摘要
一季不施氮对冬小麦产量影响显著,对夏玉米产量影响不大;连续二季和三季不施氮使冬小麦和夏玉米产量都大幅度减产;连续四季以上不施氮使冬小麦和夏玉米产量分别稳定在1693～1807kg/hm2和4575～4782kg/hm2范围的较低水平。不施氮条件下,冬小麦的减产幅度大于夏玉米。不施氮主要通过降低两种作物的穗粒数影响产量。一季和连续两季不施氮使土壤无机氮含量迅速下降,连续两季以上不施氮使土壤无机氮含量稳定在较低水平。
No nitrogen fertilizer (NNF) for one season had significant influence on the yield of winter wheat and a little impact on the yield of summer maize. NNF for more than two seasons reduced both winter wheat and summer maize yield significantly. The yield of winter wheat and summer maize were kept quiet low and steady when NNF was applied for more than 4 seasons. Winter wheat yield was much reduced comparing with that of summer maize under NNF. Nitrogen deficiency reduced grain yield mainly through decreasing grain number per ear for both winter wheat and summer maize. N_(min) level of soil was fall down significantly under NNF.When NNF was adopted for more than three seasons, N_(min) level kept low and steady like grain yield.
出处
《华北农学报》
CSCD
北大核心
2004年第1期93-96,共4页
Acta Agriculturae Boreali-Sinica
基金
国家自然科学基金(30070451)
中德合作项目(0339712A)A2子项目
