RESEARCH OF SOIL-CLIMATIC CONDITIONS OF LAND LOCATED NEAR KAVARNA TOWN AND ASSESSMENT OF THEIR SUITABILITY FOR VINES CULTURE

RESEARCH OF SOIL-CLIMATIC CONDITIONS OF LAND LOCATED NEAR KAVARNA TOWN AND ASSESSMENT OF THEIR SUITABILITY FOR VINES CULTURE Mladen Almaliev, Krasimir Trendafilov, Violeta Valcheva, Stefka Todorova, Nikolay Minev, Nedialka Yordanova Agricultural University, Agronomy Faculty, 12 Mendeleev str, 4000, Plovdiv, Bulgaria Abstract The research object belongs to the Eastern terroir "Black Sea" and in terms of climate conditions the land of the Kavarna town belongs to the Black Sea climatic sub-region and the climatic region of the northern coast. The main soil difference spread within the research object are Haplic chernozems and of limited size plots are spread following soil differences: Gleyic chernozems in the west part and Rendzinas - in the north-east and east part. In this study successively were research and described the morphological characteristics of the main soil incisions and were determinate by soil characteristic - mechanical composition, soil reaction, content of total and alkaline earth carbonates, content of active calcium, humus content, content of easily absorbable iron and content of nutrient macro elements. Soil - climatic conditions of the research area are suitable for growth of vines for producing quality wines. The established temperature conditions in the area and respectively of the research terrain allows growth of quality white wine varieties, such as Sauvignon Blanc, Chardonnay, Traminer, etc., as well as growth of medium-early varieties for quality red wines such as Cabernet Sauvignon, Merlot, Pinot Noir, etc. It is not recommended growth of late and very late vine varieties. Keywords: soil, vineyards, chernozems, rendzinas, wine 1. INTRODUCTION The variety of soil conditions in Bulgaria is large and in terms of opportunities for wine viticulture in the recent years was formed specific areas for production of quality wines, which according to the methodology for determination of areas for their production (Mihalev Trendafilov, 2005) should cover certain requirements regarding to the location of the vineyards. In this sense, the location determines the specificity, and the specificity is due to the advantages and disadvantages of the region, including its soils. The aim of this study was to determine soil and climatic characteristics of the land in the area of Kavarna town and to assess their suitability for creation of new vineyards for growth of high-quality wine grape varieties. 2. MATERIAL AND METHODS Object of this study were terrains, part of the area of Kavarna town, Dobrich region, located in the northern part of the Bulgarian Black Sea coast. The soil samples were taken from the terrain with a soil probe, as sample points were located within the borders of the field in a square grid, regardless of the borders of the different soil types of the terrain (BDS ISO 10381-2:2002). Two areas were studied with a total area of 12,5 ha. Samples were taken in three depths 0-25; 25-50 and 50-75 cm. After standard preparation, soil samples were analyzed to establish the indicators: mechanical composition with fotosedimentograf (Trendafilov and Popova, 2007), ph - potentiometric in aqueous extract (Arinushkina, 1970), content of total and alkaline earth carbonates gas metrically by Page 296

Scheibler apparatus (Arinushkina, 1970), activate calcium precipitable with (NH 4 ) 2 C 2 O 4 Druinnot- Gallet (NO1085/NFX31-106), humus content by method of Turin (Trendafilov and Popova, 2007), water-soluble salts (BDS ISO 11265:2002), content of easily absorbable iron, total nitrogen in the soil (BDS ISO 11261: 2002), mobile forms of phosphorus and potassium (GOST 26209-91/01.07.93). 3. RESULTS AND DISCUSSION 3.1. Identification of the object Object of this study was the properties: Property 043009 with area 5,8 ha, located in the area of Kavarna town, Kavarna municipality, 35064; field; category of the land (in not irrigative conditions) - fourth Property 043010 area 6,7 ha, located in the area of of Kavarna town, Kavarna municipality, 35064; field; category of the land (in not irrigative conditions) - fourth 3.2. Climatic characteristics Climatically, the area of Kavarna town belongs to the Black Sea climatic sub-region and climatic region on the northern coast. The average annual rainfall amount in the region was 480-580 mm. The maximum of the rainfall was in October and November, and the minimum - in August and December. The average annual air temperature was 12,22 С. The data of the climatic characteristic of the region shown in Table 1. Table 1. Total climatic characteristic of the climatic regions of the northern Black sea coast Climate indicator Measure Value Average starting date of permanent retention of the temperature above 10 о С Date 21 ІV Average end date of permanent retention of the temperature below 10 о С Date 9 ХІ The earliest date of the last spring frost Date 17 III Average date of the last spring frost Date 4 IV The latest date of the last spring frost Date 25 ІV The earliest date of the first autumn frost Date 24 Х Average date of the first autumn frost Date 13 ХІ The latest date of the last autumn frost Date 17 ХІІ Average duration of free of frost time Days 222 For characterization of the elements of the climate were used data registered by meteorological station of Balchik town. Page 297

