Single irrigation at the four-leaf stage in the spring optimizes winter wheat water consumption characteristics and water use efficiency

Abstract

Water scarcity is a key constraint to crop production in North China Plain (NCP), which produces the majority of the country’s winter wheat (Triticum aestivum L.). The objective of this three-year field study was to see whether and when irrigation one-time in spring improved grain productivity and water use efficiency. Four sets of irrigation were established at the 3-leaf visible stage (L3) and the L4, L5, and L6 stages. When irrigation time was postponed, the spike number, 1000-grain weight, and water consumption increased progressively, whereas grain yield, grain number, dry matter, harvest, and WUE grew, then dropped, and peaked at L4. The increased grain number can be attributed to the L4's higher daily water consumption and water consumption percentage throughout the jointing-anthesis stages compared to the L3, L5, and L6. The cumulative (37 days), whereas it was longer in L3, L5, and L6(40, 42, and 43 days, respectively). Furthermore, flag leaf senescence was postponed in L4 with a higher post-anthesis leaf area index, photosynthetic rate, chlorophyll content, higher superoxide dismutase activity, and lower malondialdehyde concentration. As a result, single irrigation at the 4-leaf visible stage optimized water deficit and consumption before and after anthesis, resulting in higher yield and WUE in the NCP.

Optimizing nitrogen rate under single irrigation can maintained a high yield and increased economic benefits in winter wheat

“…Compared with the traditional crop growth stage, irrigation according to wheat leaf age has gradually become a new water-saving irrigation strategy that can accurately control wheat growth and yield formation. Our previous studies con rmed that single irrigation at spring 4 leaf age of winter wheat is an e cient water-saving irrigation technique (Bao et al 2022;Liu et al 2021). However, how to make up for the yield loss caused by single irrigation by changing agronomic practices needs further study.…”

“…Notably, irrigation at spring 4-leaf age is approximately one week later than irrigation at spring 3leaf age, resulting in a more balanced distribution of water consumption before and after the wheat jointing stage. Our prior research found that irrigation at spring 4-leaf stage achieved the highest yield and WUE with a single spring irrigation by increasing water consumption during the jointing-anthesis stage, reducing the duration of drought stress, and delaying leaf senescence (Bao et al 2022). Furthermore, it is essential to acknowledge the synergistic effects of water and nitrogen Liu et al 2022).…”