Continental Climatic Conditions Research Articles

Impact of deficit irrigation and planting density on grain yield and water productivity of maize grown under temperate continental climatic conditions

Variable frequent drought periods in Vojvodina region (the southeastern part of the Pannonian Plain, Serbia), severely limit maize (Zea mays L.) production under rainfed conditions. A four-year field experiment was conducted to investigate the effects of sprinkler deficit irrigation and plant density on yield and water use efficiency of maize grown on silty clay loam soil under temperate continental climate. The experiment included fully irrigated crop (I1), three deficit irrigation treatments (I2, I3 and I4 corresponding to 80, 50 and 40 % of crop evapontranspiration, respectively) and non-irrigated treatment (I0), and three plant densities (LPD: 54,900 plants ha–1; MPD: 64,900 plants ha–1; HPD: 75,200 plants ha–1) in four replicates. The results showed that grain yield, CWP (crop water productivity) and IWP (irrigation water productivity) varied significantly with irrigation amounts, plant densities and seasons. The irrigation rates and plant density interact significantly. MPD and HPD differed significantly from LPD in almost all seasons. With increasing irrigation and plant density, yield and CWP showed an increasing trend. The relative values of IWP increased with the rise of plant density and decreased with the amount of irrigation. The highest four-year average yield (15.03 t ha–1) was obtained in the I1-HPD treatment, while the lowest (9.30 t ha–1) was obtained in the I0-HPD treatment. The highest average values of CWP and IWP were recorded at I3-HPD or/and I2-HPD. The lowest CWP and IWP values were determined for I4-HPD and I4-MPD, respectively. In the pedo-climatic conditions of Vojvodina and similar regions, we recommend growing maize under the I1-HPDtreatment to achieve high yields. Under the water shortage conditions, the application of I2-HPD treatment is a favorable strategy saving 37 % of irrigation water, while reducing maize grain yield by ∼10 %.

Low Concentrating Photovoltaic Geometry for Retrofitting Onto European Building Stock

Abstract The most appropriate low concentrating photovoltaic (LCPV) technology suitable for European buildings located in mid-high latitudes under both maritime and continental climatic conditions has been identified as the asymmetric compound parabolic concentrator (ACPC). To date, there is no published experimental data at different latitudes on the long-term performance of these systems at these latitudes nor how location would modify the optical characteristics of deployed systems. Previous theoretical research by the authors has demonstrated the superiority of the ACPC with this additional work experimentally confirming the robustness of the design. To investigate how seasonal and locational variations affect their measured technical performance two identical ACPC-LCPVs were installed, instrumented, and monitored at two different climatic locations (Uxbridge, UK, and Vevey, Switzerland) from May 2020 to September 2020. A valid comparative performance investigation characterizing two geometrically equivalent ACPC-based LCPV systems using real-life experimental data collected is presented in this paper. Locations at higher latitudes experience greater transverse angles more frequently compared to locations nearer the equator making ACPC geometries more appropriate than symmetrical concentrator configurations for building retrofit. This is shown in this paper over a latitudinal expanse of 31.35 deg for four separate locations; Tessalit (20.19 deg N, 1.00 deg E; Mali), Timimoun (28.03 deg N, 1.65 deg E; Algeria), Uxbridge (51.54 deg N, 0.48 deg E, UK), and Vevey (46.6 deg N, 6.84 deg E, Switzerland).

Adaptability and prospects for the use of introduced representatives of the genus Weigela in different climatic conditions

The use of highly decorative and beautifully flowering shrubs in urban green spaces, especially in sharply continental climatic conditions, is extremely important. In this regard, representatives of the genus Weigela are highly valued in the in different climatic conditions. The main indicators of eco-physiological adaptability of plants, such as intensity of transpiration and photosynthetic productivity, water deficiency and the total water content, quantity of the plastids, have been studied for the representatives of highly ornamental shrubs of the genus Weigela Thumb. The object of the research was the following representatives of the genus Weigela: W. praecox, W. coraeensis, W. floribunda, W. florida and W. florida ʺVariegataʺ, which were introduced into different climatic conditions in order to climate train and replenish the dendro-collections. Physiological research was conducted, during the vigorous vegetative period (May–June months). All the measurements were carried out within the 11:00–13:00 time period, in 9 repetitions (7–10 shoots were chosen for each sample). The nature of ecological adaptability of the studied species, along with the perspective of their application in the landscaping practices in different climatic zones was revealed. At the same time it was revealed that the studied species can be used not only as solitary plants (especially on the background of green lawns) but also in groups in long blooming gardens (with flowers with different colours and blooming phases) and in decorating rock gardens.

