Soil physical properties and textural map in Guyana

Abstract

The main objective of this work was to determine the physical properties of the soils of Guyana by textural class and their spatial distribution. An evaluation study of different pedotransfer equations was carried out to select those that best fit the results of a study carried out in the central rainforest of Guyana. For this, statistical parameters such as regression coefficient (R²), multiple correlation coefficient (r), root mean square error (RMSE) and agreement index (d) were determined, for a level of statistical significance of (P ≤ 0.05). ArcGIS software was also used to group the existing geodatabase files of Guyana soil groups by textural classification, thus creating the texture map. The results showed that Rawls's equations were the most adequate to estimate the field capacity and the permanent wilting point, obtaining values of (R² = 0.75, r = 0.87, RMSE = 8.47, d = 0.95) and (R² = 0.84, r = 0.91, RMSE = 5.48, d = 0.95) respectively. While for the estimation of the bulk density, the Saxton saturation moisture equation was the most acceptable with values of RMSE = 0.25 and d = 0.65. Finally, the physical properties of the soils according to textural class were established with these equations and the texture map of Guyana was obtained.