田间持水量含水状态下土水势的研究

Studies on Soil Water potential on the Condition of Fied Capacity

本文通过在潮棕壤上进行的田间持水量占水状态下１０～７０ｃｍ各上层土壤上水势（吸力）的试验研究没现田间持水量相对应的土水势在同一土壤剖面的不同层次间有一定差异。在１０～７ｄｃｍ土层内灌水后２４ｈ的土壤水吸力测定值为３．３～５．６ｋＰａ；而在中等质地土壤上影响田间持水量上水势高低的因素，主要有土层深度、地温和地表覆盖物等．田间持水量应是充分灌水或降雨后土壤水运移相对稳定时的土壤含水量．

This paper mainly deals with soil moisture potential (or suciton )under the conditionof field water capacity in different layers (10--70cm) of meadow brown earth As the resultsshowed,there existed certain difference of soil water potential (or suction) in 10--70cm layers of meadow brown earth fully irrigated and the potentials or suction were 3.6--5.6kPa. Meanwhile,the influential factors of soil water potential in middle texture soil,such as loam,mainlyinvolved the measured depth,soil temperature and covering situation soil surface, etc..Fieldwater capacity should be the soil water content when the movement of water in soil fallyirrigated or rained became stabte.