3.3. Solar radiation, radiation balance and sunshine duration. The main indicators, characterize the radiation conditions shown in Table 2. The total solar radiation for the period with an average daily air temperatures above 10 С was about 4100MJ/m 2. The radiation balance for the period with an average daily air temperature above 10 С was 1800MJ/m 2. Photosynthetic active radiation for the period with an average daily air temperatures above 10 С was 1900 MJ/m 2. Table 2. Monthly and annual amounts of the sunshine duration in hours, total solar radiation (MJ/m 2 ) and the radiation balance (MJ/m 2 ) Indicator I II III IV V VI VII VIII IX X XI XII Year Sunshine duration, h Total solar radiation Radiation balance 81 90 128 168 228 269 316 299 228 160 95 74 2136 158 230 370 482 632 720 811 720 500 293 170 114 5200 3 40 135 215 327 370 398 336 127 72 22 0 2045 3.4. Temperature conditions The probability for establishment of extremely low temperatures below -20 о С during the cold period of the year and under -2 о С in April was low - less than 5%. The absolute temperature maximum, measured in the region was in July 37,8 о С. The probability for registration of temperatures above 35 о С in June was less than 10%, in July less than 30% and in August - less than 20%. The average temperature amount of the biologically active temperatures was 3470 о С. The temperature conditions in the region guarantee normal ripening of medium early vine varieties and were not sufficient for ripening of late and very late varieties. Table 3. Temperature conditions, station Balchik town Indicator I II III IV V VI VII VIII IX X XI XII Annually Average monthly air temperature о 0,6 С 2,0 4,5 9,8 15,3 19,7 22,2 22,3 18,6 13,2 8,8 4,2 11,8 Absolute maximum air temperature о С 17,6 20,3 25,1 28,8 32,5 33,0 37,8 35,5 31,0 28,0 26,6 19,5 37,8 Absolute minimum air temperature о С -21,1-20,0-13,4-3,9 2,5 6,3 9,0 8,6 2,8-8,3-12,0-15,9-21,1 Duration of the period with temperature above 10 С 204 Temperature amount о С 3470 Page 298

3.5. Regime of the atmospheric humidity Table 4 shown the average monthly rainfall amounts. The month with the most rainfall was November and with the least was February. Table 4. Monthly, annual and vegetative amount of the rainfall, mm Indicator I II III IV V VI VII VIII IX X XI XII Annually Rainfall, mm 28 23 27 31 32 49 42 30 27 53 53 48 443 Rainfall, vegetative period, mm 211 The normal growth of the vine was secured at an average annual rainfall amount 600-800mm, which in the studied region was 443 mm and was not sufficient to provide the required moisture for the vine. The deficit was an average 157-357 mm. The rainfall amount during the vegetative period of the vine (April 1 to September 30) was average value 211 mm, at established necessity of 400-500mm. 3.6. Wind regime The average speed and frequency of the wind in directions for January and July shown in Table 5. The average wind speed in January was 7,3 m/s. The distribution of wind frequency shown, that during the winter period most frequent were the winds from the northwest and north. The average wind speed in July was 4,3 m/s and in the summer period prevalence the northwest and north winds. Table 5. Average speed and frequency of the wind in directions for January and July Indicator N NE E SE S SW W NW Average wind speed in directions, January (m/s) 9,8 6,8 6,1 5,3 3,4 4,4 7,3 7,6 Average wind speed in directions, July (m/s) 5,9 6,1 4,9 4,5 3,5 3,8 8,1 6,5 Wind frequency in directions, January (%) 21,6 4,9 3,3 6,1 10,4 10,4 9,3 34 Wind frequency in directions, July (%) 20,8 8,6 2,1 8,7 27,2 4,7 5,9 22 3.7. General characteristics of the soil The main soil diversity widespread within the borders of the studied object was Haplic chernozems. In limited areas were spread the following soil diversity: Gleyic chernozems in the western part of property 043010 and Rendzinas - in the north-east part of property 043010. 3.8. Morphological characteristic Figure 1 shown the soil diversity and the location of the points of the soil sections. Page 299

