Effect of population density and nitrogen levels on the efficiencies of soil and fertiliser nitrogen, yield and uptake of rice in inceptisols of western zone

Field experiments were conducted in Typic Ustropepts (Irugur series) of western zone of Tamil Nadu during 1998 99 and 1999-2000 to study the influence of population density and nitrogen levels for various yield targets on the efficiencies of soil (Cs) and fertiliser nitrogen (Ct) as well as yield and uptake of rice. The results revealed that there was a significant increase in the efficiencies of soil and fertiliser nitrogen under 80 hills m as compared to 66 hill m population density. Irrespective of the population densities, N levels for various yield targets had significant influence on Cf. In all the experiments application of higher doses of nitrogen (for 8 t ha¹ yield target) with 80 hills m population density recorded significantly higher yields of rice and N uptake