The Study Of Heavy Metals Impact On Manural Loessial Soil Phosphatase Activity

Soil is a special kind of soil strongly influenced by human activities, heavy metals pollution also has a certain buffer capacity, it is an object that is contaminated crops are also sources of pollution.In different areas, different types of heavy metals there are significant differences between different soil types, the performance of heavy metal pollution are not the same.Therefore, this paper selected manural loessial soil as the main object of study, to Xi'an, manural loessial soil represented.This article by adding heavy metals Pb, Cd, Cr, to simulate different concentrations of heavy metal pollution, study Chinese cabbage and soil phosphatase sensitivity of heavy metals, conclusions were as follows:1.The effects of different concentrations of Pb, manural loessial soil mainly by inhibition of phosphatase activity. With the increase of the concentration the inhibition increased. Without Pb the soil phosphatase activities reached 51 g/kg, when the concentration between 250-350 mg/ kg,it become the lowest 44.2 g/kg.Phosphatase activity can be used as heavy metal Pb contamination of the enzyme target.2.When the Cd concentration is smaller than 0.2 mg/kg, the soil phosphatase activity reduces unceasingly, During the period of concentration is 0.2-0.7 mg/kg, the phosphatase activity change fluctuation is greatly basic in 48 g/kg about; When the density is 0.4 mg/kg, the phosphatase is activated achieves 52 g/kg; But along with the raise time's extension, the enzyme activity has reduces the tendency, drops to 39.7-44.5 g/kg. Phosphatase activity can be used as heavy metal Cd contamination of the enzyme target.3.The Cr concentration between 80 to 110mg/kg, the activity is relatively high to 54 g/kg; and compared to Pb and Cd, phosphatase activity under the influence of Cr change in the most gentle, no significant inhibition or activation. Phosphatase activity can not be used as heavy metal Cr contamination of the enzyme target. 4. Under the Pb, Cd pollution, the phosphatase activity were 53.7,46.2,38.7 g / kg; 52.24,47.12,34.98 g / kg on the pollution level of 1,2,3;5. Under a single pollution,the order of Pb,Cd and Cr inhibitory effects soil phosphatase activity is Pb >Cd>Cr. With time, the more activity tends to stabilize; the order of cabbage growth was inhibited is Cr>Pb>Cd; soil phosphatase activity has little effect on the growth.