不同植被下复垦土壤腐殖质与Cd形态的关系

目的]揭示不同植被下土壤腐殖质与镉(Cd)形态的关系,为控制复垦土壤中Cd的活性提供理论依据。方法]选择淮南市大通区煤矸石充填复垦区3种典型植被恢复模式下(模式A丁香+刺槐、模式B石楠+小巢菜、模式C臭椿+小巢菜)人工恢复7a的土壤,用tessier五步提取法和腐殖质修改法测定其Cd的化学形态及腐殖质组分,运用多元统计分析方法探讨复垦土壤中腐殖质与Cd的有效态间的相互作用。结果](1)矿区复垦地C(臭椿+小巢菜)植被配置模式的土壤腐殖化程度较A,B模式高;(2)矿区复垦地C植被配置模式下Cd的可交换态含量显著低于其他2种配置模式;(3)矿区复垦区土壤中Cd的有效态与富里酸(FA)的含量显著正相关(p0.01)。结论]通过适宜的植被模式C(臭椿+小巢菜)调节复垦土壤腐殖质的组成和性质,可以进而控制土壤镉的潜在生物有效性。

Relationships Between Humus and Cadmium Speciation of Reclaimed Soil Under Various Vegetation

Objective] Clarifying the relationship between soil humus and Cd in different vegetation was supposed to provide a support for controlling cadmium activity in reclaimed soil.Methods] The 7-year soil at coal gangue reclamation area in Datong District, Huainan City, was taken as research samples. The contents of humus and cadmium chemical speciation in this region were measured under three typical plant restoration patterns (A Syzygium aromaticum+Robinia pseudoacacia, B Photinia serrulata+Vicia hirsuta, C Ailanthus altissima+V. hirsuta). The chemical morphology of Cd and humus components were determined by tessier five-step extraction method and modified humus analytical method, respectively, and the relationship was illustrated by multivariate statistical analysis.Results] (1) The humification degree of the C plant allocation pattern was higher than those of A and B in the reclamation area of the mining area; (2) The content of exchangeable Cd in the C plant allocation pattern of the reclaimed land was lower than those in the other two plant allocation patterns; (3) The positive correlation coefficient between available Cd and fulvic acid (FA) was significant in the reclamation area.Conclusion] Not only can the appropriate plant restoration pattern C adjust the properties and forms of humus in reclaimed soils, but also can affect the potential bioavailability of cadmium.