关键词: 设施土壤, 水分特征曲线, 持水性, 供水性

Abstract: Soil water characteristics under the condition of protected cultivation were analyzed by measuring soil water structure and soil water retention curves.The results showed that soil water retention curve in greenhouse soil was lower than that of the same level in the open-air soil, and soil water holding capability declined in greenhouse soil.There was a significant power function relationship between soil moisture and soil water suction.Soil total porosity and soil capillary porosity increased at 0~40 cm soil layer under the condition of protected cultivation, thus increasing soil water constant such as field capacity and available water content and so on.Protected cultivation would help to improve soil structure of the arable layer.Soil water supply in greenhouse soil and the open-air soil decreased progressively with soil suction increasing, and water supply capacity of the upper-layer soil was better than that of subsoil.The water capacity reached 10-2 level at soil suction of 0.06 MPa.The soil water was more available for plant uptaking at 0~20 cm layer to greenhouse soil than that of the open-air soil when soil suction was less than 0.06 MPa.

Key words: greenhouse soil, water retention curve, holding capability, water supply capacity