Characterization and crop planning of rabi fallows using remote sensing and GIS

Rice is the principal crop during kharif (rainy) season in eastern India, which occupies 26.8 M ha accounting for 63.3% of the total rice-growing areas of the country. However, this area is not fully utilized for crop production in the subsequent rabi (post-rainy) season and kept fallow due to a number of biotic, abiotic and socio-economic constraints. If this rabi fallow area can be effectively utilized, it will help in improving the economy of this region, which is yet to be benefited from the green revolution. The objectives of the present study include: (i) delineation of rabi fallow areas of eastern India using remote sensing and GIS technique; (ii) characterization of soil resources of the rabi fallow regions, and (iii) suggesting site-specific crop planning for this region. It was estimated that about 12.54 M ha area in the rabi season is left fallow in eastern India. The soil properties like soil texture, soil moisture retention at field capacity and permanent wilting point, saturated hydraulic conductivity, soil pH, electrical conductivity, soil organic carbon, etc. were determined at the representative profiles distributed in different agro-ecological sub-regions (AESRs) of this region and mapped in a GIS environment. Using water balance studies, site-specific crop planning based on available residual soil moisture has been suggested. In most of the AESRs, pulses and oil-seeds like green gram, black gram, Sesamum and mustard can be grown successfully on residual soil moisture content. Crops which suffer from water deficit during maturity stages can also be grown during rabi season with one or two supplemental irrigations, wherever possible. If the site-specific constraints to crop production can be alleviated and these fallow lands can be brought under cultivation through proper crop planning as suggested, poverty in this resourceful region can be eradicated to a great extent.