Testing an adapted beerkan infiltration run for a hydrologically relevant soil hydraulic characterization

Improved Beerkan run methodology to assess water impact effects on infiltration and hydraulic properties of a loam soil under conventional‐ and no‐tillage

“…A Beerkan infiltration run making use of 15 water volumes, each establishing an initial water depth of nearly 1 cm on the soil surface, is the standard protocol to obtain a cumulative infiltration curve in the BEST methods of soil hydraulic characterization (Lassabatère et al., 2006). Fifteen water volumes were considered a reasonable compromise between the need to reach a near steady‐state infiltration rate at the end of the run and to use water volumes as small possible for field campaigns (Auteri et al., 2020). The fact that, with the L runs, the last Δ t values were nearly constant in both the NT and CT plots (Figure 3) suggested that the established infiltration process was consistent with the theory of single‐ring, three‐dimensional infiltration into an initially unsaturated soil (Elrick & Reynolds, 1992), and also that the standard experimental protocol was appropriate to capture both the transient and the nearly steady‐state phase of the infiltration process.…”

“…The funnel‐shaped diffuser was created by superimposing two layers of plastic mesh of about 9 × 9 mm arranged orthogonally, a layer of nylon and an aluminum mesh of about 1 × 2 mm (Supplemental Figure S2). Smaller rings were not used in this investigation because their use for multi‐height experiments was tested before (Alagna et al., 2016; Auteri et al., 2020; Bagarello, Castellini, et al., 2014). Larger rings were not tested in this case, because the need to homogeneously disturb the infiltration surface is practically impossible with a simple methodology, which represents a distinctive element of the Beerkan infiltration runs.…”

“…According to some recent investigations, however, single‐ring infiltration methods appear usable to both test water impact effects on infiltration and determine the hydraulic properties of a soil in which the upper layer deteriorates (Alagna, Bagarello, Cecere, Concialdi, & Iovino, 2018; Alagna et al., 2019; Auteri, Bagarello, Concialdi, & Iovino, 2020; Bagarello, Castellini, Di Prima, & Iovino, 2014; Bagarello, Cecere, Di Prima, Giordano, & Iovino, 2017; Bagarello, Cecere, David, & Di Prima, 2020). In particular, ponding infiltration experiments of the Beerkan type (Lassabatère et al., 2006) can be performed with different heights of water pouring (e.g., low [L], and high [H], equal to 3 and 150 cm, respectively) to mimic rainfall impact effects (null and appreciable, respectively) on the soil surface.…”

“…The possible interest for a hydrologically relevant soil characterization by the L–H methodology (Auteri, Bagarello, Concialdi, & Iovino, 2020) justifies additional investigations and developments because not all is known. In particular, issues that were never investigated in detail for the multi‐height methodology include: (a) water energy effects on the measured soil hydrodynamic parameters, (b) performances of the methodology with relatively large rings, and (c) ability of the experiment to detect tillage effects on the dynamics of soil hydraulic properties under water impact.…”

“…The energy of the applied water for the infiltration experiment, E p , appears to have a major impact on the soil surface alteration because an inverse relationship between K s and E p was detected by using L and H runs (Auteri et al., 2020; Bagarello, Castellini, et al., 2014). However, due to the different applied water volumes and techniques for determining K s , these investigations did not clarify if soil alteration was impulsive or gradual.…”