Y5Cafe would like to introduce the “Completed Process for Converting Coffee Husks into Organic Bio-Fertilizer,” a guide provided by the Dak Lak Provincial Agricultural Extension Center.
Introduction
Table of Contents
The Central Highlands is a vast region rich in agricultural potential, with ideal soil and climate for cultivating industrial crops, especially coffee and rubber.
However, natural factors, steeply divided terrain, and improper soil exploitation have degraded the soil’s productive capacity—first reducing its organic matter content and subsequently lowering fertility and soil structure.
Practical farming experience confirms the essential role of organic fertilizers in maintaining soil fertility, stabilizing crop yields, and supporting sustainable agriculture. Yet organic manure from livestock waste has become increasingly scarce, unable to meet the agricultural demands of the Central Highlands. Meanwhile, coffee husks (CH)—an abundant and inexpensive organic by-product—can be transformed into organic fertilizer to partly or completely replace animal manure. Unfortunately, many households still overlook this valuable resource and even discard it.
Recognizing the potential of coffee husks to support sustainable agriculture in Dak Lak, the Dak Lak Rural Development Project cooperated with the Dak Lak Agricultural Extension Center and the Agricultural Extension Stations of Lak and Ea H’leo districts. Starting in early 2005, they carried out pilot projects to process coffee husks into organic bio-fertilizer.
This handbook compiles the results and lessons from those pilot models to provide farmers and agricultural extension workers with practical guidance for producing organic bio-fertilizer from coffee husks at the household level.
Benefits of Using Coffee Husks to Produce Organic Bio-Fertilizer
With the current coffee acreage in Dak Lak and the Central Highlands, hundreds of thousands of tons of coffee husks are discarded annually during hulling. Processing this material into organic bio-fertilizer brings tremendous benefits:
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Cost savings: By using household labor, coffee husks, and small amounts of biological agents, manure (if not self-produced), urea, phosphate fertilizer, lime, and sugar, farmers can produce high-quality organic fertilizer at only about 30% of the market price for similar fertilizers.
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Stable crop yields and reduced chemical fertilizer use: Applying this bio-fertilizer helps stabilize yields and cut mineral fertilizer needs, lowering production costs.
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Environmental advantages:
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No ecological pollution; safe for humans, plants, and animals.
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Improves soil structure, porosity, and fertility.
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Balances soil microflora.
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Decomposes and transforms other organic matter into nutrients for crops.
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Increases the efficiency of chemical fertilizers and reduces leaching into groundwater or volatilization into the atmosphere.
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Materials Required
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Main materials:
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Coffee husks: 1,000 kg (from processing 3,000 kg of parchment coffee)
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Manure: 200 kg
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Fused phosphate fertilizer: 50 kg
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Urea: 10 kg
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Lime powder: 15 kg
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Granulated sugar: 2 kg
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Biological culture (microbial inoculant): 2 kg
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Note on biological inoculant types:
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Strains that decompose cellulose and protein and neutralize odors.
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Strains containing Trichoderma fungi or Streptomyces actinomycetes.
Labor Requirements
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Total: 5 worker-days, divided into two stages:
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Stage 1: 3 worker-days to complete the initial compost pile.
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Stage 2: After about 40 days, 2 worker-days to turn the pile.
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Tools
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Hoes: 2
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Shovels: 2
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Rakes: 2
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500-liter water container: 1
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Watering can: 1
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Water pump: 1
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Hose long enough to reach the compost site
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Old sacks or tarpaulin to cover the compost pile.
Activating the Biological Inoculant
Four to five hours before starting:
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Pump about 500 liters of clean water into the container.
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Add:
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2 kg biological inoculant
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2 kg sugar
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0.2 kg (200 g) urea
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Stir thoroughly until dissolved.
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Stir again every hour, at least 4 times, to fully activate the inoculant for rapid coffee husk decomposition.
Composting Procedure
Mixing the Dry Materials
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Spread the coffee husks evenly on the ground to a 40 cm thickness.
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Sprinkle the manure evenly on top.
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Evenly distribute the remaining 9.8 kg of urea, fused phosphate fertilizer, and lime powder.
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Turn the pile thoroughly to mix all dry ingredients.
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While turning, gradually water the pile so that it is 70–80% moist. Ensure even wetness; excessive water can cause nutrient leaching.
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Let the moist pile rest for 15–20 minutes for even absorption, then lightly water again.
Layering and Inoculating
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Clear and level the ground where the compost pile will be built.
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Lay a 10 cm base layer of wet straw or coffee husks.
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Stack 20–25 cm layers of the moistened material, each time sprinkling the activated inoculant evenly on top.
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Repeat layering and sprinkling until the pile reaches at least 1.2 m high and 2–2.5 m wide to retain heat for decomposition.
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Cover the pile with a thin 10–20 cm layer of wet straw or coffee husks, then lightly water.
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Finally, cover the pile tightly with old sacks, tarpaulin, or plastic sheet, weighing down the cover to prevent wind displacement.
Monitoring and Turning the Pile
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After 15 days: Check the pile by digging a hole in the center. White microbial fungi should be visible, and the temperature can reach up to 80°C, which helps decompose material and kill pathogens. If the pile is dry, water it thoroughly, rebuild, and re-cover.
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After 25–45 days: Remove the cover, turn the pile thoroughly while watering to ensure moisture, then rebuild into a pile at least 1 m high and re-cover.
Final Inspection
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After 110–120 days (or 70–80 days after the second turning), the material should be soft and crumbly—ready for use as fertilizer.
Important:
Always check the pile’s moisture. The outer layers may seem wet while the inside is dry; water as needed to maintain ideal moisture for microbial activity and rapid decomposition.
Yield
From the given input materials, the process produces about 1,300–1,400 kg of organic bio-fertilizer with a moisture content of 20–25%.