Combined application of low-accumulation crops and amendments on remediation of Cd -contaminated soils

Abstract

A total of 51 studies were screened and obtained from databases including China National Knowledge Infrastructure (CNKI) and Web of Science (Thomson Reuters, NY, USA), which focused on effects of the combination of low Cd accumulating crops and amendment on Cd-contaminated soils. Both the available Cd content in soil and the Cd target rate of crop edible parts were investigated from three aspects, namely, the types of soil Cd contamination risk, soil remediation method, and types of amendment. All of the statistical analysis and figures were conducted and prepared using IBM SPSS Statistics 22.0 and Origin 2018 software, to obtain the changes of four indicators including the drop of available Cd content in soil, the drop of Cd content of crop edible parts, growth rate of crop yield and target rate of crop edible parts. Results showed that, the Cd content of agricultural products from low-Cd risk soil can meet the standard of ‘GB 2762-2017 national standards for food safety, limits of contaminants in food’ by planting low Cd accumulating crops alone. For medium-Cd risk soil, the remediation effect (96%) of combined treatment with low-accumulation crops and amendments was obviously better than that of low-accumulation crops alone (18%), and the organic-inorganic compound amendments showed the best comprehensive remediation effectiveness. The Cd target rate of crop edible part from high risk soil can be improved by combination of low accumulating crops and amendment (∼17%), however, the land use risk is too high that its use needs to be strictly controlled. This study can provide theoretical basis for the safe utilization and engineering remediation of Cd contaminated soil.