Holocene history of the Kungur forest-steppe (cis-Urals, European Russia): case study Uinskoe mire

The formation and development of the Kungur forest-steppe has been a controversial topic for almost 150 years due to its location within the belt of hemiboreal forests in the pre-Urals of European Russia. To further the knowledge on its manmade versus natural origin we conducted a palaeoecological study reconstructing the regional vegetation history in the Mid-Kama region as well as local bog development and additional archaeobotanical studies nearby. Detailed loss-on-ignition analysis, peat properties and high resolution radiocarbon dating were carried out to obtain long-term carbon accumulation rate estimates. The data document the presence of the pine-dominated forest-steppe with spruce and birch during the major part of the Holocene (∼9.7–5.5 ka) and the development of the modern hemiboreal forests from 5.5 ka onwards. Since 3.5 ka, the hemiboreal forests were increasingly influenced by human action, corresponding to the development of local archaeological cultures. The earliest human impact is observed during the Garinskaya culture (4.5–3.5 ka). It increased during the Early Iron Age with the Ananyino (2.8–2.2 ka) and Glyadenovo (2.2–1.6 ka) cultures and during the Medieval with the Nevolino culture (1.6–1.1 ka). Archaeobotanical data reveal consumption of Triticum aestivum and T. aestivum/spelta by bearers of the Nevolino culture as well as a local cultivation of emmer. The formation of the recent Pinus-Betula forest-steppe took place in the last 300 years during the Russian colonisation. In conclusion, continental and warm climatic conditions as well as fire activities were maintaining semi-open landscapes of the forest-steppe during the Early and Middle Holocene, while land use became the dominant factor since 3.5 ka.

Impacts of N-P-K-Mg Fertilizer Combinations on Tree Parameters and Fungal Disease Incidences in Apple Cultivars with Varying Disease Susceptibility.

Adequate mineral fertilization helps to ensure optimal tree growth, fruit development, and predictable yield of apple trees. This 7-year study (2016-2022) aims to investigate the effect of nitrogen (N), phosphorus (P), potassium (K), and magnesium (Mg) fertilizer combinations (NP, NPK, NPKMg, and control) on eight parameters (trunk cross-sectional area-TCSA; fruit yield-FY; number of fruit per tree-FNT; crop load-CL; fruit diameter-FD; fruit weight-FW; fruit scab incidence-FSI; and powdery mildew incidence on shoot-PMIS) on the cultivars (cvs) 'Golden Reinders' (disease susceptible) and 'Pinova' (scab and mildew tolerant). In the 7-year period, TCSA values continuously increased for both cultivars over the years. Fertilizer treatments showed significant differences on TCSA but the effect varied greatly annually among fertilizer treatments. Fertilizer treatments had increasing effects on FY and FNT in 2018 and 2022, on CL in 2018, on FD in 2018 and 2019, and on FW in 2016 and 2018 in both cultivars compared to the control treatment. FSI values were the lowest in the NPKMg treatment for cv. 'Golden Reinders' in 2016, 2017, and 2022; for cv. 'Pinova' in 2016; PMIS values for cv. 'Golden Reinders' in 2017, 2018, 2021, and 2022; and for cv. 'Pinova' in 2018. Correlation and regression analyses revealed strong and significant (p = 0.05) relationships between FNT versus (vs.) TCSA, FNT vs. FY, FW vs. TCSA, CL vs. FY, FW vs. FD, and FSI vs. FW. In conclusion, our study showed that multiyear application of fertilizer combinations can successfully increase TCSA and yield parameters as well as reduce fungal disease incidences, especially on the disease-susceptible cultivar in sandy soil with moderate fertility, under Central-European continental climate conditions.

A Case Study of RNA-Silencing Resistance against Potato Virus (PVY) in Condition of Climate Change

Abstract Global environmental issues shift crop production to the new conditions. This increases all kinds of biotic and abiotic stresses, beside others also plant diseases. Such changes are also in Kazakhstan where potato production is dramatically increasing, and crop is growing in regions with continental climate. Problems with potato virus type Y (PVY) need cultivars with better resistance. Introduction of silencing small interfering RNA (siRNA) is new technology. In vitro experiment was done on potato (Solanium tuberosum L.) local cultivar Izolda. Results show significant effect of siRNA in decreasing mortality and occurrence of PVY symptoms and allow expansion of potato cultivation to continental climate conditions, where are faced with new virus problems.

