The surface crust formed by the drop impact of rainfall and/or irrigation is a prevalent characteristic in many Mediterranean soils. However, the temporal variation of soil hydraulic properties induced by surface crust during the high-frequency irrigation has rarely been investigated.

Beerkan infiltration tests in conjunction with the BEST method were used to investigate the effects of surface crusting on the spatio-temporal variation of saturated soil hydraulic conductivity (K_s, mm s⁻¹), sorptivity (S, mm s^−0.5), mean pore size (r, mm), number of effective pores per unit area (N, m⁻²) in Agramunt, NE Spain.

In response to autumn tillage, intensive tillage (IT) increased K_s and S due to higher r and N, but both declined after 60 days. Reduced tillage (RT), maintained comparable K_s and S values, despite having a lower N value. After the spring tillage, both IT and RT developed crusted layers, resulting in decreased K_s, S and N. Long-term no-tillage (NT) showed an increasing trend of K_s and S over time, except for the last sampling. Spatial variation (i.e., between the rows, B-row vs. within the row of crops, W-row) of K_s and S was found, and non-crusted soils (W-row) had consistently higher K_s and S than crusted soils (B-row).

Conservation tillage i.e., RT and NT improve the surface soil structure and reduce the risk of crust development. Surface cover by crops may help to prevent crust formation within the row of crops, improving soil hydraulic conductivity.