Integrated nutrient management for sustainable productivity of basmati rice in alluvial soils

Abstract:

Continuous reliance on chemical fertilizers alone has degraded alluvial rice soils across the Brahmaputra-Jamuna floodplain, lowering organic carbon, weakening soil structure, and plateauing yields. Integrated Nutrient Management (INM) combining inorganic fertilizers with organic manures and biofertilizers offers a path to sustain productivity while restoring soil health. A two-year field experiment (kharif 2022 and 2023) was conducted on alluvial soil at Bangladesh Agricultural University research farm, Mymensingh, Bangladesh, to evaluate seven INM treatments on aromatic rice variety BRRI dhan50 (Banglamati). Treatments included an unfertilized control, 100% recommended dose of fertilizers (RDF), and five combinations of 50–75% RDF with farmyard manure (FYM, 5 t ha⁻¹), vermicompost (3 t ha⁻¹), and biofertilizers (Azospirillum + PSB). The treatment combining 75% RDF + FYM + biofertilizers produced the highest grain yield (5.23 t ha⁻¹), 15.7% above 100% RDF alone, and improved soil organic carbon by 0.14 percentage points over the two-year period. Nutrient use efficiency for nitrogen was 38.7 kg grain per kg N applied under INM versus 29.4 under 100% RDF. These results support a 25% reduction in chemical fertilizer input when supplemented with FYM and biofertilizers for aromatic rice on alluvial soils.