Micro‐sprinkling irrigation improves yield, water productivity, and nitrogen use efficiency in purple wheat

Abstract

The North China Plain (NCP) faces severe water scarcity, threatening sustainable agriculture. Micro‐sprinkling irrigation (MSI) has been instrumental in enhancing crop yield. Nevertheless, there is a paucity of research on the impact of MSI on purple wheat ( Triticum aestivum L.). A 2‐year field experiment comparing the effects of conventional flood irrigation (CI) and MSI on purple wheat was conducted, in which grain yield and its components, dry matter (DM) and nitrogen (N) accumulation and partitioning, N use efficiency (NUE), and water productivity (WP) were measured. The findings indicated that MSI observably boosted grain yield by 12.0% and protein yield by 9.7%, driven primarily by more spikes and grains per unit area. The DM accumulation of MSI at various growth stages surpassed that of CI. It also improved canopy architecture, increasing leaf area index and specific leaf N while decreasing specific leaf area. Furthermore, MSI enhanced leaf area duration compared to CI. Crucially, MSI altered resource partitioning, reducing the contribution of pre‐anthesis DM and N remobilization to grain, respectively, while increasing the contribution of post‐anthesis accumulation. Although crop evapotranspiration was similar between treatments, the higher yield under MSI resulted in significantly greater WP. The improvement in NUE under MSI was solely attributed to higher N uptake efficiency. MSI is an effective water‐saving strategy for purple wheat production in the NCP, achieving synergistic improvements in yield, WP, and NUE without increasing seasonal water consumption. This technology offers a feasible pathway for sustainable intensification of functional cereal crops in water‐scarce regions.