【摘要】 【目的】适宜的密度与氮肥运筹是提高玉米抗倒伏能力、保证高产稳产和提高生产效益的重要措施。探讨不同施氮量与种植密度对春玉米产量及抗倒伏性能的影响，以期为山西春玉米的高产高效栽培及籽粒机收的发展提供理论支撑。【方法】于2018和2019年在山西晋中进行玉米田间试验，供试玉米品种为‘郑单958’。设置4个施氮水平：0、120、180、240 kg/hm~2 (N0、N1、N2、N3);3个种植密度：60000、75000、90000株/hm~2(D1、D2、D3)。调查玉米吐丝期茎秆农艺性状，生理成熟期穗位以下茎秆生物学、力学性状及倒伏率，并测定产量。【结果】随着种植密度和施氮量的增加，玉米产量呈先增加后降低的趋势。在D2密度下达到最高值，两年平均产量为13792 kg/hm~2，较D1和D3密度下分别增加了4.8%和8.3%。与N0相比，N1、N2和N3处理分别增产24.3%、26.7%和23.9%。N3处理对穗粒数与千粒重无显著影响，但产量低于N1和N2处理。增密导致玉米茎秆变细，株高、穗位上升，玉米第3～6节长粗比增加，穿刺强度、抗压强度、抗弯折力等茎秆力学特性变差。D2和D3密度下两年玉米平均倒伏率较D1分别升高了1.33、3.73个百分点。N1、N2、N3处理两年玉米平均倒伏率较N0分别增加了2.50、3.25、4.80个百分点。适当增氮有利于消减因密度增加导致的生物学、力学特性变差，D2和D3密度下，N2处理第3～6节穿刺强度、抗压强度和抗弯折力维持在较高水平，显著高于N3处理。【结论】合理的氮肥用量可改善因密度增加导致的茎秆细弱、玉米茎秆力学特性变差问题，降低倒伏风险，因而增加产量。在山西中部春玉米种植区，种植密度为75000株/hm~2、施氮量180 kg/hm~2，是玉米产量、茎秆力学特性及抗倒性能和谐的密度肥料组合。更多还原

【Abstract】 【Objectives】Suitable density and nitrogen fertilizer management are important measures to improve maize lodging resistance, ensure high and stable yield and improve production efficiency. The objective of this experiment is to study the influence of nitrogen application rate, planting density and their interaction on maize yield, lodging resistance. 【Methods】Field experiments were conducted in Jinzhong City, Shanxi Province in2018 and 2019, using maize cultivar ‘Zhengdan 958’ as the test materials. Four N application rates 0, 120, 180and 240 kg/hm~2(denoted as N0, N1, N2, and N3), three planting densities 60000, 75000 and 90000 plants/hm~2(denoted as D1, D2, D3) were setup. The agronomic traits of stalk at silking stage, the length-to-thickness ratio,mechanical traits, and lodging rates of stalks below the ears were investigated at physiologically maturing stage,and the yields were recorded at harvest of spring maize.【Results】The maize yield showed a trend of first increasing and then decreasing with the increase of planting density and nitrogen application rate. The average yield under D2 of two years was 13792 kg/hm~2, which was 4.8% and 8.3% higher than that under D1 and D3,respectively. Compared with N0, N1, N2, and N3 increased yields by 24.3%, 26.7%, and 23.9%, respectively. N3was recorded lower yield than N1 and N2, although N3 did not impact the kernel number per ear and 1000-grain weight significantly. With the increase of planting density, the stem diameter was significantly decreased, but the plant height, ear height, the length-to-thickness ratio of the third to sixth internode above ground were increased,and the rind penetration strength, bending strength, crushing strength became worse. D2 and D3 were recorded1.33 and 3.73 percentage point higher than D1 in the two-year average lodge rate, and N1, N2, and N3 were recorded 2.50, 3.25, and 4.80 percentage point higher than N0. Proper increasing of N rate offset the deterioration of stalk biological and mechanical properties which were caused by increased planting densities. Under D2 and D3, the third to sixth above ground internodes in N2 treatment remained similar or even higher rind penetration,bending, and crushing strength, while N3 decreased the mechanical properties, relative to D1.【Conclusions】Reasonable nitrogen application rate can prevent the stalk thinning caused by the increased planting density,improve the mechanical properties of maize stalks, reduce the lodging risk, and increase yield at last. In the central area of Shanxi Province, planting density 75000 plants/hm~2 and nitrogen application rate 180 kg/hm~2 appear the optimum combination in consideration of maize yield, stalk mechanical properties and lodge resistance comprehensively.更多还原