Soil organic carbon mapping and prediction based on depth intervals using kriging technique: A case of study in alluvial soil from Sudan

Abstract

Soil organic carbon plays a vital role in the arid and semiarid regions. This study aimed topredict and map soil organic carbon content at soil depth intervals of 0-0.3 m, 0.3-0.6 m,0.6-0.9 m, and 0.9-1.2 m in alluvium soils along Blue Nile and River Nile, Sudan. Ordinarykriging (OK) technique was used as a geostatistical tool and applied to model the spatialvariability of soil organic carbon in the study area. A total of 38 soil profiles were excavatedin the study area and 152 samples from the four depths intervals were collected fordetermining organic carbon content. Results revealed that, the spatial autocorrelation forthe different soil layers was moderate to weak with a nugget to sill ratios ranging from 0.21to 0.86 suggesting their controlled by both intrinsic and extrinsic factors. The root meansquare error standardized (RMSE) of the predictions ranging from 0.79 to 0.83 indicatingthat the model which generated by ordinary kriging was correctly estimating the variabilityof soil organic carbon in the study area.