Effects of intercropping on safe agricultural production and phytoremediation of heavy metal-contaminated soils

Intercropping with hyperaccumulators is believed to be an important and efficient way to achieve simultaneous safe agricultural production and phytoremediation of polluted soils. However, some studies have suggested that this tech-nique might facilitate the uptake of heavy metals by crops. To investigate the effects of intercropping on the heavy metal contents of plants and soil, data from 135 global studies were collected and analyzed by meta-analysis. The re-sults showed that intercropping could significantly reduce the contents of heavy metals in the main plants and soils. Plant species was the main factor that affected plant and soil metal contents in the intercropping system, and the heavy metal content could be significantly reduced when members of the Poaceae and Crassulaceae were used as main plants or when legumes were used as intercropped plants. Among all the intercropped plants, the best one for removing heavy metals from the soil was a Crassulaceae hyperaccumulator. These results not only highlight the main factors affecting intercropping systems but also provide reliable reference information for the practice of safe ag-ricultural production coupled with phytoremediation of heavy metal-contaminated farmland.

Automated summary

Intercropping with hyperaccumulators is an important and efficient method for safe agricultural production and phytoremediation. However, there have been concerns about the potential uptake of heavy metals by crops in this technique. A meta-analysis of 135 global studies showed that intercropping can significantly reduce the contents of heavy metals in plants and soils. The choice of plant species plays a crucial role, with Poaceae, Crassulaceae, and legumes being effective in reducing heavy metal content.