植物根际土壤中铅形态与土壤酶活性的关系

The relationship between heavy metal forms and soil enzymatic activities in rhizosphere of different plants

采用根袋法进行盆栽试验,研究了黄壤中添加不同浓度的铅后,外源铅总量对4种土壤酶(脲酶、过氧化氢酶、中性磷酸酶、淀粉酶)活性的影响,以及黄壤中不同植物根际土壤中铅的化学形态特征及其与土壤酶活性的关系,结果表明,在0～3000mg·kg-1的铅浓度下,淀粉酶活性被抑制;过氧化氢酶活性总体趋势上被激活,在0～1000mg ·kg-1的铅浓度范围内,脲酶、中性磷酸酶活性被激活,大于1000mg·kg-1的铅浓度抑制其活性;用Pb的化学形态研究重金属对土壤酶活性的影响明显好于总量铅,碳酸盐结合态和铁锰氧化物结合态铅对淀粉酶活性有显著抑制作用,呈显著负相关(R=-0.998),因此可以把碳酸盐结合态和铁锰氧化物结合态铅与淀粉酶活性总体共同作用作为评价黄壤铅污染程度的主要生物学指标.

Rhizobox method was used to study the relationships between the total quantity of lead and four soil enzymatic activities(urase,catalase,amylase,neutral phosphatase)in yellow soil.The result showed that amylase activities are inhibited in 0-3000mg·kg~ -1Pb.Between 0-1000mg·kg~ -1 Pb,urase and neutral phosphatase are stimulated.The more successive extraction method was adopted to study the characteristics of chemical forms of lead and the soil enzymatic activitces,the result showed that the most contributions to inhibiting effect of soil enzymatic activities,especially to amylase activities in polluted soils(R=-0.998) were the carbonate combined and Fe-Mn oxide combined Pb.In yellow soils,it was feasible to use the carbonate combined and Fe-Mn oxide combined Pb and amylase activities as primary biochemical index to evaluate Pb polluted soils.