The article highlights the research results on the assessment of natural moisture supply in Ukraine, the state of water resources and agricultural production in the face of modern climate change taking into account the forecast for the medium and long term prospects. It was established that the rate of air temperature growth for the period of 1975-2019 in Ukraine ranges from 0.61 to 0.82oC, while in neighboring post-Soviet countries (Russia, Moldova, Belarus) – this figure is 0.47 - 0.59oC, and in the northern hemisphere and Europe – it is 0.34 and 0.47oC respectively. These data show that the rate of air temperature rise in Ukraine is much higher compared to European countries and the whole world. The rapid rise in average annual temperature in Ukraine is not accompanied by a significant increase in precipitation. Its amount in Ukraine as well as in some other regions remains virtually unchanged. Due to the steady increase in temperature, the area of ​​Ukraine with a significant deficit of natural moisture supply for the period of 1990-2015 increased by 7%, and with excessive and sufficient natural moisture supply, on the contrary, decreased by 10%. If the current warming rates are kept until 2050 and 2100, the territory of the country with insufficient humidity will increase up to 56 and 71%, respectively. As a result of such changes, there is a high probability of medium and long-term prospects of increasing arable land with insufficient natural moisture supply up to 20.6 million hectares (67%) and up to 24.9 million hectares (80%) with a simultaneous decrease in arable land with sufficient natural moisture supply up to 5.5 - 1.8 million hectares. At present, the potential total evaporation is 40-45 km3/year higher than in 1990. As a result, despite the decrease in water consumption, the total amount of water consumption taken from the territory of Ukraine is 20-25 km3 higher. Further climate change will lead to an increase in the volume of additional water consumption till 2050 by 80 km3, and till 2100 - by almost 150 km3 compared to 1990. Modern climate change has significantly affected the cropping systems and their productivity at regional level. The average yield of grain and legumes in the Forest-Steppe and Polissya compared to 1990 increased by 46-61%, and in the Steppe it decreased by 10%. A similar trend is observed with regard to the changes in the productivity of other major cereals, except corn, the yield of which increased in all areas, but in the Forest-Steppe and Polissya by 71-82%, and in the Steppe - only by 9%. The general increase in the production of grain and legumes in the country for the last years was only due to more humid regions - Polissya and Forest-Steppe. Climate change, which has already taken place, proved to be favorable for the spread of the most economically profitable crops in the north of the country, while limiting their production in the south. Thus, in the face of climate change, the conditions of moisture supply in the territory of Ukraine are the main limiting factor that limits not only the level of crop productivity, but also the use of natural and anthropogenic potential of agriculture.

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Climate change has caused rapid soil dehydration in Ukraine; therefore sustainable agriculture will only be possible applying throughout irrigation or water regulation. Meanwhile, the use of the irrigation and drainage systems potential remains extremely unsatisfactory. In 2019, 532,000 ha were actually irrigated, and water regulation was performed on less than 300,000 ha. The purpose of the research. To analyze the existing state and substantiate the areas of the irrigation and drainage sector development to ensure the sustainable agriculture in the face of a changing climate. Materials and methods of the research. In the work, a set of methods was used: analytical, expert evaluations, surveys, comparisons and analogues, experimental. Observation data from the state meteorological stations network were used to evaluate hydrothermal conditions and the data from the network of hydrological posts of Ukrhydrometcentre were used to evaluate the river condition. To assess the technical condition of the engineering infrastructure, methodological approaches were used in accordance with the requirements of the international and European standards and the normative documents currently in force in Ukraine. To identify the possible ways and mechanisms to restore the irrigation and drainage systems potential, the reasons of the existing state were analyzed and it was determined that the uncompleted land and economic reforms, imperfections in the existing legislation and state support mechanisms, especially in the sector management, caused the long-year underfunding of irrigation and drainage facilities operation and restoration and resulted in the crisis situation in the sector. Conclusions. Based on the study of the world experience and the carried out research, it was established that the restoration and development of irrigation and drainage in Ukraine are possible only along with the implementation of a legal and institutional reform to introduce decentralization, improvement of the existing legislation, modernization of irrigation and drainage systems through the development and implementation of investment projects for restoration and development of irrigation and drainage systems, creation of attractive investment environments, development and introduction of a financing mechanism to cover management, operation and maintenance costs based on a new tariff formation system, introduction of the scientific support and staffing system for the land reclamation sector. The basis for the deployment of irrigation and drainage restoration should be the "Irrigation and Drainage Strategy in Ukraine until 2030", and the appropriate plan of measures, formed on the basis of fundamentally new institutional, scientific, technical and technological, economic, organizational, social and environmental approaches, should become a tool for achieving the goals of the "Strategy ...". Successful implementation of the goals of irrigation and drainage restoration in Ukraine will create the conditions to sustainable and profitable agricultural production in the face of climate change, to restore irrigation on the area of about 1,0 to 1,2 mln. ha and drainage on the area of 1,0 mln. ha and to additionally get up to 10 mln. tons of grain, 8-10 mln. tons of fruit, berries and vegetables annually.

