Moisture Supply Research Articles

DRIP IRRIGATION REGIMES AND EFFICIENCY OF WATER USE BY SUNFLOWER HYBRIDS

The article presents the results of experimental research on the effect of drip irrigation system designs on the formation of irrigation regimes, productivity, and efficiency of water use by sunflower hybrids. In addition, the main components of evapotranspiration were taken into account, and coefficients of water consumption (WCC), irrigation efficiency (IE), and irrigation water use efficiency (WUE) were chosen as criteria for the efficiency of drip irrigation. Short-term field research was carried out during 2020-2022 on the lands of the Brylivske experimental field of the Institute of Water Problems and Reclamation of the National Academy of Agricultural Sciences (Kherson region, subzone of the Dry Steppe). Analytical and mathematical as well as statistical methods were used to process experimental data. The scheme of the three-factor field experiment provided various options for laying irrigation pipelines of drip irrigation systems (in the horizontal and vertical planes), as well as the implementation of a pulsed water supply mode (standard). The version with a natural moisture supply (without irrigation) was the control. The results of experimental research proved that the method of laying drip irrigation pipelines had a direct effect on the parameters of the formation of drip irrigation regimes and the productivity of sunflower hybrids in the conditions of the Dry Steppe. The mechanism of evapotranspiration formation of sunflower crops in irrigated and non-irrigated conditions has been determined. It was statistically proven that the application of subsoil drip irrigation with the laying of irrigation pipelines at a depth of 0.3 m and a distance between them of 1.0 m is the most appropriate for growing sunflower hybrids. This is explained by biological features, namely drought resistance of this crop. Thus, in field experiments, the variant with in-soil laying of drip irrigation pipelines provided almost identical yield (4.01-4.09 t/ha) when having lower crop water consumption coefficients (1088.7-1125.7 m3/t) and higher efficiency of irrigation water use – 2.27-2.41 kg of grain per 1 m3 of irrigation water.

Modern agro-climatic resources of Kazakhstan and Central Asia

The article considers the agro-climatic resources of the Republic of Kazakhstan and Central Asia for the period from the beginning of the XXI century to 2021. The spatial distribution of the sums of precipitation during the active vegetation period, the sums of active temperatures and HTC in eastern Uzbekistan, Tajikistan, Kyrgyzstan and southeastern Kazakhstan was studied. Calculated indicators for the allocation of agro-climatic zones of the flat part of Kazakhstan and Central Asia. The zoning of the heat supply during the active vegetation period according to the sums of active temperatures (above 10°C), moisture content according to the sums of precipitation during the active vegetation period, the Selyaninov State Customs Committee, the humidification coefficient (HC), which also takes into account the precipitation of the cold period of the year, was carried out. For the flat territory of Kazakhstan and Central Asia, the nature of the latitudinal and meridional strike of zones and their conditional boundaries is considered. For the study area, 20 agro-climatic zones of heat supply during the period of active vegetation and moisture supply during the year were determined.

Effects of Lower Troposphere Vertical Mixing on Simulated Clouds and Precipitation Over the Amazon During the Wet Season

AbstractPlanetary boundary layer (PBL) schemes parameterize unresolved turbulent mixing within the PBL and free troposphere (FT). Previous studies reported that precipitation simulation over the Amazon in South America is quite sensitive to PBL schemes and the exact relationship between the turbulent mixing and precipitation processes is, however, not disentangled. In this study, regional climate simulations over the Amazon in January–February 2019 are examined at process level to understand the precipitation sensitivity to PBL scheme. The focus is on two PBL schemes, the Yonsei University (YSU) scheme, and the asymmetric convective model v2 (ACM2) scheme, which show the largest difference in the simulated precipitation. During daytime, while the FT clouds simulated by YSU dissipate, clouds simulated by ACM2 maintain because of enhanced moisture supply due to the enhanced vertical moisture relay transport process: (a) vertical mixing within PBL transports surface moisture to the PBL top, and (b) FT mixing feeds the moisture into the FT cloud deck. Due to the thick cloud deck over Amazon simulated by ACM2, surface radiative heating is reduced and consequently the convective available potential energy is reduced. As a result, precipitation is weaker from ACM2. Two key parameters dictating the vertical mixing are identified, p, an exponent determining boundary layer mixing and λ, a scale dictating FT mixing. Sensitivity simulations with altered p, λ, and other treatments within YSU and ACM2 confirm the precipitation sensitivity. The FT mixing in the presence of clouds appears most critical to explain the sensitivity between YSU and ACM2.

