%0 Articles %T Soil water-retention characteristics and fertility of afforested arable land %A Wall, Antti %D 2005 %J Dissertationes Forestales %V 2005 %N 14 %R doi:10.14214/df.14 %U http://dissertationesforestales.fi/article/1797 %X From the standpoint of evaluating site quality for growing forest trees, the soil chemical and physical properties of cultivated arable land are poorly known. Therefore, soil matrix, water-retention characteristics and fertility of afforested arable land were studied. Subsequently, the implications of these soil characteristics for productivity of tree stands were assessed. The results indicated that the soil properties of afforested arable land differ markedly from those of forest soils. The changes in the composition of the soil matrix due to former agricultural land use manifested as increased organic matter content in mineral soils and, in contrast, as increased mineral matter content in peat soils. In general, afforested arable lands were characterized by soils having high contents of nutrients, high content of organic matter, high pH, and low air-filled porosity at field capacity, which resulted from the predominance of small pores. In all investigated soils, the air-filled porosity was less than 20% in the topmost soil layer and decreased significantly with increasing soil depth. The results suggested that soils of afforested arable land commonly have critically low aeration for tree growth. It appears that due to management history, afforested arable lands have a higher level of soil fertility compared to their inherent soil fertility. The high soil fertility of former arable land was, however, also attributed to the inherent properties of fine-grained soils. Consequently, based on of densities of Ca, P, silt and pH in the 0-10 cm soil depth, derived discriminant functions classified all sites from afforested arable land into forest site types of high productivity. Among these soils, those with high clay and silt content were the most fertile. The changes in the physical and chemical properties of soils due to former agricultural land use seem to be significant and long lasting to such a degree that afforested arable land is very unlikely to regain its inherent soil fertility even over an extended period of time.