Evaluation of Soil Fertility in Some Farmlands in the North and South of Brebes District, Central Java, Indonesia

Abstract Brebes District, known for its diverse agricultural commodities, relies heavily on intensive farming practices with synthetic fertilizers, making soil fertility evaluation essential to address nutrient constraints. This study aimed to evaluate soil fertility across 39 locations in northern and southern Brebes. The research involved several stages: soil sampling, analysis of chemical properties, cation ratio assessment using the Base Cation Saturation Ratio (BCSR) approach, fertility evaluation, nutrient mapping (N, P, K), and data analysis. Results indicated that northern Brebes soils generally exhibited moderate fertility, with organic carbon (C) as a limiting factor, while southern Brebes soils had a high fertility status. A t-test revealed signiLicant differences between the two regions in pH, organic C, total nitrogen (N), K 2 O HCl 25%, cation exchange capacity (CEC), base saturation, and exchangeable calcium (Ca), magnesium (Mg), and sodium (Na), except for P 2 O 5 HCl 25% and exchangeable potassium (K). Intensive farming practices in both regions caused imbalances in base cation proportions, with high Ca and Mg levels potentially impeding K uptake by plants. These Lindings underscore the impact of intensive farming on regional soil fertility and nutrient imbalances, emphasizing the need for tailored soil management strategies to address base cation disparities and improve agricultural sustainability.