Spatio-temporal variation of surface soil hydraulic properties under different tillage and maize-based crop sequences in a Mediterranean area

Abstract

Aims 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. Methods 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. Results 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). Conclusions 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.

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