Digital Soil Mapping and Content Nutrient Prediction Modeling of Abaca Plantation

This study assesses soil fertility across six abacagrowing barangays in San Miguel, Catanduanes—a key region in Philippine abaca productionmd —to establish baseline data for sustainable soil management. Despite Catanduanes being the “Abaca Capital of the Philippines,” abaca plantations here rely solely on natural soil fertility, as farmers traditionally avoid fertilization. Using a portable soil nutrient tester and geospatial mapping integrated with regression analysis, the study evaluated nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), pH, and moisture levels from 600 soil samples. Results revealed widespread deficiencies: moisture levels ($41.86-56.04 \%$) were suboptimal, soils were highly acidic (pH 2.75-4.69), and critical nutrient shortages were observed, particularly phosphorus (3.20-6.01 ppm) and calcium (1.27-3.34 ppm). Regression analysis identified barangay-specific nutrient interactions, such as Kilikilihan’s phosphorus-nitrogen inconsistency, Buhi’s potassium-calcium connection, and San Juan’s potassium-magnesium competition, emphasizing the need for localized interventions. Magnesium was found to significantly improve pH and calcium availability, suggesting its strategic use in soil amendments. The study’s integration of field data, machine learning, and geospatial visualization provides a foundational dataset for monitoring soil health and guiding precision agriculture. These findings highlight urgent soil management needs to sustain abaca productivity in unfertilized plantations, recommending targeted nutrient supplementation and further research to validate long-term trends. This work serves as a critical reference for policymakers and farmers in optimizing abaca cultivation while preserving soil health in Catanduanes.