Recently, 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) unveiled the microbial mechanism behind the reduction of nitrous oxide emissions in maize fields by green manure combined with zeolite. The related findings were published under the title "Green manuring combined with zeolite reduced nitrous oxide emissions in maize field by targeting microbial nitrogen transformations" in the international journal "Science of the Total Environment."

The cultivation and utilization of green manure can reduce the application of chemical nitrogen fertilizers, demonstrating a certain potential for reducing nitrous oxide emissions. Zeolite's adsorption of ammonium nitrogen reduces the substrate for nitrification process, thereby decreasing soil nitrous oxide emissions. Exploring the significance of green manure combined with zeolite in reducing nitrous oxide emissions for soil fertility improvement and carbon sequestration is of great importance.

This study, utilizing field positioning experiments and cultivation trials, along with isotope labeling and metagenomic sequencing, investigated the mechanisms by which green manure combined with zeolite reduces nitrous oxide emissions in maize intercropping systems. The results showed that under conditions where green manure was combined with a 30% reduction in nitrogen fertilizer application, zeolite significantly reduced the emission coefficient of chemical nitrogen fertilizers. Green manure reduced the relative abundance of ammonia-oxidizing microbes, weakening nitrification and reducing nitrous oxide production. Zeolite decreased the relative abundance of denitrifying microbes, increasing the proportion of nitrous oxide converted to nitrogen gas, thus reducing nitrous oxide emissions. This study provides theoretical and technical support for utilizing green manure combined with zeolite to reduce nitrous oxide emissions in maize intercropping systems in the northwest region of China.

Dr. Liu Rui from Gansu Agricultural University is the first author of the paper, with Researcher Cao Weidong and Professor Chai Qiang from Gansu Agricultural University as the corresponding authors. The research was supported by the National Key Laboratory for Efficient Utilization of Northern Arid and Semi-Arid Cropland, the 14th Five-Year National Key Research and Development Program (2021YFD1700200), the National Natural Science Foundation of China (32072678, 32202609), and the National Green Manure Industry Technology System (CARS-22).

Original Article Link: https://doi.org/10.1016/j.scitotenv.2024.175382