Spatio-temporal distribution of renewable freshwater resources and their availability in Kosovo—an analysis from the Eastern Region

The study aims to analyze the availability of renewable freshwater resources and their spatiotemporal distribution in the Eastern Region of Kosovo (ERK). As a crucible resource for agricultural, industrial, and commercial activities, water scarcity will lead to water shortages. Kosovo is a landlocked country, and ERK is the most important region for industrial activities (coal, mines) and agricultural use (plains). Located in continental climate conditions, surrounded by middle to high-altitude mountains, the region does not have a favorable spatio-temporal distribution of freshwaters. The determination of the water resources is based on the amount of surface runoff, which being divided per capita, gives indications of the water resources of a region (catchment). For our aims, main river discharge and population statistics are used to analyze the spatiotemporal distribution and availability of renewable freshwater in ERK. Falkenmark Freshwater Indicator with 1.483 m³/capita/year shows that ERK lies under water scarcity, and existing water reservoirs offer low security for water withdrawals, and further reservoirs would prevent water scarcity in the region.

Heat transfer through a three-layer wall considering the contribution of phase change: A novel approach to the modelling of the process

A novel analytical solution to the time-dependent heat transfer equation for a multi-layer wall considering the contribution of phase change is obtained. Based on this solution a new numerical algorithm is developed for the analysis of variations in temperature and heat flux in a three-layer wall of a building in the presence of transient ambient temperature. In this algorithm, the new analytical solution at the end of the previous time step is used as the initial condition for the following time step with adjusted values of input parameters (ambient temperature). The novel algorithm is verified based on a comparison of the predictions of COMSOL Multiphysics (version 6.1) with its predictions for the same input parameters assuming that the time dependence of the ambient temperature follows the sine law. The new code is used for the analysis of heat transfer through a three-layer building wall assuming typical continental climate conditions. The inner and outer layers were filled with polyurethane foam, while a thin middle layer, located in the centre of the wall, was filled with the phase-change material (paraffin). Using the new numerical algorithm it is demonstrated that the presence of the thin paraffin layer in the wall leads to two orders of magnitude reduction in the amplitude of temperature oscillations on the room side of the wall compared to those on its outer side. It is shown that the presence of paraffin layer in the wall leads to an increase in the phase shift between the temperature on the outer side of the wall and the heat flux on the room side from about 1 hour (homogeneous wall) to about 5.5 hours (wall with the paraffin layer).

Spatiotemporal management of solar, wind and hydropower across continental Europe

Weather climate fluctuations cause large variations in renewable electricity production, which requires substantial amounts of energy storage to overcome energy drought periods. Based on daily hydroclimatic data and information about renewable power systems covering Europe, here we quantify the complementarity in the solar-wind-hydro energy components of the continental climate system. We show that the spatiotemporal management of renewable electricity production over Europe can induce a virtual energy storage gain that is several times larger than the available energy storage capacity in hydropower reservoirs. The potential electricity production matches the consumption by spatiotemporal management of suitable shares of solar and wind power complemented with the present hydropower. While the mixed renewable energy potential varies less than anticipated at the continental scale, utilization of the complementarity requires new continental electrical transmission lines and stable international trade. We highlight that management models need to consider incentives beyond national boundaries to appropriately benefit from continental climate conditions.

Productivity and milk quality of Saanen and Anglo- Nubian breeds of goats under the conditions of the Lower Volga region

Prospects for the development of dairy goat farming and goat milk production in many countries of the world, including Russia, are directly related to the dietary and healing properties of the product. An urgent problem is the comparative assessment of the adaptive and productive traits of dairy goats of imported selection under various ecological and climatic conditions of Russia, including the conditions of the sharp continental climate of the Lower Volga region. The purpose of the work was to give a comparative assessment of the eff ectiveness of breeding lactating goats of Saanen and AngloNubian breeds of imported selection under the conditions of the sharp continental climate of the Lower Volga region. The object of research was imported dairy goats. Two groups of female goats of Saanen and Anglo-Nubian breeds of the fi rst lactation of 10 heads in each were formed, taking into account their live weight, age of insemination and origin. The duration of the scientific and farm experiment was 210 days.Consistently high milk yield was found in goats of Saanen breed compared with the milk yield of their herdmates of Anglo-Nubian breed. The signifi cant diff erence in milk yield in favor of Saanen goats by months ranged from 13,24 to 16,51 % (p < 0,05). In general, during lactation the superiority of Saanen goats over their Anglo-Nubian herdmates in terms of milk yield was 61,2 kg or 15,75 %. A comparative analysis of quality indicators revealed a significant superiority of milk from goats of Anglo-Nubian breed such as in the mass fraction of fat by 1,48 abs.% (p < 0,05), in the mass fraction of protein by 0,24 abs.% (p < 0,05), in terms of milk fat yield by 3,15 kg (p < 0,05). It was found as a result that in the production of milk from goats of Anglo-Nubian breed, the level of profitability of milk with basic fat content (3,5 %) was higher by 27,78 abs.% compared with herdmates of Saanen breed.

