Organic carbon and nitrogen stocks and storage profiles in cool, humid soils of eastern Canada

Current interest in carbon (C) exchange processes between terrestrial ecosystems and the atmosphere have identified a need to assess soil C stocks or inventories for specific soil types and climates. In this study, the mean store of C and nitrogen (N) was determined in the soil profile of several Gleysolic, Podzolic, Luvisolic, and Brunisolic soils under different agricultural management systems, in the cool, humid region of eastern Canada. Based on a total of 69 management treatments from 16 agroecosystem sites, mean soil C and N densities (to a soil depth of 60 cm) ranged from 3.1 to 13.1 kg C m(-2) and from 0.36 to 1.05 kg N m(-2). The C:N ratio ranged from 8.3 to 17.1. Distribution of C and N down the soil profile showed a relatively regular pattern of C and N decrease with depth. Estimated C stocks or storage for the 1-m soil depth ranged from 8.3 to 13.3 kg C m(-2) for the Gleysolic soils, and 5.4 to 10.5 kg C m(-2) for the Podzolic soils, with an overall range and mean for all soils of 3 to 16 kg C m(-2) and 9.8 kg C m(-2) +/- 2.8. This indicates that some agricultural soils in eastern Canada possess a relatively high potential for organic matter storage.