Exploring the Inﬂuence of Diverse Viticultural Systems on Soil Health Metrics in the Northern Black Sea Region

: The present study investigates the functionalecological status of typical light clay soils in vineyards in the southern region of Crimea, using both traditional (including fallow soils) and organic land-use systems. This analysis was carried out by examining agrochemical indicators, microbial respiratory activity, microbial biomass, and the ecological status of the microbial community. In organic vineyard soils, the mean substrate-induced respiration, microbial biomass carbon and the ratio of microbial biomass to organic carbon were found to be 2.8, 4.0, and 4.1 times higher, respectively, compared to conventional farm soils. On the contrary, the microbial metabolic coefﬁcient was 1.4 times lower, signifying more favorable conditions for the functioning of the soil microbiota. The increased mobile sulfur content in organic vineyard soils (18.3 mg kg − 1 vs. 8.0 mg kg − 1 in traditional farms) and inadequate mobile phosphorus supply in some farms present potential risks. The suboptimal functional state of the microbiome in fallow soils previously under traditional plant protection necessitates comprehensive ecotoxicological analyses before development. Assessing the soil functional ecological status through an ecophysiological evaluation of the microbiome is vital for understanding ampelocenosis soils and making informed decisions on vineyard management practices.


Introduction
The Crimean peninsula is characterized by distinct soil, climatic and agroecological conditions that support contemporary grape cultivation and the production of various types of wine and brandy wine materials. Grape cultivation in the northern Black Sea region can be traced back to the early settlements of the ancient Greeks and Romans, reflecting deep historical roots and cultural traditions in the area [1]. Currently, a key objective for Crimean winemaking is to expand the range of high-quality wines with geographical status. However, the development of winemaking on the peninsula faces specific challenges due to regional climatic changes and inherent agricultural intensification factors, such as high pesticide loads, the long-term cultivation of genetically homogeneous plants over vast areas, reduced biodiversity, and the risk of erosion resulting from the predominant location of vine plantations on sloping terrain with varying steepness and exposure.
Meteorological observations suggest that the peninsula's climate changes are primarily associated with a general trend of rising temperatures, which is not synchronous and is complicated by a wide variety of climatic conditions, increased aridity in certain areas, and increased frequency of adverse weather phenomena (return frosts, heavy rainfalls, squally winds, droughts, dust storms, etc.) [2,3]. moderate-to-heavy contamination and moderate ecological risk in organic farms were higher than ones in conventional farms [14].
All of the above mentioned are intrinsically linked to soil, which is responsible for generating and maintaining biodiversity, as well as providing environmental, regulatory, protective, and informational functions. The properties directly influence the quantity and quality of products, particularly in industries such as viticulture and winemaking.
The effectiveness of soils in the performance of their ecological functions is highly dependent on the condition of the soil microbiome [15], which provides a broad array of nutritional, regulatory, and support ecosystem services [16,17]. The soil microbiota facilitates ongoing processes of organic matter synthesis and degradation, humus formation, the cycling of plant ash and nitrogen nutrients, atmospheric nitrogen fixation and incorporation into the biological cycle (approximately 100 megatons annually), as well as the detoxification of various pollutants. Disruptions in the functioning of the soil microbial community may result in reduced quantity and quality of the products obtained.
Soil scientists used to speak of soil quality, a concept expressing a soil «fitness for purpose». Soil quality is a rather abstract concept, and in recent years, the term has been replaced by soil health. One consequence of this change is an increasing focus on the state of the soil's biology, or life in the soil-an emphasis that is expressed through the promotion of organic and biodynamic systems of farming.
The Cornell Soil Health Assessment provides a more balanced assessment of soil health [18]. The underlying concept is that soil health is an integral expression of soil's chemical, physical, and biological attributes, which determine how well a soil provides various ecosystem functions.
According to Lehmann et al., soil chemical and biological attributes such as organic carbon and microbial biomass are vital in terms of representing soil health and quality [19].
