Optimization of Date of Sowing in a New Groundnut-Wheat Relay Cropping System in Semi-Arid Tropics of India

Abstract

ABSTRACT A two-year field study was conducted on a vertisol in a new system of summer groundnut-relay cropping (SGRC) to find out the optimum date of sowing of groundnut in a relay cropping system with wheat and to assess the productivity and profitability of the system. In SGRC wheat was sown at 30 cm and 45 cm row spacing. Groundnut was sown in furrows between 45 cm wheat rows and hand dibbled between 30 cm wheat rows at 3 growth stages of wheat (heading-19th January, grain filling-31st January and 15 days before harvest-10th February). The results revealed that sole groundnut emerged 2-3 days earlier than relay groundnut under the shade of the wheat canopy. Biomass production, crop growth rate (CGR), leaf area index (LAI), pod yield and haulm yield of relay groundnut were much lower than sole groundnut particularly when relay groundnut was sown at heading stage of wheat (19th January). However, total system productivity and net returns in the relay cropping system were higher than sole cropping groundnut and these were maximum when relay groundnut was sown at grain filling stage of wheat (25 days before harvest of wheat). Groundnut hand dibbled between 30 cm spacing of wheat was superior to groundnut sowing in furrows spaced at 45 cm. This is a promising system for the semi-arid tropics of India.