中国主要土壤溶质运移阻滞因子土壤传输函数及其应用

Too much chemicals used in intensive agriculture and the polluted water and municipal waste released by industries are accounted for soil and environment degradation. Soil solute transport studies can uncover the fate of chemicals, the reaction between soil and solute, and the solute movement with water flows. Thus, Soil solute transport is essential to environmental protection. Our project is focused on the relationship between soil solute transport parameters and soil chemical-physical properties, to get pedo-transfer functions of soil solute transport parameters. The solution/soil ratio is defines as the ratio of soil solution volume to the mass of soil solid phase. The solution/soil ratio influences the solute distribution between soil solid and solution phase and the amount and types of soil pores, thus affect soil solute transport. For tested soils, the increase of the solution/soil ratio from 0.3672 to 0.7134, the retardation factor of ammonia transport decreased from 7.494 to 4.568. The mineral components and surface absorption properties are very different among different particles. The effective cation adsorption capacity of particles <0.1μm、<1μm、1~2μm、2~5μm，> 5μm are 0.5736、0.4638、0.2589、0.0798、0.0210 mol/kg, respectively. The adsorption amount of <2μm can account for 85% of the soil cation capacity. Soil clay content, soil bulk density, and soil water content affect potassium transport. The pedo-transfer function of potassium transport retardation factor was established as ： R = 1 + ρb (0.4135 + 6.6224 Clay)/ θ。Beside the soil texture, soil bulk density, and soil water content, soil solute transport are effected by temperature and displacement concentration. The retardation factors of potassium and ammonia decreased as displacement concentration and temperature increase. The relationship between retardation factor and temperature and displacement concentration can be expressed by R = a + b/co - k TR = a + b/co - k T. The characteristics of N, P , K transport in main soils in China are different. The solute peak for breakthough appears more quickly, but the total break though need more much time. At displacement concentration 0.05 mol/L, the relative time of P breakthough was 10 at least. Soil texture, soil minerals, soil organic content, free oxides, and free calcium carbonate can affect P transport greatly.

通过对我国各主要土类土壤理化性质的分析，及不同养分离子和重金属离子在各土壤剖面不同层次运移实验，明确供试离子在我国主要土壤剖面不同层次中运移阻滞因子的变化规律，建立我国主要土壤不同离子运移阻滞因子与土壤理化性质之间的溶质运移阻滞因子土壤传输函数（Ｒ－ＰＴＦｓ），初步建立描述溶质运移特征的土壤系统分类指标体系。