Accepted Manuscript

Soil distribution and properties in the subalpine region of Kazbegi; greater Caucasus; Georgia: rating of agricultural

Thomas Hanauer, Carolin Pohlenz, Besik Kalandadze, Tengiz Urushadze, Peter Felix-Henningsen

PII: S1512-1887(16)30073-2 DOI: 10.1016/j.aasci.2016.12.001 Reference: AASCI 76

To appear in: Annals of Agrarian Sciences

Received Date: 5 October 2016 Revised Date: 6 December 2016 Accepted Date: 16 December 2016

Please cite this article as: T. Hanauer, C. Pohlenz, B. Kalandadze, T. Urushadze, P. Felix-Henningsen, Soil distribution and soil properties in the subalpine region of Kazbegi; greater Caucasus; Georgia: Soil quality rating of agricultural soils, Annals of Agrarian Sciences (2017), doi: 10.1016/j.aasci.2016.12.001.

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. ACCEPTED MANUSCRIPT 1 Soil quality assessment

2 SOIL DISTRIBUTION AND SOIL PROPERTIES IN THE SUBALP INE REGION 3 OF KAZBEGI; GREATER CAUCASUS; GEORGIA: SOIL QUALITY RATING 4 OF AGRICULTURAL SOILS

5

6  Surnames, first names and patronymics of the authors. 7 8 Hanauer, Thomas*; Pohlenz, Carolin*; Kalandadze, Besik**; Urushadze, Tengiz***; Felix-Henningsen, Peter** 9 10  Name of the institution, address, positions and scientific degrees of the authors. 11 12 *Justus Liebig University Giessen, Institute of and Soil Conservation 13 Heinrich-Buff-Ring 26-32, Giessen, 35392, Germany; [email protected]: M.Sc. / Dr. / 14 Prof. Dr. 15 **Ivane Javakhishvili Tbilisi State University, Department of Geography 16 1, Chavchavadze ave., Tbilisi, 0179, Georgia; [email protected]: Prof. Dr. 17 ***Mikheil Sabashvili Institute of Soil Science, Agrochemistry and Melioration, Agricultural University of 18 Georgia, 13 km, David Agmashenebeli Ave., 0159, Tbilisi; [email protected]: Prof. Dr. MANUSCRIPT

ACCEPTED ACCEPTED MANUSCRIPT 1 Soil quality assessment

2 SOIL DISTRIBUTION AND SOIL PROPERTIES IN THE SUBALP INE REGION 3 OF KAZBEGI; GREATER CAUCASUS; GEORGIA: SOIL QUALITY RATING 4 OF AGRICULTURAL SOILS

5

6 7 8 9 Keywords: Muencheberg Soil Quality Rating; Alpine Soils; (Humic); Cambic Umbrisols; Kazbegi 10

11 ABSTRACT

12 Soils of the alpine ecosystem of Kazbegi region were investigated according to the Muencheberg Soil Quality 13 Rating (M-SQR). Most limiting factors are as well as steepness, while the low nutrient supply and soil 14 acidity can be tackled by adequate fertilization and liming practice. Inorganic or organic pollutions were not 15 detected. Soils on sediment fans as well as glacial sediments, mostly Cambisols (Humic) , are characterized by a 16 low to moderate yield potential while high-yield soils, mostly Cambic Umbrisols , can be found on volcanic 17 plateaus. A common element of all soils is the high humusMANUSCRIPT content. Actually, most of them are used only for 18 pasture, due to poor accessibility. Soils on fluvial deposits, mostly , show a very high range of M-SQR- 19 scores. Altogether, the soils of the study area have the actually untapped potential to optimize the basic supply of 20 the local population as well as tourism also by cultivation of . Nevertheless, variety trials on different soil 21 forming substrates as well as control are major preconditions for successful implementation of new 22 cropping systems in the Kazbegi region. Furthermore, particularly rare soils, e.g. Cambisols on Tephra, should 23 be protected.

24

25 1. INTRODUCTION

26 Soil quality is, beside climate, the fundamental requirement for prosperity and development of a rural 27 population. Therefore, assessment of soil quality, yield potential and soil ecological functions are essential parts 28 of the interdisciplinaryACCEPTED AMIES II ‐project, which aims to support the rural development of the Kazbegi district in 29 the Greater Caucasus. It focuses on the human ‐environment interface and comprises ecological and socio ‐ 30 economic research to develop sustainable, agricultural land ‐use options.

31 Due to the Soil Science Society of America (SSSA) soil quality is defined as: ‘the capacity of a specific kind of 32 soil to function, within natural or managed ecosystem boundaries, to sustain plant and animal productivity, 33 maintain or enhance water and air quality, and support human health and habitation’ [1]. In the frame of the 34 project the Muencheberg Soil Quality Rating (M-SQR) for crop and farmland as well as grassland designed by ACCEPTED MANUSCRIPT 35 [2], valid for a wide range of soils, was applied in the mountainous area of Kazbegi to evaluate the potential of 36 agricultural soils of the area on an international basis. The M-SQR was chosen for this purpose, due to its 37 concept to ‘measure long-term soil quality and estimate of the local crop potential’, its suitability for grassland as 38 well as arable land and especially due to its internationality, because of using the FAO Guidelines for soil 39 description [2]. This article summarizes the results of field campaigns in 2014 and 2015.

40

41 2. STATE OF KNOWLEDGE

42 Due to increasing pressure on existing and potential agricultural land a multitude of approaches exist to quantify 43 agricultural soil quality resp. the production function. However, due to differing input data ratings are not 44 transferable or universally applicable [3]. Soil rating focuses on the evaluation of soil fertility, e.g. yield potential 45 of arable soils [4]. Due to Müller et al. [27] three natural limits to growth can be distinguished (1) temperature 46 and moisture regime of the soil, (2) internal soil deficits, e.g. a substrate hindering root growth and nutrition 47 supply, and (3) the relief. A brief summary of the different approaches has to start with the Californian Storie- 48 Index Rating (SIR), evaluating , texture and further parameters (nutrients, erosion etc.) and developed 49 already in 1933. It is a multiplicative and parametric System, multiplying percentage performance levels (x:100) 50 to get the final so called Storie-Index [4] [5]. The FAO developed rating systems, too. At first the Land 51 Suitability Classification (LSC), developed in 1960 and focusing on natural conditions limiting the yield 52 potential: Thermal and moisture regime, nutrient supply and relief as well as socioeconomic factors of the site. 53 Hence, more emphasis is on rating of climatic and edaphic factors then soil rating itself. In a second project, the 54 ‘Agro Ecological Zones’, agro-climatic zones were combinedMANUSCRIPT with the already existing of The World 55 (1:5.000.000) to get suitability classes for different crops [4]. Furthermore, national soil ratings exist like the 56 German ‘Amtliche Bodenschätzung’, rating the natural yield potential by soil properties, relief, climatic 57 conditions and moisture regime [6]. From its basic it is a fiscal instrument but often used for agro-ecological 58 issues, actually. To get an international consistent rating scheme the Soil Quality Assessment was developed in 59 the USA. It focuses on small data sets of the evaluated soils to determine soil quality by only a few 60 measurements [7]. A method explicitly accounting for the soil productivity of arable land as well as grassland is 61 the Muencheberg Soil Quality Rating (M-SQR) [2]. For example, M-SQR was already applied extensively in 62 Germany, based on soil maps (1:100.000) [8]. Furthermore, the practicability and reliability was confirmed by 63 field tests in several countries and the rating scores are well correlated with crop yields, especially at a moderate 64 level of farming intensity [3], as it is typical for the study area. The results of the M-SQR and the soil properties 65 primarily concerning the yield potential are discussed here. By means of this rating, the arable productivity can 66 be estimated on a globalACCEPTED scale [8]. Hence, M-SQR was chosen for the purpose of this article.

