水氮优化条件下在华北平原冬小麦/夏玉米轮作中化肥氮的去向  

FATE OF FERTILIZER NITROGEN FOR WINTER WHEAT/SUMMER MAIZE ROTATION IN NORTH CHINA PLAIN UNDER OPTIMIZATION OF IRRIGATION AND FERTILIZATION

作　　者：潘家荣[1,2] 巨晓棠[1] 刘学军[1] 陈新平[1] 张福锁[1] 毛达如[1] 

机构地区：[1]中国农业大学植物营养系,农业部植物营养学重点实验室,北京100193 [2]中国农业科学院农产品加工研究所,农业部农业核技术与农产品加工重点实验室,北京100193

出　　处：《核农学报》2009年第2期334-340,307,共8页Journal of Nuclear Agricultural Sciences

基　　金：国家自然科学基金倾斜项目(39870479);北京市自然科学基金重大项目(6980001)

摘　　要：针对华北平原冬小麦/夏玉米轮作区水肥高投入的特点,引入以土壤Nmin(NO3--N+NH4+-N)为基础的优化施氮技术和以土壤水分含量为基础的优化灌溉技术对施氮量和灌溉进行优化,大幅度降低了作物氮肥用量和灌溉量,且生物产量和籽粒产量均未发现显著降低。微区结果表明,传统灌溉方式下,传统施氮处理的化肥氮利用率很低,冬小麦当季为22.7%,夏玉米当季25.7%,整个轮作周期为28.44%;氮损失率较高,冬小麦当季为52.9%,夏玉米当季35.7%,整个轮作周期为47.0%;而优化施氮可大幅度提高化肥氮利用率,降低损失,冬小麦当季、夏玉米当季和整个轮作周期的化肥氮利用率分别达到45.1%,42.9%和46.1%,损失率分别为33.3%,7.1%和34.5%。优化灌溉下的优化施氮与传统灌溉的优化施氮相比,虽然化肥氮利用率未有显著差异,但是却显著降低了损失,显著增加了化肥氮的土壤残留,建议在化肥氮优化中考虑水分管理。研究还表明,在华北平原冬小麦/夏玉米轮作区,反硝化损失是化肥氮损失的主要途径。A 15^N-microplot experiment for determination of fertilizer nitrogen fate in winter wheat/summer maize rotation was conducted in North China Plain, where irrigation and nitrogen fertilizers are conventionally over used. In this experiment, the fate of fertilizer nitrogen between conventional irrigation-fertilization and an optimized irrigation-fertilization, which was based on the soil Nmin （NO3^ --N ＋ NH4^＋ -N） and soil moisture, was compared. It was shown that the optimized irrigation and nitrogen fertilizer could decrease agricultural input on the basis of maintenance of grain yield as conventional practices. It was found that only 22.7 % and 25.7 % of applied nitrogen under conventional irrigation-fertilization was recovered by above- ground parts of winter wheat and summer maize in the growing crop season, respectively, and 28.44 % for the whole rotation perod. Loss was 52.9 %, 35.7 % and 47.0% of applied nitrogen in winter wheat season, summer maize season and the rotation period, respectively. While optimization of nitrogen fertilization under conventional irrigation practices could greatly increase crop recovery and decrease the loss, the corresponding recoveries were 45.1%, 42.9% and 46.1%, and the corresponding loss were 33.3 %, 7.1% and 34.5 %, respectively. With comparison of irrigation optimization and conventional irrigation, there was no significant difference in fertilizer nitrogen recovery under optimized fertilization, but optimized irrigation could increase the soil fertilizer nitrogen residue and decrease the loss. Due to effect of irrigation on mineralization of soil nitrogen, irrigation should be considered when nitrogen optimization was introduced. It was also showed that, in general, leaching played a minor role in the loss of applied nitrogen for winter wheat/summer maize rotation in North China Plain, denitrification would be the primary mechanism of fertilizer nitrogen loss.

关 键 词：水肥优化 化肥氮去向 15^N冬小麦/夏玉米轮作 华北平原 

分 类 号：S512.11[农业科学—作物学] TQ225.241[化学工程—有机化工]