The impact of warming climate on Himalayan silver fir growth along an elevation gradient in the Mt. Everest region

The impacts of rapid climate change in the Himalayan region on growth and sensitivity of tree species across their entire elevation distribution range are not well understood. This study investigates the growth and climate sensitivity of the endemic species Himalayan silver fir (Abies spectabilis, D.Don) along an elevation gradient in the sub-alpine belt in the Mt. Everest region. We developed tree ring-width chronologies, spanning 98 to 310 years, from six sites along an elevation gradient (3400–4100 m a.s.l.). The growth of Himalayan silver fir is primarily limited by low temperatures during the growing season and moisture availability during spring. Significant positive correlations were found between tree growth and mean, minimum and maximum temperatures for most parts of the vegetation period except spring. In contrast, significant positive correlations are apparent for precipitation, self-calibrated Palmer drought severity index (scPDSI), and standardized precipitation-evapotranspiration index (SPEI) during the spring season (March–May) at most of the elevations except for the upper treeline site. Thus, low summer temperatures are the primary limiting factor at all investigated elevations, while moisture supply during spring triggers growth variations at low- to mid-elevations. The long-term growth trends of A. spectabilis have decreased at low- to mid-elevation sites but increased at the treeline during the period 1981–2011. Warming and intensified moisture stress during spring could have negative effects on tree growth, potentially resulting in growth decline and forest dieback at middle and low elevations. These findings emphasize the importance of understanding the vulnerability of forests at middle and low elevations to future climate change.

Transpiration rates decline under limited moisture supply along hillslopes in a humid karst terrain

Topographic positions can mediate subsurface water availability, but its effects on tree transpiration are controversial. In humid karst regions, climax forests are usually not limited by moisture supply, even at the summit, through absorbing water from deep layers. However, little is known on the transpiration pattern and its limiting factor on the shrubland widely distributed along the karst hillslopes. In the current study, Rhus chinensis, a widely spread constructive species in natural restoration was selected. Meteorological factors, 0–300 cm soil–epikarst moisture, sap flow, and root water uptake were studied during an entire growing season to assess how hillslope positions affected transpiration. We found the mean water content in uphill was only around 60 % of that in downhill, indicating a contrasting water supply along the slope. However, there were no significant differences in the xylem isotopic composition and lc–excess which suggested the similar water uptake strategies in both uphill and downhill. R. chinensis primarily relied on the soil water rather than epikarst water (groundwater) along the hillslope because of the MixSIAR model results and more negative lc–excess values (−13.18 ‰). R. chinensis exhibited decreases of nearly half in the transpiration rate and amount in uphill compared to those in downhill. In downhill with sufficient water availability, transpiration followed the variation in atmospheric water demand. In uphill, a poor moisture supply limited tree transpiration and its response to atmospheric water demand. Our findings revealed that the early successional species did not entirely depend on atmospheric water demand, absorbing deep epikarst water as the mature forest. The transpiration rates of those species declined by nearly half to adapt to the water–limited environment along the hillslope in the humid karst region. This study can contribute to the evaluation of eco–hydrological functions during natural restoration.