67

68 3. STUDY AREA

69 3.1. Location and climate ACCEPTED MANUSCRIPT 70 The Kazbegi study area is located in the Mtskheta ‐Mtianeti region and aprox. 155 km 2 in size (aprox. 270 ha are 71 settlements). The Kazbegi district (population approx. 6,500) as an administrative unit stretches from the 72 dividing Jvari Pass (‘Cross Pass’) to the Russian border (North ‐Ossetia and Ingushetia) on the northern slope of 73 the Great Caucasian Ridge. It is characterized by the valley of the Tergi (Terek) river and the Georgian Military 74 Highway, one of the major routes crossing the Caucasus ( Fig. 1). The main town Stepantsminda (‘Kazbegi’ in 75 Russian, 1,850 m a.s.l.; population 1,700) is characterized by a moderately humid climate with relatively dry, 76 cold winters and long, cool summers. The average annual temperature is 4.9 °C. January is the coldest month 77 with an average temperature of ‐5.2 °C, while the maximum average temperature is 14.4 °C in July [9]. Besides 78 Stepantsminda, the region is sparsely populated.

MANUSCRIPT

ACCEPTED

79

80 Fig. 1 Location of the study area in N Georgia according to [10] (modified); total size of study area: 81 154.94 km 2

82 3.2. Soil resources of the study area ACCEPTED MANUSCRIPT 83 Elevation of the study area is restricted to the montane to alpine zone [11]. The landscape morphology is diverse 84 and shaped by quaternary fluvial and glacial sediments, Tertiary and Quaternary volcanic rocks and Jurassic 85 sedimentary rocks [12][13][14][15]. The study area belongs to the geomorphological zone of the Tergi-Arguni 86 interridge isoclinal depression (Kazbegi-Khevi intermontane basin) [16] and is characterized by high tectonic 87 and geomorphologic activities. The Kazbek Neovolcanic center was still active in late Quaternary until less than 88 50 k. y. BP. The last satellite volcano Tkasrsheti erupted in middle Holocene, approx. 6 k. y. BP. The 89 stratovolcano Kazbek became a center of eruption with lava flows extended up to 15 km. Its lavas have a mixed 90 mantle-crustal origin composition of mainly porphyry, rarely aphyric, rocks varies from basaltic andesites 91 (basaltic trachyandesites) to dacites with a leading role of dacite lavas [17]. Three small explosive apparatuses 92 are localized in the study area: near Pkhelshe, downward Sioni and at the mouth of the Chkheri River [17] NE’ 93 Stepantsminda.

94 The second important bedrocks are flysch terrigenous and carbonate sediments of the complete Jurassic [16] 95 (primary slates but also marlstone) and lower Cretaceous (limestone) [12][13][14][15]. The quaternary 96 fluvial and glacial deposits are composed of both of these bedrocks. Due to this, a sediment cascade typical for 97 the alpine geosystems [18] can be found in the study area: rock face, valley head (regolith), slope (debris/ talus 98 fan), valley plain (alluvial sediments, terraces). Pediments are formed by sediment fans (e.g. talus) of Jurassic 99 sediments or by slope and debris of volcanic rocks.

100 Mudflows are a common natural hazard in Georgia (about 37 occurrences in the past 200 years), mainly due to 101 intensive precipitation and consequent flooding with hot spots e.g. in the Tergi river basin [19]. However, due to 102 [19] the study area is only in a zone of medium landslide hazard level. Furthermore, >70% of the territory of the 103 Tergi river basin is subject to avalanches [20]. MANUSCRIPT 104 Dominating soil types are , Cambisols, Gelysols and [21]. Due to Urushadze [22] - 105 Meadow soil ( Leptosols ) are spread in the study area (1,800 to 3,200 m a.s.l.), bordered by Leptosols (upper 106 zone) and Cambisols (lower zone). These soils are characterized amongst others by acid and weakly acid 107 reaction, a high content of humus as well as deep humus penetration [22]. As the study area is situated in the 108 hypsometric level for (peri)glacial processes of the middle belt e.g. alpine to subalpine landscape (1,750 – 2,300 109 m a.s.l.), slope (solifluction, rock-streams, snow avalanches, talus trains and mudflows) as well as plane 110 (polygonal-structural) processes of periglacial morphogenesis prevail [20]. The soil-climatic conditions in the 111 study area are characterized by a soil temperature at surface resp. at 20 cm depth of <10 resp. 0-10 °C during 112 growing season as well as a reserve of productive moisture in the 1-m layer of 100-200 [mm a -1] [23] on a 113 regional scale. 114 3.3. Land use ACCEPTEDof the Kazbegi region 115 Land use is characterized by the declining agricultural sector and rural poverty. Small natural remnants 116 occur mainly on steep, northern slopes. During Soviet times, Pinus sylvatica stands were afforested in the 117 vicinity of the villages to provide wood for the local communities [24]. Furthermore, due to Hansen et al. Betula 118 litwinowii shrubbery is encroaching and has spread its distribution since 1987 by nearly 25% [25]. However, the 119 subalpine and alpine areas in the region are dominated by grasslands. Accordingly, land use in the Kazbegi area 120 was traditionally dominated by large ‐scale pastoralism, which had its peak in terms of livestock numbers during ACCEPTED MANUSCRIPT 121 Soviet times when overgrazing led to severe erosion events [24]. Today, however, small herds of domestic cattle 122 free ‐range the vast, subalpine grasslands, while husbandry has lost its former significance. Until Soviet 123 times, the Kazbegi pastures were important summer pastures in a traditional transhumance system, which relied 124 on winter pastures in the Nogay district in Northern Dagestan (). Due to security concerns related to the 125 conflict in Chechnya and the tensions between Georgia and Russia, this transhumance has been abandoned [26]. 126 Although the number of sheep has declined considerably from more than one million, there are still around 127 20,000 sheep owned by local Kazbegi livestock owners the subalpine and alpine grasslands (estimated, 128 based on interviews of the former AMIES-project; unpublished data ). While in soviet times even cereals were 129 grown (Regional Museum in Stepantsminda, oral communication 2015 ), cropping is restricted to potato growing 130 on small fields (mainly <1 hectare), today.

131

132 4. MATERIAL AND METHODS

133 4.1. Soil quality rating

134 Just a brief description of the M-SQR will be provided, for more details see [3] [27] [2] [28]: The M-SQR bases 135 on the evaluation of properties of the rooting zone for cropping and uses indicators concerning the natural yield- 136 potentials. These indicators are distinguished in 8 so called ‘basic soil indicators’ and 13 ‘soil hazard indicators’. 137 While the basic indicators concerning criteria for plant growth (e.g. texture, rooting depth, wetness, ponding) and 138 range from 0 (poorest) to 2 (best), hazard indicators concerning potential yield-limiting factor (e.g. 139 contamination, acidification, drought) and range from 0.1 (maximum limitation) to 3 (no limitation). All basic 140 indicators are summed up and multiplied by the lowest respective MANUSCRIPT most limiting hazard indicator to get the final 141 soil score (M-SQR score) between 0 (poorest) to 100 (best). Additionally, the M-SQR-score can be grouped in 142 five classes from very poor (<20) up to very good (>80) and pedon rating can be transferred to landscapes. All 143 basic indicators can be determined in the field preferably by a regular soil pit or otherwise a small soil pit 144 (0.2*0.3 m and 0.4 m depth) and auguring at the bottom of the pit down to at least 1.4 m below surface. While 145 some hazard indicators can be determined in the field (e.g. soil depth above hard rock, steep slope) others must 146 be determined by evaluating the regional climatic data or laboratory data of soil analyses (e.g. salinity, total 147 nutrient status). Hence, the final M-SQR-score integrates the field work, rating the pedon as well as the 148 topography, climate data research and results of the laboratory work. A special aspect of the study was to 149 investigate potential hazards of the food chain (hazard indicator No. 1 ‘contamination’ [2]) due to anthropogenic 150 inputs or background concentrations of potential harmful substances or elements. Selected topsoils were 151 analyzed for persistent organic pollutants (POPs) to get an idea of background concentrations by traffic and 152 industrial emissions,ACCEPTED application of plant protectants or due to ‘global distillation’ (also known as ‘grasshopper 153 effect’). By ‘global distillation’, POPs are transported from emission areas to cooler regions via the atmosphere: 154 Recurring volatilization and cold condensation ultimately result in accumulation of POPs in cold regions, i.e. 155 high and Polar Regions [29]. In these regions, POP concentrations are found to increase with altitude 156 as a result of the cold-trapping effect and accumulate in forest soils near the tree-line, which is attributed to the 157 filter effect of trees. Recently, these phenomena were observed in mountainous regions of , North 158 America and in the Himalaya [29] [30]. Furthermore, a low phosphorous availability is a well-known ACCEPTED MANUSCRIPT 159 phenomenon of soils from volcanic parent material [31]. Hence, phosphorous sorption was comparatively 160 investigated on selected soils from volcanic as well as non-volcanic parent material referring to hazard indicator 161 No. 5 (‘low total nutrient status’).

