International Journal of Environment and Climate Change

Under changing climatic scenario, the rainfall amount and its distribution over space and time have become uncertain during the rice growing season which is also affecting  rice production very often. Under deficit rainfall (50% & 19% in 2010 and 2012) from dry sowing or dry transplanting of rice to its harvest (48-52 cm rainfall from August to October), 42.8 q/ha coarse rice (cv, Annada) and 29-45 q/ha medium rice (cv. Satabdi and Himsagar) were harvested with one irrigation of 7.5 cm at panicle initiation stage. Water productivity ranged from 1250 to 1810 lit/kg of raw rice in different years. Dry seeded/dry transplanted rice was established receiving 55 to 74 mm rainfall within seven days. However, one supplemental irrigation following dry sowing/transplanting will ensure better seedlings establishment. Soil mulching by CRIJAF nail weeder at field capacity at 6-21 days after rice dry transplanting/dry sowing will maintain better hydro thermal regime and aeration of soil under deficit rainfall and ascertain composite weed control. Field capacity moisture during rice growth was enough to produce 45q/ha grain yield. This practice of rice production will mimimise methane gas emission over waterlogged rice paddies. In situ rain water harvesting in micro pond (12 m x 10 m x 1.5 m)  sacrificing 9 per cent of total area (1333 m²) at lowest corner of the field provides life saving irrigation and produced 3-3.5 tonnes medium rice/ha. Through these micro ponds (7 in one hectare), in porous alluvial or sandy loam soils, annually around 3.58 to 7.47 crore litres of water can be recharged/ha to the unconfined aquifer in rainy season (July to September). Inter/relay cropping in rice field will produce 3.5 to 4.5 tonnes of rice along with 15- 200 q of different vegetables/ha, increase nutritional security of resource poor farmers, net return and make effective utilization of rainwater. Under deficit rainfall, as alternate crops of rice, yield of rain fed green gram (cv. Pant mung-5, RMG 62), arhar (UPAS -120) and sweet corn green cobs on ridges, were  21-23 q, 30 q/ha and 1,20,000 numbers/ha respectively. Adopting these rice production/intercrop/alternate crop/water harvesting technologies, sustainability can be ensured under a deficit rainfall, in current changing climatic scenario.