斥水土壤中的水热运动规律与数值模型

斥水土壤很难被雨水湿润，影响种子发芽出苗而造成农业减产。由于地表干燥而引起风蚀水蚀，造成土地退化。这一问题在澳大利亚、荷兰、新西兰与美国引起重视。斥水土壤中水分分布往往是无规律的“指状”，到目前为止，没有成功的数学模型。作者从研究斥水土壤地区的耕作工程实践出发，采用沟种之后，水分的分布就有了规律性。开沟播种时，耕作机械把表层斥水性特别强的土壤推到垄上而形成几乎不透水的垄，下雨时雨水只能从沟中渗入形

MODELING HEAT AND WATER MOVEMENT IN A WATERREPELLENT SANDY SOIL

Water-repellent soils are difficult to wet and cause crop production losses and land erosion by wind and runoff. Research programs on soil water repellency have been conducted in Australia, the Netherlands, New Zealand and America for many years. Because wetting patterns in water-repellent soils are quite irregular and incomplete, there has been no successful model for heat and water movement in water-repellent soils. Based on our tillage research work in water-repellent soils in Western Australia, the water movement in furrow sown water-repellent sandy soils is quite regular. As making furrows, the extremely water-repellent surface soils are moved to form the ridges with dry cores. This leads to rainfall runoff from the ridge and infiltration into furrow. Furrow tillage not only increased the gemination, but also make it possible to develop a model. A numerical model of heat and water movement in furrow sown water-repellent sand was developed and validated by the authors in Western Australia in 1991.