Oil Palm Agroforestry Can Achieve Economic and Environmental Gains as Indicated by Multifunctional Land Equivalent Ratios

Abstract

Driven by increased global demand for vegetable oil in the food and biofuel sectors, oil palm plantations based on monoculture technology have expanded into lowland tropical forests. Interest in diversified, mixed oil palm systems is increasing as these might increase efficiency of the use of land and other resources, reduce farmer risk, and decrease greenhouse gas (GHG) emissions per unit product. Land Equivalent Ratio for provisioning services (LER P) values above 1.0 show that at least some diversified systems use land more efficiently than monocultures and are thus "land sparing," where monoculture LER P cannot exceed 1.0. Diversification also modifies climate and water regulating functions ("land sharing") relative to a forest reference, as indicated in the LER R index. A "multifunctional" LER M indicator combines both; land sparing plus land sharing effects jointly determine expected regulating services. Empirical assessment of multiple ecosystem services in agricultural landscapes is assisted by models that synthesise process-based knowledge, especially for perennial systems where welldesigned experiments require a full production cycle, and are costly and scarce. Agroforestry models explore spacing, intercropping and soil management options, predicting harvestable yields, impacts on water flows, nutrient leaching, and greenhouse gas emissions. We used the process-based Water, Nutrient and Light Capture in Agroforestry System (WaNuLCAS) model to explore mixed oil palm + cocoa and oil palm + pepper intercrop systems with modified ("double row") planting patterns for Indonesian contexts and estimated consequences for the carbon footprint. The oil palm + cocoa intercrop provided a high LER P (1.4), while also replenishing more ground water and having a lower C footprint. This combination also has a return to labour equal to that in oil palm monocultures and a higher benefit cost ratio than the oil palm + pepper combination that maximizes Net Present Value. Oil palm + cocoa systems are also less sensitive to price uncertainty for oil palm, and buffer for oil palm and cocoa production risks, assumed to be independent of each other. Considerable economic and environmental system improvements appear to be feasible through mixed oil palm systems and diversification as a pathway to intensification deserves full attention of research and policy development.

Climate change adaptation in and through agroforestry: four decades of research initiated by Peter Huxley

“…Canopy development was linked to the C (Nygren et al 1996) and N balance (Nygren and Leblanc 2015), as in the shade and mulch model of alley-cropping systems (van Noordwijk 1996). More comprehensive process-level understanding of tree-soilcrop interactions, informed by various tree-crop interface experiments, has been captured in the 2D Water, Nutrient, Light Capture in Agroforestry Systems (WaNuLCAS) model (Van Noordwijk et al 2011b), and used, for example, in a bioeconomic exploration of plant density and thinning scenarios for teak (Tectona grandis)-maize systems (Khasanah et al 2015), water use in trees of different leafing phenological stages in semi-arid Kenya (Muthuri et al 2004) and exploration of intercropping options for oil palm (Khasanah et al 2020).…”

Impacts of and adaptation to climate change on the oil palm in Malaysia: a systematic review

“…Intercropping, such as legumes and cereals, in oil palm plantation between rows can increase the income level of farmers and improve food security, should in case of climatic uncertainties (Nchanji et al 2016;Khasanah et al 2020). Mulching is an effective strategy that conserves soil moisture in oil palm plantation (Mohsen et al 2014;Iqbal et al 2020).…”

Agriculture Practice and Food Supply in Malaysia for last 50 years

“…Mono-cropping cause biodiversity loss even may cause extinction of less performing varieties of the same species. Degradation of soil health, pollution, creation of superbugs, spreading disease and pests are other major concern of mono-cropping (Dhandapani et al, 2020, Khasanah et al, 2020. Mono-cropping economy is a threat for a country also.…”