An assessment of the Beerkan method for determining the hydraulic properties of a sandy loam soil

Abstract

Establishing the ability of the Beerkan Estimation of Soil Transfer parameters (BEST) procedure to reproduce soil properties is necessary for specific soil types. In this investigation, the BEST predictions for a sandy loam soil were compared with water retention data obtained by a standard laboratory method and with the saturated soil hydraulic conductivity, Ks, obtained by both the Wu et al. (1999) method, applied to the BEST infiltration data, and the Simplified Falling Head (SFH) technique. When the original BEST-slope algorithm with the infiltration constants fixed at β = 1.9 and γ = 0.79 was applied, the agreement between the predicted and the measured retention data was satisfactory in terms of similarity of the means and correlation and coincidence between the regression and identity lines. The prediction of Ks at a sampling point differed by not more than a factor of two from the Ks value obtained by the Wu et al. (1999) method. The SFH technique yielded Ks values approximately five times higher than those of BEST, probably because soil disturbance during water application, swelling and air entrapment phenomena had a lower impact on the measured infiltration data with the former technique. In conclusion, BEST is a promising approach for easily characterizing a soil, but its method of application should be adapted to the particular situation under consideration. Additional investigations carried out on different soils would allow development of more general procedures for applying BEST.