两种硝化抑制剂对不同土壤中氮素转化的影响

Effects of Nitrification Inhibitors on Transformation of urea in Different Soils

采用实验室人工气候箱培养的方法,研究了两种硝化抑制剂双氰胺和硫代硫酸钾在两种碱性土壤中对土壤pH值变化、氨挥发特性及铵态氮转化的影响。实验结果表明,各处理在两种碱性土壤中的pH值都是先上升到一个峰值,然后下降,且速率先快后慢。硫代硫酸钾处理和对照处理的pH值约在实验第4天出现峰值,双氰胺处理pH值出现峰值的时间较硫代硫酸钾处理及对照处理土壤推迟了3天左右。整个实验期间,双氰胺处理的pH值一直处于较高水平,硫代硫酸钾处理的次之,对照处理的最小。氨挥发强度与土壤pH值同步,各处理氨的挥发量一般在第7天达到最大值,此时双氰胺处理氨的挥发量最大,硫代硫酸钾处理的次之,对照处理的最少。在晋城菜园土中,双氰胺和硫代硫酸钾处理的土壤比未添加硝化抑制剂的对照土壤中氨挥发的总量分别增加523.0%,33.6%,在北京菜园土中,双氰胺和硫代硫酸钾处理的土壤比未添加硝化抑制剂的对照土壤中氨挥发的总量分别增加575.8%,125.0%。土壤中铵态氮含量与土壤pH值的变化趋势相似,先快速上升到一个峰值,然后开始缓慢下降。硝化抑制剂的添加能使两种碱性土壤中铵态氮的释放时间延长3天左右。

Incubation studies on the effect of two nitrification inhibitors（IN） dicyandiamide and potassium thiosulfate on pH value＇s change, ammonia volatilization and ammoniacal nitrogen transformation of garden soils in the suburbs of Jincheng and Beijing show that in these two alkaline soils, the soil＇s pH in all treatments increased to maximum quickly at the beginning and then decreased at a slow rate. The peak of soil＇s pH appeared at the 4 th day of the experiment in potassium thiosulfate treatments and no-NI control, while it was postponed about three days in dieyandiamide treatments. During the whole experiment, the soil＇s pH in the treatments with dieyandiamide was higher, followed by the treatments with potassium thiosulfate, and the soil＇s pH in the no-NI control was minimum. Ammonia volatilization intensity followed the changes of soil＇s pH, the peak of ammonia volatilization occurred at the 7 th day of the experiment in ali treatments generally, and meantime, the content of ammonia volatilization with dieyandiamide treatments was higher, followed by the potassium thiosulfate treatments, and the content of ammonia volatilization with no-NI con-rol was minimum. The total amount of ammonia volatilization was increased by 523.0 %, 33.60% in the treatments with dieyandiamide and potassium thiosulfate when compared with the no-NI control of garden soils in Jincheng, respectively. And trend were similar to the garden soils in Beijing with the total amount of ammonia volatilization was increased by 575.8 %, 125.0 % in the treatments with dicyandiamide and potassium thiosulfate when compared with the no-NI control, respectively. The variety of soil＇s ammoniacal nitrogen content and soil＇s pH have the similar trend, they both climed to maximum quickly and then slowly declined. The time of release of ammoniaeal nitrogen was prolonged about three days by adding nitrification inhibitors.