穴施条件下肥料养分在土壤中迁移规律的初步研究  

Primary Study on Nutrient Migration Under Hole Fertilization in Soils

作　　者：张磊 宋航 陈小琴[1] 卢殿君[1] 王火焰[1,2] ZHANG Lei;SONG Hang;CHEN Xiaoqin;LU Dianjun;WANG Huoyan(State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]土壤与农业可持续发展国家重点实验室(中国科学院南京土壤研究所),南京210008 [2]中国科学院大学,北京100049

出　　处：《土壤》2020年第6期1145-1151,共7页Soils

基　　金：国家重点研发计划项目(2018YFD0200901,2016YFD0200108)资助。

摘　　要：根区施肥是高效施肥的重要措施,确定根区施肥的最佳位置,需要了解肥料施用后养分在土壤中的迁移规律。本研究通过室内模拟试验来研究尿素、聚磷酸铵和氯化钾复合肥穴施条件下,土壤含水量、培养时间对两种土壤中氮磷钾养分迁移的影响效果。结果表明:随土壤含水量由300 g/kg增加到420 g/kg,氮磷钾在土壤中的迁移距离都会显著增加,培养15 d的姜堰和广德两种土壤中,铵态氮、速效磷和速效钾的迁移距离分别由9~11、4~10和9~10 cm增加到12~14、5~6和11 cm。土壤含水量增加使氮磷养分的迁移距离平均增加了约1/3。随培养时间从15 d延长到30 d,300 g/kg土壤含水量条件下两种土壤中速效磷迁移距离无显著变化,而速效钾的迁移距离显著增加,铵态氮迁移距离在广德水稻土中增加显著,但在姜堰水稻土中增加幅度较小。肥料穴施条件下铵态氮的硝化作用除受土壤含水量、pH和时间因素影响外,还受肥际高浓度养分的强烈抑制作用,这种抑制作用延缓了铵态氮向硝态氮的转化,是根区一次施肥技术中氮肥持续高效供应的重要原因。总体而言,氮磷钾养分迁移距离表现为:硝态氮>铵态氮>速效钾>速效磷,肥料氮的迁移受硝化作用影响大,速效磷的迁移受土壤含水量影响较大,而速效钾与铵态氮的迁移规律较为类似,都因土壤含水量的增加和时间的延长而逐渐增加。Root zone fertilization is an important measure for efficient fertilization.To determine the optimal location of root zone fertilization,it is necessary to understand the law of nutrient transfer in the soil after fertilization.The effects of soil water content and incubation time on nitrogen,phosphorus,and potassium migration of point-applied compound fertilizer which composed of urea,ammonium polyphosphate and potassium chloride were studied with laboratory incubation experiment.The results showed that with the increase of soil water content from 300 g/kg to 420 g/kg,the migration distances of nutrients increased significantly.After incubated for 15 d in soils of Jiangyan and Guangde,the migration distance of ammonium nitrogen,available phosphorus,and available potassium increased from 9–11 cm,4 cm and 9–10 cm to 12–14 cm,5–6 cm and 11 cm,respectively.With the increase of soil water content,the distance of N and P migration increased by about one third on average.With the increase of incubation time from 15 d to 30 d,there was no significant change in the migration distance of available phosphorus,but the migration distance of available potassium increased significantly.The migration distance of ammonium nitrogen increased significantly in Guangde paddy soil with weak nitrification,while it increased slightly in Jiangyan paddy soil with strong nitrification.The nitrification of ammonium nitrogen under fertilizer hole-application was not only affected by soil water content,pH and time but also strongly inhibited by high concentration nutrients of ferti-sphere.High concentration nutrients delayed the transformation of ammonium to nitrate,which was an important mechanism account for the efficient nitrogen supply under root zone fertilization technology.In a whole,the nutrient migration distance is as follows:nitrate nitrogen>ammonium nitrogen>available potassium>available phosphorus.Nitrogen migration is easily affected by nitrification,while the available phosphorus migration is greatly affected by soil w

关 键 词：穴施 根区施肥 肥际 迁移规律 硝化作用 

分 类 号：S143[农业科学—肥料学]