Growth, yield and economics of rice fallow castor under different levels of N and P applied to preceding Kharif rice and different fertilizer schedules given to succeeding castor crop

A field experiment was conducted during 2008–2009 and 2009–2010 on sandy clay loam soil of Agricultural College Farm, Bapatla during kharif to study the effect of different levels of nitrogen and phosphorus on yield and economics of rice fallow castor under different levels of N and P applied to kharif rice and different schedules given to succeeding castor crop. The treatments consisted of four N levels i.e. 80 kg N ha⁻¹, 120 kg N ha⁻¹, 240 kg N ha⁻¹ and green manuring @5 t ha⁻¹, three P levels i.e. 0, 30 and 60 kg P₂O₅ ha⁻¹ to preceding rice and three fertilizer schedules i.e 0, 50 and 100% recommended dose of fertilizers (RDF) to succeeding castor. Application of 240 kg N ha⁻¹ in combination with 60 kg P₂O₅ ha⁻¹ and 100% RDF to castor significantly increased the growth, yield and economics of castor over other levels of nitrogen phosphorus and fertilizer schedules.