Abstract

In the last few decades, several studies have documented the effect of land use on soil C pools but studies relating to soil N pools and land use are scarce. Since C and N cycles are interrelated, it is important to study the two nutrients simultaneously to understand the processes leading to their stabilization and mineralization in soil. We studied the effect of land use viz., arable, grassland and deciduous forest at two different locations (Hordorf and Warmbüttel) in North Germany with similar soil conditions on total, biological and extractable pools of soil C and N and nitrification potential of soils. Soils at Hordorf location were fine textured and were characterized by higher total C and N concentrations than the soils at Warmbüttel. However, at both the locations, C and N stocks in the 60 cm soil profile were highest in the forest soil. Averaged across both the locations, soil C and N stocks in forest soils were higher by 78–97 and 39–55%, respectively, compared to arable and grassland soils. Land use influenced N mineralization differentially at the two locations. While at Hordorf highest N mineralization potential was observed in forest soils followed by grassland and arable soils; at Warmbüttel grassland soils exhibited the greatest N mineralization followed by forest and arable soils. Compared to arable soils nitrification activity was limited in forest soils because of low pH. Hot water-soluble C and N fractions which varied with land use significantly influenced mineralization and nitrification processes in soils.