Typical hydrothermal conditions of the Right-bank Forest-step zone and their influence on corn productivity

2019 ◽  
pp. 55-64
Author(s):  
A. Malienko ◽  
N. Borys
Keyword(s):  
Sharp Decrease ◽  
Weather Conditions ◽  
Vegetation Period ◽  
Forest Steppe ◽  
Corn Yield ◽  
Hydrothermal Conditions ◽  
Hydrothermal Coefficient ◽  
Adverse Weather ◽  
Corn Productivity ◽  
The Right

Corn is a highly productive crop of universal purpose, which is grown for food – 20–25 %, forage – 60–65 and technical purposes – 15–20 %. Increasing its yield is possible due to the improvement of the elements of the technology of cultivation taking into account biological characteristics. The growth and development of corn, the production of high yields, as well as the improvement of the quality of the main products are determined by factors of anthropogenic origin and weather conditions. Hydrothermal conditions of Ukraine have already begun to change significantly during the last decades, which resulted in a shift in the climatic seasons, changes in the vegetation period duration (depending on the zone and the biological features of the crops it can either decrease or expand), the decrease in the duration of a stable snow cover, changes in water resources of local drainage. The period 2005–2016 was analyzed for the reliable estimation of the typicality of weather conditions and their influence on the corn productivity under the following basic cultivation methods: ploughing at the depth of 28–30 cm (control), flat-cut tilling at the depth of 28–30 сm, chisel ploughing at the depth of 43–45 cm and disking at the depth of 10–12 cm. The dynamics of precipitation in the northern part of the Right Bank Forest Steppe during the corn vegetation period for the last 2005–2016 testifies to the noticeable tendency of increasing the amount of precipitation in May-June and their sharp decrease in July-August. It was determined that the conditions for eight years – 2006–2008, 2011–2014 and 2016 were optimal for their hydrothermal indices for the production of corn yields at the level of 5.83–9.47 t/ha. The hydrothermal coefficient for vegetation was 1.13–1.76. Weather conditions were unfavorable in 2005, 2009–2010, and 2015 with the amount of precipitation for vegetation of 120–288 mm, which is below the long-term amount by 120 mm, or 36 %. The peculiarity of these years was 37–61 % lower precipitation level in June–July with the grain yield of 3.12–6.51 t/ha. The mathematical-statistical analysis allows to characterize features and typicality of weather conditions of 2005–2016 and to estimate the influence of hydrothermal years and separate months on corn crops productivity. It has been established that there is the following correlation between weather conditions in July and the yield of corn: high correlation for disk soil cultivation (r=0.75–0.86), the average – for ploughing and chyzel loosening (r=0.49–0.53). Thus, the formation of a deep layer of soil with the best water–physical characteristics and fertility in these cultivation modes reduced the dependence of the elements of yield formation from the adverse weather conditions and provided a higher yield of corn by 6.0–8.0 %. Key words: hydrothermal conditions, hydrothermal coefficient (HTC), vegetation period, corn yield.

scholarly journals Evaluation of climate change influence on agroclimatic conditions of sunflower growing in Ukraine

2017 ◽  
pp. 86-92
Author(s):  
О.L. Zhygailo ◽  
T.S. Zhygailo
Keyword(s):  
Climate Change ◽  
Comparative Analysis ◽  
Climate Change Scenario ◽  
Weather Conditions ◽  
Vegetation Period ◽  
Change Scenario ◽  
Forest Steppe ◽  
Precipitation Regime ◽  
Temperature And Precipitation ◽  
The Right

The problem of climate change and global warming both in whole and in particular has become one of the most serious and urgent directions of scientific and technical activity at the present stage. The future food security of Ukraine depends on the effectiveness of adaptation of agriculture to new conditions dictated by the global anthropogenic warming. In order to evaluate possible impact of climate change in Ukraine on agroclimatic indicators the scenario A1B - "moderate" was used providing a balance between all energy sources. Researches of sunflower harvest formation are carried out using a dynamic model of agricultural crops productivity. For a comparative analysis of scenary meteorological variables with previous data the period from 1986 to 2005 is taken from agroclimatic directory of Ukraine. It serves as a base when performing calculations. According to calculations of A1B climate change scenario, periods of sowing and subsequent phases of development will occur earlier than at present, which will lead to reduction of the whole vegetation period at most parts of the area under study. As a result of comparative analysis of temperature and precipitation regime it was found that, subject to implementation of the climate change scenario under study, expected weather conditions will be more favourable for cultivation of sun-flower in the Western and Central forest-steppe, as well as at the Right-Bank Ukraine and in the Donetsk sub-zone of Northern steppe of Ukraine.

