丹江口库区石渣土土壤水分有效性研究

土壤水分有效性的高低是制约石渣土生产能力的关键因素之一。对丹江口库区郧县石渣土 3种不同土石比土壤水分有效性的研究表明 :土壤水分有效性与土壤中的土 (<2 mm)石 (>2 mm)比关系密切。土壤蒸发、持水、导水和供水能力均与土壤中的土石比的大小有关。 3种土壤的持水能力 ,以石砾含量较少、质地较粘的土壤最强 ,以石砾含量较多、质地为壤质的土壤最低。而土壤水分蒸发能力与砾石含量呈负相关 ,土壤水分扩散率则与砾石含量呈正相关。适中土石比的土壤可提高入渗性能 ,减少蒸发量 ,提高供水性能。

Study on Soil Water Availability of Lithosol in Danjiangkou Reservoir Basin

Soil water availability is one of the key factors on the productivity of lithosols. The study results showed that the soil water availability has a closely relationship with the ratio of soil(fine earth <2 mm) and gravel (grain more than 2 mm). The abilities of soil vaporization, water retention, water conductivity and water supply are associated with the ratio of soil and gravel. Among the studied three types of soils with different ratio of soil and gravel, the soil with the lowest ratio of soil and gravel had highest water retention ability, while the soil with higher ratio of soil and gravel had lowest one. There was a positive relationship between soil water diffusivity and gravel capacity, but a negative relationship between soil vaporization and gravel capacity. A mezzo soil gravel ratio has a benefit on increasing water infiltration, soil water supply, and reducing soil water vaporization.