种植密度和施氮量对小麦-玉米轮作体系下周年产量及氮肥利用率的影响

小麦-玉米是河南省主要的轮作模式,其习惯种植密度与专家推荐种植密度间差距较大。本研究旨在为不同种植密度下小麦和玉米匹配适宜的氮肥用量,以达到最佳经济效益和氮素利用率。选用不同小麦品种（矮抗58和百农207）和不同玉米品种（北青340和登海605）为供试材料,设置农民习惯和专家推荐2个种植密度,0、180和360kg N/hm² 3个供氮水平,分析比较了不同处理下小麦和玉米的干物质、产量、氮素利用率和经济效益。结果表明,小麦的农户习惯种植密度比专家推荐高75kg/hm²,相比农户习惯处理,专家推荐种植密度处理下的小麦产量提高了10.0%~15.7%,提升了经济效益。小麦产量随穗粒数的增加而增加。农民习惯种植密度下,随施氮量的增加,小麦产量没有明显差异,氮肥农学效率降低。专家推荐种植密度下,百农207在N₁₈₀处理下产量最高。玉米的农民习惯种植密度比专家推荐低22 500kg/hm²,相比农民习惯处理,专家推荐处理的玉米产量提高了17.8%~22.7%。玉米产量随种植密度的增加而增加。农民习惯种植密度下,随施氮量的增加,玉米产量呈降低趋势,氮肥农学效率降低。专家推荐种植密度下,玉米在N₁₈₀处理下经济效益最高。

Effects of Planting Density and Nitrogen Application Rate on Annual Yield and Nitrogen Use Efficiency of Wheat-Maize Rotation System

The gap between the customary seeding rate of wheat-maize growers in Henan province and the recommended seeding rate by experts is large.This study aims to match the appropriate amount of nitrogen fertilizer for different seeding rates to achieve the best economic benefits and nitrogen use efficiency.Wheat varieties(Aikang 58 and Bainong 207)and maize varieties(Beiqing 340 and Denghai 605)were selected as test materials,and two seeding doses of farmers'habits and experts recommend were set,and the three nitrogen supply levels 0,180,and 360kgN/ha were compared and analyzed.The dry matter amount,yield,nitrogen use efficiency and economic benefit of wheat and maize of different treatments were compared.The results showed that the habits of wheat farmers were 75kg/ha higher than those recommended by experts.Compared with the customary treatment of farmers,the wheat yield increased by 10.0%to 15.7%,and the economic benefit was improved.The yield of wheat increased with the increasing of the number of kernels.Under the habit seeding rate of farmers,with the increase of nitrogen application rate,there was no significant difference in wheat yield,and the agronomic efficiency of nitrogen fertilizer decreased.Under the recommendation of the experts,the output of Bainong 207 reached the highest under the treatment of N180.The amount of maize used by farmers is 22500kg/hm² lower than that of recommended by experts.Compared with farmers'customary treatment,the yield of maize recommended by experts increased from 17.8%to 22.7%.Maize production increased with seeding rate increasing.Under the habit seeding rate of farmers,with the increase of nitrogen application rate,the yield of maize decreased,and the efficiency of nitrogen fertilizer agronomy decreased.The economic benefit of N180 treatment was the highest under the planting density recommended by experts.