Analysis of the comprehensive utilization of rice straw and its potential in carbon sequestration and emission reduction based on bibliometrics

In order to systematically and objectively assess the research status and development trends on the utilization of rice straw, and provide a reference for the efficient utilization of rice straw in China, the literature research was conducted in this field from 1995 to 2024 based on the core database of Web of Science using the Citespace. The number of annual published literatures, the main published countries, research institutions, keyword co-occurrence network, and keyword clustering were visually analysed. On this basis, the current status, key common technologies, and the carbon sequestration and emission reduction potential of rice straw utilization in China were systematically summarized, and future research trends and priorities were also proposed. The annual publications had showed a continuous upward trend in the field of global rice straw utilization, and the number of publications showed an exponential growth trend after 2008, indicating that this research field had received extensive attention world widely. As a major rice producer in the world, China had a strong scientific research force and strong influence in this research field, with the highest citation frequency and H-index index of publications. Domestic research institutions such as the Chinese Academy of Sciences and the Chinese Academy of Agricultural Sciences had close cooperation relationships with domestic and foreign institutions. In the past 30 years, the impact of rice straw utilization on rice growth and yield, soil carbon and nitrogen nutrients, and greenhouse gas emissions were the research hotspots in this field. The accumulation, biological properties, and toxicity of heavy metals (such as arsenic, cadmium, lead, etc.) in soil by rice straw returning or rice straw biochar returning was also a hot topic. In addition, the anaerobic fermentation and biogas production during the pretreatment process of rice straw had gradually increased attentions. Recently, the greenhouse gas emissions and global warming potential after rice straw utilization were the major research focus. Based on China's national conditions, this study conducted an in-depth analysis of the current status and key common technologies of the comprehensive utilization pattern of rice straw characterized by “agricultural application as the priority and simultaneous development of five utilization pathways” (fertilization, feedification, fuelification, substrate application, and raw material utilization). According to statistical analysis in 2016, the main utilization methods of rice straw were fertilization and fuel utilization, accounting for 69.0% and 14.7% respectively, following by the feed utilization, base material utilization, and fuel utilization, which accounted for 8.6%, 3.7%, and 4.0% respectively. Compared with direct incineration, the potential contribution of five material utilization to greenhouse gas emission reduction and carbon sequestration were greater. The carbon sequestration and emission reduction potential of different utilization methods were also evaluated. The research proposed that future efforts should focus on expanding diversified carbon sequestration and emission reduction technologies, innovating high-value and large-scale utilization pathways, and establishing intelligent monitoring, traceability, and decision-making systems. These initiatives would advance research on the high-value and intelligent utilization of rice straw through interdisciplinary approaches. This study provided critical decision-making references for promoting the recycling of straw resources, facilitating green and low-carbon transformation in agriculture, and supporting the achievement of national carbon peak and carbon neutrality goals.