State Key Laboratory of Nutrient Use and Management, College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, China Agricultural University, Beijing 100193, China; National Observation and Research Station of Agriculture Green Development (Quzhou, Hebei), China Agricultural University, Beijing 100193, China.
Oil Crops Research Institute, Chinese Academy of Agricultural Sciences/Key Laboratory of Biology and Genetics Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan 430062, China.
Sci Total Environ. 2024 Nov 1;949:175108. doi: 10.1016/j.scitotenv.2024.175108. Epub 2024 Jul 30.
Winter wheat production is influenced by climate extremes worldwide. Heavy precipitation induced delay of sowing generates limited photothermal resources for wheat early growth. However, how wheat build resilience from stunted seedling growth has not been fully explored. Here, a twelve-year farmers' survey of wheat yield was recorded and four-year field experiments of wheat grown in normal and late-sowing were performed under zero nitrogen (N0) and optimum nitrogen (Opt.N) supply. Wheat growth and N uptake were measured at both vegetative and reproductive stages alongside photothermal resource-use efficiency. Farmers' survey showed 10.4 % yield losses due to delayed sowing compared to the normal. However, four-year field trials revealed that the combination of increasing seeding rates and Opt.N application recovered grain yield of sowing-delayed wheat and even increased by 13.2 % compared to plants in the normal seasons. Although delayed sowing substantially suppressed seedling growth and tillering before winter dormancy, the Opt.N application increased spring tillers by 2.4-fold which were productive at maturity. Further, plant growth and N uptake from jointing to anthesis of sowing-delayed wheat were accelerated by Opt.N, but not by N0 treatment. Delayed sowing significantly shortened the duration of lag phase of grain filling by 3.5 days and by 183 growing degree days compared with the normal, which initiated the linear and fast filling earlier. Increased leaf photosynthesis by 27.4 % during grain filling further supported the fast recovery of grain filling in the sowing-delayed wheat. Concomitantly, the physiological N-use efficiency increased by 46.7 % during grain filling and by 41.5 % at maturity by enhancing N availability and seeding rates, and photothermal resource-use efficiency increased by 1.3- to 1.7-fold for wheat with delayed vs. normal sowing. Overall, these findings highlight the integrated management of nutrient and cultivation to mitigate the impacts of climate extremes on crop productivity through building plant reproductive resilience.
冬小麦的产量受到全球气候极端事件的影响。强降水导致的播种推迟，使得小麦早期生长的光热资源有限。然而，小麦如何从幼苗生长受阻中恢复生长能力尚未得到充分探索。在这里，我们对小麦产量进行了为期 12 年的农民调查，并在零氮（N0）和最佳氮（Opt.N）供应下进行了为期 4 年的正常播种和晚播田间试验。在营养和生殖阶段，我们测量了小麦的生长和氮吸收以及光热资源利用效率。农民调查显示，与正常播种相比，推迟播种导致 10.4%的产量损失。然而，4 年的田间试验表明，增加播种量和 Opt.N 应用相结合，恢复了晚播小麦的籽粒产量，甚至比正常季节的植株增加了 13.2%。尽管晚播在冬季休眠前大大抑制了幼苗生长和分蘖，但 Opt.N 应用增加了春季分蘖数，使它们在成熟时具有生产力。此外，Opt.N 而不是 N0 处理加速了晚播小麦从拔节到开花期的植株生长和氮吸收，但 Opt.N 处理并没有加速晚播小麦从拔节到开花期的植株生长和氮吸收。晚播显著缩短了籽粒灌浆的滞后期 3.5 天，比正常播种少了 183 个生长度日，从而更早地启动了线性和快速灌浆期。籽粒灌浆期叶片光合作用增加了 27.4%，进一步支持了晚播小麦灌浆的快速恢复。同时，通过提高氮素有效性和播种量，生理氮素利用效率在灌浆期提高了 46.7%，在成熟期提高了 41.5%，光热资源利用效率提高了 1.3-1.7 倍，晚播小麦的光热资源利用效率提高了 1.3-1.7 倍。总之，这些发现强调了通过建立植物生殖恢复力来整合养分和栽培管理，以减轻气候极端事件对作物生产力的影响。
