Managing Coffee Fruit Husk as Compost to Improve Soil Fertility and Yield of Radish (Raphanus sativus L.)

Abstract

Coffee fruit husk, one of the residues in coffee agroforestry systems, is potentially managed into organic fertilizer to improve soil fertility and plant production. The study aimed to assess the compost quality from coffee fruit husk (i.e., fine and granular) and its impact on soil fertility and the production of radish. The research was conducted in 3 steps, including 1) compost preparation, 2) incubation research, and 3) field experiment for the application of coffee fruit husk compost on radish cultivation, starting from May 2018 to September 2019. The incubation and field research were designed with 9 treatments and 3 replications, including control, fine and granular compost of coffee fruit husk forms with four different application doses for each form. The result showed that granular compost was slowly decomposed, and consequently, the nutrient released was longer than fine compost. This was proven by the soil pH, soil organic C and soil exchangeable K were 5% to 63% lower in the application of granular compost than in the application of fine compost during 8 weeks incubation. Furthermore, in the field research, the application of 2.7 kg granular compost/plot (~ 9 tons/ha) increased 91% and 65% to 84% of radish production as compared to control and application of all doses of fine compost at 12 weeks after application.