Abstract:

In recent years, frequent soil degradation has severely constrained food security. Microalgae, as a novel soil conditioner, has demonstrated significant potential in enhancing degraded soil quality and sustainable agricultural productivity, becoming a current research hotspot. To investigate the research status and trends of microalgae-mediated soil improvement, 164 Chinese and 688 English papers were separately retrieved from China National Knowledge Infrastructure (CNKI) and Web of Science core collection (WOS). Bibliometric approaches combined with CiteSpace software were used for systematic analysis of domestic and international publications. Results indicate that annual publication volume has risen overall since 2001. China and India hold prominent research positions, accounting for 32.85% of total WOS publications; among these, the Chinese Academy of Sciences leads globally in both publication volume and influence. Domestically, research efforts are primarily concentrated in the Northwest and North China regions. Chlorella vulgaris is the most studied core microalgae species in both Chinese and English literature, with Chinese studies emphasizing practical agricultural applications while English literature covers both fundamental research and macro-level ecological-economic topics. Chronologically, early CNKI literature (2001-2014) examined microalgae-soil interactions, while the mid-period (2015-2019) emphasized algal fertilizer development, soil conditioning, and pollution remediation. Recent research (2020-present) focuses on precision improvement of specific soils and key production indicators. WOS literature evolved from ecological remediation (2010-2017) to system optimization research integrating circular economy concepts (2018-present). Looking ahead, efforts should focus on four key areas: integrating the deepening of micro-level mechanisms with the expansion of macro-level applications; shifting from single-purpose soil improvement to “multifunctional synergy”; achieving breakthroughs in key technologies that reduce costs and enhance efficiency; and advancing research through cross-disciplinary integration. This research provides a theoretical foundation for degraded soil remediation and green transformation of agriculture, while offering technical support for the global synergistic application of microalgae.

Key words: microalgae, soil improvement, bibliometrics, CiteSpace, knowledge graph