Augmentation of nitrogen management reduce nitrogen stress and enhance productivity of super-seeder sown wheat under rice residue incorporation

Abstract

Abstract The in-situ management of rice straw incorporation is now an essential practice in the rice-wheat cropping system with the growing adoption of super-seeder among farmers. However, the effect of nutrient immobilization due to incorporation of massive organic residues at the initial stage of the decomposition is a major constraint for better yield and productivity. This study investigates the effect of bio-decomposer, nitrogen (N) level, and N scheduling on N immobilization status, dry matter, N accumulation, and remobilization and productivity in super-seeder sown wheat for two consecutive years (2020-21 and 2021-22). The experiment was laid in split-plot design with two factors in the main plot viz., without (B0) and with (B1) application of bio-decomposer and nitrogen levels 150 (N1) and 180 (N2) kg ha− 1; and three N splits (%) in sub-plot viz., 50: 25:25 (S1), 40: 30: 30 (S2), and 30 :35:35 (S3) and replicated thrice. N content and uptake at pre- and post-anthesis were recorded significantly higher with N2 and S1 compared to N1 and S2 and S3 in both the years. Post-anthesis N accumulation (post-NA) and N remobilization (NR) with N2 was significantly higher to the tune of 22% and 17% than N1. Dry matter accumulation (DMA) at anthesis and harvest with N2 was significantly higher by 5.7%, while with S1 there is an improvement of 6.2% over S3. The grain yield with N2 and S1 significantly improved by 8.3% and 10.9% (two years mean) compared to N1 and S3, respectively. Soil urease activity was significantly enhanced with the application of microbial formulation (bio-decomposer), N2, and S1 in comparison to B0, N1 and S3 at 30 and 60 DAS (days after sowing). Hence, the present study revealed that the application of microbial-formulation and higher N level coupled with higher proportion of basal N could be propounded for sustainable production and higher productivity. Besides, use of bio-decomposer also improved soil health. The result presented here assumes great significance in proper utilization and conservation of rice residue under rice-wheat cropping system.