Recently, the Qiyang Station of the Institute of the Institute of Agricultural Resources and Regional Planning (IARRP) in the Chinese Academy of Agricultural Sciences (CAAS) has made significant progress in determining the impact of nitrogen and potassium fertilizer application on greenhouse gas emissions in agricultural ecosystems. The findings were published with the title "Optimizing potassium and nitrogen fertilizer strategies to mitigate greenhouse gas emissions in global agroecosystems" in the journal "Science of the Total Environment" (IF = 9.8).

Potassium, as one of the three essential nutrients for plants, plays a crucial role in regulating crop yield and quality. However, research on its impact on greenhouse gas emissions is scarce. To fill research gap and determin the main factors affecting greenhouse gas emissions, our research team conducted an in-depth meta-analysis of 205 independent global experiments. The results showed that applying potassium fertilizer on the basis of nitrogen fertilizer significantly altered the cumulative soil greenhouse gas emissions. Specifically, nitrous oxide(N2O) and methane(CH4)  emissions increased significantly by 39.5% and 21.1% respectively, while carbon dioxide(CO2) emissions decreased significantly by 8.1%. Notably, field experiments showed that potassium fertilizer application reduced N2O emissions and increased CO2 emissions, but in the incubation experiments, the opposite result was observed. This indicated that the impact of potassium fertilizer on N2O emissions may be overestimated under incubation experiments, while its impact on CO2 emissions may be underestimated. Overall, the ratio of nitrogen and potassium fertilizer application rate is a key factor influencing N2O emissions, while the type of potassium fertilizer plays a crucial role in CH4 and CO2 emissions. These findings provide a foundational framework and practical guidance for optimizing fertilizer application in the development of GHG emission reduction models.

Ph.D student Li Jiwen from the IARRP and Ph.D Han Tianfu from the College of Agriculture at Zhengzhou University are the co-first authors, with professor Zhang Huimin as the corresponding author. This research was supported by the National Natural Science Foundation, the Jinggangshan Agricultural High-tech Zone Provincial Science and Technology Special Project, and the Innovation Project of the Chinese Academy of Agricultural Sciences.

Paper link: https://doi.org/10.1016/j.scitotenv.2024.170270