矮壮素配合氮肥基施对夏玉米氮代谢及氮素利用特征的影响
试验于2018年在中国农业科学院作物科学研究所河南新乡试验站进行，以京农科728为试验材料，在相同施肥量条件下，设置4个CCC施用梯度C1（225g/hm2）、C2（450g/hm2）、C3（675g/hm2）和C4（900g/hm2），通过与氮肥（124.95kg/hm2）拌肥处理一次性基施，研究矮壮素对华北夏玉米产量、氮代谢及氮素利用率的影响，筛选最佳的矮壮素施用量。结果表明：相对常规氮肥处理，CCC处理增加了玉米产量、千粒重和穗粒数，干物质积累量在花期之后显著增加，叶面积指数显著高于常规氮肥对照，增强了叶片硝酸还原酶（NR）、谷氨酰胺合成酶（GS）及花后34天到收获期的谷丙转氨酶（GOT）等氮代谢酶活性，提高了叶绿素总含量、可溶性蛋白含量；氮素利用率得到了提高，最佳施用量是675g/hm2，在最佳施用量下，氮肥偏生产力、氮肥农学效率和氮肥生理利用率分别比常规氮肥对照增加5.4%、45.8%、22.7%。本研究表明，CCC能调动氮代谢关键酶活性，增强氮代谢，从而提高了氮素利用率，达到高产。
英文摘要:
Randomized block field experiments were conducted using maize variety of Jingnongke728 in Xinxiang Experimental Station in Henan province in 2018. The experiment include four chlormequat chloride（CCC） treatments，that’s C1 (225 g/hm2), C2 (450 g/hm2), C3 (675 g/hm2 and C4 (900 g/hm2) ,and maize cultivar of ‘Jingnongke728’. Aiming to explore the effects of CCC mixed with nitrogen fertilizer on summer maize yield, nitrogen metabolism and nitrogen use efficiency of North China Plain.The results showed that compared with conventional nitrogen fertilizer treatment，CCC treatment increased maize grain yield, 1000-kernel weight and kernel number, post-silking aboveground dry matter accumulation significantly, and the leaf area index as well, enhances the leaf nitrogen-metabolizing enzyme activities such as nitrate reductase (NR), glutamine synthetase (GS), increase the total chlorophyll content and soluble protein content. Nitrogen utilization rate was improved. The optimum application rate was 675g/hm2. Under the optimal application amount, partial productivity of nitrogen fertilizer, agronomic efficiency of nitrogen fertilizer and physiological utilization rate of nitrogen fertilizer have increased by 5.4%, 45.8% and 22.7% respectively，compared to CK. This study showed that CCC mixed with nitrogen fertilizer could mobilize the key enzyme activity of nitrogen metabolism ,thus enhance the metabolism of nitrogen, thus improving the utilization rate of nitrogen and achieving high yield.
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