ON-FARM RAINWATER AND CROP MANAGEMENT FOR IMPROVING PRODUCTIVITY OF RAIN-FED AREAS

Scarcity of water is a critical limitation to adoption of modem techno logy for increasing productivity of traditional rainfed rice growing a reas of eastern Madhya Pradesh, India. The shortage of water results f rom uneven distribution of rains, significant gaps between rain events and field water losses rather than from low seasonal or annual rainfa ll totals. A feasible strategy to alleviate this limitation is to harv est excess rainwater in a farm pond during the wet season and use the conserved water for crop production in both wet (as insurance against drought) and dry seasons by adopting suitable crop and cropping system s. The results of water balance in a 1.05 ha field, on which a farm po nd was built using 0.09 ha area, showed that 28-37% of seasonal rainfa ll was available as surface runoff from microcatchment (0.66 ha growin g soybean, peanut and pigeonpea) for collection in the pond, This was sufficient for saving rice in a 0.30 ha area (in the lower side of the field) from drought stress, and for establishment of chickpea and mus tard (in 0.90 ha) in the post-rainy season after harvest of rainy seas on crops, Soybean, peanut and pigeonpea, grown in the microcatchment d uring the rainy season, utilized respectively 371-726, 364-733 and 535 -920 mm water in evapotranspiration (E(t)) and deep percolation (P). R ice grown below the pond required 28-317 mm water in different seasons to save the crop from in-season drought stress which commonly occurre d during vegetative and reproductive stages. Water requirement (E(t) P) of rice was 816-1342 mm in different seasons. Residual soil moistu re after rainy season soybean, peanut and rice was sufficient (172-203 mm) to support post rainy season crops of chickpea and mustard, Howev er, the losses of moisture from the soil surface layer after harvest o f rainy season crops were rapid (7-23 mm), which necessitated a light irrigation (21-45 mm) for establishment of chickpea and mustard in the post-rainy season. The water balance results of soybean-mustard, pean ut mustard and peanut-chickpea were near identical to soybean-chickpea cropping, Similarly the water balance of rice-mustard was identical t o rice-chickpea in the vertisols. Soybean-mustard and rice-chickpea we re the suitable and economical cropping systems for the microcatchment and service area of the farm pond.