Abstract

                                Field experiments were conducted during 1996-97 to 1999-2000 at Regional Research Station. Aruppukottai to find out the optimum combination of inorganic fertilizers with organic manure to cotton and their residual effect on sorghum grown after cotton in rainfed Vertisol. The four years mean data revealed that application of inorganic fertilizer at 40:20:0 kg NPK ha -1 every year and FYM 25 t ha-1 once in two years recorded higher mean gross income (Rs.14119 ha-1) with a cotton yield equivalent of 949 kg ha-1 and net income, (Rs.8439 ha-1) which was closely followed by application 40:20:0 kg NPK + FYM 12.5 ha-1. Application of either inorganic fertilizer or organic manure alone gave lesser yield and income.

Key words : Cotton-sorghum crop sequence, Inorganic fertilizers, Organic manure