Analyzing the Relation between Loss-on-Ignition and Other Methods of Soil Organic Carbon Determination in a Tropical Cloud Forest (Mexico)

The objective of this study was to analyze the relationship between soil organic carbon content, determined by dry combustion (%OC_LECO) and the Walkley–Black method (%OC_WB), and loss on ignition (LOI). Soil samples were collected from noncalcareous O and A1 horizons within a tropical cloud forest. Linear regression equations were developed to estimate organic carbon from LOI. The applicability of the predictive equations was evaluated by comparison of measured and predicted organic carbon data for independent soil samples. The results showed that the LOI method produced a better linear relationship with the %OC_LECO (R ² = 0.96, P < 0.001) than with the %OC_WB (R ² = 0.88, P <0.001) method. These results also showed that %OC_WB and %OC_LECO prediction equations underestimate and overestimate soil organic carbon by 0.74% and 0.56%, respectively. This study suggests that LOI may be a good estimator of soil organic carbon for noncalcareous O and A1 horizons in a tropical cloud forest.