Some Techniques for the Measurement of Plant and Soil Water Potentials with Thermocouple Psychrometers.

摘要

Studies of soil water-plant growth relationships have been hampered by the lack of an accurate,rapid method for the measurement of the tension (potential) water is under in the plant and in the soil. Recently a new method,called the thermocouple psychrometer technique has been developed whereby these measurements can be made. Thermocouple psychrometry is based on the assumption that the relative humidity near a leaf surface or in a soil mass reflects the water potential of that leaf or soil. The techniques involve measuring the relative humidity in or near a plant or soil system with ultra-fine thermocouples which,by employing the Peltier effect,can be made to function as psychrometers. The measurement of soil moisture stress with the thermocouple psychrometer is very rapid and relatively easy. (Author)