In a 2023 study, Higo Forlan Amaral and colleagues determined how different grapevine-growing seasons (organic or conventional) affect soil chemical and microbial characteristics compared to the soil characteristics of adjacent natural forests [20]. Variations in microbiological and chemical attributes during different seasons are specific to each vineyard management system. Soil under vineyard organic management maintained organic carbon and microbial biomass indices like those of a forest, of which were higher and more stable than those of a conventional system.
Soil microbiological indicators are used in conjunction with physicochemical and geochemical characteristics to evaluate the ecological functions of soils [21,22]. The soil microbial community responds rapidly to the presence of pollutants, showing alterations in the total number of microorganisms, species diversity, soil enzyme activity, soil respiration, and processes influencing the cycling of essential nutrients [23].
Microbial ecophysiological indicators, which characterize the specific activity of the microbiome (respiratory and enzymatic activity per unit biomass), are highly informative for evaluating organic matter decomposition efficiency, reflecting a wide range of ecosystem services, exhibiting considerable reliability and recognition, and possessing standardized and relatively straightforward methods for their determination [24].
Several authors have highlighted the high variability of soil microbiological parameters, with the most significant factors being climate [25], landscape position [26], land-use patterns [27], and vegetation composition [28]. At the same time, soil respiration measurements can be performed under laboratory-controlled conditions, mitigating the influence of abiotic and biotic factors (e.g., plant root effects) and enabling the standardization of environmental conditions.
The respiration of microorganisms serves as the most informative and widely used indicator of microbiological activity. Throughout their life cycle, microorganisms produce carbon dioxide and nitric oxide (I), consume oxygen, and perform nitrogen fixation in an outperformance, among other processes [29,30]. Apart from microbocenosis, plant roots also contribute to soil respiration processes [31,32]. Basal respiration (BR) generally refers to soil respiration that is devoid of roots and determined only by microbial activity. This indicator is widely used to determine the physiological state of microorganisms [33,34]. An increase in the basal respiration rate suggests a favorable condition of the soil microbiome. However, evidence indicates that soil contamination can cause a distinctive increase in the soil respiration rate compared to optimal values [35].
The substrate-induced respiration (SIR) method is now considered the standard approach for the quantification of microbial carbon (C mic ) [36]. This technique involves measuring microbial respiration (CO 2 release) for a duration of three to five hours (to prevent microbial multiplication) [37] after the introduction of a readily oxidizable substrate. However, the SIR method exhibits certain limitations. It is not applicable to extremely acidic (pH < 2.5) or highly alkaline (≥8.5) soils [38] due to the dissolving of microbial CO 2 in the soil solution [39], leading to its underestimation [40,41].
The microbial metabolic coefficient (qCO 2 ), which represents a specific respiration derived from the ratio of basal respiration to carbon from microbial biomass, is a crucial indicator in ecological monitoring [42]. This coefficient reflects the physiological state of the microbiota. Some papers showed that the qCO 2 index is sensitive to any change in land use [43][44][45], and it is applicable to assess the physiological state of microbial communities and the level of disturbance to them. Elevated qCO 2 values are characteristic of soils subjected to various anthropogenic interventions, as well as degraded and contaminated soils [46][47][48], including heavy metal pollution [49][50][51][52][53]. Numerous studies indicate that a decrease in the basal respiration rate leads to an increase in the qCO 2 C org −1 ratio [54], which characterizes the utilization of organic carbon (this indicator is higher in disturbed soils).
A key advantage of determining soil respiration parameters and the ecophysiological indices based on them is the ability to assess the response of soil microbial communities to agroecosystem management elements. Several studies suggest the utilization of microbiological indices for the ecological evaluation of land-use systems and analysis of the changes that occur during the transition from one system to another [55,56].
The active transformation of vineyards from traditional to organic management systems [57], as well as the involvement of fallow lands in viticulture, increase the value of the soil biological activity assessment as one of the most important indicators of its condition, including the ampelocenoses of the Northern Black Sea region. In this scenario, the soil microbial respiration, the microbial activity and biomass, and the changes in ecophysiological status may indicate unfavorable processes induced by a combination of agrogenic factors.
