This document discusses a study on estimating oil palm leaf nutrient levels using optical sensors as a non-destructive alternative to traditional leaf sampling and chemical analysis. The study was conducted in two phases: the first phase evaluated different sensor types and developed preliminary models, while the second phase refined the models. Results found that spectroradiometers showed potential for estimating most nutrients, while vegetation indices from other sensors worked best for boron. Overall, the study demonstrated the feasibility of using optical sensors to estimate oil palm nutrient levels in a precision agriculture approach.