The effect of coffee waste on the growth and development of soybean (Glycine max L. (Merr.))

Abstract

This study was conducted to determine the effects of coffee waste on the morphological and physiological characteristics of soybean (Glycine max L. (Merr.)) plants. Experimental groups were prepared by adding different amounts of coffee waste (5g, 10g, 15g, 20g, 25g, 30g) to the growth medium. After 28 days of cultivation, root and stem lengths, fresh and dry weights, and leaf chlorophyll, malondialdehyde (MDA), and proline contents were measured. The results indicated that low and moderate levels of coffee waste—particularly the 20 g treatment-significantly promoted plant growth by increasing root and stem elongation, biomass accumulation, and chlorophyll content. In contrast, higher doses (25 g and 30 g) elevated MDA and proline levels, indicating the induction of oxidative stress in soybean plants. These findings suggest that coffee waste can be effectively utilized as an organic fertilizer when applied in appropriate amounts. This approach not only contributes to waste recycling but also supports environmentally and economically sustainable agricultural practices.