Effect of crop intensification on productivity, profitability, energetics and soil fertility in rice (Oryza sativa)-wheat (Triticum aestivum) cropping system of north-western plains

Abstract

A field experiment was conducted during 1996-2000 at Karnal with 7 wheat (Triticum aestivum L. emend. Fiori & Paol.)-based crop sequences to intensify the rice Coryza sativa L.)-wheat system by introducing short-duration and/or green-manuring crops for enhancing the productivity and profitability on sustainable basis. After 4 years of study, rice- . potato (Solanum tuberosum L.)-wheat-green-manure rotation recorded the maximum equivalent wheat yield, energy input and output, gross return and total cost of cultivation. The organic carbon and available soil N contents were also higher than the other crop sequences, but the benefit: cost ratio was the lowest under this sequence. On the other hand, growing of vegetable pea (Pisum sativum L.) between rice and wheat gave the maximum net return (Rs 42 512/ha), energy output: input ratio (3.36) and build-up soil fertility level similar to rice-wheat-green-manure rotation. Incorporation of prickly sesban or dhaincha [Sesbania cannabina (Retz) Pers.] continuous for 4 years and growing of vegetable pea and potato between rice and wheat increased 8.7, 8.9 and 17.1 % organic carbon; 12.1, 6.3 and 8.3 % available Nand 10.1,6.3 and 19,0 % available P respectively compared with rice-wheat system.