春玉米生长发育、产量和籽粒品质对减量施氮的响应

针对当前东北地区过量施氮的问题，研究减量施氮对春玉米生长发育、产量及籽粒品质的影响，对优化氮肥的科学管理技术，促进春玉米生产绿色高效发展具有重要意义。本研究以丹玉405为试验材料，通过大田播种的方式，以农民习惯性施氮量为对照，设置11.1%、55.5%和100%三个水平减量施氮试验，分析春玉米生长发育、产量和籽粒品质对减量施氮的响应机制。结果表明：玉米苗期，减氮导致生长发育指标（株高、茎粗、叶面积指数、生物量干、鲜重、叶片比重等）均减少，不利于地上部的生长和干物质向叶片分配，随着减氮量的增加，减少幅度增加。苗期以后，适量减氮促进玉米地上部的生长，株高、茎粗、叶面积指数、生物量和叶片占比等生物学性状有增加趋势。适量减氮导致果穗长、果穗粗、百粒重、理论产量、籽粒含水量和淀粉含量增加，籽粒脂肪含量减少，氨基酸和粗蛋白含量呈先增加后减少。随着减氮量的增加，果穗长、果穗粗、百粒重和理论产量增加幅度均减小，籽粒含水量和淀粉含量增加幅度增大，脂肪含量减少幅度减小。减氮11.1%时，果穗长、果穗粗和理论产量增加幅度最大，分别为1.9%、3.7%和11.5%。当施氮量为240 kg·hm^-2（减氮11.1%）时，玉米产量达到最大，为945.4 g·m^-2，籽粒脂肪含量最少，为2.4 g·100 g^-1；氨基酸含量最大，为83.9 μmol·g^-1；粗蛋白含量最高，为6.8%。研究结果可为当地的玉米生产提供更加完善的施肥管理，指导农户科学施肥。

Responses of growth,yield, and grain quality to reduced nitrogen application of spring maize

Given the current problem of excessive nitrogen application in Northeast China, studying the effects of reduced nitrogen application on spring maize growth and development, yield, and grain quality were of great significance to optimizing scientific management techniques of nitrogen fertilizer and promoting the green and efficient development of spring maize production. In this study, the Danyu 405 was used as the experimental material, and the farmer's habitual nitrogen application rate was used as the control. Three levels of 11.1%, 55.5%, and 100% nitrogen reduction experiments were conducted. The response mechanisms of yield and grain quality to reduced nitrogen application were analyzed. The results showed that at the seedling stage of maize, nitrogen reduction results in the reduction of growth and development indicators (plant height, stem diameter, leaf area index, dry and fresh weights of biomass, leaf specific gravity, etc.), which is not conducive to the growth of shoots and the distribution of dry matter to leaves. As the amount of nitrogen reduction increases, the reduction rates increase. After the seedling stage, the appropriate amount of nitrogen reduction promotes the growth of maize shoots, and the biological characteristics such as plant height, stem thickness, leaf area index, biomass, and leaf proportion have an increasing trend. A moderate amount of nitrogen reduction results in an increase in ear length, ear thickness, 100-kernel weight, theoretical yield, grain water content, and starch content, and a decrease in grain fat content, as well as a first increase then decrease in amino acid and crude protein content. With the increase in nitrogen reduction, the increased amplitudes in ear length, ear thickness, 100-kernel weight, and theoretical yield all decrease, and those in grain water content and starch content increase, and the decreased amplitude in fat content decreases. When the nitrogen application rate is 240 kg·hm^-2 which is reduced by 11.1%, the increase rates of ear length, ear thickness, theoretical yield reach peak values which are 1.9%, 3.7%, and 11.5%, respectively, and the maize yield reaches the maximum i. e. 945.4 g·m^-2, while the fat content of the grain i. e. 2.4 g·100 g^-1 is the least, the amino acid content i. e. 83.9 μmol·g^-1 is the largest and the crude protein content i. e. 6.8% is the highest. The research results provide more complete fertilization management for local corn production and guidance for farmers to apply fertilizer scientifically.