【作者】 田霄鸿； 李生秀；

【Author】 Tian Xiaohong Li Shengxiu(Department of Natural Resources and Environment Sciences, Xinong District, Northwest Sci-Tech University of Agriculture and Forestry, Yangling, Shared 712100)

【机构】 西北农林科技大学西农校区资源与环境科学系；

【摘要】 应用改进常规耗竭法测定,并采用3种不同的表示吸收速率的单位,依据酶动力学方程V=Vmax×C/（Km+C）的两个直线转换式Lineweaver-Burke方程和Hofstee方程,经综合评价后求出冬小麦等5种不同类型作物的幼苗对NO₃^--N和NH₄⁺-N的吸收动力学参数km和Vmax。结果表明,大青菜、油菜和冬小麦对NO₃^--N的亲和力大于对NH₄^--N的亲和力,而黄瓜、大豆2种作物与此相反。供试作物苗期对NO₃^--N的亲和力大小依次为:大青菜>油菜>冬小麦>黄瓜>大豆（km值依次为314.8、362.2、792.4,947.9,2785.4μmol/L）,黄瓜和油菜对NH₄⁺-N的亲和力也较大。一定苗龄的作物幼苗对两种形态氮素的吸收动力学参数与同期幼苗对氮素的吸收量基本吻合。更多还原

【Abstract】 In this experiment the improved normal depletion method was adopted and NO3-N and NU4+ -N absorption dynamical parameters were determined according to two types of transformation a enzyme dynamical equation. The results showed that garden sass, cole and winter wheat had higher affinity to NO3-N than NH4+-N, but cucumber and soybean had opposite tendency.The affinity to NO3-N of five crops at seedlings stage in turns was garden sass > rape > winter wheat > cucumber > soyabean ( Km values are 314.8, 362.2, 792.4, 947.9, 2785.4umol/L, respectively) .Cucumber and rape had higher affinity to NH4+ -N at seedings stage, and generally speaking, absorption dynamical parameters of two forms of nitogen were indentical with nitrogen uptake by crop seedlings.更多还原