设施栽培对土壤结构及水分特性的影响

在测定土壤水分特征曲线和土壤结构的基础上,就设施栽培对土壤水分特性及结构的影响进行了研究。结果表明:设施栽培后土壤水分特征曲线均低于同层露地土壤,土壤持水性降低;设施土壤与露地土壤水吸力与土壤含水量之间均存在显著的幂函数关系,具有良好的拟合性。设施栽培后0～40cm土层土壤总孔度和毛管孔度均有所增加,土壤田间持水量、有效水含量等水分常数显著提高,有利于改善耕层土壤结构。设施土壤和露地土壤供水性随土壤吸力增加呈递减变化趋势,上层土壤供水性优于下层土壤,两种土壤比水容量均在0.06MPa时达到10-2数量级,土壤吸力小于0.06MPa时设施土壤0～20cm土层对作物有效水的供给能力强于露地土壤。

Effects of Protected Cultivation on Soil Structure and Soil Water Characteristics

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.