Influence of Abandoning Agricultural Land Use on Hydrophysical Properties of Sandy Soil

• Main Author: Edyta Hewelke
• Format: Article
• Language: English
• Published: MDPI AG 2019-03-01
• Series: Water
• Subjects: soil water repellency; land use change; agrohydrology; water retention; surface runoff
• Online Access: http://www.mdpi.com/2073-4441/11/3/525

Soil water repellency can significantly degrade its agricultural utility and bring aboutnegative environmental consequences (i.e., reduced infiltration capacity, enhanced overland flow,increased erosion rates, and water infiltration occurred in irregular patterns). The presented studyaimed to establish whether excluding albic Podzols from agricultural production and theirspontaneous inhabitation by a pine tree stand affected their hydrophysical properties. Studies withthe application of the water drop penetration time (WDPT) test showed that a change in the landuse increased the potential water repellency of the surface layer (horizon A) and caused itschangeover from strongly repellent class (Class 2) to extremely repellent (Class 5). The relationshipbetween soil moisture content and wettability made it possible to determine the critical soil moisturecontent (CSMC) for the occurrence of the phenomenon of water repellency. It was confirmed thatthe CSMC value increased along with a change in use. For the site under arable use, it was 9–10vol.%, whereas for the site formerly under arable use and currently covered predominantly by apine tree stand, a value in the range of 14–16 vol.% was reached. A laboratory experiment on surfacerunoff of the soil formerly under arable use showed that over half of the rainfall may be transformedinto surface runoff as a result of occurring water repellency. This means that exceeding the criticalsoil moisture content makes the recharge of soil retention difficult and may significantly influencethe water balance of soil, as well as increasing its susceptibility to drought.