Evaluating Biochar as a Potting Mixture Substitute: Impacts on Coffee Seedling Growth and Soil Properties

Abstract

Biochar is a carbon rich product derived from agricultural waste biomasses through pyrolysis widely reported to enhance the soil fertility. Coffee cherry husk, a by-product of the hulling process in coffee curing factories presents an opportunity for biochar production. While previous studies have explored biochar as a peat substitute in growth media, research on its role in nursery potting mixtures for coffee seedlings is lacking. This study aimed to evaluate the effects of biochar derived from cherry husk on the growth of coffee seedlings and soil properties. Biochar was produced using an electric biomass pyrolyzer at 500°C for one hour and incorporated into the nursery potting medium. The experiment included four treatments: T1 (jungle soil: farmyard manure: sand, control), T2 (biochar: farmyard manure: sand), T3 (jungle soil: biochar: sand), and T4 (jungle soil: farmyard manure: biochar). Results showed that seedling growth in T1 and T4 was statistically similar (CD-0.05%), while growth in T2 and T3 was comparatively lower. Substitution of biochar at the rate of 2% in the potting mixture was found to be optimal for the better growth of coffee seedlings. These findings suggest that biochar can serve as a viable alternative to sand in nursery potting mixtures, potentially improving soil properties and promoting sustainable seedling production.