Effects of rice hull and rice hull biochar on soil fertility and cadmium availability in cadmium contaminated soil
The effects of different materials on the physical and chemical properties,fertility,enzyme activity and available content of heavy metal cadmium(Cd)in Cd contaminated soil were studied by adding rice hull and rice hull biochar with equal carbon content to Cd contaminated soil.In this study,four treatment groups were set up,including soil not polluted by Cd(CK),soil polluted by Cd(CD),soil polluted by Cd with 2%biochar(BO),soil polluted by Cd with rice hull with equal carbon content(DK).The results showed that the total orgnic carbon content in the soil of BO and DK groups was 10.05%and 5.02%higher than that of CD group respectively,the dissolved organic carbon content of DK group was 43.90%higher than that of CD group on the 60th day,and the dissolved organic carbon content of BO group was 13.00%higher than that of CD group on the 90th day of culture;The content of alkali-hydrolyzed nitrogen in BO group was significantly lower than that in CD group,while that in DK group was significantly higher than that in CD group.Different treatment groups had different effects on the enzyme activity.On the 45th day,the urease activity of BO and DK groups was significantly higher than that of CD group,increased by 10.14%and 8.61%,respectively;The application of rice hull and rice hull biochar could significantly increase the activity of invertase in soil,but the activity in BO group was significantly lower than that in DK group.Different treatments had different effects on soil physical and chemical properties.DK and BO groups significantly increased the soil porosity,initial void ratio,and the proportion of sand and clay in soil.The experimental results of available forms of heavy metals in soil showed that the content of extractable forms of Cd acid in Cd contaminated soil in DK group decreased significantly.Compared with applying rice hull biochar,application of rice hull could improve soil fertility in a short time;Both biochar and rice hull could increase soil porosity and specific gravity,and increase the proportion of clay in soil;Both rice hull biochar and rice hull could alleviate the inhibition of Cd on enzyme activity;Compared with biochar,rice hull could significantly reduce the acid extracted Cd content in soil.
万方数据
维普
