Nitrogen Use Efficiency of Rice (Oryza sativa) in Systems of Cultivation with Varied N Levels Under ¹⁵N Tracer Technique

G. Senthil Kumar, A. Rajarajan, N. Thavaprakash, C. Babu and R. Umashankar

Asian Journal of Agricultural Research 2 ( 1 ): 37 - 40 , 2008