Abstract: The preliminary results of our findings are summarized as follows:1. Annual variation of the urease activity of citrus orchard soil of red earth in southern subtrOpics. The urease activity was the lowest in winter, it rose quickly during spring and dropped gradually in summer and Autumn. 2. The hydroquinone was selected for laboratory test as urease inhibitor. The results showed that the hydroquinone exhibited significant inhibitive effect. The inhibitory rate increased as the increased concentration of hydroquinone while decreased with the increase of culture time. Duration of urea hydrolysis with the application of hydroquinone is once as long as that of the control.

Key words: Citrus orchard soil, Seasonal variation, Urease activity, Inhibitor, Hydroquinone

摘要： 本研究初步探明南亚热带赤红壤柑桔园土壤脲酶活性的年周期变化:冬季最低,春季升至高峰,夏季开始下降,直至秋季仍处于较低水平。室内模拟试验表明:氢醌对柑桔园土壤脲酶活性有明显抑制作用,其抑制率随浓度提高而增加,且随着培养时间的延长而逐渐下降;添加氢醌处理的尿素水解持续时间,比不加氢醌的延长约1倍。

关键词: 柑桔园土壤, 脲酶活性, 年周期变化, 抑制剂, 氢醌