Ammonium and Nitrate as Nitrogen Sources for Plant Growth

氮是植物需要量最大的矿物元素，其可得性常常限制农业或自然系统的生长。植物主要以铵离子或硝酸盐离子的形式获得氮。虽然从理论上讲，从土壤中吸收铵和硝酸盐以及将这些离子同化为有机化合物应该是生命中最耗能的过程之一，但没有对与这些过程相关的能源成本进行直接测量。拟议的研究将使用新开发的植物材料和仪器来评估这些能源成本。本研究结果将提高肥料施用的能源效率。

Nitrogen is the mineral element that plants require in greatest amounts and whose availability often limits growth in agricultural or natural systems. Plants obtain nitrogen predominantly in the form of ammonium or nitrate ions. Although the absorption of ammonium and nitrate from the soil and assimilation of these ions into organic compounds should theoretically be among the most energy-intensive processes in life, no direct measurements of the energy costs associated with these processes have been made. The proposed research would use newly developed plant material and instrumentation to assess these energy costs. The results of this research should improve the energy efficiency of fertilizer applications.