The effect of natural moisture availability on the yield of Agropyron in arid conditions of the south of Russia

The Volgograd right bank belongs to a very arid natural and climatic zone (HTC 0.3-0.7), the main limiting factor of which is the moisture supply of plants. Therefore, this study was aimed at establishing the influence of the moisture availability of the region and meteorological factors, as well as the timing and methods of sowing on the yield of Agropyron cristatum and Agropyron fragile in arid agro-climatic conditions on light chestnut salty soils of southern Russia. The research was carried out at the experimental production field of the Research Centre of Agroecology of the Russian Academy of Sciences in the period from 2019 to 2022. Field experiments, records, analyses and statistical processing were carried out in accordance with the methodology of field and agrotechnical research with forage crops. Methods of mathematical statistics of the STATGRAPHICS program and the MatLab package were used to process and analyze the results obtained. A close correlation was noted between the yield of Agropyron and moisture reserves (r=0.935) at the autumn sowing period. A close positive relationship (r=0.859-0.856) was noted with the ordinary and cross-seeding method between the moisture reserves in the soil and the crop yield, which indicates a high value of moisture availability during the formation of the phytomass of the crop. Close links between the hydrothermal coefficient (HTC) of the growing season and the yield of Agropyron were noted in April (r=0.960), when plants grew intensively and required sufficient moisture. A promising species can be called Agropyron fragile, the yield of which is 5.0-8.4% higher than the yield of Agropyron cristatum. Moreover, Agropyron produces the highest yields in the third year of life (3.16-3.30 t/ha).

The influence of seeding rates on the yield of pea grain in the conditions of the Pre-Ural steppe of the Republic of Bashkortostan

Relevance. Leguminous crops are the main source of vegetable protein in the world, among which pea is the most common in Russia. Among agrotechnical practices, the seeding rate plays an important role in forming the yield of this crop and obtaining high and stable grain yields. The purpose of the work is to study the influence of various seed sowing rates on the yield of pea varieties in the Republic of Bashkortostan. The experiments were carried out in the conditions of the Pre-Ural steppe subzone in 2017–2020. Pea varieties Chishminskiy 95, Chishminskiy 229, Pamyati Khangilʼdina, Pamyati Popova served as the material for the study.Methods. Sowing qualities of seeds were determined in accordance with GOST 12038-84, GOST 10968-88, GOST 12042-80, GOST 12036-85. Field assessments, phenological observations were carried out according to the methodology of the State cultivar testing of agricultural crops.Results. In our experiments, different conditions of moisture supply, illumination and nutrition of pea plants, due to different seeding rates, had a significant impact on the grain yield in the studied varieties. The increase in the number of plants preserved for harvesting, which depends on their survival and the number of seedlings, was accompanied by an increase in yield. It has been established that pea varieties Chishminskiy 95, Chishminskiy 229, Pamyati Khangilʼdina and Pamyati Popova form the highest and most stable grain yields at early sowing dates with a seeding rate of 1.2 million pieces of germinating seeds per 1 ha. With a decrease in the seeding rate, the weediness of crops increases, and with an increase in the seeding rate, pea plants experience a lack of moisture and nutrients, which leads to a decrease in yield by 0.4–1.0 c/ha.

Role of the Low-Latitude Quasi-Biweekly Oscillation in the Extreme Persistent Heavy Rainfall in the Mei-Yu Season over the Middle and Lower Reaches of the Yangtze River

