Division of Soil Science and Agricultural Chemistry, Indian Agricultural Research Institute, New Delhi, 110012.
* Present address: Division of Environmental Sciences, Indian Agricultural Reesarch Institute, New Delhi, 110 012.
An attempt was made using incubation-leaching method to assess N mineralization potential (N0) and rate of mineralization (k) in soils amended with manures, urea and their combinations. The rate of releaseofN was very slow in the beginning followed by sharp increased reaching a peak rate in 3 to 4 weeks followed by a gradual decline thereafter. Minearlization potential recorded by dhaincha (Sesbania aculeata) plus urea was the highest (197.2 mg kg−1) followed by cowpea plus urea (185.3 mg N kg−1) and urea (171.9 mg N kg−1). Amongst the green manure-amended soils the highest release of N was registered by Sesbania followed by cowpea and sunnhemp. Mineralization rate constants ranged from 0.02 to 0.04 per week. It was observed that N0 was influenced by the total N content; C/N ratio and lignin content of the manures, cowpea, sunnhemp.
N mineralization potential, mineralization rate constant, Sesbania aculeata, cowpea, sunnhemp, FYM, biogas slurry, 15N method
