Transforming agriculture with vermicompost: 7-year empirical evidence from drought-prone and salinization-affected regions of Bangladesh

Global agricultural production has been affected by the increased frequency of climate extremes (e.g., droughts) in dry regions and heightened soil and water salinity in coastal regions. Exploration of sustainable agricultural practices is central to addressing the impacts of climate-induced shocks, restore soil fertility, and ensure food security. While there is growing evidence of crop losses due to increased drought and soil salinity, empirical evidence on nature-based solutions for increasing crop production through soil fertility recovery remains limited and poorly understood. Investigating the soil nutrients (nitrogen, phosphorus, potassium) and salinity from the 37 field experiments (22 treatments and 15 control plots in 11 villages) over 2017–2023, this study examined the effects of vermicompost on soil nutrients and salinity (electrical conductivity [EC]) in drought-prone and salinization-affected regions of Bangladesh. Results reveal that the application of vermicompost reduced soil salinity in salinization-affected region and enhanced soil nutrient contents in both regions over 7 years. In vermicompost-utilized experiments in the salinization-affected region, soil salinity (EC1:5) levels decreased from 5.56–7.65 dS m⁻¹ in 2017 to 4.93–5.89 dS m⁻¹ in 2023. Soil salinity and nutrient contents showed significant differences among the vermicompost-applied experiments, while no detectable changes in salinity and nutrient contents were found in the controlled experiments. None of the cropping patterns in salinization-affected region (brinjal-watermelon and potato-watermelon) and drought-prone region (brinjal-pointed gourd and brinjal-sesame) had significant effects on the observed changes in soil salinity and nutrient contents. These findings suggest that regardless of the crop combinations, vermicompost is a sustainable and versatile soil amendment, which can be effectively used in diverse agricultural systems and environments. The study provides empirical evidence to support policy decisions aimed at promoting sustainable agricultural practices and enhancing soil health using vermicompost. The findings inform strategies for reducing soil salinity and enhancing sustainable agriculture in comparable regions worldwide.