At the peak of the 2009 coffee harvest, the Agricultural Center of Di Linh District (Lam Dong Province) introduced a technical process for turning coffee husks into bio-organic fertilizer. The goal is to make full use of this byproduct and increase farmers’ income.
According to Mr. Doan Dinh Hai, Director of the Di Linh District Agricultural Center, the process was first transferred to four communes: Tan Chau, Dinh Lac, Gia Bac, and Hoa Bac. These are remote areas with many ethnic minority farmers who are given priority to access advanced science and technology in coffee production and processing. After these four communes, the Center plans to extend the program to other villages and communes throughout the district.
Di Linh District currently has 41,000 hectares of coffee plantations. With an average yield of 2.5 tons per hectare, the area produces more than 100,000 tons of coffee annually, generating a huge amount of husks. Previously, farmers simply dumped the husks in their fields after hulling the coffee.
Coffee husks decompose very slowly and plants cannot absorb their nutrients directly. This practice not only pollutes the environment but also spreads many plant pathogens. To address this problem, the Agricultural Center has subsidized 40% of the cost of microbial agents and recommends that farmers process coffee husks before using them as fertilizer, following the procedure below:
Materials
Table of Contents
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Coffee husks: 1,000 kg (about 4 m³)
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Manure: 100 kg
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Urea: 0.7 kg
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Phosphate fertilizer: 25 kg
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Molasses: 0.1 liter
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Microbial inoculant: 0.1 – 2 kg
Activating the Microbes
Dissolve 0.1 kg of microbial inoculant in 50 liters of water, add 0.1 liter of molasses or 1 kg of dark sugar, and stir well until dissolved. Allow the mixture to activate for 3–5 hours before applying it to the compost pile.
Mixing and Composting
Moisten the coffee husks thoroughly and mix evenly with the manure, phosphate fertilizer, and urea. Pour the activated microbial solution over the pile. Form the pile into a windrow 1.3–1.5 m high and 2.3–3 m wide; the length depends on the quantity of material. Cover with tarpaulin or straw to retain heat and moisture.
After 25–30 days, turn the pile and add water if it becomes dry. After three months, the coffee husks will have fully decomposed and can be used as fertilizer.
Benefits of the Final Product
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Adds organic matter, beneficial microorganisms, and trace elements to the soil, improving soil structure and stimulating root development.
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Provides nutrients, especially potassium (0.4%), helping to reduce the cost of chemical fertilizers.
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Helps reduce rural environmental pollution.
Product Quality
Compared with high-quality traditional manure, bio-organic fertilizer made from coffee husks contains twice as much nitrogen, three times as much potassium, and 1.5 times as much phosphorus.