Vermicompost Improves Physicochemical Properties of Growing Medium and Promotes Plant Growth: a Meta-analysis

The use of vermicompost (VC) in growing medium can potentially promote plant growth and provide a way to reuse biowaste. Although VC has widely been studied recently in the production of growing medium, a quantitative assessment of the effects of VC on the physicochemical properties of the growing medium and plant growth is lacking. Therefore, we conducted a meta-analysis to synthetically evaluate the effects of VC on the physicochemical properties of growing medium and plant growth. We observed that VC significantly increased the nutrient content of the growing medium; in particular, it increased the contents of available nitrogen and phosphorus by 133.8% and 256.7%, respectively. Furthermore, VC significantly improved the water-holding porosity of the growing medium by 25.3% but slightly reduced total pore space by 2.6%. Moreover, during plant growth, VC increased seed germination rate, seedling index, shoot biomass, root biomass, and total biomass on an average by 30.4%, 57.8%, 52.6%, 58.3%, and 54.4%, respectively. Comprehensively, we also observed that cattle manure-VC was the most promising material for the production of growing medium and that the optimum proportion of VC for plant growth in growing medium was 40-60%. These results are therefore proposed to provide a reference for the regulation of the physicochemical properties of growing medium, including the selection of waste materials and the VC proportion during the production of growing medium. Similarly, the positive effects of VC on plant growth will provide more possibilities for reducing fertilizer input and cycling waste.

Automated summary

The use of vermicompost in growing medium can improve the physicochemical properties of the medium and promote plant growth. This study provides quantitative evidence of the positive effects of vermicompost on nutrient content, water-holding porosity, and plant growth parameters.