选用多穗型小麦品种豫麦49-198和大穗型小麦品种兰考矮早八，以河南温县和兰考为试验地点，在0、90、180、270、360 N kg·hm-2 水平下，通过田间试验对小麦群体动态、产量和土壤氮素变化进行了研究.结果表明：两个品种小麦都是从出苗开始群体数量不断增加，到拔节期达到最大，然后开始下降.在不同施氮水平和试验点间，豫麦49-198在越冬期和返青期群体数量没有显著差异，拔节以后不同氮水平间群体数量差异显著；而兰考矮早八在所有生育时期，不同施氮水平间群体数量都没有显著差异.随氮肥用量的增加，小麦产量增加，但过量施氮则使小麦产量下降，豫麦49-198以270 N kg·hm-2水平下产量最高，在温县和兰考点分别为9523和9867 kg·hm-2，兰考矮早八以180 N kg·hm-2水平下产量最高，在温县和兰考点分别为9258和9832 kg·hm-2.随着氮肥用量的增加，土壤硝态氮含量和氮素表观损失增加，豫麦49-198在温县和兰考点的氮素表观损失分别占氮肥用量的32.56%～51.84%和-16.70%～42.60%，兰考矮早八则分别占氮肥用量的18.58%～52.94%和-11.50%～45.80%.在本研究条件下，兼顾产量和环境效应，0～90 cm土壤硝态氮累积量不应超过120～140 kg·hm-2，小麦氮用量不能超过180 kg·hm-2.
Taking wheat varieties Yumai 49-198 (multi-spike phenotype) and Lankao Aizao 8 (large-spike phenotype) as test materials, field experiments were conducted at Wenxian and Lankao sites of Henan Province to study the effects of nitrogen fertilization on their population dynamics and yield and on the alteration of soil nitrogen. Five nitrogen application rates, i.e., 0, 90, 180, 270, and 360 N kg·hm-2 were installed. The population amount of the two test varieties were all increased after emergence, reached the highest at jointing stage, and decreased afterwards. As for Yumai 49-198, its population amount had no significant differences at wintering and turning-green stages among the five nitrogen application rates and two experimental sites, but differed significantly after jointing stage with the nitrogen application rates. For Lankao Aizao 8, its population amount had no significant differences among the nitrogen application rates during whole growth period. The grain yield of the two varieties increased with the increase of nitrogen fertilization rate, but excessive nitrogen fertilization decreased the grain yield. Yumai 49-198 had the highest yield at 270 N kg·hm-2, being 9523 and 9867 kg·hm-2 at Wenxian and Lanako sites, respectively, while Lankao Aizao 8 had the highest yield at 180 N kg·hm-2, being 9258 and 9832 kg·hm-2 at Wenxian and Lanako sites, respectively. With the increase of nitrogen fertilization rate, soil nitrate N concentration and apparent nitrogen loss increased. At Wenxian and Lankao sites, the apparent soil nitrogen loss for Yumai 49-198 was 32.56%-51.84% and -16.7%-42.6% of fertilized nitrogen, and that for Lankao Aizao 8 was 18.58%-52.94% and -11.5%-45.8% of fertilized nitrogen, respectively. Considering the yield and environmental effect comprehensively, the nitrate N concentration in 0-90 cm soil layer in our case should not be exceeded 120-140 kg·hm-2, and the maximal nitrogen application rate should not be exceeded 180 kg·hm-2.