Abstract Persistent heavy rainfall events (PHREs), as a result of the interaction among multiscale systems, are prone to continuously affect the middle and lower reaches of the Yangtze River valley (MLYR). Based on the observation and reanalysis data, a total of 41 PHREs during the mei-yu seasons of 1979–2020 are first identified over the MLYR and divided into prolonged (over 5 days) and normal (3–5 days) groups. The contributions of quasi-biweekly-scale and synoptic-scale components to the abovementioned two types of PHREs are analyzed. Prolonged PHREs are dominated by the quasi-biweekly component of precipitation (QBW_Pr), while normal PHREs depend on synoptic-scale components (SS_Pr). The quantitative moisture budget indicates that the favorable environment for the QBW_Pr of prolonged PHREs is associated with the interaction between background moisture and quasi-biweekly circulation disturbances. Approximately 80% of prolonged PHREs occurred in phases 6–8 of the boreal summer QBWO (BSISO2) life cycle. The large-scale meridional vertical circulation along the South China Sea (SCS)–MLYR, and the westward-propagating suppressed convection at low latitudes, accompanied by the substantial northward and upward moisture supply, significantly promotes and maintains the QBW_Pr for prolonged PHREs. In contrast, the QBWO signals are relatively insignificant in the evolution of normal PHREs. The impact of the low-latitude QBWO on the prolonged PHREs is further confirmed by sensitivity experiments with RegCM4.9. As the QBWO are weakened on the southeast lateral boundary near the SCS, the vertical circulation and moisture transport clearly diminish along the SCS–MLYR. Consequentially, precipitation reduces visibly during prolonged PHREs. Significance Statement Persistent heavy rainfall events (PHREs), as the reflection of the interaction among multiscale circulation systems, characterized by high intensity and wide coverage, are prone to cause severe flooding and death in the middle and lower reaches of the Yangtze River valley (MLYR). This study aims to investigate the connection between PHREs and different time scales of atmospheric variability, thus elucidating the crucial factors and the influencing mechanisms for the prolonged PHREs during the mei-yu season. Our results reveal that the prolonged PHREs are dominated by the quasi-biweekly component of precipitation, while normal PHREs depend on the synoptic-scale component. The quasi-biweekly precipitation of prolonged PHREs is promoted and maintained by the meridional vertical circulation along the South China Sea (SCS)–MLYR, which is accompanied by the westward-propagating SCS QBWO-related suppressed convection at low latitudes. This study highlights the specific role of the low-latitude QBWO to the formation of prolonged PHREs relative to normal PHREs.

The influence of the aftereffect of long-term use of mineral fertilizers on sorghum grain productivity and quality on ordinary blackearth of the Central Pre-Caucasus

There have been presented the study results of the experiment of the Geographical Network of Experiments with fertilizers, established in 1975 on ordinary chernozem under conditions of unstable moisture in the Stavropol Territory. The purpose of the current study was to reveal the influence of the aftereffect of the long-term use of mineral fertilizers on the agrochemical properties of soil, productivity, and quality of sorghum grain, depending on the weather conditions of the year. There has been established that, after 30 years of action and 14 years of aftereffect of the use of phosphorus fertilizers in doses of 60–180 kg/ha of a.i. the content of residual phosphorus in the soil layer of 0–20 cm before sowing sorghum varied from 25 to 55 mg/kg. The crop productivity was closely dependent on weather conditions and the agrochemical condition of the soil. In arid conditions in 2020, the largest grain productivity (2.5–3.16 t/ha) was obtained in areas of phosphorus fertilizer’s aftereffect with a high content of P2O5 in soil (more than 30 mg/kg). In the wet year, the largest productivity (5.10–5.64 t/ha) were obtained in nitrogen fertilizers’ aftereffect against the background of low phosphates availability (12–16 mg/kg). In different weather conditions, the maximum level of sorghum productivity was obtained in the aftereffect of complete mineral fertilizer or with a balanced nutrient regime of the soil, in 2020 it was 3.81–4.96 t/ha and in 2022 it was 5.4–6.14 t/ha. Sorghum grain quality was also determined by the weather and soil properties. Grain with the highest crude protein percentage (9.9–13.6 %) was obtained in a dry year after the effect of nitrogen fertilizer. In both years of the study, the products obtained after the application of high doses of one phosphorus fertilizer (120–180 kg/ha a.i.) had the least nutritional value. The crude protein percentage in grain did not exceed 2.2–7.8 %. To stabilize productivity and increase the nutritional value of sorghum, it is necessary, first of all, to optimize the nitrogen nutrition of plants, especially in conditions of good moisture supply.

