CAJ | 학술논문

采用田间微区~(15)N示踪技术,研究了冬小麦季化肥氮去向及土壤氮素平衡.结果表明,在供试土壤肥力水平和生产条件下,N 150 kg/hm~2的施肥量已达到较高产量,再增加氮肥用量小麦产量不冉增加.随着施肥量的增加,地上部吸氮量有所增加,氮肥的表观利用率和农学利用率持续下降,而生理利用率则表现为低一高一低的变化趋势.在低施氮条件下,小麦主要吸收土壤氮的比例高于化肥氮;在高施氮条件下,小麦吸收土壤氮的比例下降.冬小麦收获后,仍有26.7%～40.6%的氮肥残留在0-100 cm土层中,17.4%～24.8%的氮肥损失.残留在土壤剖面中的氮肥主要分布在表土层.随着施氮量的增加,土壤氮素总平衡由亏缺转为盈余;土壤根区硝态氮也由播前消耗转为在播前的基础上累加,两个小麦品种表现为相同的趋势.
채용전간미구~(15)N시종기술,연구료동소맥계화비담거향급토양담소평형.결과표명,재공시토양비력수평화생산조건하,N 150 kg/hm~2적시비량이체도교고산량,재증가담비용량소맥산량불염증가.수착시비량적증가,지상부흡담량유소증가,담비적표관이용솔화농학이용솔지속하강,이생리이용솔칙표현위저일고일저적변화추세.재저시담조건하,소맥주요흡수토양담적비례고우화비담;재고시담조건하,소맥흡수토양담적비례하강.동소맥수획후,잉유26.7%～40.6%적담비잔류재0-100 cm토층중,17.4%～24.8%적담비손실.잔류재토양부면중적담비주요분포재표토층.수착시담량적증가,토양담소총평형유우결전위영여;토양근구초태담야유파전소모전위재파전적기출상루가,량개소맥품충표현위상동적추세.
The fate of N fertilizer and balance of soil N under winter wheat farming were studied using filed ~(15)N microplot.The results show that crop yield would not increase when the nitrogen application rate is above N 150 kg/ha.Apparent recovery efficiency and agronomic efficiency of nitrogen fertilizer are constantly decreased with increasing of rate of nitrogen fertilizer,while the trend of physiological efficiency is low-high-low.At lower N rate,more soil N is absorbed by winter wheat than that from fertilizer N,and the ratio of soil N absorption to fertilizer N absorption is decreased under high N application.After the harvest of winter wheat,26.7%-40.6% of fertilizer N is resided in 0-100 cm,and 17.4%-24.8% of fertilizer N is lost.With increasing of nitrogen fertilizer application,the total balance of soil N is from deficiency to surplus,and NO_3~--N in the root zone soil is from consuming nitrogen to cumulating nitrogen before seeding.There is similar trend between two wheat varieties.