The primary objective of this study was to perform a comparative assessment of the functional and ecological state of the vineyard soils cultivated using traditional (including fallow) and organic farming systems in 14 farms in the Northern Black Sea region ( Figure 1). This assessment is based on soil agrochemical properties, soil respiration parameters and soil microbiocenosis ecophysiological conditions. The climate of the studied farms is Mediterranean; moderately warm; with moderately hot, dry summers and mild winters with frequent thaws. Monthly precipitation in the autumn-winter period is significantly higher than the average annual values, while in the spring-summer period, it is much lower. Consequently, precipitation serves as the main limiting environmental factor in the cultivation of field crops, and sustainable yields are unattainable without irrigation. However, agroclimatic and soil conditions in the region are favorable for the growth and development of viticulture and winemaking.

Materials and Methods
Soil samples were collected using a soil auger at depths of 0-10 cm and 10-20 cm The most typical areas in terms of landscape conditions were chosen as soil sampling site The so-called "envelope" method was used to obtain a generalized picture of soil proper distribution for each farm. This method involves taking five samples from a 5 m by 5 plot (at the corners of the plot and in the middle of the plot). A sample of 0.5 kg weig was taken from each point. The five individual samples were then combined, mixed an one combined sample weighing 1.0 kg was retained from the total mass. All operatio were carried out separately for samples with depths of 0-10 and 10-20 cm. Mixed sampl were collected from 5 sites for each farm, and those mixed samples was mixed accordin to the abovementioned procedure and analyzed. Soils on all farms were identified as Ha lic KASTANOZEMS/Haplic CALCISOLS according to WRB.
Soil preparations included milling, removing plant roots, stones and other inclusion Water pH was analyzed potentiometrically with a glass electrode using a SevenCompa pH meter S220 (Greifensee, Switzerland, Mettler Toledo). The organic matter content w measured by the photometric method using a strong oxidizing agent (K2Cr2O7) in the pre ence of H2SO4 (Walkley and Black method [58]) with a Leki UV2107 (Helsinki, Finlan MEDIORA OY) spectrophotometer at a wavelength of 600 nm. Mobile sulfur content w determined using a 0.15 percent CaCl2 solution [59]. The mobile phosphorus and pota sium content in soils was determined by an ammonium carbonate extraction, accordin to the Machigin method (with pH = 9.0 and 1:20 soil/solution ratio) [60]. After extractio potassium content was determined using flame emission photometry. Phosphorus w

Materials and Methods
Soil samples were collected using a soil auger at depths of 0-10 cm and 10-20 cm. The most typical areas in terms of landscape conditions were chosen as soil sampling sites. The so-called "envelope" method was used to obtain a generalized picture of soil property distribution for each farm. This method involves taking five samples from a 5 m by 5 m plot (at the corners of the plot and in the middle of the plot). A sample of 0.5 kg weight was taken from each point. The five individual samples were then combined, mixed and one combined sample weighing 1.0 kg was retained from the total mass. All operations were carried out separately for samples with depths of 0-10 and 10-20 cm. Mixed samples were collected from 5 sites for each farm, and those mixed samples was mixed according to the abovementioned procedure and analyzed. Soils on all farms were identified as Haplic KASTANOZEMS/Haplic CALCISOLS according to WRB.