162 For this study the basic parameters were determined in the field while most of the hazard indicators were 163 deduced from results of the laboratory analyses described below.

164 To get an exact idea of soil distribution in landscape, geomorphological as well as geological representative 165 areas were chosen for mapping of catenae, consisting of up to four profiles in different relief positions, while the 166 interspace between the profiles was mapped with augers of 1 m depth. In total 43 soil pits and 32 augers were 167 investigated in July and August 2014 and 2015. Soil mapping in field was conducted due to [32] as well as 168 Error! Reference source not found. according to [3], representative mixed samples were taken from every soil 169 horizon for determination of physical and chemical parameters (see below). SQR was conducted on 36 profiles 170 (regular soil pits) and 3 augers due to [2] and [28] (adjusted climatic hazards). Highest soil exploration was 171 located at 2.421 m a.s.l. (P23, N’ Juta) and lowest at 1.760 m a.s.l. (B24, E’ Pansheti). As SQR distinguishes 172 between grassland and arable land, actual land use was documented. Hence, change of land use might lead to a 173 different scoring.

174 A further task was the creation of a synthetic soil quality map based on the surveyed profiles as well as soil 175 substrate, inclination, elevation and aspect (based on a digital elevation model, cell size 20*20 m). Taking into 176 account the SQR-factors ‘slope and relief’ as well as the hazard indicator ‘steep slope’, mapped SQR- 177 Classification was additionally adapted to inclination. As a result soils in an area with >15° inclination were 178 scored as ‘(very) poor’, regardless of soil type or substrate.MANUSCRIPT In case of the parent material ‘volcanic influenced 179 unconsolidated rocks’ (see below) a further restriction was made: so a ‘moderate’ or better rating is restricted to 180 areas with an inclination <10°. For cartographic depiction ArcMap 10.2.1 (ESRI Inc.) was used.

181 4.2. Laboratory analysis

182 Soil samples for chemical and physical analyses were dried at 40°C, sieved for 2 mm, partially finely ground in a 183 hand mortar and stored at room temperature until analysis. Partly, field fresh samples were also frozen (-30 °C)

184 for analyzing POP. Soil pH was measured in suspension of soil and 0.01 M CaCl 2 with a ratio of 1:2.5 [33]. 185 Electric conductivity was measured in suspension of soil and deionized water with a ratio of 1:2.5 [35]. Contents 186 of carbonates were determined by the gas-volumetric method using a calcimeter [36]. The total amount of carbon 187 (Ct) was determined by a C-N-S element analyzer (Elementar). Inorganic C was calculated from the carbonate

188 content by using the factor 0.1199, while the amounts of C org result from the difference between Ct and inorganic 189 carbon. Particle size distribution was determined by a combined sieving ( and coarse fractions) and 190 pipette method (mediumACCEPTED silt and clay fractions) after decomposition of carbonates (HCl) and organic matter

191 (H 2O2) and dispersion in Na-Pyrophosphate [[37]]. The (pseudo-)total content of elements was extracted with

192 aqua regia (3 parts 32% HCl and 1 part 65% HNO 3) and microwave extraction from finely ground samples [38] 193 [39]. As the total content is not sufficient to determine eco-toxicologically relevant trace metals, the mobile and

194 exchangeable fraction (potentially plant available and easily leachable) was also extracted with 1 M NH 4NO 3 195 [40]. All extracts were stored in polyethylene bottles until analysis. Element concentrations were determined 196 with ICP-OES (Agilent Technologies, Modell 720ES). Plant-available inorganic P and K was extracted by the ACCEPTED MANUSCRIPT 197 CAL (Ca-acetate-lactate) method using a spectral photometer (T80 UV/VIS Spectrometer, PG Instruments Ltd.) 198 [41] for P, resp. an atomic absorption spectrometer (AAS) (FAAS 4100, Perkin Elmer) for K. Potential CEC was 3+ 2+ 2+ 2+ + + 199 determined at pH 7.2 with 0.1 M BaCl 2, measuring Al , Ca , Mg , Mn , Na , and K [42]. Organic pollutants 200 were extracted and measured by soild-phase microextraction (SPME) coupled to GC/MS (ITQ, Thermo). 500

201 mg of soil were weighted to 20 mL brownglas headspaces vials with 10 mL of 0.01 M CaCl 2 solution. To 202 enhance extraction, 10% NaCl was added. Quantification was performed with external standard calibration and a 203 validation with soil samples of known pollutant concentration. SPME extraction was performed in headspace 204 mode with 100 µm PDMS coated filters (Supelico). With this approach, concentrations >50 µg kg -1 can be 205 determined (quantification limit).

206 For climatic issues of the M-SQR (hazard indicators no. 7 and 12 ‘drought’, ‘unsuitable soil thermal regime’) 207 data of the Department of Hydrometrology from 1961 to 1990 [43] were used. For deduction of the hazard 208 indicator ‘contamination’ background concentrations of trace metals and organic pollutants/chemicals typical for 209 Georgia (PAH, DDx, HCH, PCB, Dieldrin, Aldrin, Endosulfan I and trifluralin) were chosen.

210 Phosphate-adsorption was determined according [44] by measuring the P-sorption of 0.5-1.0 g fine earth <2 mm 211 from batch-solutions with defined phosphorous concentrations (0 up to 275 mg l -1).

212

213 5. RESULTS AND DISSCUSSION

214 5.1. Soil Quality Rating 215 For the purpose of evaluating and classifying soil quality, a MANUSCRIPTclassification by soil types due to Error! Reference 216 source not found. proved difficult, because Cambisols and Umbrisols developed on stony sediments fans as 217 well as on volcanic influenced substrates with very different properties and yield potentials. However, due to the 218 dependency of soil quality from soil substrate (see below) a rough classification due to the six main parent 219 materials of of the study area was developed. The general term ‘parent material’ is used, because 220 different substrates might be included, e.g. loam or even gravel in case of fluvial deposits. For practical reasons 221 and for sake of clarity, such a simplification is appropriate. The results are summarized in Table 1 and discussed 222 in the following.

