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

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