Topographic Appraisal for Irrigation Suitability in a Part of Jayakwadi Command Area, Parbhani District, Maharashtra

Land evaluation for cotton-based cropping systems was carried out based on detailed soil survey data in part of Jayakwadi command area under irrigation. The study of soil-landscape relationships showed that the variations in micro-relief have a marked influence on the soil profile characteristics, internal drainage and degree of sub-soil sodicity. The shrink-swell sodic soils (Parbhani series-P5) with hard, angular blocky aggregates over middle slopes (<6%) retained only 7.5% plant available water in the root zone thus reducing both productivity and irrigation efficiency. The irrigability analyses showed that land grading and levelling were prerequisite for designing surface irrigation systems in cracking clay soils over middle slopes. The irrigation analyses for cotton showed that the soils on middle slopes require an irrigation frequency of 14 days for deep and 9 days for shallow black soils. The present study showed the limits of soil–topography-yield variations in interpreting site-specific data for irrigation.