223 Table 1: Muencheberg Soil Quality Rating (SQR), agricultural potential and soil type (dominating type 224 underlined) as a function of parent material; amedian // minimum – maximum; b median //arithmetic mean and 225 standard deviation; n.a.: not analysed; (): small sample size 226 ACCEPTED Parent Solid rock Debris of Glacial Volcanic Fluvial Material Jurassic sediments influenced sediments sedimentary (pumice, ashes) rocks unconsolidated rock Soil types Skeletic Umbrisol/ Umbrisol / , ACCEPTED MANUSCRIPT , , Cambisol Fluvic Skeletic Regosol Cambisol, Cambisol/ Regosol Umbrisol (Fluvic) SQR-class Very Poor (Very) Poor Poor – (Very Poor) – (Very) Poor Moderate – Moderate Moderate Moderate – – Moderate (Good) Main limiting Steep High High Acidification / High Flooding e.g. hazard slope/ percentage percentage Low total percentage and extreme factors (except High of coarse of coarse nutrient status, of coarse waterlogging thermal percentage soil texture especially soil texture regime) [2] of coarse fragments fragments phosphorous fragments / soil texture Flooding fragments and extreme waterlogging Actual land (Forrest, Forrest, Forrest, Forrest, Pasture, Pasture, Pasture, use Pasture) Pasture, Pasture, Meadow, Meadow, Meadow Meadow, Meadow, (Cropping) (Cropping) (Cropping) (Cropping) pH-value 1 Topsoil (6.5) 5.0-7.2 3.9-6.1 MANUSCRIPT 4.3-6.9 5.0-7.4 (6.9) n.a. 4.3-7.4 4.0-5.1 4.0-5.1 5.1-7.5 (4.5-5.1) Underground n.a. 4.7-7.4 4.3-6.9 3.8-5.8 5.2-7.7 (2.6-3.6) Corg [%] a Topsoil (11,2) 7.9 // 2.7- 14.2 // 6.7- 9.0 // 5.2-13.9 4.2 // 0.8-6.8 (28,6) 16.7 17.7 Subsoil n.a. 2.3 // 0.6-5.1 1.0 // 0.6- 2.7 // 0.4-5.2 1.3 // 0.9-2.3 (25.5) 6.0 Dominating texture class (FAO) Topsoil (SL) L LC L SL - Subsoil ACCEPTED L SL SL/SiL SiL - Nutrient content (Profile) b K [g m -2] 14.8 // 20.1 // 83.0 // 8.8 // (11.3) 28.5±27.1 25.7±8.2 31.0±19.6 9.8±4.9 (29.3) P [g m -2] (7.5) 4.0 // 8.7// 0.5 // 4.9±6.0 1.4 // (1.0) ACCEPTED MANUSCRIPT 7.6±8.6 7.8±1.7 1.7±2.1 Nmin [g m -2] 7.6 // 11.2 // 16.8 2.9 // (1.8) 7.9±4.0 ±8.1 7.9 // 9.0±4.5 2.6±1.3 (4.8) Nres. [g m -2]2 1,899.3 // 4,093.9 // 1,855.4±110 3,725.7±57 2,520.0 // 776.7 // (501.0) 3.9 3.4 2,210.6±1,499.2 820.8±607.3 (2,392.2) C:N (Topsoil) (11:1) 11:1 10:1 10:1 14:1 (1:16) N profiles 1 11 4 15 7 1 227 1No averaging, due to aggregation of substrates with different basicity 228 2Nres = Nitrogen-reserve, based on total N [%]

229 A general characteristic of all soils of the study area is the high Corg content in combination with a narrow C/N- 230 value. Hence, nitrogen supply is mostly on a high or very high level [44]. Most of the soils show a low bulk 231 density, in some cases even down to 0.5 g cm -3 (Ah-horizon of P22, a Cambic Umbrisol on glacial sediments) 232 due to the high content of Corg and the stabile crumbly . By contrast, the phosphorus supply is a 233 limiting factor in nearly all soils, independent from parent material. In addition, potassium deficiency is a 234 problem, though less severe. 235 Furthermore, drought or too cold climate conditions are the critical hazard indicators [28]. Due to the relatively 236 high precipitation of 442 mm during the vegetation period (May to August), there is no risk of drought. 237 Nevertheless, an ‘unsuitable thermal regime’ is a general SQR-hazard indicator due to a mean annual 238 temperature of 4.9°C (see above) resulting in a lower graduation for arable land [28]. The soil thermal regime is 239 critical for germination. Most grasses germinate at temperaturesMANUSCRIPT above 5°C, while crops need for germination 240 temperatures between 5 and 10°C [28]. However, due to the increased radiation budget SE to WW exposed 241 slopes are characterized by a more favorable microclimate, leading to an extended vegetation period of 2 to 3 242 weeks ( Otte, oral communication 2016 ). 243

244 5.2. Properties of the parent materials

245 Soils of the alpine ecosystem are regarded to be shallow, rocky, and mostly used as pasture. Indeed, we find such 246 soils largely extended in the study area. However, they are not as characteristic for the Kazbegi region as they 247 seem to be at the first sight. On very steep slopes with an inclination >30° or on exposed slope areas soils above 248 solid rock, maybe underlain by a shallow regolith layer only, are widely spread (45.55 km 2 or 29% of the study 249 area) especially in higher elevations at the transition zone from pediment to the open rock surface. Due to Error! 250 Reference source notACCEPTED found. such soils have to be classified as Leptosols (partly Humic ). Depending on coarse 251 fraction and bedrock the qualifiers (Hyper)Skeletic and/or Calcaric might be prefixed. Obviously due to the 252 shallow root zone and steepness that influence further soil parameters, e.g. water capacity or thermal regime, an 253 agricultural potential is strongly limited or nonexistent. Due to limited access and the assumption of a spatially 254 homogenous soil development from such parent materials, only one example profile (P44, close to Akhaltsikhe) 255 was classified with M- SQR, resulting in only 11 points or ‘Very Low’. Even if in some areas site conditions are 256 slightly better, e.g. a deeper regolith layer, it can be assumed that these soils belong to the M-SQR-class ‘very 257 low’ due to steepness, shallow profile, low nutrient status as well as small water capacity. Hence, only fallow, ACCEPTED MANUSCRIPT 258 extensive pasturing or the use of extensive forestry is possible, strongly connected to accessibility and steepness, 259 but erosion control must have highest priority, because the unconsolidated rocks at steep slopes of the study area 260 are exposed to slides like incase of the mud slide in Mleta in 2010 [45].

261 Hence, below the Leptosols above solid rock deeper soils can be found on weathered debris. It has to be 262 distinguished between soils formed on accumulated debris from the Jurassic sedimentary rocks and soils formed 263 on parent material, which was more or less mixed with pyroclastic materials. The soils mentioned first are very 264 rich in stones with up to 75% coarse fraction in the subsoil resulting in a low water capacity combined with 265 limited nutrient supply and difficult conditions for cultivation. However, due to the loose substrate, roots can be 266 found down to more than 1 m. Most of the settlements in the study area, e.g. itself, are built on these debris fans. 267 Hence, main SQR-hazard indicators are, beside the thermal regime that is a problem for all soils in the study 268 area, ‘high percentage of coarse soil texture fragments’ and ‘steep slope’. Chemical alteration of the subsoil is 269 partly masked by the primary dark rock color of slate debris. If chemical alteration can only be traced in 270 laboratory by analyzing crystalline and amorphous iron oxides these soils are no Cambisols as described by 271 Urushadze et al. [Error! Bookmark not defined. ]. Instead of this, they have to be classified as . Under 272 intensive cultivation in house gardens or fields close to the settlements, Hortisols have developed as well. They 273 are characterized by a high content of Corg, accumulated in the topsoil. However, the blackish color is not only 274 the result of humus accumulation, but results also from lithogenic carbon of the Jurassic silt stones and clay 275 slates. These soils cover 5,039 ha or ca. 32.5 % of the study area. The agricultural potential due to SQR ranges 276 from very poor in case of steep slopes and/or a high proportion of coarse fraction, to moderate on lesser steep 277 parts of the sediment fans. 278 Concentrations of primary nutrients differ, while (in non-cultivated MANUSCRIPT soils) potassium and phosphorus reserves of 279 the profiles are low [44], nitrogen reserves as well as actually available nitrate and ammonia are mostly (very) 280 high due to the high humus content, high mineralization rates and low rates during the dry phases of the 281 vegetation period. Therefore, most of these soils, even with a good accessibility, are used as pasture, hay 282 meadow or small potato fields. At least in case of soils on the lower parts of the sediment fans, this kind of land 283 use is far below their potential. This also becomes evident if the former land us is taken into account: In the 284 second half of the last century barley was grown on a large scale on the lower parts of the sediment fans close to 285 Stepantsminda (Regional Museum in Stepantsminda , oral communication 2015 ).