Peculliarities of seasonal the plum fruit moth (Grapholita fune-brana Tr.) flight dynamics of in plum orchards (Prunus domestica L.)

2020 ◽  
pp. 78-86
Author(s):  
I.V. Shevchuk ◽  
Keyword(s):  
High Intensity ◽  
Flight Dynamics ◽  
Weather Conditions ◽  
Vegetation Period ◽  
Forest Steppe ◽  
Summer Generation ◽  
Two Factors ◽  
Sum Of Effective Temperatures ◽  
The Right ◽  
In The Beginning

As a result of the long-term (2011-2018) researches in plum orchards the intensity types of the plum fruit moth butterflies flight seasonal dynamics – low, normal and high have been established which are observed during the vegetation period. The two latters are dangerous for crop so they are problematic for producers and require the flight dynamics control. The weather conditions indicators have been systematized. The mathematical parameters have been determined between those indices and the insect imago population density. The types of intensity of the seasonal flight dynamics (low, normal, and high) that can be observed during the vegetation period have been established. The onset of the imago flight of the plum fruit moth after overwintering at the normal intensity is observed under the sum of effective temperatures (SET) of 80.9 and precipitations up to 33.1 with a probability of 0.545, whereas at high the intensity these indicators were 116.0 °C, 26.3 mm and 0.273 respectively. As for the generation which overwintered the usual flight type of G. funebrana Tr. has been noted at SET 332.7, precipitations 44.8 with a probability of 0.636, and high type, at 410.1 °C, 37.5 mm and 0.182 respectively. The summer generation under the normal intensity developed at SET 710.7, precipitations sum 48.3 and probability 0.555, at high intensity, 604.3 °C, 52.6 mm and 0.364 respectively. In the right-bank part of the Western Forest-Steppe of Ukraine, the imago flight began at the end of April – in the beginning of May. The imago flight ends mostly at the end of September but may last until mid-October when autumn is warm. The average number of the butterflies of the generation wich overwintered under normal and high intensity types, varied to 15.1 and 20.9 respectively, and in the summer generation decreased to 7.8 and 10.5 specimens. Under the low intensity type, the amount of imago after wintering average at 5.0 and for the summer generation 5.8 specimens. The maximum G. funebrana density after wintering under the normal and high types of flight intensity was 19.4 and 30.1 and for the summer generation 15.7 and 27.1 specimens respectively. These figures under the low flight intensity for the both generations were 8.7 and 5.9 specimens respectively. The analysis of variance showed that the average imago number in traps (56.9 %) was determined by the intensity type, the generation share was 24.7 %, and the interaction between the two factors was within 12.6 %. The maximum imago trapping rates depended mainly on the intensity type – 90 %, and the other factors proportions studied were 3.3 and 6.7 %.

scholarly journals The Typicality of Hydrothermal Conditions of the Forest Steppe and Their Influence on the Productivity of Crops

2020 ◽  
Vol 76 (3) ◽  
pp. 84-95
Author(s):  
Andrii Butenko ◽  
Dmytrо Litvinov ◽  
Natalia Borys ◽  
Olena Litvinova ◽  
Ihor Masyk ◽  
...  
Keyword(s):  
Air Temperature ◽  
Spring Barley ◽  
Weather Conditions ◽  
Maize Yield ◽  
Vegetation Period ◽  
Steppe Zone ◽  
Forest Steppe ◽  
Hydrothermal Conditions ◽  
The Impact

Analysis of changes in hydrothermal conditions of growing crops in the forest steppe zone of Ukraine over a period of 2004–2016 showed that by the average monthly air temperature more than a half of the years under study and by rainfall nearly a third of the researched period differed significantly from the average long-term value and were close to extreme weather. Statistical analysis of long-term indicators of the air temperature regime is evidence of a steady trend towards an increase in average annual air temperature with significant fluctuations in indices in separate periods from 7.9 ± 2.9 to 10.0 ± 2.5oС and a decrease in the amount and instability of natural moisture entry. The influence of weather conditions on the formation of productivity of spiked cereals (winter and spring wheat, spring barley) and maize was assessed at the current agrometeorological risks in the forest steppe of Ukraine. Based on the correlation-regression analysis, mathematical models were created that reproduce the dependence of grain yields upon the complex weather conditions of the growing season, the impact of which reached 60–70%. The conditions of eight years (2006–2008, 2011–2014 and 2016), when the hydrothermal index for the vegetation period was 1.13–1.76, turned out to be optimal by hydrothermal indicators to harvest maize yield at 5.83–9.47 t/ha. However, the years of 2005, 2009–2010 and 2015 were unfavorable as they received precipitation by 120 mm lower than a norm or 36% of the norm. The rainfall by 37–61% lower than a norm in June–July and grain yield 3.12–6.51 t/ha were also characteristic of the years mentioned above.

