Abstract:

The rational use of sewage sludge as a fertilizer substitute plays an important role in improving the physicochemical and biological properties of farmland soils. Clarifying the research and development trend of agricultural utilization of sewage sludge at home and abroad can provide a reference for realizing the resource utilization of domestic waste and improving farmland fertility. Based on the analysis of domestic and foreign published English literature on the agricultural utilization of sewage sludge during 1990-2025, this study analyzed the development history, hot spots and frontier differences between domestic and foreign research in this field by using literature co-citation, keyword co-occurrence and other bibliometric analysis methods. The results showed that: compared with developed countries such as European countries and the United States, although China published fewer articles in English in the late 1990s and early 21st century, China had become the country with the largest number of publications by 2025, accounting for 15% of the global total, with a betweenness centrality of 0.13. The number of papers published in the United States was slightly lower than that of China, but the betweenness centrality was the highest of 0.26. Among the world’s top 20 highly cited hot papers, 2 were from China. The Chinese Academy of Sciences ranked first in the world in terms of the number of papers published among research institutions. China, European countries and the United States and other developed countries had the greatest influence and played leading roles in this research field. Overall, research in this field both domestically and internationally focused on sewage sludge, soil, heavy metals, etc. Particularly from 2020 to 2025, the research focused in this field was mainly biased toward agriculture, composting, co-digestion, digestate and other technical means. In conclusion, China, European countries and the United States are in the forefront of the world in the field of farmland utilization of sewage sludge, the current domestic and foreign research mainly focus on sewage sludge treatment technology and its reasonable application in farmland. In the future research, attention should be paid to the safety and stability of new sewage sludge products in the field of farmland, with particular attention to the environmental risks posed by emerging contaminants such as microplastics in sewage sludge and its by-products. In addition, in-depth research on the mechanism of sewage sludge on soil microbial form and quantity can be conducted, as well as improving the nutrient recovery and utilization system of sewage sludge. While improving the quality of research papers, we should actively promote the combination of scientific research and production practice, build a development model of multi-disciplinary and multi-field cross-integration, and maximize the promotion of sustainable development of agriculture.

Key words: sewage sludge, agriculture, visual analysis, bibliometrics, CiteSpace