Pola Hubungan Ketersedian Hara dan Sifat Fisika Gambut Berdasarkan Pendekatan Principal Component Analysis (PCA)

Abstract

Tropical peat has interrelated chemical and physical properties, so managing its fertility requires an understanding of how these properties relate to one another simultaneously. This study aimed to map the relationships between nutrient availability and physical properties of peat and to identify the main factors controlling their variability across four land-use types: oil palm, mixed fruit garden, mixed vegetable garden, and shrubland. The research was conducted in January 2026 in Kuala Dua Village, Kubu Raya Regency, West Kalimantan. Twenty soil samples (4 land-use types × 5 replicates) were collected at a depth of 0–30 cm and analyzed for 10 chemical and physical variables, then processed using Principal Component Analysis (PCA) with Varimax rotation. The peat was very acidic (pH 3.23–3.65), with very high cation exchange capacity (>110 cmol(+)kg⁻¹) and very low base saturation (3.62–6.27%). PCA yielded four principal components that explained 90.29% of the total variance. PC1 (39.59%) linked pH, organic carbon, and phosphorus; PC2 (27.31%) linked Ca, Mg, and base saturation; PC3 (12.92%) linked bulk density and moisture content; and PC4 (10.47%) linked land-use type and total N. Improving peat fertility therefore requires an integrated approach that combines acidity control, cation balancing, and water management. The marginal KMO value (0.502) calls for cautious interpretation of the results.