Aftergrass ability of grass stands for hay-pasture use in the autumn period

Aim. To identify the best types of perennial grasses in terms of fertility in their pure form and mixtures, and to develop a technology for the formation and use of sown meadow phytocenoses in the Forest Steppe during their autumn alienation in the system of an extended pasture conveyor for meat breeds of cattle. Methods. Field, laboratory, mathematical, system analysis. Results. The article on onion growing considers the problems of quality provision of meat cattle with green fodder not only in the summer, but also in the autumn period. On the basis of many years of experimental research, the article reveals the processes of formation of perennial grasses depending on the weather and climate conditions, species composition, fertilization system, and the timing of the removal of the pasture mass in the fall. The indicators of the transformation of the quality of the green mass of аftergrass depending on the terms of deepening of the autumn period are given. According to the results of field research, it was established that early-ripening and medium-ripening perennial grasses in the autumn period form a sufficient supply of grass at the root (oats) for livestock grazing, in the range of 2.3-3.1 t/ha with moderate moisture supply and application of nitrogen fertilizers with a dose of N20 under the pasture moving. Early-ripening and medium-ripening perennial grasses produce a 1.4–1.6 times higher yield than late-ripening coenoses over the years of use. This pattern was stable over the years of use. Аftergrass cereal grasses of the autumn period were of sufficient quality and met the zootechnical standards for feeding cattle of the meat sector. The supply of green fodder with organic nutrients and mineral elements for the cultivation of аftergrass on the background of N20 was characterized by the following indicators: the content of raw protein in the dry weight of the fodder was in the range of 11–15.3%, fat – 2.4–3.1%, raw fiber – 27.7–35.3%, potassium – 2.39–2.75%, calcium – 0.51–0.68%. The digestibility of cereal grass fodder was 58-72%. Conclusions. Among the perennial grasses, the following types of grasses showed better seeding in the autumn period on dry meadows with the application of nitrogen fertilizers with a dose of N20: thornless sedge, oriental sedge and ryegrass, the share of which in the yield of seeded grass mixtures depends on the intensity of precipitation after 3 years of use was at the level of 62–71%, and in some dry years even more.

Land–atmosphere feedbacks contribute to crop failure in global rainfed breadbaskets

Global crop yields are highly dependent on climate variability, with the largest agricultural failures frequently occurring during extremely dry and hot years. Land–atmosphere feedbacks are thought to play a crucial role in agricultural productivity during such events: precipitation deficits cause soil desiccation, which reduces evaporation and enhances sensible heating from the land surface; the amplified local temperatures and moisture deficits can be detrimental to crop yield. While this impact of local land–atmosphere feedbacks on agricultural productivity has recently been reported, the dependency of crop yields on upwind regions remains understudied. Here, we determine the spatio-temporal origins of moisture and heat over the world’s largest 75 rainfed breadbaskets, and illustrate the crop yield dependency on upwind regions. Further, we disentangle the role of local and upwind land–atmosphere interactions on anomalous moisture and heat transport during low-yield years. Our results indicate that crop failure increases on average by around 40% when both upwind and local land–atmosphere feedbacks cause anomalously low moisture and high heat transport into the breadbaskets. The impact of upwind land–atmosphere feedbacks on productivity deficits is the largest in water-limited regions, which show an increased dependency on moisture supply from upwind land areas. Better understanding these upwind–downwind dependencies in agricultural regions can help develop adaptation strategies to prevent food shortage in a changing climate.

Assessment of the current physical and chemical status of the alluvial soils of the Volga-Akhtuba floodplain and the Volga delta

The article dwells upon the study of the current physico-chemical status of the alluvial dark-humus soils of the floodplain hayfields of the Volga-Akhtuba floodplain and the Volga delta. Alluvial soils are formed in special semiaquatic conditions; they are the result of alluvial and soil-forming processes. Considered to be dynamic both in natural and anthropogenic conditions. They have subordinate status and remain to be barriers and accumulators of various chemical elements while performing a sanitary and hygienic role in floodplain and delta ecosystems. Due to the increased anthropogenic load on alluvial soils, the study of their physico-chemical status, which affects the migration of chemical elements, becomes particularly significant. The alluvial soils of the Volga-Akhtuba floodplain and the Volga delta are characterized by a polynomial profile in which soil horizons of varying development degrees alternate with river sediments. The soils of the studied landscapes are characterized by good agrophysical and relatively satisfactory agrochemical condition. It was found that bunds on the territory of the delta as well as in the floodplain have negative impact on the physico-chemical status of alluvial soils and actively develop secondary salinization. The focus is on the agrochemical properties of alluvial dark-humus soils, particularly on the content of humus and nutrients. According to the granulometric composition, the studied soils are medium and heavy loamy, they have a good supply of productive moisture. In the soils of the Southeastern part of the floodplain, the processes of salinization, dehumification and alkalization are most present.

