Effects of a single biochar application in a water-stressed maize cultivation

Biochar amendment improves crop yield and mitigates climate change, but the lasting effect of biochar application on crop and soil properties under water scarcity conditions in tropical soils remains unexplored. We examined how a one-time biochar application alone and co-applied with vermicompost, with application rates of 25 and 50 ton ha⁻¹, affected the growth of Zea mays L. and the related physicochemical and hydraulic properties of a clay soil after three years. Analyses included pH, electrical conductivity, the availability of cations and phosphorous, carbon to nitrogen ratio, soil water characteristics, crop growth and biomass. The results showed that 50 ton ha⁻¹ of biochar co-applied with vermicompost produced more beneficial effects on the maize crop than 25 ton ha⁻¹ biochar, in the first cycle and to a lesser extent in the third cropping season, caused mainly by the availability of phosphorous and potassium, and the enhancement of bulk density, porosity, and moisture retention. Our results suggest that a one-time application of biochar combined with vermicompost enhances maize growth under limited water conditions. However, further research is necessary to understand the long-term effect of biochar on the soil structure of clay soils, crucial for effectively managing crops in water-scarce conditions.