Research About Influence Of Heavy Metal On Soil Microbial Activity

Soil is one of important resource which we couldn't live without, and it also has important meaning to the quality of ecology environment and man's health. With the development of industry and up-date of agriculture, the pollution in soil becomes worse daily. The polluted by heavy metal in soil is a problem which all global people have to face. As one of heavy metal in soil, Cadmium is also this article's object. Under the test chamber condition, We studied what happened to the soil biological activity and the soil enzyme activity if we add the heavy metal cadmium pollution of different concentration to extraneous source. The result indicated that the heavy metal cadmium pollution has different effects on different soil biochemical processes, the lower concentration of cadmium was helpful to increase most of the biochemical processes, but the higher concentrations of cadmium greatly inhibited microbial activities. The cadmium pollution has some influences on the soil enzyme activity , and it has very remarkable inhibitory action to the soil urease activeness, but only has little influence on Oxidized hydrogen enzyme and phosphatase. We calculated the quantity of cadmium pollution soil microbe by notation, and the quantity reduced obviously. Tests of the soil breath intensity, the soil enzyme activity and the soil microbe determination have shown that it is feasible that urease activeness can be used as the evaluating indicator of soil Cd pollution and the critical content of Cd, as the enzyme urease in soil is very sensitive to Cd with different concentrations. It may provide the highest limiting value of the cadmium's concentration to the sewage irrigation areas, which guarantees crops there are safe to eat and soils there are sustainable .The study has the vital significance to the local economical development and the environmental safety.