Effects of desiccation of soil samples on easily mineralizing nitrogen

The effect of desiccating soil samples (field fresh, fumigated with CHCl3, drying at temperature of room, 40℃ and 105℃) on extractable nitrogen fractions, especially on easily mineralizing nitrogen (Norg ) was studied The results showed that there was a little effect onNO3--N contents, but higher NH4+-N and N org contents were observed while the drying temperature increased The Norg contents of samples dried at 105℃ was highest among the samples of field fresh, being fumigated with CHC3, drying at temperature of room, 40℃ and 105℃, which came from not only a part of the microbial biomass nitrogen, but also from the decays of large organic molecules of soil nitrogen constituents