Cultivation effects on biochemical properties, C storage and 15N natural abundance in the 0-5Â cm layer of an acidic soil from temperate humid zone

Changes in some soil chemical, including 15N values, and biochemical properties (microbial C, FDA hydrolysis, glucosidase and urease activities) due to two tillage systems, conventional tillage (CT) and no-tillage (NT), were evaluated in an acid soil from temperate humid zone (NW of Spain) and compared with values obtained for a reference forest soil. The results showed that in the surface layer (0-5 cm depth) tillage tended to increase soil pH and to decrease organic matter levels and microbial biomass and activity values. The data also indicated that 8 years of NT, compared to CT, resulted in greater organic matter content and increased microbial biomass and activity, the changes being more pronounced for the microbial properties. Adoption of NT resulted in an increase of soil C storage of 1.24 Mg C ha−1 year−1 with regard to CT. The suitability of 15N as a potential tracer of land-use in this acid soil was also confirmed.