Obtaining a primary suspension cell culture of Dracocephalum palmatum Stephan ex Willd

Dracocephalum palmatum Steph. grows on the southern slopes of the Oymyakon plateau in Yakutia (Northeast of Russian Federation) in conditions of harsh continental climate with continuous permafrost. The aboveground phytomass of the plant contains various complexes of secondary metabolites including polyphenolic compounds. It is a potential source of secondary metabolites needed for practical use in the pharmaceutical industry. The aim of the study is to obtain a primary suspension cell culture of Dracocephalum palmatum, growing in the conditions of the Cold Pole — Oymyakon. The work includes optimization of the nutrient medium for introducing calluses into a suspension culture, analysis of the dynamics of biomass growth of the obtained suspension culture, and morphological characteristics of the cells of the suspension culture. The callus cell cultures of Dracocephalum palmatum, cultivated on Murashige-Skoog (MS) medium with the addition of 0.5 mg/L α- naphthylacetic acid (NAA) and 0.2 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D), were most successfully transitioned into suspension culture. The maximum biomass growth of cell suspension culture was observed when cultivated in liquid MS medium with the addition of 2,4-D (0.5 mg/L), 6- benzylaminopurine (0.5 mg/L), and NAA (0.5 mg/L). The primary cell suspension culture of Dracocephalum palmatum, cultivated for 22 days, had an increase in wet weight of 9,2084 g, dry weight — 0,34135 g, and contained dedifferentiated aggregates of parenchyma-like cells and single round-shaped cells. Samples of the obtained cell suspension culture of Dracocephalum palmatum will be used for the analysis of secondary metabolites and for the development of optimal cultivation conditions in a bioreactor.

Calculation of base loadings of cement concrete roads in extreme continental climate conditions

Calculation of base loadings of cement concrete roads in extreme continental climate conditions

Growth Responses to Climate and Drought in Relict Cork Oak Populations as a Benchmark of the Species Tolerance

We still lack information on the long-term growth responses to climate of relict tree populations, which often persist in topoclimatic refugia. To fill that research gap, we studied three relict cork oak (Quercus suber) populations located in northern Spain using dendrochronology. The sites were subjected to humid (Zarautz), continental (Bozoó) and xeric (Sestrica) climate conditions. Cool–wet conditions during the current spring enhanced growth in Bozoó and Sestrica, whereas wet conditions in the previous October enhanced growth in Zarautz. In this site, growth also increased in response to dry conditions in the prior winter linked to high North Atlantic Oscillation indices. Correlations between the precipitation summed from the previous September to the current May peaked at the driest site (Sestrica). The strongest growth responses to drought severity were also found at this site, where growth negatively responded to 9-month early-summer droughts, followed by the continental Bozoó site, where growth was constrained by 1-month July droughts. Growth declined in response to 6-month January droughts in the wettest site (Zarautz), where cork oak was vulnerable to previous late-summer to autumn drought stress. Despite warmer and drier spring conditions that would negatively impact cork oak at the Bozoó and Sestrica sites, trees from these populations could tolerate further aridity.

Effect of Common Vetch (Vicia sativa L.) Green Manure on the Yield of Corn in Crop Rotation System

Regenerative farming systems are gaining increasing attention in crop production worldwide. The challenge of the future is to find and apply farming methods that not only reduce the carbon footprint of cultivation, but also produce sustainably through an optimal choice of inputs. We set up our crop rotation experiment in 2019 in order to evaluate the role of common vetch (Vicia sativa L.) as a green manure crop in a crop rotation system. The results were compared with nitrogen fertilizer (80 kg ha−1 N) and control (no green manure and no fertilizer) treatments. Based on the three years of results, it can be concluded that the biomass production capacity of common vetch sown in August is determined by the amount of precipitation in October under continental climatic conditions. In an optimum year for corn, common vetch as a forecrop was found to be equivalent to the effect of fertilizer application at all three applied seed rates, but under stress conditions in a drought year, significantly higher corn yields were obtained when common vetch green manure was applied. Our results suggest a justified role for the use of common vetch green manure in crop rotation systems.

