A four-year monitoring of beerkan infiltration rates in a sandy-loam soil

Abstract

Long-term investigations on temporal variability of infiltration rates are important for characterizing the porous medium but they are challenging and infrequent. Infiltration rates were measured in a sandy-loam soil by performing 16 beerkan infiltration runs on 14 sampling dates during a nearly four-year period. The means of the initial infiltration rates ( i ₀ ) varying by approximately four times, were less variable than the means of both the final ( i _f ) and the mean ( i _med ) infiltration rates, varying by 13 and nine times, respectively. The means of all considered parameters decreased as the antecedent soil water content ( θ _i ) increased but the θ _i effect was stronger for i ₀ (coefficient of determination, R ² = 0.84) than both i _f and i _med ( R ² = 0.55-0.68). With reference to these last two parameters, θ _i effects were significant for the lowest measured values ( R ² = 0.63-0.76) but not for the highest ones ( R ² = 0.12-0.13). Particularly small i _f and i _med values were obtained in initially very wet soil conditions. The antecedent soil water content can be expected to strongly control infiltration rates in a sandy-loam soil. Sampling the widest possible range of θ _i values is recommended to obtain the most complete information about temporal variability of infiltration rates.