Crop-water relations in rice-wheat cropping under different tillage systems and water-management practices in a marginally sodic, medium-textured soil
2002
Sharma, P.K. | Bhushan, L. | Ladha, J.K. | Naresh, R.K. | Gupta, R.K. | Balasubramanian, B.V. | Bouman, B.A.M
Management of resources and sustainability of the rice-wheat cropping system have become a matter of concern in South Asia, especially where water is increasingly scarce. New soil and water management technologies, such as aerobic cultivation of rice on raised beds or on flat nonpuddled, and zero-tillage in wheat, are rapidly emerging. This paper reports on a field experiment carried out at Modipuram, Uttar Pradesh, India, to study some of these new technologies. Rice (Pro-agro 6111) was direct-seeded on raised beds and on flat land and grown under two aerobic water regimes : (1) irrigation was applied when the soil water tension at 15-cm depth reached 10kPa or (2) when it reached 20 kPa. The control was continuously flooded transplanted rice. Wheat (BPW 343) was sown after rice using five tillage practices: conventional tillage, zero-tilage with or without controlled traffic, zero-tillage with paired-row planting, and bed-planting (same beds as used for rice). Flooded transplanted rice and conventionally tilled wheat gave the highest yields. With irrigation at 10 or 20kPa soil water tension, bed-planted rice reduced water input by 45-51% but lowered yield by 52-53% compared with transplanted rice, whereas dry-seeded rice on flat land reduced water input by 51-57% and lowered yield by 36-46%. Zero-tilled wheat with controlled traffic gave yields similar to those of conventional wheat and had the same water use. More study is needed to understand the effect of aerobic rice on flat land or on raised beds, and of wheat under zero-tillage, on soil properties, crop productivity, and water use.
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