Effect of agrotechnological elements on milk thistle (Silynum marianum) productivity

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

Ocena wiarygodności programu CROPWAT 8.0 do obliczania ewapotranspiracji i zapotrzebowania roślin na wodę

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 dripirrigated 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.W artykule przedstawiono wyniki badań poświęconych ocenie dokładności i wiarygodności obliczeń ewapotranspiracji i zapotrzebowania roślin na wodę z zastosowaniem programu CROPWAT 8.0. Podstawą badań były wyniki wieloletniego eksperymentu polowego prowadzonego od 2012 do 2017 r. na nawadnianych polach południowej Ukrainy z różnymi uprawami: kukurydzy cukrowej, kukurydzy zwykłej, soi i sorgo. Oceniono dokładność wyników uzyskanych za pomocą CROPWAT 8.0 przez porównanie wartości obliczonych z wartościami rzeczywistymi. Stwierdzono znaczne różnice między obliczonymi wartościami ewapotranspiracji upraw i ich zapotrzebowaniem na wodę a wartościami rzeczywistymi z eksperymentów polowych. Największe różnice stwierdzono w przypadku kroplowo nawadnianych upraw kukurydzy cukrowej i wynosiły one 46,05% w odniesieniu do ewapotranspiracji i 89,20% do zapotrzebowania na wodę do nawodnień. Obliczenia ewapotranspiracji za pomocą CROPWAT 8.0 były bardziej dokładne w odniesieniu do upraw nawadnianych deszczowniami. Najmniejszą rozbieżność między obliczonymi a rzeczywistymi wartościami badanych parametrów stwierdzono w przypadku deszczowanych upraw kukurydzy zwykłej, gdzie różnice wynosiły 15,86% w odniesieniu do ewapotranspiracji i 41,63% do norm nawadniania. Wyniki badań dają podstawy do wnioskowania, że CROPWAT 8.0 nie powinien być stosowany bez wstępnej kalibracji i dostosowania współczynników upraw do konkretnych warunków produkcji rolniczej