Electrical Conductivity as an Effective Tool for Soil Fertility Assessment: A Living Laboratory Approach for Case Method Learning

Abstract

This study explores the application of electrical conductivity (EC) as a tool for soil fertility assessment through a living laboratory approach at Glugur Rimbun. The research integrates practical field measurements with case-based learning methodology to evaluate the effectiveness of EC in predicting various soil fertility parameters. Soil samples were collected systematically and analyzed for EC, Cation Exchange Capacity (CEC), organic matter content, available nutrients (N, P, K), pH, and texture. Statistical analysis using MATLAB revealed strong correlations between EC and key fertility indicators, notably CEC (r = 0.82, p < 0.05) and organic matter content (r = 0.78, p < 0.05). A predictive model for CEC estimation was developed with high accuracy (R² = 0.85). The living laboratory approach demonstrated significant educational value, with 87% of students successfully interpreting EC-fertility relationships and 82% showing improved analytical skills. Cross-validation results showed reliable prediction accuracy with mean absolute percentage errors ranging from 8.5% to 15.7%. This study confirms EC as an effective rapid assessment tool for soil fertility while highlighting its potential in agricultural education through case-based learning methods.