水土保持学报2018，Vol.32Issue(2)：58-66,9.DOI:10.13870/j.cnki.stbcxb.2018.02.009
土壤初始含水率对浑水膜孔灌肥液自由入渗水氮运移特性影响
Effects of Soil Initial Water Content on Transport Characteristics of Free Infiltration Water and Nitrogen Under Film Hole Irrigation with Muddy Water
摘要
Abstract
In order to explore the water and nitrogen transport characteristics under water and fertilizer integration of film hole irrigation with muddy water irrigation,through the indoor fertilizer infiltration test,the migration characteristics of infiltration wetting front migration,soil moisture,ammonium nitrogen and nitrate nitrogen were studied under different soil initial water content (6.02 ％,7.40 ％,8.23 ％,10.08％ and 13.20％).The relationship between cumulative infiltration volume,the wetting front migration distance and the soil initial water content of liquid fertilizer infiltration of film hole irrigation with muddy water were established.An empirical model was proposed to calculate the cumulative infiltration volume and the wetting front migration distance under different soil initial water content.Results showed that:The cumulative infiltration,the wetting front migration distance,the water transport in wetting body,the distribution and transformation of nitrogen were all affected by the soil initial water content.At the same infiltration time,the cumulative infiltration reduced,while the wetting front migration distance increased,with the increase of soil initial water content.The higher the soil initial water content was,the larger the wetting volume was,and the wider water,ammonium nitrogen and nitrate nitrogen in soil distributed.The higher the soil initial water content was,the smaller the value of infiltration parameter K was,and the larger the value of infiltration index α was.After irrigation,ammonium nitrogen was mostly distributed in the wetting body with humid radius which was less than or equal to the range of 5 cm.Meanwhile,ammonium nitrogen content decreased with the increase of soil depth in the wetting body when the wetted radius was larger than 5 cm and less than l0 cm.The ammonium nitrogen content obviously decreased when the humid radius was larger than 10 cm.Nitrate nitrogen was mainly distributed in the range from the center of the membrane pore to the wetting radius of 10 cm.The nitrate nitrogen content in the horizontal direction and the vertical direction decreased with increasing distance from the center of the film hole,the nearer was away from film hole center the higher nitrate nitrogen content was in both vertical and horizontal direction.The greater the initial soil water content was,the higher the mass fraction of ammonium nitrogen and nitrate nitrogen was at the same position.With the redistribution of soil moisture,the wetting front gradually went down,the wetting of ammonium nitrogen gradually downwardly migrated and its content decreased.Nitrate nitrogen concentration front transported with time prolongation,the soil nitrate nitrogen content decreased in the upper layer and gradually increased in the lower layer new wetting body,the content of nitrate nitrogen in wetting body tend to uniformly distribute.The research results could lay the foundation for further study on the transport and transformation of nitrogen fertilizer under the film hole irrigation with muddy water.关键词
浑水膜孔灌/土壤初始含水率/水分再分布/模型/氮素运移Key words
film hole irrigation with muddy water/soil initial water content/water redistribution/models/nitrogen migration分类
农业科技引用本文复制引用
陈琳,费良军,刘利华,王子路,钟韵..土壤初始含水率对浑水膜孔灌肥液自由入渗水氮运移特性影响[J].水土保持学报,2018,32(2):58-66,9.基金项目
国家自然科学基金项目(51479161,51779205) （51479161,51779205）
国家重点研发计划项目(2016YFC0400204) （2016YFC0400204）
陕西省教育厅项目(16JK1539) （16JK1539）
中国博士后基金项目(2015M582763XB) （2015M582763XB）
中央级公益性科研院所基本科研业务费专项(HKY-JBYW-2016-26) （HKY-JBYW-2016-26）
