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The article analyzes available information on the application of the Internet of Things (IoT) for agriculture. It is pointed out that for large areas remote from cities and power supply sources for fields and farms, the construction of traditional communication channels is expensive enough, and classical mobile technologies for solving business problems are only partially suitable. Therefore, the article analyzes the practical approaches to using the Internet of Things (IoT) to monitor irrigated lands. The possibility of connecting soil moisture, temperature, pressure, direction and speed wind sensors based on LoRaWAN protocol to Internet gateways (base stations) without payment for cellular communication, additional power supply, deployment of complex Wi-Fi networks in the field was studied. Practical results on the characteristics of the sensors in the field, setting up a guaranteed LoRaWAN base station (gateway) connection, technical characteristics and causes of possible equipment malfunction were obtained. That is, the purpose of the study was to develop a budget solution for practical research and use of the Internet of Things (IoT) using the LoRaWAN protocol to monitor weather and soil moisture on irrigated lands. Among the main results of the study are the following. Equipment features and the specifics of sensors allocation and their terrain settings based on LoRaWAN protocol were studied, in particular: technical characteristics (operating frequencies, material, length, connection types and antenna placement height, radio signal transmission range and quality); use of different power sources (different types of batteries and solar panels surfaces); features of field operation (possible interference with radio signal propagation, dependence on the effect of pests, temperature fluctuations); encryption when exchanging data. A budget solution for monitoring meteorological indicators, soil moisture on irrigated lands was developed. A wireless monitoring network based on the LoRaWAN protocol was deployed in the irrigated fields of the SE ES of Askaniye of Kakhovsky District State in the Kherson region, consisting of 1 base station and 5 terminal units up to 2 km away. It was found that LoRa technology enables to control the channel expansion coefficient by determining the data transmitted over a period of time. It is determined that for the successful operation of wireless systems, an important issue is the proper radio planning and designing solutions for specific customer tasks. When deploying wireless networks, basic requirements for the reliability of the base stations and terminal units were identified and investigated. The developed budget solution for practical research and application of the Internet of Things (IoT) using the LoRaWAN protocol was compared with the Pessl Instruments GmbH and Davis Instruments Co brand developments to monitor weather, soil moisture on irrigated lands were. Among the most important findings are the development of a budget solution for monitoring meteorological indicators, soil moisture on irrigated lands consisting of 1 base station (gateway) of and 5 terminal units (monitoring stations). The coverage area of the base station with a base antenna for LoRaWAN was 0.6 km, with augmented and refined antenna - 2 km. Sensor data is advisable to transmit in 30-40 bytes per a send, with an expansion factor of SF = 12 without loss of quality. The best signal quality was ensured in the line of sight from the base station to the monitoring station.

The paper provides an overview of models and software used in decision support systems in irrigation. The models of biomass accumulation or evapotranspiration are the base of decision support systems in irrigation. The overview of the most famous systems is given, as well as an innovative irrigation control system "Irrigation online" is presented. The objective of the work is to share the experience of development and implementation of irrigation management systems and outline the ways of their improvement. The "Irrigation online" system consists of hardware and software components. The part of the system's hardware is located in the field consisting of iMetos or Davis weather stations, as well as of own-developed equipment. The software part, intended for storing, processing and providing recommendations, is hosted and run on a server. It sends the recommendations about start watering and necessary irrigation rates to a user’s computer or mobile device. The system is based on modelling of moisture transfer, automated measurements of soil moisture and meteorological indicators in the field and weather data from automated forecast web-sites. Water retention curve of  soil and the dependence of the moisture transfer coefficient on the head, which are the input parameters of the model, are given  for every layer according to the van Genuchten-Mualem Model. The application of the system took place in 2019 in SE EF“Askaniiske” Kherson region and LLC “APC “Mais” in Cherkasy region. The system "Irrigation Online" provided the recommendations on watering winter rape, wheat, corn, soybeans, alfalfa and potatoes. The system provided the recommendations on watering winter rape, wheat, corn, soybeans, alfalfa and potatoes. It was specified that the use of the system "Irrigation Online" enables to schedule irrigation regimes, the implementation of which requires watering with less (by 15-25%) in comparison with the current irrigation rates, due to which  more favourable conditions for the maximum realization of crop varieties and hybrids potential  are created. It is accompanied by enhancing the environmental safety of irrigation as a result of minimization of irrigation water losses for infiltration. Irrigation control system "Irrigation Online" uses a range of soil moisture suction pressure rather than a soil moisture range as an optimum moisture supply range for plants. For setting up irrigation terms and rates, the value of suction pressure, which corresponds to the part of water field capacity when it is determined by water retention curve of soil, is taken. The pre-irrigation threshold of suction pressure is the value, which at non-irrigation for some short period will not cause water stress for plants Monitoring of meteorological parameters and soil moisture level in the "Irrigation Online" system allows daily adjusting irrigation terms and rates for next 5 day period and significantly improves the accuracy of their forecasting.

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.