RATIONAL USE OF WATER RESOURCES WITH AUTOMATED CALCULATION OF IRRIGATION NORMS AND TIMINGfor CROPS ON THE IRRIGATED FIELD

Crop production is accompanied by a set of tasks, each of which for different soil and climatic conditions has its own characteristics and standards. Irrigation is one of the types of water reclamation in areas with insufficient and unstable natural moisture, aimed at preventing soil and partially atmospheric droughts. Determination of crops moisture supply and irrigation norms is the most important task when growing crops in arid regions. The objective of our work is to develop an automated information technology for decision-making during irrigation. The main indicators of moisture supply of the irrigated field is the reference, potential and actual evapotranspirations, crop water stress index. Indicators of moisture supply are determined according to the monitoring of agro/meteorological, physiological parameters of crops. For monitoring tasks in the Agro/physical Institute (St. Petersburg), an automated mobile field agro/meteorological complex (AMFAC) was created. The software of the complex allows real-time saving of synchronously measured data time series, which are used for automated calculation of reference, potential and actual evapotranspirations, crop water stress index and irrigation norms. As a result of the field experiments, methods for assessing the evapotranspiration and crop water stress index were tested. Automated information technology, including monitoring, the creation of a database, and computational algorithms for models of energy exchange in the «soil – plant – atmospheric surface layer» system can serve as the basis for an expert decision-making system for irrigation.