Transforming coastal deltaic agriculture: A pathway to doubling farmers’ income in Karaikal

Rice cultivation in coastal river deltaic regions faces increasing challenges due to declining on-time river water availability, soil salinity and stagnating yields, which limit income growth for smallholder farmers. This study hypothesised that integrating water-saving irrigation, hydrogel application and intercropping could significantly improve aerobic rice performance and economic returns in coastal conditions. A field experiment was conducted during the summer season of 2022 at Karaikal, a coastal region in southern India, to assess the effects of two irrigation methods (drip irrigation and surface irrigation), two hydrogel levels (with and without application) and four intercropping systems (no intercrop, black gram, green gram and onion) on aerobic rice. The treatments were arranged in two separate two-factor randomised block designs under each irrigation method. The results showed that hydrogel application increased the grain yield of aerobic rice by 2.5 % from 4807 to 4923 kg ha-1. Surface irrigation produced 28 % higher yield of aerobic rice (5464 kg ha-1) than drip irrigation (4266 kg ha-1). The most profitable treatment was surface-irrigated aerobic rice intercropped with black gram and supplemented with hydrogel, which achieved the highest gross return (₹ 219450 ha-1), net return ( ₹ 162103 ha-1) and benefit-cost ratio (3.83). Here, we demonstrate that the strategic integration of surface irrigation, hydrogel application and legume intercropping can substantially improve rice yield and profitability under coastal conditions. This is the first study to evaluate such combined interventions for aerobic rice in the deltaic ecosystem of Karaikal. The findings offer a practical and scalable approach to enhance resource-use efficiency, income and sustainability in climate-vulnerable rice farming systems.