Climate change and water shortage are the two important driving factors for food insecurity. It is a common concern to ensure food security to cope with climate change by adopting the best management practices (e.g., irrigation methods and sowing date). A field simulation experiment was conducted to investigate the effects of management practices (water-saving irrigation and delayed sowing) on yield and greenhouse gas emissions (CH and NO) in a rice-wheat rotated field under nighttime warming. A randomized complete block design with three factors and two levels was adopted in this study. The two levels of nighttime temperature were set as ambient temperature (CK, control) and nighttime warming (NW). The crop canopy was covered with aluminum foil film at night (19:00–6:00) to simulate nighttime warming. The two levels of irrigation in rice-growing season were set as conventional irrigation (F, intermittent flooding with 5-cm water layer) and water-saving irrigation (M, moistening without water layer). The two levels of sowing date of winter wheat were set as normal sowing date (NS) and delayed sowing date (DS). The results indicated that, compared with the control, nighttime warming or water-saving irrigation decreased rice biomass and yield by 14.69%–18.16% and 7.27%–9.14%, respectively, whereas delayed sowing increased wheat yield by 0.71%. Compared with the CH efflux with ambient temperature and flooding irrigation, CH efflux from rice field significantly declined with nighttime warming or water-saving irrigation but significantly increased with nighttime warming under water-saving irrigation. Under ambient temperature, compared with flooding irrigation, water-saving irrigation significantly reduced the cumulative CH emission by 79.46% but significantly promoted the cumulative NO emission by 97.21%. Under nighttime warming, water-saving irrigation significantly increased the cumulative CH and NO emissions by 39.98% and 45.62%, respectively, compared with flooding irrigation. Compared with the control, delayed sowing significantly reduced the cumulative NO emission by 21.46%–53.77% in wheat field. The contribution of CH emissions from the rice field was dominant in all the treatments. Nighttime warming significantly decreased the greenhouse gas emission intensity (GHGI) in the rice-wheat rotated field with flooding irrigation and normal sowing but significantly increased GHGI in the field with water-saving irrigation and delayed sowing. Given the increased yield and environmental benefits, this study suggests that conventional irrigation (intermittent flooding) for rice and normal sowing for wheat are the effective practices for the rice-wheat rotated field to cope with global warming in the lower reaches of the Yangtze River.

中文翻译：

---

节水灌溉和延迟播种增加了夜间增温下稻麦轮作田CH4和N2O的排放强度

气候变化和水资源短缺是粮食不安全的两个重要驱动因素。通过采用最佳管理实践（例如灌溉方法和播种日期）来确保粮食安全以应对气候变化是人们普遍关心的问题。通过田间模拟试验，研究夜间增温下稻麦轮作田管理措施（节水灌溉和延迟播种）对产量和温室气体排放（CH 和 N2O）的影响。本研究采用三因素二水平的随机完全区组设计。夜间温度的两个水平被设置为环境温度（CK，对照）和夜间变暖（NW）。夜间（19:00-6:00）作物冠层覆盖铝箔膜，模拟夜间变暖。水稻生长季灌溉设置为常规灌溉（F，间断漫灌，5cm水层）和节水灌溉（M，无水层湿润）两个级别。冬小麦播期设置两个水平：正常播期（NS）和延迟播期（DS）。结果表明，与对照相比，夜间增温或节水灌溉使水稻生物量和产量分别下降了14.69%~18.16%和7.27%~9.14%，而延迟播种使小麦产量增加了0.71%。与常温和漫灌条件下的CH排放量相比，夜间增温或节水灌溉下稻田CH排放量显着下降，但节水灌溉下稻田CH排放量随夜间升温显着增加。常温下,与漫灌相比,节水灌溉显着降低了累积CH排放量79.46%,但显着促进了累积NO排放量97.21%。夜间变暖情况下，节水灌溉使CH和N2O累积排放量较漫灌显着增加，分别增加了39.98%和45.62%。与对照相比，延迟播种麦田NO累积排放量显着降低21.46%~53.77%。在所有处理中，稻田 CH 排放的贡献均占主导地位。夜间变暖显着降低了稻麦轮作漫灌和正常播种田间的温室气体排放强度（GHGI），而显着增加了节水灌溉和延迟播种田间的温室气体排放强度（GHGI）。考虑到产量的增加和环境效益，本研究认为水稻常规灌溉（间歇性淹水）和小麦正常播种是长江下游稻麦轮作田应对全球变暖的有效做法。