Anadolu sarıçamının (Pinus sylvestris L. var. sylvestris) doğal yayılış alanı ve vejetasyon bileşimi

Anatolian Scots pine (P. sylvestris var. sylvestris) forests spreading in the northern part of Anatolia, Türkiye, and covering 2.1 million hectares show great variation in terms of the vegetation composition depending on both ecological conditions and human interference. The spreading and/or growing of Scots pine is mostly related to the sunny cold, subhumid continental climatic conditions as well as the cold and semiarid climate. It begins at the coastal belt of the Black Sea coast and rises up to 2700 m in the NE part of Anatolia, and continues towards the semiarid continental part of Central Anatolia. Scots pine is associated with Fagus orientalis, Castanea sativa, Tilia rubra, T. tomentosa, Alnus barbata, A. glutinosa, Quercus sp., etc. in the lower belt of the Black Sea coast, with Picea orientalis and Abies nordmanniana in the eastern upper belt of the Black Sea Mountains, and with Abies bornmulleriana in the middle and western parts of the Black Sea Region. It is composed of Pinus nigra and A. nordmanniana subsp. equi-trojani in the backward or southern parts of the Black Sea Region. Pure Scots pine stands occur in the subhumid continental part of NE Anatolia and the semiarid-subhumid continental part of Inner Anatolia. This study aims to highlight the natural occurrence of its forests, and to introduce their main vegetation composition reflecting ecological conditions.

PRUNUL TRANSGENIC HONEYSWEET ARE EFECT NEUTRAL ASUPRA DIVERSITĂȚII ȘI DINAMICII POPULAȚIILOR DE AFIDE ÎN CONDIȚII DE CLIMAT TEMPERAT- CONTINENTAL

‘HoneySweet’ is a genetically engineered plum resistant to Plum pox virus. Potential risks such as its impact on the diversity and dynamics of indigenous aphid populations was assessed. The study compared winged population of aphids visiting transgenic and conventional plums under continental temperate climatic conditions of Romania. The experimental analysis was conducted during three years (2016-2018) within an experimental plot containing transgenic (‘HoneySweet’) and conventional (‘Reine Claude d’Althan’ and ‘Stanley’) plums. This study revealed a similarity of both flight curves and the number and species of aphids landing on the two types of plum. Overall results showed no statistically differences between aphid species visiting the three cultivars, respectively the two types of plum. Consequently, our results support the hypothesis of the neutral effect of the transgenic plum on indigenous populations of aphids.

ПОДВОИ И НОРМА НАГРУЗКИ ДЛЯ ВИНОГРАДА ЛИВИЯ

In the course of the experiment, the differentiat-ed influence of various rootstocks and the norms of the bush load with shoots on the agrobiologi-cal indicators of grapes was established. The ob-ject of research was the grapevine variety Livia, rootstocks SO4 and 41B. The studies were car-ried out in the conditions of a moderate conti-nental climate in the Central agroecological zone of viticulture of the Krasnodar region, on irrigat-ed vineyards in a covering culture. Scheme of planting bushes was 3.8×2 m. The soils are low-humus, leached powerful chernozems. The most productive were the vineyards on the rootstock 41B. The bunch size on the 41B rootstock was 1.34 times greater than on SO4, the yield capaci-ty – 1.56 and amounted to 696 g and 28.23 t/ha, respectively. The predominant influence of the 41B rootstock in comparison with SO4 on the productivity of the Livia grapes is preserved with a differentiated load of grape bushes with bunches. With a maximum load of bushes with bunches (SO4 – 33, 41B – 38 pcs./bush), their weight on the 41B rootstock was 43 % higher than on SO4, yield capacity – by 62 %, with an average load (SO4 – 27, 41B − 32 pcs./bush) – by 27 and 48 %, respectively, at minimum load (SO4 – 19, 41B – 23 pcs./bush) – by 32 and 59 %, respectively. The influence of rootstocks on the norm of bush load by shoots is not unam-biguous. Against the background of the maxi-mum number of bunches on bushes, the highest values of bunch weight and grape yield capacity on SO4 and 41B were at loads of 25 and 26 shoots/bush, average – 25 and 33 shoots/bush, minimum – 31 and 20 shoots/bush, respectively. For growing high yields and attractive sizes of bunches of table grapes of Livia variety in the Central agroecological zone of the Krasnodar re-gion, it is recommended to use rootstock 41B, the load norm of bushes with shoots of 26 and bunches of 38 pcs./ bush.

