Effect of crop diversification on productivity and profitability of rice (Oryza sativa) – wheat (Triticum aestivum) cropping system

A field study with eight crop sequences was conducted at Karnal during 2001–06 to diversify or intensify the rice (Oryza sativa L.) - wheat (Triticum aestivum) cropping system and to select suitable cropping system based on productivity and profitability. Combined analysis of the data of 6 years showed that rice - vegetable pea - wheat - greengram sequence produced 27.91% higher wheat equivalent yield than rice - wheat system. Diversification or intensification of rice - wheat system, once in 3 years, improved the net returns when all the crops (except rice) were grown on raised-bed in a system approach. Inclusion of oilseed or pulses in rice - wheat system once in 3 years or intensification by growing vegetable pea in between rice and wheat or greengram after wheat showed higher net returns and sustainable value index (SVI) compared with rice - wheat system. Maximum SVI (0.92) and net returns (Rs 38.6 x 10³/ha/year) were recorded in rice - Indian mustard - greengram - rice – wheat – greengram - rice – wheat - greengram crop sequence. Benefit: cost ratio (1.74) and profitability (Rs 124/ha/day) were highest in pigeon pea - wheat - rice - wheat - rice - wheat crop sequence. Growing of berseem in the rotation reduced the weed population in the subsequent wheat cycle. After 6 years, rice - vegetable pea - wheat - greengram, rice - Indian mustard – greengram – rice – wheat – greengram - rice – wheat - greengram and pigeonpea – wheat - rice – wheat - rice - wheat showed 37.5, 25.0 and 20.0% increase, respectively in organic C content (0–15 cm) than continuous rice-wheat system.