Robusta coffee and black pepper sustain the livelihoods of around 800,000 households in Vietnam's Central Highlands. Facing market fluctuations, farmers increasingly diversify cropping systems by combining coffee, black pepper, and fruit/nut trees. To assess whether diversification improves land and labor productivity, profitability, and labor dynamics in coffee- and black pepper-based systems. Survey data from 238 households were used to classify cropping systems into monocultures and three diversified systems, and to compare input use, productivity, labor dynamics, and profitability. Regarding agronomic performance, diversification increased planting density and land-use efficiency. Diversified systems displayed improved nutrient-use efficiency, while maintaining yields per tree/pole for coffee and black pepper. In diversified systems, lower coffee/black pepper yields per hectare were compensated by yields from other crops. Black pepper systems used more phosphorus and pesticides, whereas coffee systems used more nitrogen and water. Diversified coffee systems irrigated more frequently but with lower volumes per tree, reducing water use. Regarding labor, black pepper systems were the most labor-intensive, driven by harvest labor (also the most labor-demanding practice in coffee systems), while diversification reduced labor peaks by spreading workloads across the year. Regarding economic performance, black pepper systems generated higher gross products but had higher operating costs, resulting in comparable gross margins across systems, while diversified systems provided a higher return to labor. Despite increased management complexity and trade-offs shaped by the initial cropping system, diversification displays resource-use and labor benefits, while profitability remains comparable across systems under 2023 market conditions. • Diversification improves land and input use efficiency and reduces labor peaks. • Labor use is the lowest in coffee systems and the highest in black pepper systems. • Coffee diversified systems display the highest return to labor. • Initial cropping system shapes labor and agroeconomic trade-offs.
Duong et al. (Mon,) studied this question.