Intercropping has become an important trend for coffee growers in Vietnam’s Central Highlands. It is both an economically viable and environmentally sustainable technique, according to Dr. Trần Vinh, Acting Director of the Western Highlands Agriculture and Forestry Science Institute (WASI), in an interview with Vietnam Agriculture Newspaper.
Why Intercropping Matters
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Dr. Vinh explains that WASI has long recommended intercropping as a technical solution for coffee production. Planting suitable companion crops alongside coffee diversifies farm output, creates jobs, stabilizes income, and reduces risks from market price fluctuations. Shade trees also protect coffee plants from wind, reduce evaporation, and help retain soil moisture—benefits that are especially valuable under today’s changing climate.
A decade ago, research showed that about 80% of Central Highlands farmers planted coffee without shade trees or intercrops. Driven by the desire for high yields and short-term profits, they pursued intensive monoculture. But within a few years, many of these unshaded, high-yield plantations began to degrade: soils weakened, coffee trees suffered from diseases such as root rot and yellowing leaves, and long-term sustainability was threatened.
Adoption and Current Practices
Today, intercropping with high-value crops is widely practiced in robusta coffee farms across the region. These systems not only produce a range of marketable products but also provide clear ecological benefits compared with pure coffee monoculture.
Earlier, even though Central Highlands coffee brought high export revenues, most plantations were monocropped at high intensity, a practice that proved fragile in the face of extreme weather and climate change. Price volatility in both coffee and companion crops such as durian, pepper, and avocado has also unsettled farmers.
WASI surveys show that after about 10 years of chemical-intensive cultivation, many high-yield farms (over 4 tons of green beans per hectare) experienced declining soil fertility, stunted growth, yellow leaves, and root disease. Recently, thanks to outreach on intercropping and the rising value of other cash crops, the share of coffee land under intercrops has risen sharply—up to 50% in some areas.
Among nearly 1,000 farms surveyed, 72.5% practiced single-crop intercropping—most commonly durian or pepper planted with coffee. Avocado intercropping is more recent (8.5% of farms). Cashew is less common, found in about 6% of farms, while 13.1% practice mixed intercropping with multiple high-value species such as durian, pepper, and avocado. Durian and avocado, when planted during the productive phase of coffee, serve both as shade and as an additional income source. These models are especially popular in Đắk Nông and Đắk Lắk provinces.
Economic Impact
WASI’s studies show that the four main intercrops—durian, avocado, pepper, and cashew—consistently boost profits compared to coffee alone:
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Durian: Profit increases of 102–233 million VND per hectare (76–299% higher than monocrop coffee). The highest gains occur at a 9m × 9m planting density, and the lowest at 12m × 15m.
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Pepper: Additional profits of 107–162 million VND per hectare (83–178% higher). A 3m × 6m density yields the highest return; 6m × 9m the lowest.
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Avocado: Gains of 81–117 million VND per hectare (39–120% higher). Best returns are at 6m × 6m density.
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Cashew: At 6m × 6m density returns are lower than coffee monoculture, but at 12m × 12m density profit rises to 101 million VND per hectare (74% increase) and at 15m × 15m to 136 million VND (132% increase).
Environmental Benefits
Although unshaded monocrop coffee can yield about 3.6% more beans than intercropped coffee, the difference is small. Research shows that soils in unshaded monoculture plantations are significantly poorer: lower organic matter (by about 1.87%), lower total nitrogen, available phosphorus only 33.7% of that in shaded plots, available potassium 41.6% lower, and cation exchange capacity (CEC) nearly 30% lower. Clearly, coffee grown without shade trees loses soil fertility faster.
Intercropping also lengthens irrigation intervals because shade reduces evaporation and helps soil retain moisture, reducing water needs. Leaf and branch litter from intercrops adds organic matter, improving soil structure and enhancing fertilizer and water use efficiency. On average, intercropped coffee uses about 17.7% less water—roughly 500 m³ to produce one ton of coffee, compared with 600 m³ in monoculture. This water savings is crucial in the face of climate change.
Dr. Vinh concludes that intercropping in coffee plantations is not only a sound economic strategy but also an essential adaptation for long-term soil health and climate resilience in Vietnam’s Central Highlands.