重金属和生物有机肥对苹果根区土壤微生物的影响

Effect of Heavy Metal and Bio-Fertilizer on Microorganisms in Soil of Apple Root

通过土壤追施Cd ,Cu和生物有机肥,研究了重金属对红富士苹果根区微生物的危害以及生物有机肥减轻重金属对土壤微生物危害的效应。结果表明:施用生物有机肥后,果园根区土壤细菌、真菌和放线菌数量显著增加,细菌占绝对优势;土壤Cd浓度在10 30mg/kg范围内,随Cd浓度的增加,细菌数量大幅度减少;Cu元素对土壤微生物的危害情况与Cd相似,但程度比Cd轻;从生物有机肥中提取的有机质对Cd和Cu有明显的吸附作用,在pH值6～8的范围内,吸附率随pH升高而提高;在中性微酸的条件下(最适宜苹果栽培的土壤酸碱条件) ,有机质对Cu2 + 吸附率远高于对Cd2 + 的吸附率;生物有机肥明显减轻Cd ,Cu对土壤微生物的危害。

The harm of heavy metal on microorganism and the effect of bio-fertilizer on microorganism in polluted soil of apple root were studied. The results showed that the application of bio-fertilizer increased the amount of soil bacteria, jungi and actinomycete, especially for the bacteria. The amount of soil bacteria decreases sharp with the increase of Cd concentration from 10~30 mg/kg in soil. The effect of Cu is similar to Cd, but the degree of harm is less than Cd. Organic matter from bio-fertilizer can adsorb the dissociate cadmium and copper. The rate of adsorption increases with the increase of pH from 6 to 8. The rate of adsorption to copper is higher than cadmium under the condition of sourish soil. The bio-fertilizer can alleviate the damage of Cd and Cu to edaphons and that to Cu are more effective.