土壤硝化强度测定方法的改进

Improved Method of Measuring Soil Nitrification Activities

为了使土壤硝化强度的测定条件更加统一,结果更加准确,本研究针对土壤硝化强度测定时广泛采用的悬液法,研究了其最佳培养条件:反应体系p H 7.5,底物NH4+-N浓度为100 mg/L,培养温度为30℃,培养时间为5 h,风干土样预培养72 h后才可进行硝化强度的测定。还针对NO3--N生成法的不足,探讨了通过NO2--N生成法评价硝化强度的途径:通过向反应体系中添加1 mol/L的氯酸钠0.2 m L,有效抑制NO2-向NO3-的氧化。不同检测方法对硝化强度测定对比的结果发现,NO2--N生成法确是评价土壤硝化强度的最佳方法。

In order to unify the measurement conditions of soil nitrification activities and increase the accuracyof results, the optimum culture conditions of suspension method for measuring soil nitrification activities wereimproved： the p H of the reaction system was 7.5, the substrate concentration of NH4＋-N was 100 mg/L, culturetemperature was 30℃, culture time was 5 h, and soil nitrification activities was measured after air-dried soilsample pre-cultured for 72 h. The study also aimed at the deficiency of preparation method of NO3--N, anddiscussed the method of measuring soil nitrification activities by the preparation method of NO2-- N. Themethod was adding 1 mol/L sodium chlorate 0.2 m L to the reaction system for effective inhibition of NO2-toNO3-oxidation. By comparing different methods, the preparation method of NO2--N was the best method ofmeasuring soil nitrification activities.