A new study by Chinese researchers has revealed the critical role of no-till corn straw return in preserving soil health in Northeast China's black soil regions. The study, published in Science of the Total Environment, highlights the importance of soil microbial activity in the decomposition and transformation of organic matter, contributing significantly to soil organic carbon (SOC) accumulation.

The research team from the Chinese Academy of Sciences' Institute of Applied Ecology (IAE) conducted experiments at the "Lishu Model" research base, Jilin Province.

The study found that deterministic assembly, whereby different bacterial phylogenetic functional groups compete for resources, can retard the accumulation of microbial necromass (the remains of dead microbial cells, including cell walls and other cellular components) in SOC. Conversely, diffusion-limited assembly can advance SOC accumulation. This is because diffusion-limited assembly tends to favor saprophytic fungi, which are beneficial for storing carbon in the soil.

In contrast to no-till without returning corn straw, the researchers found that returning the entire crop residue to the soil significantly reduced the contribution of microbial necromass to SOC accumulation. This was due to an increased soil carbon-to-nitrogen ratio, which favored bacteria capable of decomposing microbial cell walls.

The study found that the way soil microbes assemble can significantly impact how much organic matter is stored in the soil. The study's findings have important implications for sustainable agriculture. By adopting no-till corn straw return and other practices that promote healthy soil microbial communities, farmers can help to improve soil health, increase crop yields, and reduce greenhouse gas emissions.

The study, titled "Microbial necromass contribution to soil carbon storage via community assembly processes," was published in Science of the Total Environment.

YUE Qian

Institute of Applied Ecology, Chinese Academy of Sciences

Tel: 86-24-83970317

E-mail: yueqian@iae.ac.cn

Web: http://english.iae.cas.cn