Silicon-mediated sustainable intensification of rice production: Impacts on yield, economic returns and pest resistance
Abstract
Rice cultivation is increasingly constrained by stagnant yields, diminishing profit margins and escalating pest pressures. These interrelated challenges compromise both crop productivity and economic viability. To address this, the adoption of integrated agronomic strategies is essential. The precise application of micronutrients and biostimulants has been shown to improve physiological efficiency, enhance nutrient-use efficiency and activate plant defence responses, thereby contributing to increased yield performance, economic returns and pest resilience under sustainable production systems. Therefore, a field study was carried out during the 2024 kuruvai season (June–September) at the Experimental Farm of the Department of Agronomy, Faculty of Agriculture, Annamalai University, Tamil Nadu. To assess the treatment effects, the experiment followed a split-plot design with 3 replications. The main plot treatments consisted of four micronutrient regimes: an untreated control (M₁), zinc sulphate (ZnSO4) applied at 25 kg ha-1 (M₂), diatomaceous earth applied at 50 kg ha-1 as a silicon source (M₃) and a combined application of ZnSO4 at 25 kg ha-1 and diatomaceous earth at 50 kg ha-1 (M₄). The subplot treatments consisted of four biostimulant regimes: an untreated control (S₁), humic acid applied at 0.3 % (S₂), seaweed extract applied at 0.3 % (S₃) and vermiwash applied at 5 % (S₄). Among all treatment combinations, the application of ZnSO₄ at 25 kg ha-1 along with diatomaceous earth at 50 kg ha-1, supplemented by foliar sprays of seaweed extract (0.3 %) at 20 and 40 days after transplanting (DAT) (M₄S₃), recorded the highest grain yield (6270 kg ha-1) and straw yield (8783 kg ha-1), resulting in the maximum net income (₹89209.5 ha-1) and benefit-cost ratio (2.44). The treatment also significantly reduced leaf folder incidence to 0.81 %, indicating enhanced productivity, profitability and pest tolerance.