Figure 1. Points of the main soil section Page 300

Morphological descriptions of the studied soil profiles SOIL SECTION 27 Name of the soil: Haplic chernozem Form of the relief and exposure: plain, slope 0-3 о Cultural type of the plot: field Composition and condition of the vegetation: plantation of rape Character and degree of moisture: dry Parent rock: carbonate loess А 1; 0-40 сm; 10 YR 3/2. Mechanical composition (clay, sandy clay, sandy loam, sand) sandy clay loam... coprolites) no...... Character and distribution of the root system (vertically, horizontally)...... Not effervesce from HCl... 1. Horizon Transition. А 2 В 1 ; 40-60 см; 10YR 4/3.. Mechanical composition (clay, sandy clay, sandy loam, sand) Sandy clay loam..... coprolites) no...... Character and distribution of the root system (vertically, horizontally) no...... Not effervesce from HCl... 1. Horizon Parent rock. В 2 С 1 ; 60-75 см ; 10YR 5/4... Mechanical composition (clay, sandy clay, sandy loam, sand) Sandy clay loam..... coprolites) carbonate spawn... Character and distribution of the root system (vertically, horizontally) no...... Effervesce from HCl in depth from 90 cm... Page 301

SOIL SECTION 28 Name of the soil: Gleyic chernozem Form of the relief and exposure: low, flow less, very wet area, altitude 105 m. Cultural type of the plot: field Composition and condition of the vegetation: grass, chamomile, panicle. Character and degree of moisture: dry Parent rock: carbonate loess А 1; 0-30 см; 10 YR 4/2. Mechanical composition (clay, sandy clay, sandy loam, sand) sandy clay loam, sandy loam... coprolites) no...... Character and distribution of the root system (vertically, horizontally)...... Not effervesce from HCl... А 2 ; 30-90 см; 10YR 3/1 Mechanical composition (clay, sandy clay, sandy loam, sand) sandy clay loam, sandy clay... coprolites) no...... Character and distribution of the root system (vertically, horizontally) no...... Not effervesce from HCl... 1.Horizon Mechanical composition (clay, sandy clay, sandy loam, sand)... Character and distribution of the root system (vertically, horizontally)......... Page 302

SOIL SECTION 29 Name of the soil: Haplic chernozem Form of the relief and exposure: plain, slope 0-3 о Cultural type of the plot: field Composition and condition of the vegetation: plantation of rape Character and degree of moisture: dry Parent rock: carbonate loess А 1; 0-60 см; 10 YR 4/2. Mechanical composition (clay, sandy clay, sandy loam, sand) sandy clay loam... coprolites) no...... Character and distribution of the root system (vertically, horizontally)...... Effervesce from HCl in depth 53 cm... А 2 ; 60-120 см; 10YR 4/4 Mechanical composition (clay, sandy clay, sandy loam, sand) sandy clay loam... coprolites) carbonate spawn increase in depth....... Character and distribution of the root system (vertically, horizontally) no...... Effervesce from HCl... 1.Horizon Parent rock Mechanical composition (clay, sandy clay, sandy loam, sand)... Character and distribution of the root system (vertically, horizontally) no...... Page 303

SOIL SECTION 30 Name of the soil: Haplic chernozem Form of the relief and exposure: plain, altitude 111 m. Cultural type of the plot: field Composition and condition of the vegetation: plantation of rape Character and degree of moisture: dry Parent rock: carbonate loess А 1; 0-60 см; 10 YR 4/2. Mechanical composition (clay, sandy clay, sandy loam, sand) sandy clay loam... coprolites) no...... Character and distribution of the root system (vertically, horizontally)...... Effervesce from HCl in depth 53 cm... 1.Horizon Parent rock А 1 С 1 ; 60-120 см; 10YR 4/4 Mechanical composition (clay, sandy clay, sandy loam, sand) sandy clay loam... coprolites) carbonate spawn increase in depth....... Character and distribution of the root system (vertically, horizontally) no...... Effervesce from HCl in depth 80 cm... 1.Horizon Parent rock Mechanical composition (clay, sandy clay, sandy loam, sand)... Character and distribution of the root system (vertically, horizontally) no...... Page 304