Soil preparations included milling, removing plant roots, stones and other inclusions. Water pH was analyzed potentiometrically with a glass electrode using a SevenCompact pH meter S220 (Greifensee, Switzerland, Mettler Toledo). The organic matter content was measured by the photometric method using a strong oxidizing agent (K 2 Cr 2 O 7 ) in the presence of H 2 SO 4 (Walkley and Black method [58]) with a Leki UV2107 (Helsinki, Finland, MEDIORA OY) spectrophotometer at a wavelength of 600 nm. Mobile sulfur content was determined using a 0.15 percent CaCl 2 solution [59]. The mobile phosphorus and potassium content in soils was determined by an ammonium carbonate extraction, according to the Machigin method (with pH = 9.0 and 1:20 soil/solution ratio) [60]. After extraction, potassium content was determined using flame emission photometry. Phosphorus was determined by a spectrophotometer after color development with ammonium molybdate and SnCl 2 . All analyses were performed in triplicate.
The determination of basal respiration (BR) was carried out in accordance with CEN EN ISO 16072-2011 Soil Quality Laboratory methods for the determination of microbial soil respiration [61]. Soil was moistened with distillated water of 0.2 mL and incubated for 24 h at 22 ± 0.5 • C. After incubation, the carbon dioxide content in 3 mL of the air probe extracted by a syringe was measured using a Chromatec-Crystal 5000.1 (Yoshkar-Ola, Russia, Chromatec) gas chromatograph. The BR rate was expressed in C-CO 2 µg −1 soil per hour, with a repeatability of five times.
Substrate-induced respiration (SIR) was determined in a similar manner, but the soil was moistened with an aqueous glucose solution (10 mg glucose g −1 soil) instead of distilled water and incubated for 3.5 h at 22 ± 0.5 • C. The SIR rate was expressed in µg CO 2 g −1 soil per hour, with a five-fold repeatability.
Soil microbial biomass carbon (C mic ) was calculated by converting the SIR rate using the formula [29]: The specific respiration of microbial biomass (qCO 2 ) was calculated as the ratio of the basal respiration rate to microbial biomass carbon and expressed in µg CO 2 C mg −1 C mic h −1 : The particle size distribution was determined using the areometric method [62]. The data were statistically processed using the R language. The "FactoMiner" package was used for Principal Component Analysis (PCA) [63] and "FactoExtra" package for visualization [64,65]. All variables except Ni, Cu, Cd, Cr and C org were normally distributed according to the Shapiro-Wilk test (p < 0.05). Hence, a non-parametric statistics test for a group comparison was used (Kruskal-Wallis).

Agrochemical Properties of Soils under Vineyards
The pH values of the aqueous extracts in farms soils of the studied ranged from 7.2 to 8.4 (Table 1), corresponding to a neutral-to-moderately alkaline environment, which is ideal for grape crops. In most cases, soil pH values increased with depth, likely due to the carbonate nature of bedrock.
Although soil types and subtypes are similar and the geographical location of the farms is comparable, the organic content in the upper parts of the soil profile ranged widely from 1.48% to 4.34%. The highest average values were found in fallow soils, 3.37% and 3.33%, which were closely followed by farms with traditional land-use systems, 3.33% and 3.01%. The lowest average organic carbon content was a property of organic farms, at 2.58% and 2.54% in the 0-10 cm and 10-20 cm horizons, respectively. As the depth increased, there was a general trend of decreasing organic matter content, although exceptions were observed in farms No 1, No 5, and No 8. The granulometric analysis revealed that the soils of the studied farms possess a light clayey texture.
The mobile phosphorus content in the soils of the studied farms ranged considerably, from 3.8 to 138.3 mg P 2 O 5 kg −1 of soil ( Figure 2C), which classifies them into different supply categories: very low for farm No 14; low for farms No 3, 4, and 9; medium for farms No 2, 7, 10, and 11; high for farms No 5, 6, and 12; very high for farm No 8; and extremely high for farms No 1 and 13 in the top soil layer (0-10 cm). In nine of the studied farms, the mobile phosphorus content in the soil at a depth of 10-20 cm decreased by 1.6-7.4 times compared to the 0-10 cm horizon. Meanwhile, in five farms, the differences between the horizons were not significant.
