摘要： 在河北省无极县壤土地上连续五年的不同施氮量定位试验研究的结果表明，在小麦玉米一体化生产中，土壤作物系统中作物对氮素的吸收和积累，土壤对氮素的积累以及氮素损失与施肥之间有密切关系。低水平施氮虽然氮的利用率高，但作物产量低，土壤养分被掠夺吸收；高水平施氮会造成作物对氮素的奢侈吸收而导致减产，土壤氮积累增加，淋溶损失增加，氮素利用率降低。按常年最高产量施氮量施入氮素，既能保持作物的持续高产，又不会造成作物对氮素养分的奢侈吸收和作物对土壤氮素养分的掠夺吸收，而且不会引起氮素在土壤中的大量积累或损失。五年试验结果显示，氮肥(包括有机氮)总利用率达76%，尿素氮总利用率达72%，土壤积累率小于5%，氮损失率小于23%。

关键词: 小麦, 玉米, 两熟制, 土壤, 作物系统, 氮素平衡

Abstract: The relations between application of Nfertilizer and Nabsorption in crops,andNaccumulation in soil and Nloss under soilcrops system in wheatcorn double croppingwere studied by location trials of Nfertilizer for five years ar the loam in Wuji county,Hebeiprovince.The results showed that:at the low level of Nfertilizer application,utilizationratio of Nfertilizer was higher,but the grain yield was lower and soilN was plundered cropsat the high level of Nfertilizer application,the grain yield decreased due tonitrogen of excessive absorption in crops,accumulation and leaching loss incrase in Soutilization ratio of Nfertilizer decreased at the rate of Nfertilizer applied which obtainedthe maximum grain yield,the excessive absorption of crops to was not appeared and soil N was plundered by crops.Naccumulation in soil and Nloss were less.Utilized coefficientsof Nfertilizer(including organicN).Thepercentages of Naccumulation in soil and Nloss were less than 5% and 23% respeectively.

Key words: Wheat-corn double cropping, Soil-crop system, Nitrogen balance

中图分类号: 

• S154.4