Irrigation regime and water consumption of potatoes in the Republic of Bashkortostan, depending on the reclamation condition of lands

2020 ◽  
Vol 0 (6) ◽  
pp. 13-19
Author(s):  
Guzel Gumerova ◽  
Georgiy Gulyuk ◽  
Dmitry Kucher ◽  
Anatoly Shuravilin ◽  
Elena Piven
Keyword(s):  
Water Consumption ◽  
Weather Conditions ◽  
Growing Season ◽  
Vegetation Period ◽  
Forest Steppe ◽  
Total Water ◽  
Total Water Consumption ◽  
Republic Of Bashkortostan ◽  
Irrigated Lands ◽  
The Republic

Data of long-term researches (2015–2018) in southern forest-steppe zone of the Republic of Bashkortostan, is justified theoretically and experimentally the mode of irrigation of potatoes on leached chernozems of unsatisfactory, satisfactory and good ameliorative condition of irrigated lands. For the growing periods of potatoes with different heat and moisture supply, the number of watering, the timing of their implementation, irrigation and irrigation norms are established. On lands with unsatisfactory meliorative state the number of irrigation depending on weather conditions of potato vegetation period varied from 0 to 3 (1.5 on average) with average irrigation norm – 990 m3/ha. With satisfactory meliorative state of lands the number of irrigation on average increased from 0 to 4 (2.3 on average) with irrigation norm – 1305 m3/ha. On lands with good meliorative state the number of irrigation was the highest – from 1 to 5 (3 on average) with average irrigation irrigation norm is 1653 m3/ha. It was noted that in the dry periods of potato vegetation the greatest number of watering was carried out (3–5 watering), and in the wet periods (2017) watering was not carried out except for the area with a good reclamation state, where only one irrigation was carried out by the norm of 550 m3/ha. Water consumption of potato was studied in dynamics as a whole during the growing season and the months of the growing season depending on weather conditions of vegetation period and land reclamation condition of irrigated lands, as well as in the control (without irrigation). The lowest total water consumption was in the area without irrigation and averaged 226.8 mm. In irrigated areas, its values increased to 319-353.4 mm. The average daily water consumption varied from 2.12 to 3.3 mm. The highest rates of potato water consumption were observed in June and July, and the lowest – in May and August. In the total water consumption of potatoes on the site without irrigation, the largest share was occupied by atmospheric precipitation and in addition to them the arrival of moisture from the soil. Irrigation water was used in irrigated areas along with precipitation, the share of which was 30.2–46.1 %.

Influence of meteorological factors on potato yield in the conditions of the Right-Bank Forest-steppe

2018 ◽  
Vol 1 (94) ◽  
pp. 55-61
Author(s):  
R.O. Myalkovsky
Keyword(s):  
Meteorological Factors ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Potato Yield ◽  
High Yield ◽  
Forest Steppe ◽  
Potato Tubers ◽  
Middle Aged ◽  
Lower Yield ◽  
The Right