Unlike mobile phosphorus, the available potassium content in the soils of the farms corresponded to an increased, high, and very high supply state and ranged from 359 to 1109 mg K 2 O kg −1 soil in the 0-10 cm horizon. Concurrently, the available potassium content in the upper horizon of soils from organic farms and fallow lands varied within a narrow range and was characterized by elevated-high and high-very high supply states, respectively. In contrast, in the soils of traditional farms, the variation in the considered indicator was significant and corresponded to the supply state level from elevated in farm No 14 to very high in farm No 12. Contrary to the available phosphorus content, the available potassium content correlated with the land management system used in the farm and was significantly higher (p = 0.0007) in organic farms compared to conventional and fallow systems (Figure 2A).
The mean mobile sulfur content in the soils of organic farms was 1.8-3.4 and 2.9-3.7 times higher compared to the soils of traditional farms and fallow lands, in upper and lower studied horizons, respectively ( Figure 2B). Unlike mobile phosphorus, the available potassium content in the soils of the farms corresponded to an increased, high, and very high supply state and ranged from 359 to 1109 mg K2O kg −1 soil in the 0-10 cm horizon. Concurrently, the available potassium content in the upper horizon of soils from organic farms and fallow lands varied within a narrow range and was characterized by elevated-high and high-very high supply states, respectively. In contrast, in the soils of traditional farms, the variation in the considered indicator was significant and corresponded to the supply state level from elevated in farm No 14 to very high in farm No 12. Contrary to the available phosphorus content, the available potassium content correlated with the land management system used in the farm and was significantly higher (p = 0.0007) in organic farms compared to conventional and fallow systems (Figure 2A).
The mean mobile sulfur content in the soils of organic farms was 1.8-3.4 and 2.9-3.7 times higher compared to the soils of traditional farms and fallow lands, in upper and lower studied horizons, respectively ( Figure 2B).

Parameters of Soil Respiration in the Ampelocenoses of the Southern Part of Crimea
A non-parametric median comparison between BR and land-use systems, using the Kruskal-Wallis criterion (p = 0.01), revealed a tendency for lower BR in traditional farms practicing chemical plant protection systems compared to organic farms. Cultivated soils exhibit intermediate values of BR ( Figure 2E, Table 2).

Parameters of Soil Respiration in the Ampelocenoses of the Southern Part of Crimea
A non-parametric median comparison between BR and land-use systems, using the Kruskal-Wallis criterion (p = 0.01), revealed a tendency for lower BR in traditional farms practicing chemical plant protection systems compared to organic farms. Cultivated soils exhibit intermediate values of BR ( Figure 2E, Table 2).
The value of substrate-induced respiration (SIR), which characterizes the potential activity of the soil microbial community, showed a wide variation in the upper 10 cm layer of soil in organic and conventional farms, ranging from 6.27 to 22.65 and from 2.11 to 6.27 µL CO 2 g −1 soil h −1 , respectively ( Table 2). In fallow soils, this value was low and varied within a narrow range of 1.98 to 3.10 µL CO 2 g −1 soil h −1 . A significant difference according to the Kruskal-Wallis criterion was observed between SIR in the soils of organic farms and those of farms with traditional land use and fallow soils ( Figure 2D).
The highest microbial biomass carbon content in the 0-10 cm horizon was found in organic farms, averaging 545.8 µg C g −1 , compared to 161.1 µg C g −1 in farms with conventional land use ( Table 2) An estimation of the right number of axes to interpret suggests restricting the analysis to the description of the first three axes (Figure 3). These axes present an amount of inertia greater than those obtained by the 0.95 quantile of random distributions (66.8% against 51.5%) and more than all other PCs altogether. This observation suggests that only these axes are carrying real information. Consequently, the description will stand to these axes. Table 2. Soil respiration indices (basal (BR, µg CO 2 C g −1 soil h −1 ) and substrate-induced respiration (SIR, µL CO 2 g −1 soil h −1 )), microbial biomass carbon content (C mic , µg C g −1 soil h −1 ), C mic /C org ratio (%), qCO 2 /C org microbial metabolic coefficient and microbial respiration ratio (QR) in soils of Crimean ampelocenoses.

