OPTIMIZING THE RICE HARVEST-TO-GROUNDNUT SOWING INTERVAL FOR RESIDUAL MOISTURE UTILIZATION AND ENHANCED PRODUCTIVITY OF RABI GROUNDNUT (ARACHIS HYPOGAEA L.) IN RICE-FALLOW SYSTEMS: A REVIEW

Abstract

Rice-fallow lands of eastern and southern India retain considerable residual soil moisture after the kharif rice harvest, offering an opportunity to intensify cropping with short-duration oilseeds such as groundnut (Arachis hypogaea L.). The success of rabi groundnut in these systems, however, depends largely on how quickly the crop is established after rice harvest, because stored soil water declines rapidly through evaporation once the rice crop is removed. This review synthesizes recent evidence on the rice–groundnut transition window, covering constraints to timely sowing, soil moisture and soil physical conditions after rice, the influence of sowing date on phenology, growth and yield, irrigation requirement, water-use efficiency, system profitability, climate variability and decision-support tools. Field studies in Odisha show that groundnut sown in the first week of December produced the highest pod yield (2,032 kg ha⁻¹), whereas sowing in the last week of January reduced yield by about 28%. Mechanized drill sowing raised groundnut pod yield by 45% over farmers’ practice, and deficit irrigation scheduling saved up to 25.6% of irrigation water without lowering pod yield. Conservation tillage, residue retention, relay (utera) sowing, short-duration rice cultivars and protective irrigation further improve the use of residual moisture. Despite this progress, no study has yet quantified groundnut response to defined harvest-to sowing intervals. Future research should treat this interval as an independent management variable and evaluate it together with soil moisture dynamics, crop establishment, yield and water productivity, supported by crop models, remote sensing and weather-based advisories, to develop location-specific sowing recommendations for rice-fallow systems.