Effects of water-soluble chitosan on Hylotelephium spectabile and soybean growth, as well as Cd uptake and phytoextraction efficiency in a co-planting cultivation system.

ABSTRACT

Intercropping a Cd-accumulator with economically valuable crops is common in slightly or moderately Cd-polluted farmland soils. A field experiment was conducted to evaluate the effects of water-soluble chitosan (WSC) on the growth and Cd uptake of the Cd-accumulator Hylotelephium spectabile and soybean (Glycine max) during a co-cultivation in Cd-contaminated agricultural soil (WSC, 0 and 10 g·m-2). The results indicated that soybean yields were highest in response to the intercropping and WSC treatment. The results from the field trials generally showed that intercropping and WSC treatments significantly decreased Cd concentrations in inedible parts of soybean by 42.9-72.1% (except for stems), in the meantime, increased 95.8%-334.6% in shoot and root tissues of H. spectabile compared with the control (p < 0.05). The data revealed that Cd uptake was highest for H. spectabile during the intercropping and WSC treatment. The application of WSC in the intercropping system significantly increased the uptake of Cd by H. spectabile, but not by soybean. The findings of this study suggest that combining an intercropping system with a WSC treatment may be better for remediating Cd-contaminated soils than other methods involving the growth of a single hyperaccumulator.

This paper clearly focused on the accumulation and uptake of Cd in the system of intercropping of Cd-accumulator (Hylotelephium spectable) and soybean (Glycine max) grown in Cd-polluted farmland soils supplied with water-soluble chitosan (WSC) under field conditions. Some studies mainly focused on active agent to promote remediation efficiency of (hyper) accumulators. This study indicated that combining the intercropping system with WSC may be better for remediating Cd-contaminated soils than the methods involving a single hyperaccumulator.