Farm Number
Depth, cm Land-Use System BR SIR C mic qCO 2 C mic /C org qCO 2 /C org QR The first two dimensions of the analysis express 48.12% of the total dataset variance; this means that 48.12% of the individual (or variable) cloud total variability is explained by the plane. This is an intermediate percentage, and the first plane represents a part of the data variability. This value is greater than the reference value that equals 30.39%; the variability explained by this plane is thus significant (the reference value is the 0.95 quantile of the inertia percentage distribution obtained by simulating 924,214 data tables of equivalent size based on a normal distribution).
The histogram in the top part of Figure 3A-C quantifies the contribution of soil properties and respiration indices in the first three axes and provides a threshold for the contribution of higher variables. It is important to note that variable grouping into principal components can be logically interpreted. Thus, the first principal component consists mainly of variables related to microbial biomass (C mic /C org , SIR, BR, C org ) and soil and ecosystem properties directly affecting it (Age, pH (H 2 O)). The second main component is determined mainly by the content of heavy metals in the soil (Cr, Pb, Ni, Cd, Zn) and the third one by the granulometric composition of the soil and the biogenic elements (clay, silt, sand, Zn, S). The first two dimensions of the analysis express 48.12% of the total dataset variance; this means that 48.12% of the individual (or variable) cloud total variability is explained by the plane. This is an intermediate percentage, and the first plane represents a part of the data variability. This value is greater than the reference value that equals 30.39%; the variability explained by this plane is thus significant (the reference value is the 0.95 quantile of the inertia percentage distribution obtained by simulating 924,214 data tables of equivalent size based on a normal distribution).
The histogram in the top part of Figure 3A-C quantifies the contribution of soil properties and respiration indices in the first three axes and provides a threshold for the contribution of higher variables. It is important to note that variable grouping into principal components can be logically interpreted. Thus, the first principal component consists mainly of variables related to microbial biomass (Cmic/Corg, SIR, BR, Corg) and soil and ecosystem properties directly affecting it (Age, pH (H2O)). The second main component is determined mainly by the content of heavy metals in the soil (Cr, Pb, Ni, Cd, Zn) and the third one by the granulometric composition of the soil and the biogenic elements (clay, silt, sand, Zn, S).
The distribution of principal component scores for three land-use systems on the first two principal component axes are shown in Figure 3E. The score diagram shows that the first principal component axis can distinguish soils sampled in farms with traditional land use from fallow lands and organics farms. Since age and pH (H2O) contributed more to The distribution of principal component scores for three land-use systems on the first two principal component axes are shown in Figure 3E. The score diagram shows that the first principal component axis can distinguish soils sampled in farms with traditional land use from fallow lands and organics farms. Since age and pH (H 2 O) contributed more to the first principal component axis and were negatively correlated ( Figure 3D), while C mic /C org , SIR, BR contribute less and were positively correlated, organic farms could be distinguished from traditional farms by a lower pH, younger vines and a higher SIR, BR and C mic /C org ratio in soils.

Discussion
The active application of soil microbiological indices is recommended for the ecological evaluation of land-use systems and the analysis of changes in soil ecological quality during the transition from one system to another [55,56]. The advantage of determining soil respiration parameters and the ecophysiological indices calculated based on them lies in the possibility of an integrated comparative assessment of the soil microbiota's response to agroecosystem management mechanisms.
The microbial metabolic coefficient (qCO 2 ) is referred to as an index of microbial stress. This index is sensitive to any change in land use [30,44] and its value can be used to quantify the ecophysiological condition of the microbial community. The studies did not show significant differences in the microbial metabolic coefficient index in conventional and organic farm soils, although there was a trend towards lower qCO 2 in the upper horizon of organic farm soils compared to conventional farm soils. In contrast, the qCO 2 values in fallow soils were significantly (p = 0.025) higher ( Figure 2F).
