Optimizing Cocopeat–Rice Husk Biochar Substrate Ratios for Improving Nitrogen Uptake, Biomass Production and Flavonoid Content of Mint (Mentha spp.) under an Urban Farming Drip Irrigation System
Asri Jum’atul Aziza, Nanik Setyowati, Yulian Yulian, Widodo Widodo, Wuri Prameswari
Asian Journal of Agricultural and Horticultural Research
Urban Farm DB summary
This two-factor (variety × growing-medium composition) completely randomized experiment, conducted in the Agronomy Laboratory Greenhouse at the University of Bengkulu, Indonesia, tested how cocopeat-to-rice-husk-biochar ratios affect nitrogen uptake, growth, yield, and flavonoid content of mint (Mentha spp.) grown in a drip-irrigated substrate hydroponic system. Three varieties (Spearmint, Chocolate Mint, Apple Mint) were tested against four medium compositions (80% cocopeat + 20% biochar through 20% cocopeat + 80% biochar), analyzed by ANOVA (5% significance) and LSD test. Variety and medium composition interacted significantly on growth parameters: Apple Mint showed the greatest stem diameter at 60% cocopeat + 40% biochar, the highest dry weight and nitrogen uptake at 20% cocopeat + 80% biochar, and the highest flavonoid content at 40% cocopeat + 60% biochar, while Chocolate Mint produced the highest fresh and dry root weights at 80% cocopeat + 20% biochar, showing that response to substrate composition depends on variety.