Closing global yield gap of rainfed wheat by optimizing nitrogen and phosphorus inputs

Abstract

Rainfed wheat is of paramount importance to global food security, representing the most extensively cultivated crop worldwide. In a considerable number of regions, wheat yields fail to reach the anticipated production levels. Although an increase in nitrogen (N) and phosphorus (P) fertilizer inputs can enhance yield and help to close the yield gap, excessive use can lead to environmental pollution and disrupt biogeochemical cycles. The objective of this study is to ascertain the optimal rates of N and P application required to achieve 50 %, 70 %, and 80 % of the water-limited potential yield (Yw) for rainfed wheat. By integrating the Global Yield Gap Atlas with regression models and meta-analysis, we evaluated the global N and P requirements for rainfed wheat. The results demonstrate that to achieve a yield target of 50 % Yw, a reduction of 40 % in the application of N is required. Conversely, a 10 % reduction in N application is necessary to reach a yield target of 70 % Yw. To reach 80 % Yw, an increase of 13 % in the application of N is required. Regarding P, a reduction of 12 % is required in order to achieve a 50 % Yw, whereas both 70 % and 80 % Yw targets necessitate an increase of 15 %. These findings offer crucial insights for policymakers and agricultural stakeholders, providing a basis for enhancing food security, improving sustainability, and addressing the global yield gap challenge.