Ammonium nitrogen release in soil as influenced by differential levels of N, P, K and yield and nitrogen use efficiency in rice soils.

摘要

A pot culture experiment was carried out to study the release pattern of NH4-N, as well as N use efficiency, in Jorhat (Inceptisol) and Titabar (Alfisol) soils of Upper Assam, India with varying application rates of NPK fertilizers. Kinetics of N release varied considerably in both soils. The rate of N release was higher in Jorhat soil, irrespective of the day of sampling. The percentage of Ndff in grain and straw of rice grown in Jorhat and Titabar soils were 26.8 and 22.4% and 30.8 and 285% at 60and 80 Kg N, respectively. N use efficiency on 15N treatments in rice for Jorhat and Titabar soil were 21.1 and 30.0%, respectively.