中文摘要：

以冬小麦＂西农9814＂为材料进行大田试验,研究施氮量对小麦产量构成因素、土壤中硝态氮变化的影响。结果表明,适宜施氮量（N 276 kg/hm2）可以显著提高小麦的穗重、穗粒数、千粒重等产量构成因素,比对照增产24.6%。产量构成因素中以穗粒数与产量的相关性最强,达极显著水平,千粒重次之。土壤耕层硝态氮主要集中在0—40 cm土层,且含量随着施氮量的增加而增加。随着小麦生育期的推移,耕层中硝态氮呈下降趋势,0—40 cm耕层变化显著,到成熟期各土层硝态氮含量基本趋于一致。施氮量在N 02~07 kg/hm2范围内,硝态氮积累的增加量变化不显著,但当施氮量高于N 207 kg/hm2时,土壤中硝态氮的积累量随施氮量增加而显著增加,增加了硝态氮的冗余和向下淋溶的可能。

英文摘要：

A field experiment was carried out to study effects of nitrogen application on grain yield winter wheat（Xinong 9814） and soil NO-3-N.The results show that the yield components such as grain weight per spike,grains per spike and 1000 grain weight are all increased under the moderate nitrogen application,and the highest yield occurs at N 276 kg/ha of nitrogen application,which is about 124.6% of the yield of the control.Among the yield components,spike number has the strongest correlation with yield,and second is kernel weight.Soil NO3-N mainly exists in 040 cm depth,and the soil NO-3-N contents are increased with the increases of nitrogen application.With the wheat grows,soil NO-3-N contents are decreased,especially in the 040 cm depth,while,those are almost the same in different depths at the mature period of wheat.Soil NO-3-N accumulations are not changed when nitrogen application rates are between N 0207 kg/ha,while,the accumulations are rapidly increased when the application rates are larger than N 207 kg/ha.These results indicate that there are NO-3-N redundancy and possible N leaching under high N application.