Impacts of calcium and nitrogen on carbon stabilizationin afforested soils

Brewer, E.A., E.A. Paul, G.P. Robertson, and S.J. Morris

Presented at the All Scientist Meeting (2004-10-08 )

Understanding of soil carbon dynamics is necessary for management decisions to mitigate elevated atmospheric CO₂. Our research evaluates the importance of Ca and N for soil C stabilization. Incubations, using soil from an afforested pine stand with low soil C, were amended with lime (CaCO₃), CaCl₂, and N separately and with litter. Nitrogen and CaCl₂ initially decreased CO₂ loss. Litter increased CO₂ evolution. Lime increased CO₂ evolution but less than that calculated for lime alone. Field plots amended with CaCl₂, N and litter initially decreased CO₂ evolution. One year after treatment, field respiration was less from Ca and N treatments. Increasing soil Ca may maximize soil C sequestration through stabilization.