DEFINITION OF FUNDAMENTAL IRRIGATION OPERATORS, TAKING INTO ACCOUNT SOIL MOISTURE CONTENT VARIABILITY

The purpose of the research is the development of an algorithm for determining the fundamental operators of irrigation control taking into account the variability of soil moisture reserves. Materials and Methods. The basic tasks of irrigation control such as the need for irrigation and the technological parameters of this irrigation are considered as the fundamental operators. The main research methodological approaches are: the concept of a unified algorithmic construction for determining the main irrigation operators, solving the problem of taking into account the variability of soil moisture content at two levels – on the area and on the soil profile, refusal to use the average humidity of the active soil layer as the main requirement criterion for irrigation. Results. The algorithm solving these problems on the basis of quantitative estimates of average humidity, moisture distribution over the soil profile and variability of moisture reserves over the irrigated area is proposed. The algorithm is presented by three sequentially organized calculation blocks, each of which solves an independent task in accordance with the above mentioned sequence. Computing procedures for solving the tasks in each of the considered algorithmically organized blocks are disclosed. The task based on average estimates of the active soil layer moisture content has a classical solution. The problem based on data on the layer-by-layer moisture distribution in soil profile is solved by sequentially evaluating the layer-by-layer data dispersion as well as the soil layer thickness with moisture below the threshold level. Conclusions: the problem of using the differential precipitation distribution mode is solved on the basis of determining the variability of average estimates of soil moisture by area of the irrigated plot. The result of the algorithm solution is the determination of requirement for irrigation at the estimated date, as well as its main technological parameters, including the irrigation rate and the need for a differentiated precipitation distribution over the irrigated area.