<![CDATA[Magnesium (Mg²⁺) is an essential secondary macronutrient that plays an important role in chlorophyll formation, enzyme activation, and photosynthesis in oil palm plants. However, the topic of chemical elements in science learning is often presented abstractly, making it difficult for students to relate scientific concepts to real-life phenomena. This study aimed to analyze magnesium (Mg²⁺) content in oil palm plantation soil as the basis for developing a science booklet based on local potential. The research employed a Research and Development (R&D) method with a quantitative descriptive approach. Soil samples were collected using purposive sampling from five locations in Pondok Kelapa District, Central Bengkulu Regency. Magnesium analysis was conducted using a colorimetric method with Eriochrome Black T (EBT) indicator and a UV–Visible spectrophotometer. The calibration curve produced the regression equation y = 0.0629x + 0.0093 with a coefficient of determination (R²) of 0.9981. The results showed that soil magnesium content ranged from 42.8 to 120.2 mg/kg or 0.35 to 0.99 cmol(+)/kg, indicating exchangeable magnesium levels from very low to low–moderate. These findings were integrated into the science booklet through science information, local potential, evaluation, and a glossary. The developed booklet provides contextual learning resources that connect scientific concepts with students’ surrounding environment and supports students’ conceptual understanding.]]>
