Impact of Duration of Land Abandonment on Infiltration and Surface Runoff in Acidic Sandy Soil

Abstract

Sandy soils are less fertile and, therefore, often abandoned in the Central European region. Land abandonment can cause the recovery of ecosystems by the replacement of crop species by vegetation that disperses from surrounding habitats and will be subsequently established (secondary succession). The objective of this study was to find the impact of secondary succession during more than 30 years of lasting abandonment of agricultural fields with acidic sandy soil on infiltration and surface runoff. The method of space-for-time substitution was used so that the fields abandoned at different times were treated as a homogeneous chronosequence. The impact of abandonment on infiltration and surface runoff was characterized by the changes in soil organic carbon content, pH, water and ethanol sorptivity, hydraulic conductivity, water drop penetration time, repellency index, time to runoff, and surface runoff coefficient. It was found that the abandoned soils previously subjected to agriculture showed a decrease in pH, a significant increase in soil water repellency, and a decrease in infiltration, which can lead to serious problems in terms of surface runoff and soil erosion. The pH(H2O) and pH(KCl) decreased monotonously and ethanol sorptivity did not change significantly during abandonment. The time to runoff did not change significantly between 10 and 30 years of abandonment, and it was not measured after 1 year of abandonment because no runoff occurred. The dependence of the other characteristics on the duration of field abandonment was not unambiguous. Water sorptivity and hydraulic conductivity showed a decrease between 1 and 10 years followed by a slight increase between 10 and 30 years of abandonment. On the other hand, soil organic carbon content, water drop penetration time, repellency index, and surface runoff coefficient showed an increase between 1 and 10 years followed by a slight decrease between 10 and 30 years of abandonment. To prevent soil water repellency and its consequences in sandy soils, an adequately high soil water content should be maintained, and mixed forest afforestation should be preferred to pine afforestation. This is extremely important in the context of climate change and the increasing frequency of prolonged dry periods.

Keywords

• land abandonment
• sandy soil
• water repellency
• infiltration
• retention
• runoff