EN
The main problem of agrophysical metrology in field experiment is the development of monitoring systems of physical parameters, characterizing soil, canopy and agroclimatological factors. The monitoring systems give us a possibility of describing and analyzing spatial and time variability of physical parameters determining the plant growth conditions. The main feature of the measuring detectors is the device, which makes it possible to transform any measured physical value into electrical signal. This signal can be easily sent, transformed and recorded. The analog electrical value is most frequently transformed into the digital form and can be easily sent, transformed and recorded in the computer memory. In the Institute of Agrophysics the method and equipment has been elaborated for soil water content measurement using time domain reflectometry (TDR). This method is based on the measurement of the velocity of electromagnetic pulse propagation in the investigated medium. The elaborated device enables the measurement of the moisture, electrical bulk conductivity and temperature simultaneously. The knowledge of bulk electrical conductivity and electrical permitivity makes it possible to determine soil salinity by calculation of salinity index value. The laboratory version of the reflectometric meter of soil water content, additionally equipped with the detectors for the measurement the soil water potential enables to determine the soil water retention curve and the water transport characteristics in the soil. These soil characteristics are the parameters used in the models describing water, salt and heat movement in the soil-plant-atmosphere system. Thermal images technology can be used for the investigations of plant water stress and for the actual evapotranspiration estimation.