Heating induced changes in mineral nitrogen and organic carbon in relation with temperature and time.

ABSTRACT

Heating effects on carbon and mineral nitrogen contents of soils within different land use types were investigated in this study. With this intention we collected soil samples from 3 different land use types which are abandoned agricultural lands (AAL), shrub land (SL) and Oak forest land (OFL) and are in neighborhood with each other. The sampling was made at mid-summer to provide a better correspondence between factual burning conditions as well. Soils are slightly acidic (pH between 4.60-5.72) and sandy, sandy loamy textured. At the study site the vegetation type is pasture at AAL, Cystus and Rubus sp. dominated shrubs at SL and mixture of Oak species such as Quercus petrea, Q. robur, Q. cerris and Q. frainetto at OFL. The results we found revealed that heating temperature has more remarkable effect on C losses and soil NH4 +-N re-mineralization and losses of NH4 +-N. Besides we could not detect remarkable differences between total N and NO3- amounts. Heating time created significant differences between NH4 +-N amounts for different land use types where SL soils showed significant difference for all temperature levels. Heating soils at 100oC created only slight differences at C and NH4 +-N budgets but heating at 200oC caused to striking results at NH4 +-N budgets and heating at 350oC led to only slight increase at NH4 +-N budget. As the temperature increased the C loss also increased linearly.