Synergistic effects of integrating date palm biochar, compost, and compost tea: an agroecological approach to enhancing tomato growth and soil fertility

Abstract

This study investigated the synergistic effects of integrating date palm biochar, compost, and compost tea on soil fertility, microbial activity, and tomato ( Solanum lycopersicum “Roma”) growth under controlled conditions within an agroecological framework. Five treatments were evaluated: control soil, compost tea, date palm biochar combined with compost tea, compost combined with compost tea, and a combined application of date palm biochar, compost, and compost tea. Soil physicochemical properties, enzymatic activities, microbial populations, and plant growth parameters were assessed. The combined application of date palm biochar, compost, and compost tea resulted in the most pronounced improvements in soil properties, including a 51.9% increase in organic carbon, a 2.1% increase in total nitrogen, and enhanced cation exchange capacity. Soil enzymatic activities, including β-glucosidase, alkaline phosphatase, and urease, increased significantly, reflecting improved nutrient cycling, while microbial populations (bacteria, fungi, and actinomycetes) were also significantly enhanced. These improvements were associated with superior plant performance, as evidenced by higher leaf nitrogen (2.19%), phosphorus (0.53%), and potassium (4.64%) concentrations, increased plant height and stem diameter, greater biomass accumulation, and improved chlorophyll content. Overall, these findings highlight the potential of date palm biochar, compost, and compost tea as sustainable alternatives to conventional fertilizers and provide the first evidence of the synergistic effects of this specific triple-amendment strategy as an integrated agroecological practice for improving soil quality and tomato production. Further research is required to validate these results under field conditions across diverse agroecological systems.