Reducing the environmental risks of using mobile energy-saturated units during seed potatoes growing taking into account the patterns of heat and moisture transfer within the root spreading zone in the soil

Because potato is a crop, demanding moisture supply conditions its yield depends on the ability to use the moisture accumulated during the calendar year by the root system during the growing season. However, the intensification of technological methods of potato production using powerful energy-saturated mobile agricultural units leads to a significant deterioration of the soil condition due to over compaction of the arable and subsoil horizons which hinders the normal mode of movement of intrasoil moisture and the development of the root system of plants. Reducing the number of passes of agricultural units across the field is possible when using combined units that perform several technological processes in one pass. For this purpose, a multifunctional combined potato-planting unit has been developed at St. Petersburg State Agrarian University that combines preplant tillage, planting potato seeds, the use of agrochemicals, pesticides and water-retaining agents, as well as deep loosening of interrow spacing and the formation of full-volume ridges. The conducted studies have shown the effectiveness of the use of such a combined unit by providing favorable soil conditions for the growth and development of plants.

ADAPTIVE VALUE OF SOYBEAN VARIETIES GROWN IN DIFFERENT ECOGRADIENTS

The further expansion of soybean acreage and increase in productivity will be facilitated by the introduction of new modern varieties, which are determined by higher productivity potential and a higher level of resistance to the main fungal and bacterial diseases. However, soybean plants are affected by more than 50 diseases. It is known that pathogenic organisms lead to significant losses of the soybean crop (by 15-20%, and by epiphytotic development – by 50%).The results of studies on the assessment of soybean varieties for adaptability (ecological plasticity and stability) in different soil and climatic conditions for resistance to diseases (ascochitosis, yellow mosaic) are presented. Soybean varieties were ranked according to ecological plasticity and stability according to their response to environmental conditions. Our studies have shown that the intensity of the development of ascochitosis and yellow mosaic depends not only on the genetic characteristics of the genotypes, but also on factors related to the growing area, especially the hydrothermal and edaphic conditions of the region. The varieties Oriana – 93.4% and Hoverla – 93.2% stood out for their resistance to ascochitosis damage under different hydrothermal and edaphic conditions, which were characterized by a low reaction to a change in the hydrothermal growing regime, the coefficient of ecological plasticity (bi) < 1. That is, these varieties soybeans provided high indicators of resistance to ascochitosis despite a deficit or sufficient moisture supply in different ecogradient studies. The following varieties stood out for resistance to yellow mosaic: Hoverla – 85.0%, Oriana – 84.9%, Amethyst – 83.0. It should be noted that according to the parameters of ecological plasticity and stability (adaptability), the listed varieties belong to genotypes with a conservative reaction to changes in the agro-environment of cultivation, the coefficient of ecological plasticity (bi) < 1.

Surface‐Atmosphere Decoupling Prolongs Cloud Lifetime Under Warm Advection Due To Reduced Entrainment Drying

AbstractAn initially well‐mixed stratocumulus deck can remain overcast for several tens of hours under warm‐advection conditions, although moisture supply is cut off from the ocean due to surface‐atmosphere decoupling (stabilization of the surface‐atmosphere interface). In this study, a set of idealized large‐eddy simulations were performed to investigate the physical mechanism of how warm‐air advection impacts the evolution of a pre‐existing stratocumulus deck. To mimic warm‐air advection, we decrease the sea surface temperature linearly over time in a doubly periodic domain. Given the same initial conditions, the stratocumulus deck is more persistent when experiencing warm‐air advection than cold‐air advection. This persistence is caused by reduced cloud‐top entrainment drying due to decoupling, a process more influential than the decoupling‐induced cutoff of moisture supply. This mechanism is more notable when the free troposphere becomes more humid. The relevance of the mechanism to previous observations of less low‐level cloudiness under warm‐advection conditions is discussed.