It is well-established that the carbon fraction of microbial biomass constitutes 1 to 5% of soil organic carbon [66], and the higher it is, the more organic carbon is available. Consequently, research on soil microbial activity often utilizes the calculation of the C mic /C org ratio as an indicator of favorable conditions for the functioning of the soil microbial community and as a characteristic of the "quality" of its organic matter [30].
In our study, the C mic /C org ratio in the 0-10 cm horizon was highest in the soils of organic farms, averaging 2.23%, while in the soils of traditional farms and fallow fields, this ratio decreased by 4 and 8 times, respectively ( Table 2). In the 10-20 cm horizon, the C mic /C org ratio was also lower in fallow soils and soils of traditional vineyards compared to organic ones. This indicates that under the conditions of organic land use in vineyards, more favorable conditions for fixing carbon in the composition of microbial biomass are created in the soil, resulting in an increase in its proportion in the soil's organic matter.
In contrast to the C mic /C org index, the qCO 2 /C org ratio was typically higher in disturbed soils. Based on the calculations performed, the highest value of the qCO 2 /C org index was observed in the 0-10 cm horizon of fallow soils, averaging 109.6 µg CO 2 C mg −1 C mic h −1 /g C org g −1 soil, which was 1.7 and 2 times higher than in the soils of traditional and organic vineyards, respectively. In the 10-20 cm horizon, the differences between farms in this indicator were less pronounced.
The microbial respiration coefficient (QR), i.e., the ratio of BR values to SIR values, is considered an integral index to assess the state of the soil and its microbial pool. A QR value between 0.1 and 0.2 is thought to indicate a favorable condition of the soil microbial community [66]. In our study, the highest QR average value in the upper 10 cm layer was detected in fallow soils (0.15). A significantly lower QR value was observed in traditional farm soils (0.08), and the lowest in organic soils (0.05).
Low QR values in operating farms, particularly organic ones, are indicative of a lack of nutrients in the soil, which correlates with the previously presented results of the content of mineral nutrients.
Comparable data are reported by Probst et al. [12], where the microbial biomass carbon content was highest in the soil of organic farms, ranging from 320 to 1000 µg C g −1 soil.
Sustainable grape cultivation is influenced by a myriad of abiotic and biotic factors [67], including the utilization of highly productive and adaptive varieties [68], a range of agrotechnological techniques that allow for the product quality management during yield formation [69], and the duration of various types of land use [70]. The cumulative impact of local, natural and agrotechnological factors is encapsulated by the term "terroir", which determines the uniqueness and quality of wine. However, there are objective limitations to obtaining high-quality products, which are associated with climatic changes on one hand, and a series of environmental risks specific to ampelocenoses on the other hand, such as a continuous long-term cultivation in a single area, a reduction in species and soil biodiversity, the development of erosion processes on trans-eluvial landscape elements, and perennial high pesticide loads.
All the negative phenomena in viticulture are reflected in the ecological state of the soil, primarily in its biological properties. Unlike humus content, which is a more stable indicator primarily dependent on several properties and genetic features of the soil, the state of the soil microbial community is considered an important indicator of the initial manifestation of negative influences on the soil and the degree of its disturbance.
Our investigations of the soil microbiota respiratory activity in ampelocenoses revealed substantial differences in the ecophysiological status of the soil microbiome in vineyards, depending on the land-use system. It has been suggested that the activity of soil microbiocenoses is more dependent on the total pool of organic carbon [71]. According to our findings, the organic carbon content in soils of organic farms was, on average, 0.7% and 0.8% lower than in the soils of traditional farms and fallow lands, respectively. However, the most favorable conditions for soil microbiota functioning were observed in organic farming, as evidenced by higher substrate-induced respiration and microbial biomass carbon (2.8 times higher than in traditional farms), the C mic /C org ratio (4.1 times higher than in traditional farms), and the lowest qCO 2 value among all investigated soils (1.5 µg CO 2 C mg −1 C mic h −1 ).
