Abstract
Aim of study: To assess the interactive effects of legume species, residue placement and temperature on the net nitrogen (N) mineralization dynamics in a sandy loam soil.Area of study: Northern PortugalMaterial and methods: Cowpea (Vigna unguiculata L. Walp), faba bean (Vicia faba L.) and pea (Pisum sativum L.) residues were incorporated or applied to the soil surface at typical field yields in Europe and incubated in aerobic conditions for up to 240 days, either at 10ºC or 20ºC. Initial chemical characteristics of the soil and residues were determined. Net N mineralization was estimated at eight time intervals.Main results: Cowpea residues caused no negative changes in soil mineral N contents and were able to release the equivalent of 21-45 kg N ha-1 in 240 days. Net N immobilization (up to 17 kg N ha-1) was observed throughout most of the trial in soil with faba bean and pea residues. Differences in mineralization patterns could be attributed to the higher quality (lower carbon to nitrogen (C:N) ratios) of cowpea. Surface placement increased net N mineralized by as much as 18 kg N ha-1. The sensitivity of N mineralization to changes in temperature and residue placement varied with legume species, likely due to effects associated with differences in C:N ratios.Research highlights: Adding cowpea residues to soil is suitable when high N availability is immediately required. Faba bean or pea residues are better suited for conservation of soil N for later release.
Highlights
Returning above-ground crop residues to the soil provides many benefits to agroecosystems, such as improved soil physical properties, conserved soil organic matter contents and increased nutrient availabilities (Chen et al, 2014)
Main results: Cowpea residues caused no negative changes in soil mineral N contents and were able to release the equivalent of 2145 kg N ha–1 in 240 days
Pulse crop residues are high in N, which can be supplied to subsequent crops when residues are returned to the soil system
Summary
Returning above-ground crop residues to the soil provides many benefits to agroecosystems, such as improved soil physical properties, conserved soil organic matter contents and increased nutrient availabilities (Chen et al, 2014). Pulse crop residues are high in N, which can be supplied to subsequent crops when residues are returned to the soil system. Nitrogen (N) release from plant residues decomposing in soil results from complex microbial processes controlled by many factors, such as the quality or chemical composition of the residues, which varies with legume genotypes (Trinsoutrot et al., 2000; Peoples et al, 2009). The carbon to nitrogen (C:N) ratio of the plant material has often been used as a predictor of residue mineralization. C:N ratios below 20 generally imply net N mineralization, while
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
