ABSTRACT
The global rainfed croplands were estimated at 1.132 billion hectares (B ha) at the end of the last millennium (Biradar et al. 2009). This is 2.78 times the net irrigated areas (407 M ha) of the world (https://www.iwmigiam.org/info/main/aboutGMRCA2 .asp). Rainfed agroecosystems occupy a considerable place in Indian agriculture too, covering 80 million ha (M ha), in arid, semiarid, and subhumid climatic zones, constituting nearly 57% of the net cultivated area. India has 18% of the world’s population, 15% of the world livestock with only 2.3% of the geographical area, 4.2% of freshwater resources, 1% of forests, and 0.5% of pastureland (Srinivasarao 2011; Srinivasarao et al. 2011a). Rainfed areas in India contribute almost 100% of forest products, 84% to 87% of coarse-grain cereals and pulses, 80% of horticulture, 77% of oilseeds, 60% of cotton (Gossypium hirsutum), and 50% of fine cereals like rice (Oryza sativa), wheat (Triticum aestivum), maize (Zea mays), sorghum (Sorghum bicolor), and so forth (Srinivasarao et al. 2010, 2011b). Rainfed regions support 60% of livestock and 40% of the human population and contribute 40% of food grains and several special-attribute commodities such as seed spices, dyes, herbs, gums, and so forth. (Srinivasarao et al. 2011a). However, the double-cropped area in rainfed farming is negligible. Rainfed agroecoregions are complex, diverse, fragile, risky, and underinvested and require regionally differentiated investments and management strategies. Achieving high production potential is difficult in these rainfed areas due to vagaries of rainfall.