Similar observations were reported by Probst et al. (2008), who examined the effects of conventional and organic grape-growing technologies on microbial biomass and ecophysiological indices in the vicinity of Colmar, northeastern France [12]. The researchers found the highest microbial biomass content and the lowest qCO 2 value in the soil of organic farms, with soil microbial activity positively correlated with the duration of organic land-use practices.
Organic farms soils were characterized by high mobile sulfur provision (18.3 mg kg −1 vs. 8.0 mg kg −1 in conventional farms), which is likely due to the use of sulfur-containing preparations approved for plant protection in organic farming. Based on the classification of soils by mobile sulfur content given by Aristarkhov [72], this parameter in soils of traditional farms and fallow lands was low (less than 6.0 mg kg −1 ) ( Figure 2B). However, it has been suggested that the increase in available sulfur in the soil of ampelocenoses enhances the availability of nitrogen to plants and the assimilation of these elements, which may collectively result in a decrease in the accumulation of phenolic compounds in grapes and a deterioration in the quality of the wine material obtained from them [69].
According to Kovalevskaya et al. [71], the conversion of arable to fallow soils led to the accumulation of organic matter in the upper soil horizons, which in turn contributed to the increased respiratory activity of soils and increased microbial carbon stocks. Our findings demonstrated that the C org content in fallow soils was indeed higher than in conventional and organic farm soils, but this did not lead to improved microbial activity indicators. Conversely, the active and potentially active (responding to readily available substrate) portion of the microbial pool, as determined by the substrate-induced respiration index, was less pronounced in fallow soils than in the soils of active vineyards. Furthermore, fallow soils exhibited the highest qCO 2 value, reaching 5.57 µg CO 2 C mg −1 C mic h −1 , although the value of this indicator in stable ecosystem soil is ≤2-4 µg CO 2 C mg −1 C mic h −1 [73]. This indicates a low efficiency of microorganisms' utilization of organic compounds to maintain their life activity, as well as a high rate of microbial biomass die-off. The latter is confirmed by the low C mic , averaging 96 µg C g −1 soil, which is 5.7 and 1.7 times lower than in the soils of organic and conventional farms, respectively. A certain imbalance in the functioning of soil microbiota in this category of soils is also indicated by the maximum value of the indicator qCO 2 /C org .
The soils of farms with traditional viticulture technologies showed inferior soil respiration indicators compared to the soils of organic farms. However, the microbiological activity and stability of the soil microbiome in these traditional farms were higher than in fallow soils. This could be influenced by the time factor, since the age of vineyards in organic and traditional farms in our study ranged from 5 to 20 years, which is relatively short for ampelocenoses. Meanwhile, fallow soils were previously used for about 40-60 years in the agricultural turnover with the application of traditional agricultural technologies and chemical plant protection systems-the effects of which could have influenced the current functioning of their microbiome.
A common problem for all studied soils was low mobile phosphorous content. Phosphorus is a vital nutrient for grapevines as it supports normal root system development and function, promotes the formation of large inflorescences, and stimulates the ripening of berries, as approximately 45% of the grapevine's active root system lies within a depth of 30 cm and about 70% within 45 cm [74]; phosphorus availability across all horizons is crucial.

Conclusions
Studies of comprehensive soil health metrics in the conditions of the Northern Black Sea region have shown significant variations due to used viticulture systems and the land-use management history. At the same time, the most significant differentiation was observed for the parameters of the soil microbiota functioning. The respiration of microorganisms in farms practicing organic land use significantly exceeds similar indicators in farms with a traditional system and in fallows.
An assessment of the available soil nutrient content showed a relatively low state of labile phosphorus and potassium form supply for most farms. The high content of mobile sulfur in the soil of organic farms can reduce the quality of the obtained wine materials. There were no excesses in the content of metal elements in any of the studied farms, as well as reliable differences in their distribution in the soil.
The influence of viticulture systems primarily affects soil microbiota and, to a lesser extent, soil macro and micro elements' supply states.