Coated controlled-release urea creates a win-win scenario for producing more staple grains and resolving N loss dilemma worldwide

Abstract

Abstract Attaining greater crop productivity to feed the increasing population while minimizing the unwanted environmental consequences is challenging for nitrogen (N) management. Coated controlled-release urea (CRU) has been widely recommended in recent decades for improving crop productivity and reducing reactive N (Nr) losses. However, the overall effects of CRU application on crop productivity, soil N transformations and N losses to the environment remain unclear. It is also unclear whether the overall benefit of CRU, including reducing N’s environmental impact and increasing crop yield, could offset or even outweigh the application cost. Thus, we conducted a global meta-analysis using 85 publications across the world to assess the above issues. We found that on average, compared to conventional urea application, CRU application significantly increased crop yield and crop N uptake by 7.7% and 12.6%, respectively. Moreover, Nr losses in the form of ammonia (NH3) volatilization, nitrous oxide (N2O) emissions and N leaching were significantly reduced by 24.3–45.9%, mainly due to the relatively slow and continuous N substrate supply from the CRU application. The cost-benefit analysis indicated that the overall benefit outweighed the CRU application cost, producing a net monetary benefit of $117.0 ha-1 that was equivalent to an increase of 6.4% in revenue. Our results highlighted that the positive effect of CRU application on crop productivity and ecosystem services achieved a win-win scenario that, unlike the enhanced NH3 volatilization by nitrification inhibitors, resolved various N-loss dilemmas while increased the economic outcome.