Effects Of Soil Amendment On Phosphorus Absorption And Desorption And Migration In Lou Soil

The effects of natural or chemo-synthesis amendments on improving soil structure, water capacity and permeability, and fertilizers availability have been paid more and more attention by researchers in soil science and environmental field. Some of amendments are widely used for desalination, afforesting desert, reducing soil erosion, increasing fertilizer efficiency and crop yield.In this paper, two kinds of soil amendments, Polyacrylamide(PAM) and Sodium carboxylmethylcellulose(CMC), were selected to added to Lou soil, and to investigated the effects of the amendments on phosphorus absorption and desorption in Lou soil and its different particle size aggragation. In addition to, phosphorus diffusion and migration in soil column and soil tray were also studied. The main results were concluded as follows:1.Mechanism of phosphorus absorption in Lou soil showed different with the concentration variation of added P, which demonstrated that with added P less than 20μgmL^-1, the P absorption was mainly by chemical retention, and more than 20μgmL^-1, mainly by physical absorption. Soil mixed with PAM, the amount of P absorption was less than contrast as added P concentration was more than 20μgmL^-1, demonstrating that PAM had the function to inhibit P physical adsorption in Lou soil, but had no inhibition to P chemical adsorption (smaller than 20μgmL^-1), and even increased the P chemical adsorption. Soil mixed with CMC at 0.1% and 0.2% ratio showed a tendency to reduce P absorption. Otherwise, the P absorption amounts by Soil mixed with CMC at 0.4% ratio was increased. The thermodynamic indexes showed that although maximum absorption amount of Phosphorus was decreased by soil with amendments, the adsorption affinity and maximum buffer capacity were increased.2.The distribution of different size aggregate showed that the macro-aggregates which was larger than 3mm were increased in soil amended with PAM or CMC, while the micro-aggregate less than 1mm were decreased. The trend of forming different size of aggregate is different for PAM and CMC. The former mainly increase medium size...