摘要
黄土高原地区夏玉米生长正逢雨季 ,是N素淋溶的主要时期 ,为此提出氮肥施用的成垄压实法 .通过连续两年的田间小区试验 ,研究了夏玉米生长期成垄压实施肥方式下夏玉米产量和氮肥利用率 ,以及土壤NO3 - N迁移规律 ,并结合室内模拟实验探讨了该施肥法的影响因素 .结果表明 ,在供水量接近研究区同期多年平均降雨量 (370mm)的年份 ,平地施肥条件下 ,NO-3 N可被淋溶至 90cm以下的土层 ;而成垄压实施肥可明显减少施肥区NO-3 N随入渗水分向土壤深层迁移 ,至 6 0cm以下土层 ,土壤NO-3 N含量小于 10mg·kg-1,NO-3 N主要累积于近地表 2 0～ 4 0cm土层 ,该土层土壤NO-3 N含量约为 80～ 90mg·kg-1.成垄压实施肥法局部存在的大容重障碍层对作物生长发育无影响 .在 2 4 0 .0kgN·hm-2 施氮量条件下 ,成垄压实较平地施肥没有显著提高玉米生物产量和经济产量 ,但却能极显著地增加作物吸氮量 ,使氮肥利用率提高 9%左右 .成垄压实施肥条件下 ,障碍层容重对NO-3 N迁移影响明显 ,随障碍层容重的增加 ,NO-3 N迁移深度减小 .大田条件下 ,垄坡度对NO-3 N迁移影响不明显 .
The primary season of nitrate leaching in the Loess Plateau region is the monsoon,which is caused by heavy rainfall during the growth season of corn ( Zea mays L.) abstract Nitrate leaching to groundwater is an increasing concern in agriculture,and is one of the major nitrogen losing ways in dryland farming system.Localized compaction and ridge fertilization is a method for nitrogen fertilizer application,by which,less fertilizer leaching would occur.The NO_3 --N transport in soil profile,corn yields and nitrogen use efficiency under localized compaction and ridge fertilization were investigated through two years field study.The factors that affect NO_3 --N transport under localized compaction and ridge fertilization were studied,combined with simulated experiment. The results showed that NO_3 --N was leached to below 90cm in plat fertilization in the year of about 370mm rainfall,a mean precipitation during the season,while the NO_3 --N leakage of the fertilizer zone was reduced by localized compaction and ridge fertilization,as a result that the NO_3 --N concentration below 60cm was less than 10mg·kg -1 ,and NO_3 --N accumulated in 20～40cm with a concentration 80～90 mg·kg -1 . There was no significant difference in yield between application methods with 240.0kgN·hm -2 . However,the absorbed amount of nitrogen was improved significantly by localized compaction and ridge fertilization,and the nitrogen use efficiency was increased by 9%. The bulk density of the barriers had an evident effect on NO_3 --N transport under localized compaction and ridge fertilization,but the effect of ridge slope was insignificant.
出处
《应用生态学报》
CAS
CSCD
2004年第1期68-72,共5页
Chinese Journal of Applied Ecology
基金
国家重点基础研究发展规划项目 (G2 0 0 0 0 1860 5 )
国家自然科学基金项目 (4 0 3 0 10 2 8)
西北农林科技大学科研专项
关键词
成垄压实施肥
氮素运移
氮肥
利用率
Localized compaction and ridge fertilization method,Nitrate transport,Nitrogen use efficiency.
