As the global population continues to grow and the demand for food increases, the efficient use of limited phosphorus resources has become a focal point worldwide. The natural balance of soil phosphorus cycling is being severely disrupted by over-fertilization, particularly from inorganic fertilizers. However, limited research has been done on how fertilization affects organic acids secreted by plant roots and how these acids, in turn, influence bacteria harboring the pqqC and phoD genes—both of which are closely related to phosphorus solubilization in soil. A groundbreaking study has now revealed the complex effects of organic and inorganic fertilizers on soil phosphorus (P) cycling, providing new insights and sustainable strategies to address global phosphorus management challenges. Conducted by Yongguan Zhu's team of scientists from the Institute of Urban Environment, Chinese Academy of Sciences, the findings , published in Soil Ecology Letters , offer significant scientific evidence to support sustainable agricultural development.
Utilizing high-throughput sequencing and quantitative PCR, the study found that both organic and inorganic fertilizers significantly alter soil pH. This change is closely associated with variations in the levels of oxalic, gluconic, and succinic acids in the soil. These organic acids modify the composition of bacterial communities carrying the pqqC and phoD genes, thereby enhancing phosphorus solubilization. The research also revealed that while inorganic fertilizers increase phosphorus-solubilizing bacterial populations by raising soil pH, organic fertilizers boost these bacterial communities and maintain soil phosphorus content, directly supporting phosphorus utilization by plants.
Lead scientist Dr. Ding explained, "Our study provides a new perspective on how fertilization impacts soil microbial communities and phosphorus cycling. By optimizing fertilizer use, we can improve phosphorus availability in soils while reducing negative environmental impacts, thereby supporting sustainable agricultural practices."
The study further discovered that after the application of organic fertilizers, the levels of lactic acid and gluconic acid increased significantly. These organic acids not only indirectly affect the abundance of phosphorus-solubilizing bacteria by raising soil pH but also directly influence the availability of phosphorus in the soil. Additionally, the combined application of nitrogen (N) and potassium (K) with phosphorus fertilization further optimizes the interaction between microbes and plants, paving the way for more efficient phosphorus use in agriculture.
Dr. Zheng added, "Our findings suggest that integrating organic and inorganic fertilizers, along with other nutrients like nitrogen and potassium, can fine-tune microbial-plant interactions and enhance phosphorus use efficiency. This approach could revolutionize how we manage phosphorus in agricultural ecosystems."
DOI: 10.1007/s42832-025-0296-0
