华中地区两种典型菜地土壤中氮素的矿化特征研究

Study on Nitrogen Mineralization of Two Typical Vegetable Soils in Central China

以华中地区两种典型的菜地土壤——黄棕壤和潮土为研究对象,利用室内连续培养试验研究了菜地土壤氮素的矿化规律和矿化特征。结果表明,黄棕壤和潮土氮素的矿化以硝态氮量较多,铵态氮较少。两种土壤的矿化速率随培养时间的延长而降低,培养13周以后黄棕壤的矿化速率为N 0.13 mg/(kg.d),潮土为N 0.32 mg/(kg.d)。随着培养时间的延长,黄棕壤和潮土的累计氮矿化量缓慢增长。培养结束时黄棕壤矿化量为N 68.65 mg/kg,潮土矿化量为N 109.37 mg/kg,分别占土壤全氮量的24.52%和21.45%。黄棕壤和潮土氮素的矿化势分别为N 74.63 mg/kg和123.45 mg/kg,分别占土壤全氮量的26.65%和24.21%。

Nitrogen mineralization of two typical vegetable soils （yellow-brown soil and fluvo-aquic soil） of central China was studied by means of indoor cultivation test. The result indicated that during mineralization of the two soils, the amount of nitrate nitrogen was more than ammonium nitrogen. The mineralization rates decreased with the culture time, after 13 weeks it deceased to N 0.13 mg/（kg·d） for yellow brown soil and to N 0.32 mg/（kg·d） for fluvo-aquic soil. The amount of accumulated mineralization increased slowly with the culture time and it was N 68.65 mg/kg for yellow brown soil and N109.37 mg/kg for fluvo-aquic soil at the end of culture, accounting for 24.52% and 21.45% of soil total nitrogen respectively. The mineralization potential were N 74.63 mg/kg for yellow brown soil and N 123.45 mg/kg for fluvo-aquic soil, accounting for 26.65% and 24.21% of soil total nitrogen respectively.