Nguyen Vu Ky, Division of Agricultural Systems, WASI.
Email: vuky124@gmail.com
Our research results indicated that the mixed intercropping system of coffee and durian (Coffee & Durian) exhibits the highest total greenhouse gas emissions. This specific configuration is identified as the most resource-intensive model among all surveyed systems in Dak Lak, resulting in a total carbon footprint of 9,407.9 kg CO₂e/ha/year.
The two key drivers of high emissions in this system:
(i) Massive Agrochemical Inputs This system recorded the highest emissions specifically from agrochemical use, totaling 8,194.3 kg CO₂e/ha. The presence of durian, a high-value crop, drives farmers to invest heavily in inputs to maximize yield, often disregarding optimal efficiency.
– Nitrogen Fertilizer: The “Coffee & Durian” system had the highest emissions from nitrogen fertilizer application alone, reaching 4,338.6 kg CO₂e/ha.
– Phosphorus and Potassium: It also led to emissions from phosphorus (P2O5) and potassium (K2O) fertilizers, contributing 1,479.2 kg and 1,629.2 kg CO₂e/ha, respectively.
(ii) Intensive Plant Protection and Energy Use: Beyond fertilizers, this system also required significant non-fertilizer emissions.
– Pesticides and Fungicides: It required the highest volume of fungicides (37.4 liters/ha) and electricity for spraying (238.5 kWh/ha), resulting in plant protection emissions of 615.9 kg CO₂e/ha.
– Transportation: It involved the longest total transportation distance (101.5 km) for moving inputs and harvests, further adding to the fuel-based footprint.
Comparison with Other Systems: To visualize the scale of these emissions, it is useful to compare this high-intensity system with the lowest-emitting model:
Highest (Coffee & Durian): 9,407.9 kg CO₂e/ha (Driven by intensive input management for durian).
Lowest (Coffee & Avocado): 5,089.8 kg CO₂e/ha (Benefiting from lower inputs, as avocado is often considered a shade tree with minimal fertilization).
In short: While the “Coffee & Durian” system sequesters a significant amount of carbon due to the biomass of the trees (4,620.7 kg CO₂/ha), the dominant volume of emissions from fertilizers and energy means it still has the highest net emissions at 4,787.2 kg CO₂e/ha. This classifies it as a substantial carbon source rather than a sink.
References: N. V. Ky (2025). Assessment of Greenhouse Gas Emissions from the Intercropping Systems in Robusta Coffee Farms in Dak Lak, Vietnam. Graduate School of Science and Technology, University of Tsukuba