Goal. The purpose of the research was to determine the influence of meteorological factors on potato yield in the conditions of the Right Bank Forest-steppe of Ukraine. Methods.Field, analytical and statistical. Results.It was established that among the mid-range varieties Divo stands out with a yield of 42.3 t/ha, Malin white – 39.8 t/ha, and Legend – 37.1 t/ ha. The most favourable weather and climatic conditions for the production of potato tubers were for the Divo 2011 variety with a yield of 45.9 t/ha and 2013 – 45.1 t/ha. For the Legenda variety 2016, the yield of potato tubers is 40.6 t/ha and 2017 – 43.2 t/ha. Malin White 2013 is 41.4 t/ha and 2017 42.1 t/ha. The average varieties of potatoes showed a slightly lower yield on average over the years of research. However, among the varieties is allocated Nadiyna – 40.3 t/ha, Slovyanka – 37.2 t/ ha and Vera 33.8 t/ha. Among the years, the most high-yielding for the Vera variety was 2016 with a yield of 36.6 t/ha and 2017 year – 37.8 t/ha. Varieties Slovyanka and Nadiyna 2011 and 2012 with yields of 42.6 and 44.3 t/ha and 46.5 and 45.3 t/ha, respectively. Characterizing the yield of potato tubers of medium-late varieties over the years of research, there was a decrease in this indicator compared with medium-early and middle-aged varieties. However, the high yield of the varieties of Dar is allocated – 40.0 t/ha, Alladin – 33.6 t/ha and Oxamit 31.3 t/ha. Among the years, the most favourable ones were: for Oxamit and Alladin – 2011 – 33.5 and 36.5 t/ha, and 2017 – 34.1 and 36.4 t/ha, respectively. Favourable years for harvesting varieties were 2011 and 2012 with yields of 45.7 and 45.8 t/ha. Thus, the highest yield of potato tubers on average over the years of studies of medium-early varieties of 41.2-43.3 t / ha were provided by weather conditions of 2011 and 2017 years, medium-ripe varieties 41.0-41.1 - 2012 and 2011, medium- late 37,6-38,5 t / ha - 2012 and 2011, respectively.

scholarly journals DYNAMICS OF FORMATION OF THE SQUARE OF BEETS PLANTS OF BEETS DEPENDING ON VARIETY SPECIAL FEATURES AND TERMS OF SEEDING UNDER CONDITIONS OF THE RIGHT-FOREST STEPPE OF UKRAINE

2019 ◽  
pp. 173-182
Author(s):  
Inna Palamarchuk
Keyword(s):  
Aerial Part ◽  
Root Formation ◽  
Weather Conditions ◽  
Forest Steppe ◽  
Sowing Time ◽  
The Third ◽  
Sowing Dates ◽  
Number Of Leaves ◽  
The Right ◽  
Sowing Period

The results of studies on the dynamics of the formation of the area of leaves of plants of beetroot canteen depending on varietal characteristics and sowing time in the conditions of the Forest-Steppe of Right-Bank Ukraine are presented. The dependence of the growth and development of beetroot plants on varietal characteristics and sowing dates, as well as on weather conditions that were in the studied time, was revealed. The largest number of leaves in the phase of intensive root formation was formed by plants with a sowing period of I decade of May: 13.3 pcs. / plant – Bordo Kharkivskiy, 13.1 pcs. / plant – Opolskiy. The greatest mass of the root crop in the phase of intensive root formation was planted at a sowing period of the third decade of April: the Bordo Kharkivskiy – 72.4 g, the variety Opolskiy – 43.5 g. The same pattern was observed when taking into account the mass of the aerial part of beetroot. In the Bordo Kharkivskiy variety, it varied from 92.4 g to 87.5 g depending on the sowing time, in the Opolskiy variety from 33.7 g to 31.7 g, that is, the beet plants of the Bordo Kharkivskiy cultivar formed a significantly larger mass of the aerial part in comparison with the Opolskiy variety. Plants were sown with the largest leaf area at a sowing period of the 3rd decade of April: in the Bordo Kharkivskiy – 1.2 – 4.0 thousand m2 / ha, in the Opolskiy variety – 1.0 – 2.3 thousand m2 / ha. According to the results of the crop accounting, it was found that it depended on the variety and sowing period of beetroot. On average, over the years of research, the highest yield was observed with a sowing period of the third decade of April: 63.1 t / ha for the Bordo Kharkivskiy variety, 55.9 t / ha for the Opolskiy variety.

scholarly journals EFFICIENCY OF THE USE OF THE PREPARATION ROSTMOMENT ON SUNFLOWER CROPS IN THE CONDITIONS OF THE FOREST-STEPPE OF THE RIGHT-BANK

2020 ◽  
pp. 17-28
Author(s):  
Ivan Polishchuk ◽  
Mykhailo Polishchuk
Keyword(s):  
Growth And Development ◽  
Oil Content ◽  
Weather Conditions ◽  
Oil Yield ◽  
Forest Steppe ◽  
Single Treatment ◽  
Time Treatment ◽  
The Right ◽  
Positive Effect ◽  
Formation Phase

