滩涂围垦农田土壤饱和导水率的影响因素及转换函数研究  

Influencing factors and pedo-transfer functions of topsoil saturated hydraulic conductivity in the coastal farmlands of reclaimed tidal flats

作　　者：姚荣江[1,2] 杨劲松[1,2] 张同娟[2] 李芙荣[1] 王相平[1] 吴晓卫[3] 

机构地区：[1]土壤与农业可持续发展国家重点实验室/中国科学院南京土壤研究所,南京210008 [2]中国科学院南京分院东台滩涂研究院,东台224200 [3]东台市黄海原种场,东台224239

出　　处：《中国生态农业学报》2014年第7期790-797,共8页Chinese Journal of Eco-Agriculture

基　　金：国家自然科学基金项目(41101199;51109204);江苏省自然科学基金面上项目(BK2011423;BK2011883);公益性行业(农业)科研专项经费项目(200903001)资助

摘　　要：确定苏北沿海滩涂围垦农田耕层土壤饱和导水率的影响因素，构建适合该区的土壤转换函数，是研究该区田间土壤水盐运动和盐渍化防控的重要前提。本文在该区典型地块实测土壤饱和导水率和相关土壤基本理化性质，探讨了该区土壤饱和导水率的剖面分布特点，对影响饱和导水率的土壤基本性质进行了主成分分析，并建立了用于该区饱和导水率间接估算的土壤转换函数。结果表明：滩涂围垦农田土壤饱和导水率随剖面深度增加呈表土层高、亚表层低、底土层又升高的趋势，20～40cm土层饱和导水率最小，介于2．75～6．73cm·d^-1，属低透水强度；土壤容重随剖面深度增加表现出与饱和导水率相反的变化特点。除了容重、孔隙度、质地等物理因素外，土壤肥力、盐分等化学性质也是影响饱和导水率的重要因素；影响滩涂围垦农田土壤饱和导水率的因素可由持水特性、盐碱状况、养分特征和土壤质地4个主成分反映，其累计贡献率达78．17％。在Vereecken转换函数中引入土壤盐分后可提高预测精度，修正函数Vereecken1是最适合滩涂围垦农区土壤、具有最佳预测精度的转换函数。本文构建的土壤转换函数，可通过较易获得的砂粒、黏粒、容重、盐分和有机质对耕层土壤饱和导水率进行较高精度的预测，其结果可为滩涂盐渍化农区田间尺度土壤饱和导水率间接估算以及水盐运动数值模拟提供支持。Determining the factors that influence saturated hydraulic conductivity of topsoils and developing appropriate pedo-transfer functions are important prerequisites for modeling field soil water and salt movement and the amendment of soil salinization in salt-laden coastal farmlands. In order to achieve these goals, soil saturated hydraulic conductivity and a number of associated soil physico-chemical properties were measured in a typical salt-laden costal farmland. The characterization of saturated hydraulic conductivity of the soil profile was discussed and principal component analysis conducted on the soil basic properties with potential impacts on saturated hydraulic conductivity. The pedo-transfer functions suitable for indirect estimation of saturated hydraulic conductivity in the study area were established. Results indicated that soil saturated hydraulic conductivity generally exhibited a decreasing trend from surface soil to subsurface soil, and an increasing trend from subsurface soil to substratum of the soil profile. The 20-40 cm soil layer had the least saturated hydraulic conductivity, with a range of 2.75-6.73 cm.d^-1. It was classified as the lowest water permeability due to the presence of soil compaction and plowpan. The profile characterization of bulk density was generally contrary to that of saturated hydraulic conductivity, and this was not surprising as bulk density represented the total state of porosity which was closely related to soil permeability. Results of correlation analysis showed that the contents of sand particles and organic matter had significant positive correlation with saturated hydraulic conductivity. Also soil bulk density, soil salinity and sodium adsorption ratio （SAR） had adverse impacts on saturated hydraulic conductivity. In addition to soil physical attributes （such as bulk density, soil porosity and soil texture）, soil chemical factors （including fertility and salinity） also considerably influenced saturated hydraulic conductivity. The correlation between

关 键 词：滩涂 围垦农田 土壤饱和导水率 土壤理化性质 土壤转换函数 

分 类 号：S152.9[农业科学—土壤学]