Biochar, Compost, and Organic Amendments in Tomato Soils: Impacts on Soil Properties and Crop Performance

The integration of biochar, compost, and other organic amendments in tomato (Solanum lycopersicum L.) cultivation addresses key challenges in modern intensive production systems, including soil degradation, nutrient depletion, reduced microbial diversity, and vulnerability to abiotic stresses such as drought and salinity. This comprehensive review synthesizes recent evidence demonstrating that biochar produced via pyrolysis of diverse feedstocks (rice husk, wheat straw, cow bone, poultry litter) fundamentally enhances soil physicochemical and biological properties. Key improvements include reduced bulk density, increased porosity and water retention, elevated cation exchange capacity (CEC), pH buffering in acidic soils, enhanced nutrient retention (nitrogen and phosphorus), and stimulated microbial biomass, enzyme activities (urease, phosphatase), and beneficial microbial communities (Pseudomonas, Bacteroidetes) that suppress soil-borne pathogens like bacterial wilt. When combined with composts (vermicompost, farmyard manure, poultry litter), these amendments exhibit synergistic effects, further boosting aggregate stability, nutrient cycling, and resilience to environmental stressors. In tomato crops, such strategies promote seedling vigor, vegetative growth, reproductive parameters (e.g., fruits per plant, fruit weight), and overall yield increases ranging from 13.7% to 33.2% (or higher in integrated systems), alongside improved fruit quality metrics such as total soluble solids, vitamin C, lycopene, firmness, and extended shelf life (notably via Ca/P-enriched cow bone biochar). These benefits are modulated by factors including biochar production conditions (feedstock, pyrolysis temperature), application rates (optimal often 10–20 t/ha or 1–2 kg/m²), soil texture/initial properties, and integration with inorganic fertilizers. Economic assessments indicate