Critical edaphic and altitudinal factors influencing cation exchange capacity in coffee-growing soils of northeastern Peru: implications for sustainable fertility management

Díaz-Chuquizuta H.; Manrique Gonzales L.F.; Sánchez Ojanasta M.; Cuevas-Giménez J.P.; Carbajal-Llosa C.; Cuellar-Condori N.; Martínez B.; Vallejos-Torres G. · Frontiers in Soil Science (2026) · DOI: 10.3389/fsoil.2026.1770292

Resumen

Introduction – Effective cation exchange capacity (ECEC) is a key indicator of soil fertility and sustainable soil management assessment in coffee-growing systems. Methods – This study aimed to identify the principal edaphic and altitudinal factors explaining ECEC variability in 69 soil samples collected from coffee farms in northeastern Peru. Results – ECEC results exhibited substantial variation, ranging from 0.14 to 55.49 cmol(+)·kg−1 (mean = 15.21; SD = 12.47), and were significantly correlated with organic matter (r = 0.71), clay content (r = 0.62), exchangeable acidity (r = –0.63), and altitude (r = 0.33). Principal component analysis accounted for 64.3% of the edaphic variability, identifying Ca2+, pH, Mg2+, and exchangeable acidity as the most influential variables. The Random Forest model demonstrated high predictive accuracy (R2 = 0.93; root mean square error (RMSE) = 2.1 cmol (+)·kg−1), outperforming the generalized additive model (GAM) and identifying Ca2+ as the most important predictor (IncMSE% = 3177.37). A functional altitudinal gradient was also evident: areas above 1150 m.a.s.l. showed higher acidity and aluminium content, whereas areas below 900 m.a.s.l. exhibited greater base saturation and higher ECEC. Discussion – These findings support the development of sitespecific fertilization strategies and soil–climate zoning, emphasizing the value of integrating multivariate analyses with machine-learning models as key tools for optimizing fertility management and coffee crop productivity in tropical mountain ecosystems; where soil texture represents a key factor influencing coffee sustainability, as greater nutrient retention capacity and improved nutritional balance are associated with enhanced potential for sustainable production and reduced environmental impact. Copyright

Instituciones: Universidad Nacional de San Martín