MONITORING RESEARCH OF FIELD SOIL MOISTURE TO PROVIDE IRRIGATION MANAGEMENT ON THE BASE OF AN EXPERIMENTAL AND CALCULATION METHOD

The article highlights the actual problems of monitoring studies of soil moisture and meteorological indicators for informational support of irrigation management systems. On the basis of literature analysis it is shown that soil moisture control can be carried out both directly on the results of soil moisture measurements and using calculated methods. In the presence of automatically obtained meteorological forecasting data, irrigation decisions are made using an experimental calculation method. Monitoring studies are part of the experiment and are used as feedback in soil moisture control. The purpose of the work is to develop an information component of soil moisture monitoring and meteorological indicators in the field to ensure a proper decision-making regarding irrigation by the experimental-calculation method. Soil moisture measurement is recommended using a variety of soil moisture sensors by indirect methods of determination. Various tensiometers, dielectric and resistive sensors can be used as sensors. They provide the feedback for irrigation management. The calculation part consists of the decision criterion for the beginning of irrigation, the balance method of calculating soil moisture or moisture reserves in the soil (or a multilayered mathematical model of moisture transfer in the presence of sufficient input parameters for that) using automatic meteorological forecast. The article is illustrated by the results of a laboratory model experiment and field research with automated measurement data transmission and feedback implementation in soil moisture control. The model laboratory experiment was used to test the design, technical and technological parameters of the equipment for automatic monitoring and testing of the experimental-calculation method. Practical forecasts, calculations and data acquisition of soil moisture and meteorological indicators for the implementation of feedback during the irrigation management are considered based on the example of a corn field in one of the experimental farms. The results of the laboratory experiment and field studies show the effectiveness of predicting soil moisture by this method. Monitoring data of soil moisture and meteorological indicators is the feedback. They are automatically transmitted and improve the accuracy of irrigation recommendations and allow for quick adjustments to forecast calculations. It is recommended to make daily soil moisture correction for direct automated field measurements using ground sensors. Further research in this area is to use one-dimensional multilayer models of moisture transfer. They provide accurate results but require more input parameters.