土壤预处理对土壤氮素组分的影响

运用室内模拟培养的方法研究了土壤预处理过程对土壤氮素组分的影响。结果表明：随着处理温度的升高，土壤铵态氮的数量有所增加；而对土壤硝态氮的数量影响不大；土壤可溶性有机态氮的数量有增加的趋势，其中１０５℃处理后的土壤可溶性有机态氮的数量明显高于鲜土、风干土和４０℃处理的土样，１０５℃处理后的土壤可溶性有机态氮除了大部分来来土壤微生物态氮的降解产物之外，尚有一部分是靠高温将土壤本身大分子含氮化合物分解而产生的。

Effects of Pretreatment of Soil Samples on Nitrogen Fractions

The effect of pretreating soil samples (field-fresh, fumigated with CHC13, drying at room temperature,40℃ and 105℃ ) on extractable nitrogen fractions, especially on soluble nitrogen (Norg) was studied. The results showed that the treatment had little effect on NO3- - N conents, but a significant effect on NH4+ - N and Norg contents when the drying temperature increased. The Norg contents of samples dryed at 105℃ was highest among the samples of fieldfresh,fumigated with CHC13, dried at room temperature,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.