Village level fertilizer management for increasing nitrogen use efficiency, rice yield and household income

Limited soil nitrogen (N) availability constrains crop growth and yield. Low N use efficiency (NUE) coupled with overuse of fertilizer-N result in environmental pollution and huge economic loss. Hence, effects of N management practices on rice grain yield and NUE were studied in two separate experiments in experimental farm and farmer’s field. Each of the study was conducted in two consecutive rice seasons of Boro (dry season rice) and Transplanted Aman (T. Aman) (wet season rice) using several N treatments. Results revealed that compared with the recommended dose of N (RDN), urea super granule (USG) and biochar with RDN (BRDN) increased grain yield by 6–18% irrespective of experimental sites and cropping seasons. USG contributed to the highest NUE, while. USG and BRDN increased agronomic efficiency (1.3–2.3 folds), apparent N-recovery (1.3–1.9 folds) efficiency and physiological efficiency (0.9–1.3 folds), compared to RDN. USG appeared to be economically the most viable option, with a benefit-cost ratio (BCR) of 1.5–1.6 over locations and seasons. BRDN showed a lower BCR (1.1–1.2) due to additional expense on biochar. Biochar might contribute towards a carbon-negative economy, and its economic benefits require to be addressed. Supportive government policies are needed for adoption of USG and biochar in agriculture.