地膜覆盖影响棕壤离子平衡规律的研究

本文研究结果表明，覆膜可促使离子从土体下层向表层迁移，并在表层积累，表层积累的离子近１／２来自４０ｃｍ以下土层，随着覆膜年限增长，离子在表层的积累量增加，施肥对离子的平衡有一定影响，但规律不明显，覆膜处理离子的表聚现象是由于覆膜改变了土壤水的运动规律，不同种类的离子在土体中的迁移和平衡规律有一定差异。其中Ｃａ＾２＋，Ｍｇ＾２＋，ＳＯ＾２－４和Ｃｌ＾－以下土层，尽管多数离子都有表聚现象，但Ｋ＾＋在一

Effect of Plastic Film Mulching on Ion Balance in Brown Earth

The research results showed that ion were accumulated in the toplayer of soil coveredwith plastic film, and the amount of accumulation increased as the years of covering plasticfilm added.The accumulation of different ions in toplaper was asulted from mere watermoving from sublayers to toplayer in the covered soil. Although the patterns of ions'movementand balance were different ions Ca2 , Mg ,SO_4 and Cl had the verysimilar Pattern. More Na moved from over 40cm depth soil to topsoil in the coveredtreatments, but K was not found to be accumulated in toplayer. It also found that ionbalance was affected by the application of rertilzers and manurs.