Comparative study between rubber agroforestry systems and rubber monocultures and soil erosion decrease via rubber agroforestry profile and crown cover in lower southern Thailand
This study aimed to compare the long-term economic margins (all revenues minus variable costs) of four pairs of rubber agroforestry systems (RASs) and rubber monocultures (RMs). The methodology consisted of data collection in the farm plots and then simulation and comparison of each pair via Olympe software as well as assessment of soil erosion decrease via profile and crown cover of the rubber agroforestry plots. The results found that the margins of rubber products per rai of the four pairs depend on many factors that have both pros and cons. For ten years (2017–2026), the estimated margins of a bamboo and rubber plot, Fan Palm and rubber plot, and Yellow Palm and rubber plot will be higher than the paired mono rubber plots. Meanwhile, the margins of an Eagle Wood and rubber plot during 2017–2025 are lower than of the monoculture but in 2026 the margins will be much higher than the monoculture because the Eagle Wood will be harvested. Also, the bamboo and rubber plot and the Fan Palm and rubber plot have the flexibility to increase the margins by adding value to the products of the intercrops through processing. These RASs give some environmental services, especially soil erosion decrease ranking from good to excellent level.