SOIL SECTION 31 Name of the soil: Rendzinas Form of the relief and exposure: plain, altitude 111 m. Cultural type of the plot: field Composition and condition of the vegetation: plantation of rape Character and degree of moisture: dry Parent rock: hard calcareous marl А 1; 0-30 см; 10 YR 4/2. Mechanical composition (clay, sandy clay, sandy loam, sand) sandy clay loam... Character and distribution of the root system (vertically, horizontally)...... Effervesce from HCl from the top... А 2 ; 30-70 см; 10YR 4/4 Mechanical composition (clay, sandy clay, sandy loam, sand) sandy clay loam... Character and distribution of the root system (vertically, horizontally) no...... Effervesce from HCl... 1.Horizon Parent rock Mechanical composition (clay, sandy clay, sandy loam, sand)... Character and distribution of the root system (vertically, horizontally) no...... Page 305

SOIL SECTION 32 Name of the soil: Rendzinas Form of the relief and exposure: plain, altitude 111 m. Cultural type of the plot: field Composition and condition of the vegetation: plantation of rape Character and degree of moisture: dry Parent rock: hard calcareous marl А 1; 0-30 см; 10 YR 4/2. Mechanical composition (clay, sandy clay, sandy loam, sand) sandy clay loam... Character and distribution of the root system (vertically, horizontally)...... Effervesce from HCl from the top... А 2 ; 30-70 см; 10YR 4/4 Mechanical composition (clay, sandy clay, sandy loam, sand) sandy clay loam... Character and distribution of the root system (vertically, horizontally) no...... Effervesce from HCl... 1.Horizon Parent rock Mechanical composition (clay, sandy clay, sandy loam, sand)... Character and distribution of the root system (vertically, horizontally) no...... Page 306

The depth of the humus horizon in Haplic chernozems vary from 40 to 60 cm, while in areas with Gleyic chernozems and Rendzinas reached 30 cm. The depth of the soil profile was not a restriction for the growth of vines in Haplic chernozems and Gleyic chernozems. In the areas with Rendzinas in depth of 70 cm was found solid rock and because of that, they can be used for growth of vine after melioration activities. 3.9. Mechanical composition of the soil The content of physical clay in the humus horizon in Haplic chernozems vary widely - from 24,3% to 73,7% and determines the soil as sandy loam, sandy clay loam and clay. The content of physical clay in the transition horizon was from 30,1% to 42,0% and defines the soil as a sandy clay loam. The topsoil horizon of the areas with Gleyic chernozems characterized with sandy clay mechanical composition. The content of physical clay in the topsoil horizon of the areas with Rendzinas defines soil as sandy loam, sandy clay loam. In depth the soil in these two soil differences was also sandy clay loam. Within the borders of the studied object prevail the soil differences with heavier mechanical composition in the topsoil horizon, which needs for creation of vineyards, vine planting material to be grafted on suitable pads. 3.10. Soil рн The values of the indicator ph (H 2 O) vary from 6,3 to 8,3 and determine the soil reaction as a weakly acidic, neutral to weakly alkaline. Weakly acidic soil reaction was found in the topsoil horizon of the area with Gleyic chernozems. In depth the reaction of the soil in the same soil diversity was neutral. The other analyzed samples showed weakly alkaline soil reaction. The values of the indicator increased in the depth of the soil profile. Soil reaction was suitable for growth of vines. 3.11. Content of total alkaline earth metal carbonates The content of total carbonates in the humus horizon in Haplic chernozems was not high and vary from 0,53% to 2,71%. The values increase in depth of the soil profile and reached to 16,33%. Content of total carbonates in Gleyic chernozems was not found. The areas occupied by Rendzinas contain in the topsoil layer 6,01% to 8,53% total carbonates. The values increased in depth as in layer 30-70 cm reached to 32,57%. 3.12. Content of active calcium The content of active calcium in the topsoil horizon in Haplic chernozems was low and in ranges from 0,55% to 0,64%. In depth of the soil profile the content of active calcium increased and reached maximum values 4,87%. Contain of active calcium in the areas with Gleyic chernozems was not found. Rendzinas characterized by a higher active calcium content. The values vary from 1,54% to 4,28% and increased in the soil layer 30 to 70 cm. 3.13. Humus content The humus content in the topsoil horizons assessed as high. The values of the indicator decreased in the depth of the soil profile and determine the soil with low to medium humus content. Page 307

