Long-term organic nutrient management for boosting growth characteristics, yield and monetary returns of basmati rice ( Oryza sativa L.) production in the Indo-Gangetic Plains of India

Rice (Oryza sativa L.)-wheat (Triticum aestivum L.) rotations are dominant food production systems in the Indo-Gangetic plains of India. However, indiscriminate use of inputs poses a threat to the long-term sustainability of these systems. Organic agriculture offers a viable alternative for enhancing productivity while conserving resources. Hence, a field experiment (2021 and 2022) investigated the sixteen-year impact of different organic nutrient management regimes on plant growth, N-accumulation, yields, and economic returns of organic basmati rice production. The strip plot design comprised two rice-based cropping systems: basmati rice-wheat-green gram (CS1) and basmati rice-wheat-sesbania (CS2) and seven organic nutrient management practices: T1, no manure application; T2, farmyard manure (FYM); T3, vermicompost (VC); T4, FYM+crop residue (CR); T5, VC+CR; T6, FYM+CR+ biofertilisers (BF); and T7, VC+CR+BF. Results showed significant effects of both the cropping systems and the nutrient practices. CS2 recorded higher plant growth, N-accumulation, grain yield, and economic return than CS1. Integrated use of organic sources improved dry matter production by 22–25% over sole applications. N-accumulation peaked in T6 at 25 DAT and T7 at 55 DAT, with increases of 20.8% and 46.7%, respectively, relative to T1. Grain and straw yields increased by 74–80% and 46–50% in T6 and T7 compared to T1. Gross returns were also 68–74% higher with integrated treatments. The cropping system with sesbania green manure combined with integrated organic amendments (T6 and T7) was shown to be the most effective and sustainable long-term approach for producing higher yields and ensuring financial security of the rice-wheat agro-ecosystem.