In situ immobilization of Cd-polluted paddy soil and improvement of soil quality by combined ameliorants
The goal of the study was to assess the impact of combined ameliorants on Cd immobilization and soil environmental quality.A three-year field experiment was carried out in Anhui Province to investigate the effects of combined ameliorants on Cd uptake by rice,soil properties,enzyme activities,microbial community and function in a Cd-polluted paddy soil.The combined ameliorants(BS means 1%biochar+0.2%silicon fertilizer,BL means 1%biochar+0.2%lime)significantly reduced the concentrations of DTPA extractable Cd by 29.4%-40.1%.Similarly,combined ameliorants reduced Cd content in rice grains by more than 60%without reducing yields,and the immobilization efficiencies were higher than with 2%biochar treatment.The application of combined ameliorants also increased soil pH(0.77-1.25 units),organic matter(13.5%-52.0%),and cation exchange capacity(8.4%-38.5%),which effectively improved the soil environmental quality.In addition,the urease,phosphatase and FDA hydrolase activities were improved by 31.3%,38.7%,and 33.1%with BS application,respectively.Furthermore,such amendments significantly altered the soil microbial structure by changing soil properties(pH,CEC,DTPA extractable Cd,etc.),but had no effect on microbial diversity,reflecting the stability of the soil microbial community's ecosystem.Furthermore,microbial function prediction showed a significant increase in the abundance of gene clusters such as carbon metabolism following BS treatment,resulting in reduced heavy metals toxicity and increased soil microbial activity.Thus,combined ameliorants(particularly BS)can effectively immobilize Cd-polluted paddy soil,improving both soil environmental quality and ecological function.
combined ameliorantsCd-polluted paddy soillong-term stability of in situ immobilizationmicrobial communitysoil environmental quality
万方数据
维普