Influence of plant density on productivity and quality indicators of sunflower oilseeds

In the agricultural technology of sunflower cultivation, plant density in crops is one of the main conditions that determine its further productivity [5]. The optimal sowing density of sunflower can vary widely and depend on various factors, such as the varietal characteristics of plant, the soil-climatic zone of its cultivation, specific weather conditions and, above all, the moisture supply of plants, especially in the critical phases of sunflower development (flowering and grain filling) [ 8]. It has been proved that the optimal plant density in sunflower crops is such that not only normal growth processes and development of each plant are ensured, but the maximum possible productivity per unit of sown area is also formed. In this regard, in 2018–2020, in the flat zone on the leached chernozems of LLC «Zarya» of the Shovgenovsky district of the Republic of Adygea, studies were carried out (according to B.A. Dospekhov «Methodology of field experience») in order to study the reaction of new promising sunflower hybrids (Gorstar, Natali, Iren, selection of Federal State Budgetary Scientific Institution «FSC «VNIIMK named after V.S. Pustovoit», Krasnodar) to change the number of plants per hectare. As a result of the research, the degree of influence of the studied factor on the formation of productive qualities of the studied sunflower hybrids has been established– the diameter of the anthode, the number of oil seeds in it, the mass of achenes from one anthode, the weight of 1000 achenes, the fulfillment of achenes, seed yield, total collection of oil from one hectare area). The studies have shown that the maximum seed yield has been achieved in the hybrids Gorstar and Iren, formed on the second variant (50 thousand pieces/ha). In the Natalie hybrid, the maximum yield was recorded in the variant with a plant density of 60 thousand pieces/ha. From this, it should be noted that with the option of 50 thousand pieces/ha, the Natali hybrid turned out to be 0.62–0.61 t/ha less productive than the Gorstar hybrid and 0.52–0.56 t/ha than the Irene hybrid.The studies were carried out on the equipment of the «Expert» Common Use Center of FSBEI HE «MSTU».

What distinguishes 100-year precipitation extremes over central European river catchments from more moderate extreme events?

Abstract. Historical extreme flooding events in central European river catchments caused high socioeconomic impacts. Previous studies have analysed single events in detail but have not focused on a robust analysis of the underlying extreme precipitation events in general, as historical events are too rare for a robust assessment of their generic dynamical causes. This study tries to fill this gap by analysing a set of realistic daily 100-year large-scale precipitation events over five major European river catchments with the help of operational ensemble prediction data from the ECMWF. The dynamical conditions during such extreme events are investigated and compared to those of more moderate extreme events (20 to 50 year); 100-year precipitation events are generally associated with an upper-level cutoff low over central Europe in combination with a surface cyclone southeast of the specific river catchment. The 24 h before the event is decisive for the exact location of this surface cyclone, depending on the location and velocity of the upper-level low over western Europe. The difference between 100-year and more moderate extreme events varies from catchment to catchment. Dynamical mechanisms such as an intensified upper-level cutoff low and surface cyclone are the main drivers distinguishing 100-year events in the Oder and Danube catchments, whereas thermodynamic mechanisms such as a higher moisture supply in the lower troposphere east of the specific river catchment are more relevant in the Elbe and Rhine catchments. For the Weser and Ems catchment, differences appear in both dynamical and thermodynamic mechanisms.

Moist and warm conditions in Eurasia during the last glacial of the Middle Pleistocene Transition

The end of the Middle Pleistocene Transition (MPT, ~ 800-670 thousand years before present, ka) was characterised by the emergence of large glacial ice-sheets associated with anomalously warm North Atlantic sea surface temperatures enhancing moisture production. Still, the direction and intensity of moisture transport across Eurasia towards potential ice-sheets is poorly constrained. To reconstruct late MPT moisture production and dispersal, we combine records of upper ocean temperature and pollen-based Mediterranean forest cover, a tracer of westerlies and precipitation, from a subtropical drill-core collected off South-West Iberia, with records of East Asia summer monsoon (EASM) strength and West Pacific surface temperatures, and model simulations. Here we show that south-western European winter precipitation and EASM strength reached high levels during the Marine Isotope Stage 18 glacial. This anomalous situation was caused by nearly-continuous moisture supply from both oceans and its transport to higher latitudes through the westerlies, likely fuelling the accelerated expansion of northern hemisphere ice-sheets during the late MPT.