286

ACCEPTED ACCEPTED MANUSCRIPT

287

288 Fig. 2 On debris fans of the Jurassic sedimentary rocks (mainly slates) , profound but skeletic soils have 289 developed; P12 Skeletic Regosol (Humic) from Jurassic clay slate on a sediment fan, SE of Stepantsminda, M-

290 SQR rating 43 points (class: moderate), used as pasture below a former potato field.

291 The third main group of soils has developed on pediments and plateaus from Andesite-Dacite and other 292 pyroclastics (e.g. tuff). This parent material (‘volcanic influenced unconsolidated rock’) covers 2,518 ha or ca. 293 16% of the study area. Depending on base saturation, Cambic Umbrisols or Cambisols (Humic ) have developed. 294 It is obvious that in case of steep slopes also on this substrate only very low or low SQR-rated soils developed, 295 e.g. P17 (19 points). But on smooth slopes or in flat areas moderate to good SQR-classes are distributed. These 296 are by far the best soils of the study area, especially if theyMANUSCRIPT have developed on colluvial loam in accumulation 297 areas (e.g. slope toe). We found rooting even down to nearly 2 m below surface. For example the Umbrisol 298 (Protoandic Colluvic Hyperhumic) (P05, see Fig. 3) roughly in the middle of the volcanic plateau close to the 299 village Ukhati gets 79 points, that is on the upper edge of the SQR-class ‘good’.

300

ACCEPTED

301 ACCEPTED MANUSCRIPT 302 Fig. 3 Umbrisol (Colluvic Hyperhumic Protoandic) above Gleyic Umbrisol , from colluvium above glacial-

303 fluvial sediments above colluvium, pasture; P05 W’ Ukhati, SQR rating 79 points (class: good).

304 Except of the thermal regime acidification could be problematic in a few cases, because soil pH in most profiles 305 is >4.5. Furthermore, phosphorus availability might be limited (referring to SQR-hazard indicator ‘low total 306 nutrient status’) if the soils show protoandic properties Error! Reference source not found. . These result in an 307 increased phosphate-fixation by allophanes and metal-humus complexes, due to a high anion exchange capacity. 308 This could also be a problem for other anionic nutrients (e.g. nitrate or chloride) [31]. In Table 2 the 309 phosphorus-retention of three different soils is shown. A Cambic Umbrisol (Protoandic) (P07) has developed on 310 slope loam over Andesite-Dacite (close to Ukhati), while a Cambisol (Humic Tephric) (P16) has developed 311 directly on significantly younger (very likely from Holocene) and only weakly weathered tephra (close to Sioni). 312 In contrasts, A Cambisol (Humic) (P11) has developed on debris of clay slate (above Stepantsmida). P07 shows 313 a dramatically higher phosphorus-retention than P16 due to the formation of Fe- and Al-oxides in the Umbrisol 314 of P07 by of silicates, with a significant proportion of allophanes and ferrihydrite (see Tab. 2:

315 Al ox +1/2 Fe ox ), certainly. Hence, cropping may need an increased phosphorus-fertilization combined with liming 316 to increase soil-pH and to decrease anion exchange capacity.

317 Table 2: P-sorption of two soils on volcanic influenced unconsolidated rock (P07, P16) and one on debris of

318 Jurassic sedimentary rocks; Al ox +1/2 Fe ox [mg kg-1] = active oxides [44], diagnostic criteria due to Error! 319 Reference source not found.

-1 -1 Profile/horizon Added P [mg l ) Sorbet P [%] Al ox +1/2 Fe ox [mg kg ] P07 / Ah2 (Cambic Umbrisol 25 MANUSCRIPT100 10.306 Protoandic) 100 93 250 61 P07 / Bw-Ah 25 100 12.815 100 95 250 64 P16 / Ah (Cambisol Humic) 25 17 5.335 100 5 150 3 P16 / Bw 25 28 4.710 100 11 150 7 P11 / Ah (Cambisol Humic Tephric) 25 76 1.087 100 37 150 27 P11 / Bw ACCEPTED25 68 1.599 100 35 150 22 320

321 Within the Pleistocene major parts of the study area were covered by glaciers, as it is easy to conclude from the 322 shape of valleys and the distribution of end and side moraines, e.g. in the Truso valley. Hence, soils developed 323 on glacial deposits partly covered by Holocene deposits. For example in the Chkheri valley, WNW’ ACCEPTED MANUSCRIPT 324 Stepantsminda, a groundmoraine is buried beneath late-glacial fluvial sediments or at the Ukhati plateau by 325 colluvium (P05, P36; see Fig. 6). Hence, only a total area of 398 ha, or less than 3% of the study area, various 326 glacial sediments are the parent material of the complete soil. However, in other soils they participate as layers in 327 deeper parts. A typical hazard indicator for these soils, mostly Cambisols or Umbrisols but also Calcaric 328 Regosols , is a ‘high percentage of coarse soil texture fragments’ due to bed load of the moraines.

329

330

331 Fig. 4 Cambic Umbrisol (Hyperhumic) (P23 N’ Juta, see Fig. 6) as a typical soil on an endmoraine, with a high 332 content of organic matter and fine earth, but rather shallow. Land use 2015: pasture; M-SQR rating 40 points 333 (class: poor). MANUSCRIPT 334 Fluvisols or soils with fluvic properties cover 2.081 ha or ca. 13% of the study area. These soils are formed on a 335 variety of substrates, depending on source area of the watercourse as well as distance to the water divide. Due to 336 dominating calcareous sedimentary rocks in the south of the study area, most alluvial sediments are calcareous. 337 Water logging and ponding up to paludification is a problem in case of the braided river beds of the Truso river 338 (below Ukhati) and the Snotskali river (SE Akhothi), resulting in the SQR-hazard indicator ‘flooding and 339 extreme waterlogging’. However, the main hazard indicator ‘high percentage of coarse soil texture fragments’ is

ACCEPTED ACCEPTED MANUSCRIPT 340 a result of postglacial outwash as well as mass movements on slopes in the study area, especially at the low

341 terraces.

342 Fig. 5 Depending on the substrate yield potentials of the Fluvisols differ within a broad range: a) Calcaric Gleyic 343 Fluvisol (P03, see Fig. 6), on haugh, Truso valley, SQR rating 50 points (class: moderate); b) Calcaric Skeletic 344 Regosol (Humic Fluvic) (P29, see Fig. 6), on coarse gravel and rubble, pasture; NE’ Achkhoti, SQR rating 34 345 points (class: poor)

346 Histosols occur in isolated and small areas in abandoned braided river beds, e.g. between Achkhoti and Sno (ca. 347 2 ha in size, see Fig. 6), or slope flattenings above an aquiclude, e.g. at the counter slope S’ Ukhati (see Fig. 6). 348 Bogs are not taken into account of the SQR-map due to the small size of the areas. Generally, similar restrictions 349 for cultivation apply as in case of the Fluvisols with an extreme MANUSCRIPT water regime as mentioned above. For example 350 the drained low-level moor between Achkhoti and Sno is used as a meadow in 2015.

