Application of Karanja-derived biochar on the growth of Tomato plant and its agronomic characteristics affecting soil properties

A 37-day pot experiment in Tarnaka, Hyderabad, evaluated the impact of Karanja derived biochar and NPK (19:19:19) fertiliser on soil properties and tomato plant growth. Biochar was produced at 500°C and applied at 7 g/kg soil, while NPK was added at 0.3 g/kg soil. Four treatments were tested: soil alone, soil with biochar, soil with NPK, and soil with both biochar and NPK. Each pot contained 1 kg of soil. Results showed that the combined biochar and NPK treatment significantly enhanced plant growth, producing the tallest plants (32 cm), with six plants yielding 21.45 g of wet biomass. This treatment recorded highest potassium content in plant tissues (498.08ppm), while NPK alone led to maximum available nitrogen content in the soil (179.4kg/ha).Biochar amended soils showed improved carbon content (0.57%), and all treatments increased soil pH by 5.5–7.0 and electrical conductivity. The cation exchange capacity of soil rose from 17.08 to 21.54 meq/100g with NPK application. Biochar addition enhanced soil structure, enhances water retention, and minimised nutrient leaching. The combination of biochar and NPK proved most effective, synergistically improving soil fertility, nutrient availability, and tomato growth. Overall, biochar, particularly when used with fertilisers, supports sustainable soil management and crop productivity.