Soil Vapor Heat, Solute-coupled Transport Numerical Simulation Study

An experiment of one-dimensional vertical water infiltration with a surface water layer about 1cm is carried out, from the results of which, it is found that soil density has a role effect on soil water infiltration. Distance of water infiltration decreases with the increase of soil density, but the degree of the decrease will decrease. Averaged water infiltration rate of sandy soil is greater as compared with Lou Soil. Effect of temperature is less than density. Averaged water infiltration rates increase while temperature increases for both sandy soil and Lou Soil. The increase of temperature is benefit for water infiltration into soil body. The effect of temperature on water infiltration of Lou Soil seems more important at common temperature range. Yet the distance of infiltration of sandy soil is longer and longer as temperature increases, but the degree will be less. Saturated conductivity increases with an increase of organic matter while organic matter content is less than 15%, and will decrease with the increase of organic matter when organic matter content is more the 15%. The relationship between saturated conductivity and organic matter content can be fit with a parabolic curve. Soil diffusivity decreases as organic matter content increases at a given water content, and increases as water content increases at a given organic matter content. This relationship can be demonstrated with an exponential function of two variations.The thermal conductivity of soil under a given set of conditions is most important as if relates to soil microclimate. The early growth and development of a crop may be determined to a large extent by microclimate. The effect of bulk density, moisture content, solute concentration, and organic matter on soil thermal conductivity of four types sandy soil, Lou-Soil, warping soil, yellow cinnamon soil, was investigated through laboratory studies. Thermal conductivity was determined using a single probe method. Two types of salts are NaCl and CaCb- The results show that thermal conductivity increased with increasing soil density and moisture content. Thermal conductivity ranges form 0.58 to 1.96 Wm-1K-1 for sandy soil, from 0.19 to 1.13 Wm-1K-1 for yellow cinnamon soil, from 0.27 to 0.77 Wm-1K-1 for warping soil, from 0.36 to 0.68 Wm-1K-1 for Lou Soil ad densities from 1.25 to 1.55 gem-3 and water contents from 1.4% to 25%. The results also show that an increase in the amount of added salts at given moisture content decreases soil thermal conductivity. Increase of organic matter content may also decrease thermal conductivity. And it was found that sandy soil had higher values of thermal conductivity than Lou Soil for the same salt type and concentrations.The result of the absorption of phosphate and the transport of Ca2+, K+, Cl-, Br- showsthat the absorptive amount of phosphate under high temperature is greater than that under low temperature for both Lou Soil and sandy soil, and that the absorptive amount increases as time lapses, but the accumulative rate will decrease as time passes away, and finally converges zero. And the absorptive amount of phosphate for Lou Soil is greater that that for sandy soil under the same temperature. The amount of phosphate absorption for both Lou soil and sandy soil will decrease after CaCOs removed. Equilibrium time of phosphate absorption is about five to six hours. The fitting equations for both general absorption equilibrium and absorption dynamics are both striking. Anion is easier to infiltrate soil column than cation. Infiltration time of Br" is about two relative time for Lou soil, but it is only 1.6 relative time for sandy soil. Accordingly infiltration time of K+ is about ten relative time for Lou Soil and about five relative time for sandy soil.Building an integrated model for soil water, vapor, heat and solute transport simulating. And the equations of the model are numerically solved using Galerkin finite element method. The flow equations consider the effect of soil temperature, solute, and sink terms on the transport of water...