Sustainable intensification of oil palm production through integration with other crops: a review

Unsustainable monoculture systems practices, driven by global demand for agricultural commodities like palm oil, contribute to deforestation, biodiversity loss, and soil degradation, compromising livelihoods and environmental health. With increasing land scarcity, sustainable practices maximizing productivity and minimizing ecological impact, such as intercropping, are crucial. This review of over 116 publications examines global oil palm intercropping systems, analysing their technical, economic, environmental, and social implications. While companion crop productivity is relatively well-studied, long-term effects on adult palms require further investigation. Crop design (species selection, type of oil palm used and spatial arrangement) and crop management are key to mitigating interspecific competition and optimizing productivity, given diverse intercropping patterns. Economic performance varies, with benefit-cost ratios from 0.26 (palm with onion) to 2.86 (palm with corn/pepper). Intercropping offers socio-environmental benefits: enhanced food security through integrating food crops, diversified income, increased biodiversity (birds, arthropods), and efficient resource use. Land equivalent ratios (LERs) range from 0.98 to 4.10, indicating more efficient land use than monocultures. However, research gaps remain regarding long-term intercropping impacts on palm cultivation, particularly fertilization and pest/disease management, water use, pollinators, yields, and environmental impacts.