ACCEPTED ACCEPTED MANUSCRIPT

351

352 Fig. 6. Map of the SQR-Score [2] of the study area, in case of the Jutistkali River no fluvial parent material is 353 shown separately, due to dominating slope processes in the steepMANUSCRIPT gorge. 354

355 5.3. Hazard indicator ‘contamination’ [28]:

356 Due to the aim of the study to supply information for a sustainable agricultural and horticultural land use 357 particular care has been given to the hazard indicator ‘contamination’. For this purpose trace metals as well as 358 organic pollutants/chemicals were measured in selected samples.

359 Trace metals increase in soils on bedrocks containing high lithogenic amounts. This is the case for sedimentary 360 resp. metamorphic as well as volcanic rocks [46]; both are more or less sources of all soil forming substrates in 361 the study area. The andesite and dacite lavas of the Kazbek nevolcanic center show e.g. Ni and Cr concentrations 362 of 15-150 resp. 30-270 [mg kg -1] [17].

363 In Table 3, selected trace metals in the topsoil horizons of the soil explorations as well as further sampling 364 points are shown. InACCEPTED a few case total concentrations exceed Georgian thresholds [47]. However, mobile forms 365 are relevant for risk assessment. Due to this 10 % of the samples, covering the range of metal concentrations,

366 were extracted with 1 M NH 4NO 3-solution to evaluate mobile species. As expected, only a very small part of 367 total concentrations belongs to the mobile fraction. Hence, elevated trace metal concentrations can be traced 368 back to lithogenic background concentrations which cause only a very small risk for a translocation into food 369 chain.

370 Table 3: Selected trace metals in the Ah horizons of soils of the Kazbegi region ACCEPTED MANUSCRIPT Trace Metal Min Max Arithmetic mean, Median Georgian N Mobil form 2 [mg kg -1] standard deviation 1 threshold (clay, pH <5.5) As 3.80 33.30 12.61±7.87 11.57 5 44 <0.1% Pb 4.84 47.64 18.81±10.14 13.26 65 44 <0.2% Co 4.97 47.34 15.18±8.24 14.25 - 44 <0.1% Cu 14.48 127.42 36.21±21.75 30.75 66 44 <0.4% Ni 18.77 73.19 40.47±13.65 39.81 40 44 <0.1% Zn 34.56 191.70 95.23±36.32 78.78 110 44 <0.2% 371 1Aqua regia-extraction 2 372 1 M NH 4NO 3-extraction 373 374 A further task was the evaluation of POPs in topsoils due to industrial and traffic emissions or application of 375 plant pesticides. In topsoils of three (former) glass houses in Kazbegi region we found residues of DDT and 376 HCH resp. their metabolites ( data not shown ), presumably due to application in Soviet times. In one case the 377 Georgian threshold for DDT was exceeded [47]. Due to this, 22 topsoils of the investigated profiles were chosen 378 for a screening on POPs. 379 However, in the investigated soils, all measured substances were below the quantification limit of the screening 380 method used. Hence, neither inorganic nor organic pollutants can be found in relevant amounts in outdoor 381 topsoils of the study area. Due to this, the hazard indicator MANUSCRIPT‘contamination’ can be excluded for all investigated 382 soils. Nevertheless, for precautionary reasons the still intensively used topsoils of the (former) glass houses 383 should be investigated in more detail. 384 385 Table 4: Persistent organic Pollutants in the topsoils of the Kazbegi region (mixing samples of A-Horizons) Substance Use/ Quantification N Detected Source limit [µg kg -1] 4.4 DDE; 2.4-, 4.4- metabolites/ insecticides 50 22 - DDD; 2.4-, 4.4 DDT; PCB e.g. trans-formators, hydraulic engines 50 22 - PAH incomplete combustion of organic matter 50 22 - α, β,γ and ∆-HCH Technical mixture, Insecticide ( γ), 50 22 - Dieldrin ACCEPTED Insecticide 50 22 - Aldrin Insecticide 50 22 - Endosulfan I Insecticide, acaricide 50 22 - Trifluralin Herbicide 50 22 - 386 ACCEPTED MANUSCRIPT 387 388 5.4. Yield potential and appropriated crops:

389 Soils with a poor (or even very poor) yield potential are rated with less than 20 and up to 40 M-SQR-points. 390 From all 39 soil explorations 21 fall into this category. These soils are suitable for grassland and (if ≥20 SQR- 391 points) for crops adapted to local conditions for subsistence farming [2]. Due to hazard indicators like ‘soil depth 392 above hard rock’, ‘flooding and extreme water logging’ or ‘steep slope’ cropping is strongly limited. While 393 excess water is limited to the Fluvisols in floodplains resp. Histosols , inclination of slopes and soil depth pose a 394 problem to all soils. But due to the further hazard indicator ‘High percentage of coarse soil texture fragments’ 395 soils on ‘debris of Jurassic sedimentary rocks’ are disproportionately represented (7 of 10) in this class. Sites not 396 that much restricted by inclination are suitable for cropping in case of an adequate soil management (erosion 397 control, fertilization). 398 Suitable soils with a low yield potential for cropping, developed from ‘volcanic influenced unconsolidated rock’ 399 are distributed e.g. on the smooth to middle steep slopes above Ukhati. Soils from ‘debris of Jurassic slates’ are 400 distributed on the unforested slopes N’ and S’ Stepantsminda. 401 If these soils are deep enough cereals could be cultivated to improve local food supply as well as local markets 402 e.g. for sustainable tourism. Many abandoned terraces indicate where grain was formerly grown in the Khevi 403 region [48] (Kazbegi). Arable crops adapted to local conditions could be Oat (Avena sativa L.), Summer-Barley 404 (Hordeum vulgare var. distichon L.) [48] and Solanum tuberosum L. [50] (list is not exhaustive; variety trials are 405 necessary). Nevertheless, erosion control must have highest priority. Furthermore, particularly rare soils, like the 406 Cambisols on Tephra close to Sioni (P 16, see Fig. 6), should be protected e.g. in form of geotopes. 407 Secale cereale shows the broadest ecological adaptability, MANUSCRIPTdue to its few demands on soil quality and climate 408 [48] [51]. Caucasian rye ( S. cereale L.) used to be cultivated in high mountain regions of Georgia (1.800-2.200 409 m) and entered into bread and beer production [48]. Actually S. cereale L. is only a local cultivar of high 410 mountain regions of Georgia and fields are now found only in Upper and Lower Svaneti (north-western 411 Georgia) and Meskheti (south-western Georgia) [52]. However, heavy rainfall, typical for the vegetation period 412 in the study area [43], could be a problem for the stability of the long haulms of S. cereale [48]. 413 H. vulgare var. distichon is a summer culture due to the limited frost hardiness of winter barley of only -12 °C 414 [53]. For summer barley the climatic preconditions, as vernalization temperature (5 to 10 days of max. 10°C) and 415 frost hardiness (-6 °C) are fulfilled [54]. Nevertheless, pH-value should be above 6, because summer barley is 416 sensible to a lower pH [50]. This might be a problem for most of the soils and therefore liming would be 417 unavoidable. H. vulgare is an ancient agricultural crop in Georgia and had particular importance in beer 418 production [48]. Avena sativa could be a further alternative but it has only a limited functionality for food 419 supply. Its frost hardiness is similar to H. vulgare but it is less sensitive to low pH-values [54], also its root 420 system is more effectiveACCEPTED [50]. 421 Solanum tuberosum could be an alternative on shallower soils or soils with a coarse fraction. It is highly 422 adaptable to soil quality and climate and grows on soils with a pH-value down to 3.7 [50]. Cultivation is possible 423 up to 2.000 m a.s.l. and soils from sandy loam or loamy sand rich in humus are most suitable, while a higher clay 424 content reduces yield [50]. It is already cultivated to some degree in the study area, even on the volcanic plateau 425 of Ukhati >2.000 m a.s.l.. ACCEPTED MANUSCRIPT 426 427 Soils with a moderate yield potential are rated between 40 and 60 M-SQR-points. From all 39 soil explorations 428 17 fall into this category. These soils, mainly developed from glacial sediments or volcanic influenced 429 unconsolidated rock, are also classified as ‘unique farmland’, characterized by a lower quality than ‘prime 430 farmland’, [55]. Due to [56] the strongly represented Umbrisols can be improved drastically by erosion control, 431 fertilization (N, P, K, Mg) as well as adapted cropping (potatoes, cereals). In addition to the above notified crops, 432 cropping of Triticum aestivum L. or other Tritium species might be possible in a few cases, e.g. on Fluvisols 433 from alluvial loam in the Truso valley (cp. Fig. 5). Nineteen species of wheat from the 26 known species of the 434 genus Triticum have been historically distributed in Georgia [52]. Summer wheat can be cultivated up to 2.000 m 435 a.s.l. with best results on calcareous, humus-rich soils [57], like the Fluvisols mentioned above. However, T. 436 aestivum needs a dry period for grain maturity. Hence, due to only short dry periods during vegetation period 437 (max. 9 days due to [43]) yield could be less than regular. Wheat fields were planted throughout Georgia at 438 elevations from 300 m to even 2.160 m a.s.l.. Almost none of these traditional wheat varieties and species occur 439 in the territory of Georgia, actually. Nevertheless, endemic T. carthlicum , that is adapted to high elevations, is 440 still grown in the mountainous area of Meskheti [52]. 441 However, cropping is restricted to the lower areas of the study area even on these soils. Furthermore, liming is 442 necessary for most soils as well as an appropriate erosion control. Soils on higher areas should stay pastures or 443 meadows, even in case of a moderate yield potential e.g. soil on glacial sediments around the village of Jutha.

