 to 3 terraces. The agricultural soil of the watershed was generally rich in terms of organic matter and nutrients (N, P, K). The nitrogen content of soil in leve lowland farm plots was higher in the 2 cropping plots compared to the 3 cropping plots. The soil pH ranged from 4.4 to 5.2 in both intensive and less intensive areas. Soil and nutrient losses were comparitively higher from intensively cropped areas; however, overall losses were less than average losses in other similar watersheds in Nepal.
Forfattere
Trond MæhlumSammendrag
Det er ikke registrert sammendrag
Sammendrag
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Sammendrag
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Forfattere
Ove BergersenSammendrag
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Forfattere
Ove BergersenSammendrag
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Sammendrag
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Forfattere
Ove BergersenSammendrag
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Forfattere
Mauritz ÅssveenSammendrag
Innlegget ga en samlet oversikt over den norske verdiprøvingen av plantesorter