Evaluation of economically valuable traits in millet cultivars bred by scientific research institutions of different geographical locations

In 2022, a study of economic traits was conducted on 16 varieties and lines of millet breeding from various research institutions (RI). The aim of the study was to investigate the productivity structure of millet varieties and lines of different ecological and geographical origins in the vegetation conditions of the Saratov region. To achieve this goal, research was conducted in experimental fields of the Federal Agricultural Research Center of South-East, where Saratov selection varieties and lines were grown, and their comparison was made with varieties of different geographical locations. Phenological and morphological measurements were carried out to assess adaptive properties. The results showed that Saratov selection varieties and lines demonstrate high adaptability to changing weather conditions in conditions of sharp continental climate in the agro-climatic region. They have high yield, economic coefficient, are resistant to smut pathogens and have high grain quality. The results of the study can be used in other research institutions to create new millet varieties combining yield, grain quality, and resistance to variation in hydrothermal conditions.

Evaluation of precipitation measurements using a standard rain gauge in relation to data from a precision lysimeter

Abstract The construction of modern lysimeters with a precise weighing system made it possible to achieve an unprecedented accuracy of precipitation measurement. This study compares two methods of measuring precipitation in the conditions of the humid continental climate of the Eastern Slovakian Lowland (Slovakia): measurement using a standard tipping-bucket rain gauge vs. precision weighable lysimeter. Data from the lysimeter were used as a reference measurement. The comparison period lasted four years (2019–2022). Only liquid rainfall was compared. The rain gauge was found to underestimate precipitation compared to the lysimeter. Cumulative precipitation for the entire monitored period captured by the rain gauge was 2.8% lower compared to lysimeter measurements. When comparing hourly and daily totals of precipitation and precipitation events, a very high degree of agreement was detected (r 2 > 0.99; RMSE from 0.22 to 0.51 mm h–1). A comparison based on precipitation intensity showed a decreasing trend in measurement accuracy with increasing precipitation intensity. This tendency has an exponential course. With increasing intensity of precipitation, increasing intensity of wind was also recorded. In order to correct measurement errors, simple correction method was proposed, which helped to partially eliminate the inaccuracies of the rain gauge measurement.

Estimation of Heterotrophic Soil Respiration Response to the Summer Precipitation Regime and Different Depths of Snow Cover in a Temperate Continental Climate

Regime of precipitation and temperature conditions are key factors that regulate the rate of decomposition of soil organic matter in terrestrial ecosystems. The aim of this work was to assess the effect of the duration of dry periods in summer and different depths of snow cover in winter on heterotrophic soil respiration. The studies were carried out as part of a 2–year field manipulation experiment organized on gray soil (Haplic Luvisol) in the temperate continental climate conditions (southern Moscow region). Three variants were organized: (1) simulation of mild weather with uniform watering of the soil in summer and the absence of freezing in winter, (2) simulating two summer dry periods lasting 1–2 months with natural winter snow cover, (3) simulation of extreme weather with one long (~3 months) dry period in summer and complete removal of snow cover in winter. Heterotrophic soil respiration was measured by the closed chamber method on bare fallow during 2 years of continuous experiment and 1 more year after its completion. Medians of heterotrophic soil respiration for the entire period of the experiment in the three above–mentioned variants of the experiment were 38, 27 and 19 mg C/(m2 h), respectively. Two short dry periods led to an increase in heterotrophic soil respiration by 7–10%, which is associated both with the drying and rewetting cycles of the soil and with an increase in the average summer temperature of a 20–cm soil profile by 1.5°C. The prolonged dry period caused a decrease in heterotrophic soil respiration by 12–16% as a result of low soil moisture. Soil freezing led to a strong decrease in winter CO2 emission from soil, which reached 34–55% in the control variant and 57–72% when the snow cover was removed. The frost period (November–March) contributed from 25–34% without of soil freezing to 14–19% when its presence to the annual CO2 flux. We conclude that the change in the winter temperature regime of the soil due to manipulations with the snow depth led to a more significant change in the annual heterotrophic soil respiration than the lack of precipitations in the summer season.