闽南农业流域土壤氮矿化作用初步研究

Field Study on Nitrogen Mineralization in Soil of South Fujian Agricultural Catchment

用原位培养法对五川流域内的香蕉地、菜地、香蕉地与菜地间作地、林地、甘蔗地土壤的氮矿化作用进行了研究,结果发现不同土地利用方式下土壤氮矿化速率平均为N0.11mgkg-1d-1,其中香蕉地土壤氮矿化最高可达N1.47mgkg-1d-1;土壤硝化速率平均为N0.27mgkg-1d-1,其中菜地下土壤硝化作用强度最高可达N0.69mgkg-1d-1。土壤矿化作用同土壤湿度、温度、C/N、土壤肥力存在明显的相关关系。不同土地利用方式下温度是土壤氮矿化最主要的影响因子。闽南流域土壤年矿化量平均为N240kghm-2,部分样地最高可达N850kghm-2,而年施肥量平均N650kghm-2。相比较而言,说明了土壤矿化是我国南方流域农业土壤氮素的重要来源。

Nitrogen （N） mineralization determines soil N availability, which limits plant growth and productivity. In this study, a field experiment was conducted to study soil nitrogen mineralization function of five different land use patterns in the Wuchuan catchment of Nanjing county of Zhangzhou city. The results showed that the average net nitrogen mineralization rate was 0.11mg N kg^-1 d^-1, and the highest of five different land use patterns was in the banana （about 1.47mg N kg^-1 d^-1）. The soil average nitrification rate was 0.27mg N kg^-1 d^-1, and the highest of five different land use patterns was in the vegetable （about 0.69mg N kg^-1 d^-1）. The soil nitrogen rate has obvious correlated relation. And the temperature was major factor in the five different land use patterns. The annual mineralization rate in the catchment was about 240kg N hm^-2, the highest rate was about 850kg N hm^-2 in some land use patterns, but the annual average fertilization was 650kg N hm^-2. It could explain the soil nitrogen mineralization as a major N source in the agricultural soil in the catchment of south of China.