Study On Prevention And Control Of Arsenic Toxicity By Calcium, Magnesium And Iron

" 311 -A " optimum compound design was used to study on prevention and control of arsenic toxicity by calcium, magnesium and iron. The results were showed as follows:1 .CaCl₂ decreased the soil pH value and affected fractions of arsenic complexly in soil. CaCl₂ could reduce diffluent arsenic, iron arsenic and increase calcium arsenic, aluminium arsenic in soil. Calcium could reduce the arsenic content in pakchoi ( Brassica chinensis ) shoots. The growth of pakchoi could be promoted by being applied appropriate amount of calcium, but excessive amount of calcium application would decrease the growth of pakchoi and depress the yield of pakchoi.2.MgSO₄ decreased the soil pH value and affected fractions of arsenic complexly in soil. MgSO₄ could reduce diffluent arsenic, calcium arsenic, iron arsenic and increase aluminium arsenic in soil. Magnesium could reduce the arsenic content in pakchoi shoots. The growth of pakchoi could be promoted by being applied appropriate amount of magnesium, but excessive amount of magnesium application would decrease the growth of pakchoi and depress the yield of pakchoi.3.FeCl3 decreased the soil pH value and affected fractions of arsenic complexly in soil. FeCl3 could reduce diffluent arsenic, calcium arsenic and increase aluminium arsenic, iron arsenic in soil. Iron could reduce the arsenic content in pakchoi shoots. The growth of pakchoi could be promoted by being applied appropriate amount of iron, but excessive amount of iron application would decrease the growth of pakchoi and depress the yield of pakchoi.4.The content of total arsenic in pakchoi was positive significantly correlated with diffluent arsenic, and was negative significantly correlated with aluminium arsenic in soil. The correlation between the content of total arsenic in pakchoi and iron arsenic, calcium arsenic and residual arsenic in soil was not significant.5.In this study, appropriate amounts of CaCl2, MgSO4 and FeCl3 could decrease the uptake of arsenic of pakchoi in arsenic contaminated soil and increase the yield of pakchoi.