Impact of the extremely warm Gulf Stream on heavy precipitation induced by Hurricane Sandy (2012) during its extratropical transition

This study investigated the role of the extremely warm sea surface temperature (EWSST) over the Gulf Stream (GS) in heavy precipitation induced by Hurricane Sandy in October 2012 during its extratropical transition (ET). A control (CTL) run with observed SST and a climate (CLM) run with climatological SST over the GS were performed using a high-resolution regional atmospheric model. Sandy-induced precipitation over the Mid-Atlantic coastal region was larger by approximately 40% in the CTL run than in the CLM run during its ET phase. The western sector of Sandy in the CTL run exhibited the westward-tilting lower-to-middle tropospheric front and the pronounced convectively unstable layer created by large surface fluxes of sensible and latent heat from the EWSST region. The intensified convective instability was released by the frontal deep updrafts, enhancing frontal precipitation in the western part of Sandy. A backward trajectory analysis demonstrated that the abundant moisture evaporated from the GS was imported into the western frontal rainbands by the low-level easterlies passing the northern sector of Sandy. The EWSST facilitated the moistening process of air parcels transported by the easterlies due to the active heat and moisture supply from the underlying current, contributing to the increase in moisture influx toward the western front. Another trajectory analysis indicated that the formation of low-level easterlies north of Sandy originated from the combination of Sandy and high-latitude synoptic-scale systems such as an anomalous high over the Labrador Sea and an extratropical cyclone east of Sandy. These results corroborate the importance of the extremely warm midlatitude ocean and complex high-latitude weather systems to the enhancement of Sandy-induced heavy precipitation.

RESEARCH ASSESSMENT OF THE QUALITY A LEGUMES BY ECONOMIC AND VALUE INDICATORS

The article analyzes global climate changes, which lead to a decrease in the sustainable production of agricultural products, as well as increased attention of the world community to the problems of ensuring food security, which requires innovative approaches to adapting agribusiness to new operating conditions. It has been established that the International Food and Agriculture Organization of the United Nations (FAO) is currently actively implementing a strategic action plan for the adaptation of agriculture to climate change, which is based on the reorientation of agro-food systems in the direction of innovative and mostly carbon-neutral climate-optimized agribusiness. It has been proven that the current trends in increasing prices for mineral fertilizers and energy carriers encourage the search for technologies for the cultivation of leguminous crops, which combine effective agrobiological measures to optimize their nutrition through the use of inoculation, a line of modern microfertilizers and their combinations, taking into account the critical phenological stages of plant development. which ultimately guarantees the realization of both the adaptive potential of the culture and the productive potential of its varieties. It is for these reasons that the scientific substantiation and development of measures to optimize lentil nutrition in the complex of modern agrotechnological methods of its cultivation in the conditions of the right-bank forest-steppe, aimed at ensuring a stable level of productivity with the preservation of quality indicators under the conditions of modern trends towards unstable moisture supply against the background of increasing average daily temperatures, is an urgent task. which requires scientific generalization and solution. The article provides an assessment of the quality of the grain of leguminous crops and highlights their main economic and value indicators, which are regulated by current standards. The assortment of leguminous crops, as well as their importance for the agricultural production of Ukraine, is presented. The issue of harmonization of the main regulatory documents regarding grain and leguminous crops with the requirements of the European Union for a more effective entry of Ukraine into the European and world markets has been studied. Analyzes of certification of grain and leguminous crops were carried out. The validity period of the certificate attesting the sowing quality of seeds has been determined. The concept of quality from the point of view of the consumer of legumes and their processing products is singled out, which is closely related to the aspect of their safety for the consumer's health. The scientific rationale for the development of measures to optimize modern agrotechnological methods of cultivation in the conditions of the right-bank forest-steppe, aimed at ensuring the stability of quality indicators against the background of increasing average daily temperatures, is provided.