Microirrigation is by far the most progressive irrigation method, with efficiencies reaching 92-98 %. According to the International Commission on Irrigation and Drainage, the world's agricultural land, which is irrigated through micro-irrigation systems, is constantly growing and now stands at over 20 million hectares. By the "Irrigation and drainage strategy in Ukraine until 2030" micro-irrigation methods are defined as one of the strategic directions of the state policy of the branch. Research on the direction of "micro-irrigation of crops" in Ukraine began from the late 60's of the last century. The historical aspect of the development of research in this area is thoroughly covered in previous scientific papers. Therefore, the purpose of this study is a comprehensive analysis of the basic fundamental and applied results of research of the scientific school on micro irrigation IWPaLR NAAS in the early XXI century and substantiation of perspective directions of their development. Using theoretical methods of scientific research (analysis and synthesis, comparison, classification and generalization), the authors systematized the most significant scientific results in terms of normative, methodological, technical and technological components. The list of normative and methodological documents prepared by IWPaLR NAAS in the direction of microirrigation is given. The results of developments in the technological component are detailed according to the research objects: water regime and processes of water consumption of crops, fertigation, pestigation, the influence of local moistening, fertilizers and water of different quality on the soil-plant-technical means of irrigation system, the formation of soil moisture zones, methods of appointment timing of vegetation irrigation and irrigation management systems. The key scientific results of the irrigation facilities’ testing laboratory are highlighted. The list of developed and implemented by the IWPaLR NAAS technical means of microirrigation systems is given. The strategic directions of further scientific research are substantiated, which should meet the global trend for environmentally friendly irrigation, as well as resource and energy conservation. The need of Ukraine in the systems of microirrigation of agricultural crops for the period up to 2030, the role of current and future developments of the scientific school of micro irrigation IWPaLR NAAS on their implementation are determined.

<p>Climate change manifested in Ukraine by rapid (over 0.6<sup>o</sup>C in 10 years) increase in average annual air temperature causes a progressive deterioration of natural water supply significantly increasing the need for irrigation to ensure sustainable agriculture.</p><p>"Irrigation and Drainage Strategy in Ukraine until 2030" provides for an  increase of irrigated lands area up to 1.5-1.7 million hectares and the corresponding significant increase in water consumption from the current 1.5-1.8 billion m<sup>3</sup> to 5-6 billion m<sup>3</sup>. Given that climate change has a negative impact not only on the state of natural water supply, but also on the state of available water resources, their rational use in irrigation is an important component of sustainable water management.</p><p>Effective tools for its implementation in irrigation are decision support systems. Their usage provides a capability to achieve maximum irrigation efficiency when complying with the following provisions:</p><p>- Irrigation should maintain root layer moisture content in a narrow range of high values (from 0.8-0.85 of field capacity to field capacity);</p><p>- Tensiometric pressure should be used as a criterion of moisture content and moisture availability for plants;</p><p>- Water retention curves should be used to determine field capacity, pre-irrigation thresholds, and optimal ranges of moisture available to plants;</p><p>- Moisture transfer models for saturated-unsaturated soils stated in terms of pressure can accurately predict irrigation schedules and rates;</p><p>- The combined use of several methods for evapotranspiration assessment improves the accuracy of calculations;</p><p>- Remote sensing data can be used to tranfer irrigation schedules and rates predictions to the areas not covered by instrumental monitoring tools.</p><p>The application of these principles provides for</p><p>- an increase in crop yields accompanied by irrigation water volumes reduction;</p><p>- irrigation with environmentally friendly rates minimizing water losses for infiltration, and the development of flooding and secondary salinization processes.</p><p>The introduction of these principles in practice will increase the sustainability of water management in agriculture in the conditions of climate change, and the use of decision support systems at full scale will ensure the maximal materialization of the potential of crops’ varieties and hybrids.</p>