Determination of hydraulic conductivity and soil-water characteristic curve of soils in three different soil textures using mathematical equations

In this study, modeling studies in agriculture were examined in line with the literature and previous studies, and the determination of hydraulic conductivity and soil water characteristic curves in soils with three different textures using mathematical models-equations was tested. 12 undisturbed and 1 disturbed soil samples were taken from the Adana province Arpacı, Çanakçı and Baharlı soil series at 0-20 cm depth. Bulk density, porosity, pH, electrical conductivity, lime, organic matter, hydraulic conductivity and pF curve were determined in the samples. The best model for the Arpacı series and for the K(P) model (0.007453) was Terleev and Sarıyev's model (s=0.015594), and for the K(W) model, the Genuchten model (RMSE=0.041119) was determined. For the Çanakçı series, the best model was the Curry and Chen model (RMSE=0.003780), the K(P) model (RMSE=0.146915) was the most suitable model suggested by Terleev and Sarıyev, and for the K(W) model, the Genuchten model (RMSE=0.293829) was selected. For the Baharlı series, the Brooks and Correy model (RMSE=0.013715), the best-fitting K(P) model was the Michurin model (RMSE=0.000014), and for the K(W) model, the Avern model (RMSE=0.482353) gave the most suitable result. With the selected relevant models, it will be possible to make irrigation water timing and amount in soils more accurately and systematically.