不同土类中外源镉对烤烟生长及土壤生物指标的影响

Effects of Exogenous Cadmium in Different Soil Type on Flue-cured Tobacco Biomass and Soil Biota Indexes

采用盆栽土培的方法,研究了不同土壤类型外源添加不同浓度的镉(Cd,0,1.5,3.0,6.0 mg/kg)对烤烟生长发育以及烤烟根际土壤微生物量(细菌、真菌、放线菌)及酶活性(脲酶、转化酶、酸性磷酸酶)的影响。结果表明:在试验的范围内,外源Cd对烤烟生长和土壤微生物数量及酶活性的影响程度与土壤类型及添加Cd浓度有关。随着添加Cd浓度增加,烤烟的生长受到抑制,在添加Cd浓度为6.0 mg/kg时,各部位的干物质降低最多,特别是红壤中烤烟根系受抑制更明显。土类和添加Cd浓度对微生物数量的影响顺序为放线菌>真菌>细菌。土类对酶活性的影响顺序为脲酶>转化酶>酸性磷酸酶,添加Cd浓度对酶活性的影响顺序为酸性磷酸酶>转化酶>脲酶。

Pot experiment was conducted to study the effect of exogenous cadmium on flue-cured tobacco biomass and soil biota indexes in different soil. The results showed that there was significantly relation between the dose of exogenous cadmium and tobacco biomass,microbe quantity and enzyme activity in rhizosphere soil. With the in- creasing of cadmium,the growth of tobacco was suppressed more seriously, and under the treatment of 6.0 mg/kg Cd,the dry weight was least, the inhibition of Cd was more seriously in red soil, especially. Moreover, it was found that inhibition of cadmium on quantity was in the order of actinomycete 〉 fungi 〉 bacteria, the effect on enzyme activity was in the order of urease 〉 invertase 〉 acid phosphatase,the effect on enzyme activity was in the order of acid phosphatase 〉 invertase 〉 urease.