Can improved plant nutrition buffer against water-related yield losses in oil palm?

Oil palm is the main source of vegetable oil in the world, with Indonesia accounting for 60 % of global production. Maintaining stable oil palm yields amidst changing climate is important given the implications for processing mills, supply chains, and socio-economic outcomes. Using monthly yield data collected over 7–9 years from four fertilization trials in water-limited environments in Indonesia, we assessed the impact of plant nutrition on the stability of oil palm yield. Each trial included three fertilization treatments (low, standard practice, and high) leading to differences in plant nutritional status across treatments as determined using leaf tissue analysis. Average yield was 77 % higher in the high- versus low-fertilizer treatments (27.1 and 15.3 t ha⁻¹, respectively), with temporal yield variation driven by water stress and vapor pressure deficit. Improved plant nutrition increased the yield response to favorable weather, leading to a concomitant increase in absolute yield variation (standard deviation and inter-quartile range), but smaller relative variation (coefficient of variation and sustainable yield index). On the other hand, improving plant nutrition had little impact on yield during low-yielding cycles due to water limitation. Despite the key role of plant nutrition to sustain high oil palm yields, our study shows limited room to stabilize yield and/or avoid climate-related yield losses. On the other hand, our findings suggest that future yield improvement will depend more on reducing yield constraints under favorable conditions, which will require greater flexibility to adjust field and mill operations to the larger yield variation.