The results of the use of a yeast preparation on sunflower crops for 2016-2017 have been presented. A positive effect of the researched preparation on the growth and development of sunflower crops of the Neoma hybrid has been established. The preparation Rostmoment increased the height of sunflower plants with a single treatment by 6 cm, and with a two-time treatment of crops by 11 cm, the diameter of the baskets increased by 2.0 cm and 6.3 cm, respectively, against untreated crops. The mass of thousand achenes has been increased by 0.7 g with a single treatment and 2.2 g with a double treatment. The oil content during one-time processing in the basket formation phase was 50.7%, when used twice in the phase of flowering, 51.9%, while in the control its content was 49.2%. Weather conditions in the years of the study significantly affected the productivity of the sunflower of Neom hybrid, especially in terms of moisture supply, and the best conditions for the study of the crop were in 2016, where 209 mm fell during the growing season. precipitation with a uniform distribution. The temperature regime of air on average over the period of sunflower vegetation was 16.5 ºС. The weather conditions of 2017 significantly differed in the amount of precipitation, their distribution and temperature regime, versus 2016. Thus, in 2017, 374 mm of rain fell in the form of prolonged and heavy rainfall, which were unevenly distributed over the decades and months. Such weather conditions caused alternation of excessive moisture and drought during certain periods of growth and development of sunflower plants of the Neoma hybrid, while the average air temperature was 16.2° C. Under such extreme conditions of vegetation periods in the years of research, on average for two years, the yield of sunflower seeds on an untreated experiment was 3.32 t / ha and oil yield 1.64 t / ha. The 2016 yield was slightly higher, 3.43 t / ha and an oil yield of 1.43 t / ha. The use of Rostmoment during a one-time treatment in the basket formation phase led to an increase in yield over two years, which amounted to 3.63 t / ha, and in 2016 - 3.82 t / ha. The use of the studied drug even in the phase of the beginning of flowering contributed to an increase in the yield of seeds in two years to 3.89 t / ha, and in a more favourable 2016 - 4.02 t / ha. The average oil yield per hectare over two years for a one-time treatment of plants was 1.87 t / ha, and for a two-time treatment it was 2.02 t / ha, whereas in 2016 these figures were respectively 1.96 and 2.11 t / ha. The research having been conducted for two years indicated the positive effect of the yeast preparation Rostmoment on sunflower crops, which positively influenced the growth and development of the crops and increased the productivity of the Neoma hybrid in the conditions of the Right-Bank Forest-Steppe. The obtained results are of practical value and can be used by producers in the development and application of technologies for the cultivation of sunflower for increasing the productivity of crops and the ecological state of the agroecosystem. The preparation Rostmoment must be introduced into vegetation plants in the basket formation phase and in the phase of the beginning of the sunflowers’ blossoming, normally 4 kg per 300 l of water per 1 ha of sowing. Key words: sunflower, hybrid, Rostmoment, plant height, basket diameter, oil content, yield, weight of 1000 seeds, oil yield.

scholarly journals Influence of climatic conditions on productivity and adaptability of Camelina sativa

2020 ◽  
Vol 224 ◽  
pp. 04006
Author(s):  
E L Turina ◽  
T Ya Prakhova
Keyword(s):  
Environmental Conditions ◽  
Steppe Zone ◽  
Camelina Sativa ◽  
Climatic Conditions ◽  
Forest Steppe ◽  
Hydrothermal Conditions ◽  
Middle Volga Region ◽  
Hydrothermal Coefficient ◽  
Climate Conditions ◽  
The Crimea

The purpose of the research is to assess the productivity and adaptability of Camelina sativa depending on the natural and climatic conditions of the forest-steppe zone of the Middle Volga region and the steppe Crimea. The researches were conducted in two regions (Penza and Crimea) with contrasting hydrothermal conditions in 2015–2019 years. Climate conditions in the years of researches were characterized by significant variability in both the degree of humidity and temperature regime in both regions. The hydrothermal coefficient in the Crimea varied in the range of 0.23–1.11, in the conditions of Penza - from 0.45 to 1.10. The index of environmental conditions varied from -0.58 to 1.28 units depending on the natural and climatic zone. On average, in 2015–2019, the productivity of Camelina changed from 1.45 to 1.79 t/ha in Penza and from 0.56 to 1.66 t/ha in Crimea. The highest yield of Camelina sativa was recorded in 2016 in Penza and in 2017 in the Crimea and amounted to 1.79 and 1.66 t/ha, respectively. The value of the index of environmental conditions is 1.17 and 1.28 with hydrothermal coefficient of 0.82 and 0.61, respectively. Depending on the conditions of the year and the region, the oil content varied from 33.9 to 43.9 %. At the same time, there is a tendency to decrease the amount of oil for all years of study in the direction from the Crimea to the zone of the Penza region. Camelina sativa is characterized by a high level of resistance to stressful conditions (0.49– 1.10), differs in environmental adaptability (bi=1.15–1.17), has a high fitness criterion, 41.2–41.5 g/m2, depending on the region.

