Improved yield, economic benefits and environmental stewardship with controlled-release urea and urea in the rice production

While blended use of controlled-release urea and common urea (BU) can improve rice yield and nitrogen (N) use efficiency, life-cycle and ecosystem economic implications of BU are not well understood. Here, we conducted field experiments in Central China to evaluate impacts of BU [mixing conventional urea with controlled-release urea at a 1:1 for N (wt/wt) ] on the agronomy, environmental footprint and economic returns of rice cropping systems. We compared BU and common urea application (CU) across five N fertilization rates ranging from 0 to 270 kg N ha⁻¹. We found that the 225 kg N ha⁻¹ treatment (N225) had the greatest yields, ranging from 9293 to 10026 kg ha⁻¹. BU increased grain yield and agronomic efficiency. For 90 kg N ha⁻¹, average N recovery efficiency for CU and BU were 74 % and 77 % respectively, while the partial factor productivity of N was 96 kg kg⁻¹ and 102 kg kg⁻¹, respectively. Nitrogen use efficiency for both treatments was 32 kg kg⁻¹. For the same N rate, BU significantly reduced reactive N losses and N footprint by 16–19 % and 37–41 % respectively, while decreasing greenhouse gas emissions and C footprint by 7–10 % and 8–12 %. BU increased ecosystem economic benefit (EEB) by 40 %, 38 %, 30 %, and 8 %–40 % at 90, 180, 225 and 270 kg N ha⁻¹, respectively. BU had the highest net energy (264000 MJ ha⁻¹) at 225 kg N ha⁻¹, and the highest energy use efficiency (7.50) at 90 kg N ha⁻¹. Our findings suggest that substituting common urea with BU can improve the sustainability of rice production. Since blending of fertilizers can be operationalised on farm, we suggest that the scalability of BU is conducive to widespread benefits for enterprise profit, environmental stewardship and agrifood security.