Developmental Research for Constructing an Equipment to Measure Electrical Potential Generating in Crops

在试验的基础上，设计了一种测量植物表面电位的实验装置来估计作物在田间条件下的水分胁迫，并在不同营养和土壤水分条件下对几种作物进行了试验。该装置由Ag-AgCl电极与高阻抗电路（10^<12> ω）的前置放大器连接而成。在同一株植物茎表面的不同部位设置一对电极。用笔式记录仪和/或数据记录仪检测和记录两部分之间的电位差。该装置在不同营养液中培养的水稻，以及在不同土壤水分条件下生长的土豆和芸豆上进行了测试。通过该装置的初步观察，我们发现不同处理的植株之间的电位差异较大，大于100毫伏。在一些测量中也表明了作物电位的昼夜节律。但是，测量结果的可靠性仍然不足以在实地条件下普遍使用。我们还需要进一步改进现有的装置和方法，特别是如何使电极与植物表面接触。

An experimental apparatus on a trial basis designed for measuring electrical potential on a plant surface was made to estimate water stress of crops under field conditions, and tested with several crops grown under various nutritional and soil water conditions.The apparatus was made up from an Ag-AgCl electrode connecting with a preamplifier of a high impedance circuit (10^<12>OMEGA). A pair of two electrodes was contacted on the different parts of stem surface in one plant. The difference in electrical potential between the two parts was detected and recorded with a pen-recorder and/or a data-logger. The apparatus was tested with rice plants cultured in various nutritional solutions, and with potatoes and kidney beans grown under different soil water conditions.As a result of the preliminary observations with this apparatus, we detected relatively large differences, large than 100 mV,in electrical potential between the plants with different treatments. A circadian rhythm of electrical potential in the crops was also indicated in some measurements. However, the reliability of the measurements was still inadequate for common usage under field conditions. We further need some improvement of the present apparatus and of the method, especially how to make contact the electrode on a plant surface.