444 Soils with a high yield potential are rated between 60 and 80 SQR-points. From all 39 soil explorations only 1 445 site falls into this category. These high quality soils are restricted to loamy colluvium at the volcanic plateaus in 446 the study area, e.g. Ukhati, Toti or Tsdo. Despite their altitudeMANUSCRIPT (>2.000 a.s.l.) and difficult accessibility, these 447 soils are predestinated to improve productivity of the local agriculture. Due to their location in the landscape 448 (accumulation area), erosion is less problematic but amelioration (liming) is still necessary due to the low pH 449 (see Table 1). 450 451 To check the plausibility of the modeled SQR-map, it was compared to a map of grassland yield, developed by 452 Magiera et al. [58], which is based on extrapolated species composition, represented by metrically scaled 453 variables in form of ordination axes. As predictive variables for plant species composition, vegetation indices 454 from Rapid Eye imagery and environmental variables from a digital elevation model were used. As a result a 455 higher yield fit well with higher M-SQR-scores. In a few cases, e.g. the N’ slope of Truso valley, higher yield 456 correspondences with a low SQR-score, as steep slopes lead to a low SQR-score but do not have that massive 457 impact on the productivity of grassland. Hence, practical applicability of the SQR can be taken for proven. 458 However, the map cannot simply be adopted as concrete options for small-scale planning. Due to the high spatial 459 heterogeneity of substratesACCEPTED and morphology of the study area, site specific validation has to be carried out first. 460

461 6. CONCLUSIONS

462 Most limiting factors are climate as well as steepness, while the low nutrient supply and soil acidity can be 463 tackled by adequate fertilization and liming practice. Inorganic or organic pollutions were not detected. Soils on 464 sediment fans (debris of Jurassic sedimentary rocks) as well as glacial sediments, mostly Cambisols (Humic) , are ACCEPTED MANUSCRIPT 465 characterized by a low to moderate fertility while high-yield soils, mostly Cambic Umbrisols , can be found on 466 volcanic plateaus, e.g. around the abandoned villages of Ukhati and Toti. Actually, most of them are used only 467 for pasture, due to poor accessibility. To exploit the moderate up to good potential fertility, road transport 468 infrastructure has to be optimized. Soils on fluvial deposits (mostly Fluvisols ) show a very high range of SQR- 469 scores. In case of loamy alluvial deposits cropping is a suitable land use (as it is partly already practiced), but 470 most of the banks are characterized by gravel-rich deposits, suitable only for pasture. Due to climate and soil 471 conditions, the most adequate crop is Solanum tuberosum L. Further cereals with respect to local conditions are 472 rye, summer barley or even summer wheat. However, heavy rainfalls could cause harvest losses and water 473 erosion and that is why the cultivation of cereals was given up and replaced by grassland management with cattle 474 and sheep. Due to this, soils with a moderate SQR-Score but a high erosion risk should remain grassland. 475 Altogether, the soils of the study area have the actually untapped potential to optimize the basic supply of the 476 local population as well as tourism also by cultivation of some special cereals. Nevertheless, variety trials on 477 different soil forming substrates are major preconditions for successful implementation of new cropping systems 478 in the Kazbegi region. Furthermore, particularly rare soils, e.g. Cambisols on Tephra, should be protected.

479 7. Acknowledgements

480 The authors wish to thank the Volkswagen Foundation for financing the project, Dr. B. Vashev for his intensive 481 support in field, M. Schatz and L. Böhm for their diligent support in POP-analytics, N. Mayerhofer for his 482 support in P-sorption experiments and Prof. Dr. A. Otte for the fruitful discussion and support as well as the 483 anonymous reviewers for their helpful comments. 484 MANUSCRIPT

