重庆市植烟区不同肥力植烟土壤氮素矿化特性研究

通过室内培养试验研究了重庆市植烟区不同肥力植烟土壤氮素矿化规律，求得土壤氮素矿化参数，并探讨了氮素矿化潜势（N0）、有机质、全氮、pH、碱解氮之间的关系。结果表明，在35℃条件下培养，一级动力学方程能够很好的拟合氮素的矿化过程，相关系数均达到显著水平（r高肥力土=0.976、r中肥力土=0.986、r低肥力土=0.996），不同肥力土壤氮素矿化量存在显著差异。矿化潜势(N0)为：高肥力土（25.0mg?kg-1±0.60）﹥中肥力土（21.5mg?kg-1±0.61）﹥低肥力土（19.7mg?kg-1±1.14）；矿化速率（k）为：低肥力土（0.1596mg?kg-1?d-1±0.0104）﹥中肥力土（0.1492mg?kg-1?d-1±0.0155）﹥高肥力土（0.1029mg?kg-1?d-1±0.0071）。矿化潜势(N0)与全氮、有机质呈正相关，相关系数分别为0.9799和0.9788，与pH之间呈负相关（R=-0.9784）。表明不同肥力植烟土壤的供氮能力存在差异，在肥料管理上要因土、因时施肥。

Study on Nitrogen mineralization characteristics of different fertility soils in tobacco-growing areas of Chongqing

Tobacco is a economic crop that has special chemical compositions. Nitrogen is one of the key factors for tobacco＇s yield and quality. Through the method of indoor culture experiment, the rule of nitrogen mineralization on different fertility soils in tobacco-growing areas of Chongqing was studied. According to the results of this experiment, the soil nitrogen mineralization parameter was obtained, and the relationship between mineralization potential（ N 0 ）, organic matter, total nitrogen, pH and available nitrogen was discussed. The results showed that the first order dynamic model can excellent fit experimental data under 35℃ . The correlation coefficients and the amount of soil mineralized nitrogen showed a high significance （r high fertile soil = 0.976 、r fertile soil =0.986 、r low fertile soil =0.996 ）, and the amount of soil mineralized nitrogen between different fertility showed the significant difference too. The sequence of soil nitrogen mineralization potential（ N 0 ） was： high fertile soil （ （25.0 ± 0.60） mg/kg ） fertile soil （ （21.5 ± 1.51） mg/kg ） low fertile soil （ （19.7 ± 0.17） mg/kg ）; The sequence of mineralization rate was： low fertile soil （ （0.9381 ± 0.0082） mg/（kg·d） ） fertile soil （ （0.7679 ±0.0539） mg/kg·d ）） high fertile soil （（0.7143 ± 0.0171） mg/（kg·d） ） .There were different degrees of positive correlation between total N, the organic matter, pH and nitrogen mineralization potential（N 0 ）. So, we should manure depend on the situation of the soil and the climate in the respect of fertility management.