乙矮合剂对不同氮水平夏玉米氮代谢及产量的调控效应

应用化学调控技术改善玉米的氮素代谢过程,从而实现“减氮增效”,是保障玉米绿色可持续生产的重要途径。试验以玉米单交种豫单9953为材料,设置乙矮合剂（ECK）和不同氮肥水平处理（0、96、132、168、204和240kg/hm²）,喷施清水为对照处理（CK）,于2019和2020年分别在河北燕郊和北京顺义进行大田试验,研究ECK对不同施氮量下夏玉米氮素代谢及产量的调控效应。结果表明,ECK处理提高了不同施氮量下夏玉米开花期叶片硝酸还原酶活性和可溶性蛋白含量,提高了施氮量204和240kg/hm²处理下叶片谷丙转氨酶和谷草转氨酶的活性以及灌浆中后期的谷氨酰胺合成酶活性。ECK处理显著提高了施氮量204kg/hm²下玉米植株氮素、籽粒氮素和总氮素积累量,较CK处理分别增加8.9%、8.3%和8.6%。ECK处理下施氮量为204kg/hm²时,夏玉米产量较CK处理显著增加7.5%。ECK处理可有效改善玉米的氮素代谢,促进氮素的吸收、同化和积累,提高产量,从而实现“减氮增效”。

Effects of Ethylene-Chlormequat-Potassium on Nitrogen Metabolism and Yield of Summer Maize under Different Nitrogen Levels

Applying chemical regulation technology to improve the nitrogen metabolism process of maize to achieve “reducing nitrogen and increasing efficiency” is an important way to ensure green and sustainable production of maize. In this experiment, the single cross maize Yudan 9953 was used as the research material, Ethylene-Chlormequat-Potassium (ECK) and nitrogen gradient treatments (0, 96, 132, 168, 204 and 240kg/ha) were set up in Yanjiao, Hebei province, and Shunyi, Beijing, in 2019 and 2020, respectively, to study the effects of ECK on nitrogen metabolism and yield of summer maize under different nitrogen application rates, water was as a control (CK). The results showed that ECK treatment increased nitrate reductase activity and soluble protein content in summer maize leaves at flowering stage, the activities of glutamic-pyrupropyl transaminase and glutamic-oxalacetic transaminase activities, and glutamine synthetase activities in the middle and late stages of grain filling at nitrogen application rates of 204 and 240kg/ha. Compared with CK, under 204kg/ha nitrogen application rate, ECK treatment significantly increased the nitrogen accumulation in plant, grain and total nitrogen by 8.9%, 8.3% and 8.6%, respectively. Compared with CK, under the condition of 204kg/ha nitrogen application rate, ECK treatment significantly increased summer maize yield by 7.5%. The treatment of ECK could effectively improve the nitrogen metabolism of maize, promote the absorption, assimilation and accumulation of nitrogen, and increase the yield, so as to realize “reducing nitrogen and increasing efficiency”.