Global research trends on microgreens: A bibliometric analysis and experimental validation using rice washing water

Abstract

Background: Limited access to land resources for cultivating nutritious vegetables in urban environments has driven the need for low-cost household-scale food production systems, with microgreen cultivation, referring to young seedlings harvested at the cotyledon stage, recognized as a rich source of micronutrients. A bibliometric mapping of the global microgreen literature revealed that research has predominantly concentrated on light-emitting diode (LED) cultivation, phytochemical and nutritional enhancement, and food safety, whereas the optimization of cultivation inputs based on household organic by-products, particularly kitchen waste such as rice washing water, remains an underexplored research area. Methods: Scopus-indexed articles were mapped using Bibliometrix and VOSviewer to identify publication trends, country productivity, and keyword co-occurrence. A controlled experiment compared plain water (A1) and rice washing water (A2) irrigation on plant height and fresh weight of mung bean (Vigna radiata L.) microgreens at 7 and 14 days after sowing (DAS), grown in cotton medium with three replications per treatment, analyzed using independent-samples t-tests and Wilcoxon rank-sum tests. Findings: The United States, India, and Italy led global output, with Italy showing the strongest collaboration network; Indonesia ranked tenth with comparatively low citation impact. No keyword themes related to rice washing water or household organic waste emerged in any visualization. Experimentally, rice washing water significantly increased plant height at 7 DAS (p = 0.021) but not at 14 DAS (p = 0.594), while plain water produced significantly higher fresh weight at both 7 DAS (p = 0.038) and 14 DAS (p = 0.017). Conclusion: Rice washing water stimulates early shoot elongation but does not enhance biomass accumulation under nutrient-free medium conditions, indicating its effectiveness depends on developmental stage and substrate characteristics. Novelty/Originality of this article: This study is among the first to combine bibliometric evidence with experimental validation of rice washing water as a zero-waste, household-scale nutrient input for microgreen production.