Optimizing nitrogen fertilizer use for more grain and less pollution

Optimal nitrogen (N) management is critical for efficient crop production and agricultural pollution control. Approximate 210–220 kg ha ?1 N fertilizer was applied in millions of small plots through broadcasting way China, resulting over loss fertilizers. However, it difficult to implement advanced practices on smallholder farms due a lack knowledge. Here, using 35,502 on-farm fertilization experiments, we demonstrated that smallholders China could actually produce more grain with less use only optimizing application rate. The yields wheat, maize rice were shown increase between 10% 19% while rates reduced by 15–19%. These changes resulted an efficiency (NUE) 32–46% reduction surplus 40% without changing farmers’ operational practices. By reducing line official recommendations would not save cost increasing yield, but also at the same time reduce environmental China. Beyond rate, improved required pollution, which need about 11.8 billion US dollars implementation 1.75 million tons environment. • Optimizing rate estimated based field experiments nationally. increased NUE lower surplus. Environmental predicted be 5.06 t Best strategies result reduction.