| In order to provide a theoretical reference for the remediation of soil heavy metal pollution by fungus chaff,
the effects of bacillary dysentery on the copper and chromium speciation in soils planting different crops in sewage irrigation
areas were investigated. A field experiment in the sewage irrigation area in Shanxi Province was carried out to study the
effects of fungus chaff application on chemical speciation of Cu and Cr in the soil with cultivation of corn, sorghum, and waxy
corn. Changes in the total contents and different chemical speciation of Cu and Cr in the soil were tested at the ripening stage
of the crops. The results were as follows: total contents of copper and chromium in the soil with fungous chaff application under the three crops showed a decreasing trend compared with those of non-application of fungous chaff. In the soil without
fungus chaff, the reduction rate ranged from 3.17% to 16.20% for Cu, and from 5.00% to 15.40% for Cr, respectively, but in
the soil with fungus chaff application, the reduction rate ranged from 6.17% to 18.60% for Cu, and from 8.94% to 20.60%
for Cr, respectively. The application of fungus chaff enhanced the reduction rate of Cu and Cr in carbonate-bound, organicbound
and residual forms. Except an increase of exchangeable Cu, all the other forms of Cu and Cr showed a decreasing
trend. Among the three crops, the reduction rate of various forms of Cu and Cr in the soil grown with corn was significantly
higher than that in the soil grown with the other two crops. And this is consistent with the reduction rate of total contents of
Cu and Cr in the soil. Except for the content of iron-manganese-oxide-bound Cu in the soil under maize, the treatments
of the other two crops with fungus chaff application were found to have higher reduction rates in various forms of Cu and Cr
than those without fungus chaff application. The results showed that the fungus chaff could promote the decrease of Cu and
Cr in forms of carbonate-bound, organic-bound and residual, and reduce the heavy metal content in soil speciation. |
