The results of the study devoted to assessment of accuracy and reliability of the CROPWAT 8.0 software application calculations of the evapotranspiration and crop water requirements are represented in the article.The study was based on the results of the perennial field experiments, conducted during the period from 2012 to 2017 at the irrigated lands of the South of Ukraine with different crops, namely: sweet corn, grain corn, soybean, sorghum. We assessed accuracy of the CROPWAT 8.0 software application by the comparison of the calculated values with the real ones. We determined considerable differences between the calculated crops evapotranspiration values and crops irrigation requirements and the real ones obtained in the field experiments. The difference was the most essential in case of the drip-irrigated sweet corn crop and averaged to 46.05% for evapotranspiration and 89.20% for irrigation water requirements, correspondingly. Overhead sprinkler irrigated crops are likely to be more suitable for accurate evapotranspiration prediction by using the CROPWAT 8.0. The slightest discrepancy between the calculated and actual values of the studied parameters were determined on the overhead sprinkler irrigated grain corn crops, where the differences averaged just to 15.86% for evapotranspiration and 41.63% for irrigation norm. The results of the study gave us an opportunity to conclude that CROPWAT 8.0 software application should not be used without previous calibration and adjustment of the crop coefficients for the concrete agricultural production conditions.

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Over the last few years, hydrogen energy has shifted from a little-studied field to the main one with which leading western countries associate the prospects of their national economies. The reasons are the unprecedented pace of development of hydrogen technologies. It turned out that they are able to provide significant reductions in greenhouse gas emissions, and thus bring closer the solution to the problem of global climate change. The first and foremost purpose of our investigation is to reveal that our country has ample opportunities to become the main supplier of hydrogen to the EU market, overtaking North Africa in the competition. Using the methods, authors studied the targets of the European funds towards development of energy production from biohydrogen, studied the potential for the implementation of hydrogen projects, possibilities of financing them and a potential ability of Ukraine to form internal and external markets for hydrogen energy. One of the main issues of Ukraine's possible participation in Europe's hydrogen energy program as a supplier and producer of renewable hydrogen is the possibility of its technically safe and cost-effective transportation to EU countries. As a conclusion to the authors’ research, the path of the hydrogen industry development in Ukraine will help to receive additional investments in the Ukrainian economy for creation of new capacities for "green" hydrogen production. In return, Europe will receive research and evolution of the bioenergy component of the economy, which will permit the safe transition of Europeans to an affordable, competitive, and stable energy system.

Херсонський державний аграрно-економічний університет С. В. КОКОВІХІН, доктор сільськогосподарських наук Інститут зрошуваного землеробства НААН В. О. ЧАБАН, кандидат сільськогосподарських наук Херсонська державна морська академія С. О. ЛАВРЕНКО, кандидат сільськогосподарських наук А. В. ШЕПЕЛЬ, кандидат сільськогосподарських наук Херсонський державний аграрно-економічний університет У статті проаналізовані багаторічні експериментальні дані ефективності багаторічного вирощування шавлії лікарської та вплив агротехнічних приймів вирощування на водно-фізичні властивості темнокаштанового залишково-солонцюватого ґрунту. Рівень урожайності суцвіть шавлії мускатної під час збору був стабільним упродовж трьох років використання. У середньому в перший рік вона складала -9,51, за другий рік -9,38, третій -9,69 т/га. На четвертому році використання посівів (п'ятий рік життя) середня врожайність знизилася до 1,40 т/га. Найвищий умовний збір ефірної олії -51,1 кг/га забезпечило внесення мінеральних добрив нормою N 60 P 90 . Скошування суцвіть культури доцільно проводити або у ранішні (з 6 до 11) або в вечірні години (з 19 до 22). Вдень (з 11 до 19 години) скошування суцвіть культури не проводити. Ключові слова: шавлія мускатна, обробіток ґрунту, строк сівби, ширина міжряддя, мінеральні добрива, водопроникність ґрунту, урожайність, олія. Постановка проблеми. Однією з причин, яка не дає стрімкого розвитку виробництва лікарських трав -це глобальні кліматичні зміни, дефіцит водних ресурсів та зростання вартості енергоресурсів [2]. Аналіз останніх досліджень і публікацій. За даними NASA у 2016-2019 рр. температура поверхні Землі сягнула максимальних показників з часу yield decreased to 1,40 t/ha. The application of mineral fertilizers contributed to the increase of essential oil synthesized by plants. Against the natural background of fertility, the highest conditional harvest was 5,05 kg/ha. The application of mineral fertilizers by the N 60 P 30 norm led to an increase in the rate to 14,45 kg/ha. The highest conditional harvest of essential oil -51,1 kg/ha provided the application of mineral fertilizers by the rate of N 60 P 90 . It is advisable to mow the inflorescences of the culture either in the morning (from 6 to 11) or in the evening (from 19 to 22). In the afternoon (from 11 to 19 oclock) mowing of inflorescences of culture not to spend.

The milk thistle is a highly valuable medicinal plant, widely used in treatment of liver diseases. Soil-climate conditions of the steppe zone of Ukraine are favourable for crop cultivation. The goal of the study was to determine relations between milk thistle productivity and elements of cultivation technology, viz., primary tillage depth (14–16 and 20–22 cm), inter-row spacing (30, 45, 60 cm), timing of sowing (3rd decade of March, middle of April, 3rd decade of April) and mineral fertilizer application doses (no fertilizers, N45P45, N90P90). Field trials were carried out during the period from 2010 to 2012 on the irrigated lands of the Institute of Rice of the National Academy of Agrarian Sciences of Ukraine by using the split plot design method in four replications. The climate of the territory of the trials is typical for the steppe zone. The soil type was dark-chestnut residual solonetz middle-loamy soil. We used the Yuhoslava variety of milk thistle in the trials. Cultivation technology was standard, excluding the studied factors. The results of the trials showed significant impact of all the studied cultivation technology elements on milk thistle seed and oil yields. The maximum average seed (1.66 t/ha) and oil (489 kg/ha) yields were obtained under the primary tillage at the depth of 20–22 cm, inter-row spacing of 60 cm, sowing in the 3rd decade of March, applying mineral fertilizers in a dose of N90P90. The highest input in seed and oil yields rise was made by the mineral fertilizers, which increased milk thistle productivity by 1.57 times comparatively with non-fertilized treatments. We also established a strong direct interrelationship between seed and oil yield: coefficient of determination was 0.96. Results of the current study are slightly limited, so further investigations in the field of milk thistle cultivation technology development and improvement are required to provide Ukrainian farmers with scientifically grounded agrotechnology of this valuable medicinal plant.