scholarly journals Feed productivity of sainfoin in the conditions of the right-bank Forest-Steppe

2019 ◽  
pp. 50-55
Author(s):  
N. Y. Hetman ◽  
Y. A. Veklenko
Keyword(s):  
Protein Content ◽  
Crude Protein ◽  
Dry Matter ◽  
Planting Date ◽  
Forest Steppe ◽  
Dry Matter Yield ◽  
Crude Protein Content ◽  
Hydrothermal Conditions ◽  
The Right ◽  
First Year Of Life

The purpose of the research was to study the effect of planting time on the formation of productivity of Hungarian sainfoin when grown for green forage. Methods are field, laboratory, statistical, correlation and regression relationships. Research results. It is established that under uneven humidity and high temperature regime in the year of sowing, Hungarian sainfoin formed two yields under spring planting date and one yield under summer planting date. In the second and third years of growth, no significant effect of the planting date on the stages of organogenesis of Hungarian sainfoin was found, where the maturity of the herbage was reached simultaneously. Productivity of Hungarian sainfoin was only conditioned by hydrothermal conditions, where the yield of green mass averaged 45.9—49.6 t/ha with crude protein content of 1.58—1.73 t/ha. At the same time, the highest dry matter yield of 10.25 t/ha and crude protein of 1.73 t/ha was provided by agrophytocenosis when sown on April 12. The productivity index of Hungarian sainfoin in the first year of life was determined, where the highest indicator was obtained during the early spring sowing period (29.04) – 7.85 kg/ha of dry matter per 1 hour of light day, whereas for the recommended summer sowing period was 1.13 kg/ha, or 6.9 times lower. The correlation equation between dry matter output, duration of daylight and the sum of precipitation from full shoots to the beginning of flowering in the first year of life is described. It is found that with increase of precipitation by 1 mm the dry matter output increases by 1.53 % and there is a tendency increase with increasing the length of daylight by 1 minute. Conclusions. It has been established that on gray forest soils of the right-bank Forest-Steppe, over two years of intensive use of the grass stand, regardless of hydrothermal conditions, Hungarian saifoin provided a stable forage productivity when sown in spring. Thus, dry matter yield was 9.38—10.25 t/ha with crude protein content of 1.58—1.73 t/ha. In particular, as for summer planting date, July 20 appeared to be the most effective planting date, which provided dry matter yield of 9.78 t/ha with crude protein content of 1.61 t/ha.

Yieldcapacity of soybean varieties with various vegetation periods, depending on sowing time in the Eastern Forest-Steppe of Ukraine

2021 ◽  
Vol 2020 (1-2) ◽  
pp. 95-103
Author(s):  
Y.M. Ohurtsov ◽  
О.О. Loshak
Keyword(s):  
Thermal Conditions ◽  
Weather Conditions ◽  
Forest Steppe ◽  
Hydrothermal Conditions ◽  
Sowing Time ◽  
Growing Period ◽  
Universal Approach ◽  
Primary Determinant ◽  
Leaf Surface Area ◽  
Soybean Plants

Sowing is one of the most important agronomic measures in soybean cultivation. However, today in Ukraine there is no universal approach to defining the optimal sowing time. Some researchers assert that one should rely on the calendar period of sowing; other specialists argue that the spring features should be the primary determinant; the third group think that the thermal conditions at a depth of 10 cm is the main factor; and according to the fourth opinion, soil and clime characteristics are critical. The hydrothermal conditions in the years of our research deviated significantly from the annual average. Thus, the hydrothermal coefficient during the soybean growing period in 2018 was 0.34, and in 2019 it was 0.52, indicating that the cultivation conditions were arid (0.5 <HTC <0.9). The experiments showed a clear downward trend in the growing period length and upward trends in the field germinability of seeds and leaf surface area when soybean was sown in soil warmed to 14-16оС on May 10-15. In this case, the biometric parameters of soybean plants improved, and the yield increased by 0.15-0.16 t/ha. Keywords: soybean varieties, weather conditions, sowing time, field germinability of seeds, plant survival, photosynthetic and symbiotic activities of plants, grain yield.

Sign in / Sign up

Export Citation Format

Share Document