甘肃旱地土壤的持水能力与抗旱能力

对甘肃中部及陇东地区的几种旱地黄绵土、黑沪土及褐土等土壤的持水能力及抗旱能力进行了初步研究。几种土壤的田间持水量（３０ＫＰａ时的含水量）为１６０～２４０ｇｋｇ￣（－１），有效水含量在８８～１７９ｇｋｇ￣（－１）之间，据此得出几种土壤１ｍ土层中有效水贮量变动在１３５～２１６ｍｍ之间。通过对土壤基质持水能力及持水特征的比较分析，认为褐土、红土抗旱能力最差，而几种黄绵土的抗旱能力相当强。黄绵土结构状况差、坡度大造成降雨入侵慢、影响深层贮水是造成生产上干旱严重的原因。

Water-holding Capacity and Drougk Resistance of Dry-land Soil in Gansu

Water holding capacity and drought resistance of soils in Gansu province wasstudied primarily. The field capacity(moisture at suction 30 KPa)of soils were 160～240gkg￣(-1),the contents of available water varied from 88 to 179 gkg￣(-1).The plant-extractable wa-ter at the 1 m depth soils calculated on the basis of above data ranged from 135 to 216 mm.It was considered that the drought resistance of drab soil,Hong soil are the lowest and thatof several yellow mean soil are the highest or at least not worse than that of Heilu soils.