The impact of agricultural land afforestation on soil water content in Central Bohemia

In the Czech Republic, the afforestation of agricultural land has been supported by providing subsidies from the government and the European Union. Afforestation of less-productive agricultural land provides many benefits including carbon sequestration, soil erosion control, biodiversity, water retention, cooling, social benefits, decreasing noise and light pollution, increasing air quality, wind speed reduction, oxygen production, wood production and non-wood products. In some aspects, it is possible to produce wood of the same quality on former agricultural land compared to permanent forest land. In this study, we attempted to find out the course of temperatures and volumetric water content as well as some other physical soil properties (at depths of 20, 40 and 60 cm) 9 years after the afforestation of agricultural land (warm, mild dry region of the Czech Republic) with a mixture of broadleaved tree species (Quercus robur L., Quercus rubra L. and Acer platanoides L.) or monospecific Pinus sylvestris L. stand; the study was performed in the period from April to the beginning of November 2020. Concerning the studied physical soil properties, the value of bulk density was higher (and total porosity lower) at a depth of 20 cm in Pinus sylvestris L. compared with agricultural land or the mixture of broadleaves; the water stability of soil aggregates was higher after the afforestation with the mixture of broadleaves. The temperature was lower in the soil of afforested plots (at all studied depths) compared to the agriculturally used land. Differences in rainfall interception, transpiration, soil(and forest floor) properties and other factors could influence the obtained values of water content in the soil of the studied plots. The average volumetric water contents were the highest in the plots with Scots pine (depth of 20 cm) and broadleaves (depth of 40 cm), and on the control plot (depth of 60 cm). The volumetric water content at a soil depth of 20 cm was not significantly (P > 0.05) different when the plot with Scots pine and agriculturally used land were compared. In all other cases and depths, the differences between plots were significant (P < 0.05).