Efficacy evaluation of livestock-derived vermicompost in alleviating the adverse effects of drought stress on spinach growth and enhancing calcareous soil properties

Abstract

Improving drought tolerance is essential to achieve high crop yields. Vermicomposting is a sustainable approach to enhance soil health, fertility, and water use efficiency, leading to higher crop yields. This study was conducted to investigate whether livestock vermicompost (V0 (control), V1 (10 g kg−1 soil), V2 (20 g kg−1 soil), and V3 (30 g kg−1 soil)) can enhance the growth and chemical composition of spinach and influence the physicochemical properties of a calcareous soil under conditions of drought stress [D0 (100% field capacity (FC)), D1 (mild drought, 80% FC), and D2 (severe drought, 60% FC)]. The results showed that the V3 treatment was the most effective in increasing the fresh (23% and 22%) and dry (16% and 16%) weight of spinach under D1 and D2 conditions. Under the D2 condition, the V3 treatment exhibited the most pronounced increase in the concentration of nitrogen (N), phosphorus (P), iron (Fe), zinc (Zn), and copper (Cu) in spinach. These concentrations increased by 31%, 49%, 23%, 16%, and 74%, respectively. The significant increases in post-harvest soil nutrient concentration, nitrate (NO3) and P, as well as electrical conductivity (ECe), organic matter (OM), porosity, and geometric mean diameter (GMD), were observed following the application of V3 treatment. Meanwhile, pH and bulk density exhibited a notable decline. Our conclusions indicate that drought stress has a markedly detrimental effect on spinach growth and composition. However, soil-applied vermicompost has the potential to significantly mitigate the impact of drought stress by promoting enhanced soil health and increased plant nutrient availability.