3.14. Content of water-soluble salts The content of water-soluble salts in the soil was very low and did not exceed the limit of harmfulness (0,25%) and it was not a restriction for the growth of the vine. 3.15. Content of easily absorbable iron The content of easily absorbable iron in the root layer of the soil vary from 12,0 to 31,0 mg/kg soil. The values decreased in depth of the soil profile. 3.16. Content of nutrients macro elements and fertilization rates The content of macro elements, found in Haplic chernozems distributed within the borders of the studied object was as follows: Table 6. Contents of macro elements Sample NH 4 mg/kg soil NO 3 mg/kg soil Total absorbable nitrogen mg/kg soil P 2 O 5 mg/100g soil К 2 О mg/100g soil 27 18,7 25,4 44,10 11,54 22,10 29 13,7 28,3 42,00 12,31 23,00 30 13,3 30,1 43,40 10,95 22,50 The soil was with average reserve of mineral nitrogen 44,1; 42,0 and 43,4 mg N/kg soil. The amount of absorbable phosphates was in range of 10-12 mg/100g, and potassium 22-23 mg/100g. Based on reported results was found, that the soil was well reserve with absorbable phosphorus and rich with potassium. Table 7. Fertilization rates with nutrients macro elements Sample Stockpiling fertilization rate Р 2 О 5 kg/ha Stockpiling fertilization rate К 2 О kg/ha Fertilization rate with triple superphosphate kg/ha 27 320 0 700 0 29 300 0 660 0 30 340 0 730 0 Average 700 Fertilization rate with potassium sulphate kg/ha Before trench of the area was applied stockpiling fertilization with triple superphosphate for the period of three years. It is recommended to apply and main fertilization with triple superphosphate in rate 700 kg/ha for the whole area of the object. Page 308

4. CONCLUSION Soil-climatic conditions of the studied area were suitable for growth of vines for the production of quality wines. The established temperature conditions in the region and consequently of the studied terrain allowed growth of varieties for quality white wines, such as Sauvignon Blanc, Chardonnay, Traminer, etc., and growth of medium early varieties for quality red wines, such as Cabernet Sauvignon, Merlot, Pinot Noir and etc. It was not recommended growth of late and very late vine varieties. The prevail direction and frequency of the winds from northwest determine orientation of the rows in the same direction in order to avoid damage to the plants from strong winds. The established values of the indicators, characterized the soil properties were not a restriction for the growth of vines, with the exception of the clay mechanical composition of the soil. At adjustment of the areas with established solid rock at a depth of 70 cm was necessary melioration to increase the depth of the root habitable soil layer. In artificial saturation of the soil with calcium contained materials to increase the content of total carbonates and active calcium was recommended the use of resistant to Са 2+ pads for graft of the seedling material. Depends on the achieved content of active calcium can use the pads: - Riparia x Berlandieri 161-49 - it agrees with active calcium content in the soil up to 25% - 140 Ruggeri - it agrees with active calcium content in the soil up to 30% - Chasselas x Berlandieri 41 В - it agrees with active calcium content in the soil up to 40% - Ferkal - it agrees with active calcium content in the soil up to 45% REFERENCES Arinushkina EV, 1970, Guidance on chemical analysis of soil Ed. MSU M. BDS ISO 10381-2:2002-Soil quality-guidance on sampling techniques. BDS ISO 11261:2002 Soil quality Determination of total nitrogen Modified Kjeldahl method. (BDS ISO 11265:2002) Soil quality -- Determination of the specific electrical conductivity. GOST 26209-91/01.07.93 Determination of mobile compounds of phosphorus and potassium by Egner-Riem method (DL-method). Mihalev D., K. Trendafilov, 2005. Methodology for determination of areas for production of quality wines. Ministry of Agriculture and Forestry. NO1085/NFX31-106 Qualité des sols. Détermination du calcaire actif 1982-05-01-0301-Norme Homologuée. Trendafilov Kr., R. Popova, 2007, Guidance for exercise of Soil Science, Academic Publishing House of Agricultural University, Plovdiv. Page 309