Spatial and temporal variability of surface soil moisture content of an Alfisol as influenced by tillage operations in Oyo State, Southwestern Nigeria

This study was carried out to evaluate the spatial variation of surface soil moisture content as influenced by tillage practices. A total of 500 samples were collected at every 3 m along the x-axis and 10 m apart along the y-axis and water content of the samples was determined gravimetrically. The data were subjected to different regression analysis to determine the best-fit model. The spatial variability of soil moisture content was extrapolated using a semi-variogram. Out of all the models tested. The 4^th degree polynomial model estimated the variogram better at R²= 0.7465 compared to the 3^rd degree polynomial of R²= 0.4679. Surface mapping was constructed using the coefficient of the best-fit model. The Contour maps so developed revealed rather uniform surface moisture content for plots with minimum tillage than the zero tilled plots.