TILLAGE AND MULCHING EFFECTS ON WATER-USE, ROOT-GROWTH AND YIELD OF RAIN-FED MUSTARD AND CHICKPEA GROWN AFTER LOWLAND RICE

Crops grown under rainfed conditions are prone to water stress, owing to rapid loss of soil moisture and development of mechanical impedance to root growth. The stress can be alleviated by enlarging rooting vol ume in the soil and/or by regulating the supply of soil moisture. This study reports the effects of zero, minimum and conventional tillage w ith and without rice straw mulch on conservation of soil moisture, roo t growth and yield of chickpea and mustard grown under rainfed conditi ons for three years (1990-91 to 1992-93) in a deep clayey soil (Typica l Chromusterts). Minimum tillage, with or without straw, enhanced soil moisture conservation and moisture availability during crop growth. A s a consequence, the root mass, yield components (plant stand, number of pods per plant and plant height) and grain yield increased. Availab ility of soil moisture during the crops growth period, maintained bett er plant water status. Zero tillage was superior to the other tillage practices for mustard. On the other hand, chickpea grain yield was sta tistically similar for zero tillage and minimum tillage. Straw mulch c onserved more water in the soil profile during the early growth period compared to no mulch. Subsequent release of conserved soil water regu lated proper plant water status, soil temperature, and lowered soil me chanical resistance, leading to better root growth and higher grain yi eld of both chickpea and mustard in straw mulch than in no mulch plots . (C) 1998 Society of Chemical Industry.