施用新型长效尿素对不同肥力土壤脲酶活性的影响

采用了康维皿连续培养法及土壤模拟培养, 对高、中、低三种不同肥力水平的土壤施用四种不同加工型号的长效尿素, 进行了脲酶活性与氨挥发量的测定及7天动态变化的比较。总体趋势表现为各种型号的长效尿素施用于高、中、低三种不同肥力土壤后, 均比施用普通尿素氨挥发量大大减少, 但不同尿素在不同肥力土壤中, 对脲酶活性抑制的速度、强度、抑制率以及氨挥发量与氨挥发率均不同。但以高、中肥力的土壤施用长效尿素, 其经济效益与环境效益最佳, 低肥土壤则应视具体情况来确定是否需施用添加有抑制剂的尿素以及施用哪种型号的长效尿素。

Effects of Applyingthe New Controlled-release Urea to Soils of Different Fertility on the Urease Activity

The determination of urease activity and ammonia volatilization and its comparison of dynamic changes within seven days were done in this paper by applying four different controlled-release urea to soils of high, medium and low fertility with the successive incubation diffusion utensil and soil simulation incubation.The quantum of ammonia volatilization reduced greatly in all treatment. But in soils of different fertility,inhibiting speed and extend of the urease activity and release rate of the two ureases were different as well as the quantum and rate of ammonia volatilization .The soils of high and medium fertility were much more profitable both in economy and in environment. By contrast, it depended on the idiographic soil that if the controlled-release urea containing incubation agent and what type of controlled-release urea should be applied to the low fertility soil.