The Innovation Team of Fertilizer and Fertilization Technology of the Institute of Agricultural Resources and Regional Planning (IARRP) of the Chinese Academy of Agricultural Sciences (CAAS) found that co-incorporation of Chinese milk vetch, rice straw, and biochar can reduced Cd accumulation in rice. 

Research findings were published in "Science of the Total Environment".

Recently, heavy metal cadmium (Cd) pollution in farmland soil is one of the major environmental problems that threatens food security in China. IIn-situ passivation technology is an economical and practical strategy, among which biochar is widely used in soil Cd remediation due to its multiple advantages, such as good passivation effect, environmentally friendly  and low cost.

Co-incorporation of Chinese milk vetch andrice straw,  can improve soil productivity and increase crop yield. It is urgent to find a way to achieve pollution control as well as fertility improvement in China, for arable land resources are scarce.

Incubation  and field experiments were used to study the effect of co-incorporation of Chinese milk vetch, rice straw, and biochar on Cd uptake by brown rice. Results showed that co-incorporation of Chinese milk vetch, rice straw, and biochar promoted the conversion of soil exchangeable Cd to stable state by increasing soil pH, leading to reduce the bioavailability of soil Cd. Simultaneously, the concentration of iron-manganese plaque on the root surface of rice was increased which further inhibit and control the Cd uptake by rice, thereby reducing the Cd concentration of brown rice.

Liang Ting, a doctoral student at the IARRP, is the first author, and professor Cao Weidong is the corresponding author. This research was supported by the National Key Research and Development Program of China (2021YFD1700200), the earmarked fund for CARS-Green manure (CARS-22) and the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences.

Paper link: https://doi.org/10.1016/j.scitotenv.2022.158060