ACCEPTED ACCEPTED MANUSCRIPT 485

486 REFERENCES

487

488 [1] D.L. Karlen, M.J. Mausbach, J.W. Doran, R.G. Cline, R.F. Harris, G.E. Schuman, Soil quality: a concept, 489 definition, and framework for evaluation. Soil Science Society of America Journal 61 (1997) pp. 4– 10. 490 [2] L. Müller, U. Schindler, A. Behrendt, F. Eulenstein, R. Dannowski, The Muencheberg Soil Quality Rating 491 (M-SQR), Leibniz-Zentrum für Agrarlandforschung (ZALF), Muenchenberg, Germany (2007) pp.102. 492 [3] L. Mueller, U. Schindler, T.G. Shepherd, B.C. Ball, E. Smolentseva, C. Hu, V. Hennings, P. Schad, J. 493 Rogasik, J. Zeitz, S.L. Schlindwein, A. Behrendt, K. Helming, F.A. Eulenstein, Framework for assessing 494 agricultural soil quality on a global scale, Arch. Agron. Soil Sci. Vol. 58, No. S1 (2012), pp. 76–82. 495 [4] K. Stahr, Bodenbewertung und Bodenschutz, in: Schachtschabel et al.: Lehrbuch der Bodenkunde, 16 ed., 496 Spektrum, Heidelberg/Berlin (2010), pp. 522-544 (in German). 497 [5] R. E. Storie, soil rating. Spec. Publ. Div. Agric. Sci., Univ. Calif. No 3203. (1978) 4 pp. 498 [6] Gesetz zur Schätzung des landwirtschaftlichen Kulturbodens (Bodenschätzungsgesetz - BodSchätzG), 499 BGBl. I p. 3150, 3176, Köln (2007). 500 [7] Department of Agriculture Natural Resources Conservation Service Soil Quality Institute 501 Guidelines for Soil Assessment in Conservation Planning, Washington (2001) 38 pp. 502 [8] A. Richter, V. Hennings, L. Müller, Anwendung des Müncheberger Soil Quality Ratings (M-SQR) auf 503 bodenkundliche Grundlagenkarten, Annual Meeting of the German Soil Science Society (2009), Bonn (in 504 German). MANUSCRIPT 505 [9] G. Nakhutsrishvili, O. Abdaladze, A. Kikodze, Khevi , Kazbegi region, SCOPES Project No. 7GEPJ062347, 506 Tbilisi, 2005, 55 pp. 507 [10] M. Wiesmair, H. Feilhauer, A. Magiera, A. Otte, R. Waldhardt, Estimating Vegetation Cover from High- 508 Resolution, Mount. Res. Develop., 36 (1), pp. 56 – 65. 509 [11] N. Tephnadze, O. Abdaladze, G. Nakhutsrishvili, D. Simmering, R. Waldhardt, A. Otte, The impacts of 510 management and site conditions on the phytodiversity of the upper montane and subalpine belts in the 511 Central Greater Caucasus, Phytocoenologia. 44(3-4) (2014) pp. 255–291. 512 [12] K38-54-A, Ministry of Geology of the USSR, Geological Map M 1:50.000, 1983 (in Russian). 513 [13] K38-54-B, Ministry of Geology of the USSR, Geological Map M 1:50.000, 1983 (in Russian). 514 [14] K38-54-G, Ministry of Geology of the USSR, Geological Map M 1:50.000, 1962 (in Russian). 515 [15] K38-54-V, Ministry of Geology of the USSR, Geological Map M 1:50.000, 1983 (in Russian). 516 [16] I. V. Bondyrev,ACCEPTED Geology in: I. V. Bondyrev, Z.V. Davitashvili, V.P. Sinngh, The Geography of Georgia, 517 World Regional Geography Book Series, DOI 10.1007/978-3-319-05413-1_7, Springer International 518 Publishing Switzerland (2015) pp. 67- 80. 519 [17] V.A. Lebedev, A.V. Parfenov, G.T. Vashakidze, I.V. Chernyshev, Q.A. Gabarishvili, Major Events in 520 Evolution of the Kazbek Neovolcanic Center, Greater Caucasus: Isotope-Geochronological Data, Earth Sci., 521 458 (1) (2014) pp. 1092-1098. 522 [18] Zepp, H. Geomorpholgie, Paderborn, UTB 6 ed. (2002) 402 pp. (in German). ACCEPTED MANUSCRIPT 523 [19] I. V. Bondyrev, Geodynamical Processes in: I. V. Bondyrev, Z.V. Davitashvili, V.P. Sinngh, The 524 Geography of Georgia, World Regional Geography Book Series, DOI 10.1007/978-3-319-05413-1_7, 525 Springer International Publishing Switzerland (2015) pp. 81-85. 526 [20] I. V. Bondyrev, Glacial and Periglacial Processes in: I. V. Bondyrev, Z.V. Davitashvili, V.P. Sinngh, The 527 Geography of Georgia, World Regional Geography Book Series, DOI 10.1007/978-3-319-05413-1_7, 528 Springer International Publishing Switzerland (2015) pp. 87-95. 529 [21] Urushadze, T. et al., Soil Map of Georgia (1:500.000), Cartography, Tbilisi, 1999. 530 [22] T.F. Urushadze, G.O. Ghambashidze, Ressources of Georgia in: Y. Yigini, P. Panagos, L. Montanarella, 531 Soil Resources of Mediterranean and Caucasus Countries, European Commission - JRC technical Report, 532 EUR – Scientific and Technical Research series – ISSN 1831-9424, Luxembourg (2013) 243 pp. 533 [23] E.Sh. Elizbarashvili, Z.B. Chavadidze, M.E. Elizbarashvili, R.V. Maglakelidze, N.G. Sulkanischvili, Sh.E. 534 Elizbarashvili, Soil-Climatic Zoning of Georgia, Eurasian Soil Sci., 39 (10) (2007) pp. 1062-1065. 535 [24] G. Nakhutsrishvili, M. Akhalkatsi, O. Abdaladze, Main Threats to Mountain Biodiversity in Georgia, 536 Mount. Forum Bullet. (2009), pp. 18-19. 537 [25] W. Hansen, A. Magiera, T. Theißen N. Tephnadze, R. Waldhardt, A. Otte, Encroachment of Subalpine 538 Betula litwinowii Doluch. Stands in the Greater Caucasus, Georgia, Annals Agr. Sci. (2016) submitted. 539 [26] J. Radvanyi, S.S. Muduyev, Challenges Facing the Mountain Peoples of the Caucasus, Euras Geograph 540 Econom 48 No. 2 (2007), pp. 157-177. 541 [27] L. Müller et al.: Assessing the productivity function of soils. A review, Agron. Sustain. Dev. 30 (2010) pp. 542 601-614. 543 [28] L. Mueller, U. Schindler, V. Hennings, E. Smolentseva, O. Rukhovich, V. Romanenkov, V. G. Sychev, S. 544 Lukin, A.K. Sheudshen, T.L. Onischenko, A. Behrendt MANUSCRIPT, W. Mirschel, F. Eulenstein, An Emerging Method 545 of Rating Global Soil Quality and Productivity Potentials in: Novel Methods for Monitoring and Managing 546 Land and Water Resources in Siberia, Springer Water, Cham/Heidelberg/New York/Dordrecht/London 547 (2015) pp. 573-595. 548 [29] X. Zheng, X. Liu, G. Jiang, Y. Wang, Q. Zhang, Z. Cong, Distribution of PCBs and PBDEs in soils along 549 the altitudinal gradients of Balang Mountain, the east edge of the Tibetan Plateau, Environ. Poll. (2012) 161, 550 pp. 101-106. 551 [30] P. Tremolada, S. Villa, P. Bazzarin, E. Bizzotto, R. Comolli, M. Vighi, POPs in mountain soils from the 552 Alps and : Suggestions for a 'precipitation effect' on altitudinal gradients, Water, air, and soil 553 pollution, 188(1-4) (2008) pp. 93-109. 554 [31] O. Arnalds, , in: W. Chesworth (Ed.) Encyclopedia of Soil, Springer, Dordrecht (2008) pp. 39-46. 555 [32] AG Boden Bodenkundliche Kartieranleitung (KA5) 5 th ed. Hannover (2006) 438 pp. (in German) 556 [33] IUSS WorkingACCEPTED Group WRB. 2015. World Reference Base for Soil Resources 2014, update 2015 557 International system for naming soils and creating legends for soil maps. World Soil 558 Resources Reports No. 106. FAO, Rome 559 [34] DIN ISO 10390 2005-12: Soil quality – Determination of pH, Deutsches Institut für Normung, Beuth Verlag 560 GmbH, Berlin (2005) 9 pp. (in German). 561 [35] DIN ISO 11265: 1997-06: Soil quality – Determination of specific electrical conductivity, Deutsches Institut 562 für Normung, Beuth Verlag GmbH, Berlin (1997) 4 pp. (in German). ACCEPTED MANUSCRIPT 563 [36] DIN ISO 10693 1997-05: Soil Quality – Determination of Carbonate Content – Volumetric Method, 564 Deutsches Institut für Normung, Beuth Verlag GmbH, Berlin (1997) 4 pp. (in German). 565 [37] DIN EN ISO 14688 – 1:2003-01 Geotechnical Investigation and Testing – Identification and Classification 566 of Soil – Part 1: Identification and description, Deutsches Institut für Normung, Beuth Verlag GmbH, Berlin 567 (2003) 38 pp. (in German). 568 [38] DIN 11466: Soil Quality – Extraction of Trace Elements Soluble in Aqua Regia, Deutsches Institut für 569 Normung, Beuth Verlag GmbH, Berlin (1995) 5 pp. (in German). 570 [39] S. Öztan, R.-A. Düring, Microwave assisted EDTA extraction-determination of pseudo total contents of 571 distinct trace elements in solid environmental matrices, Talanta, 2012, 99, pp. 594-602. 572 [40] DIN ISO 19730: 2009-07: Soil Quality - Extraction of Trace Elements from Soil using Ammonium Nitrate 573 Solution, Deutsches Institut für Normung, Beuth Verlag GmbH, Berlin (2009) 8 pp. (in German). 574 [41] VDLUFA Phosphordüngung nach Bodenuntersuchung und Pflanzenbedarf, Verband Deutscher 575 Landwirtschaftlicher Untersuchungs- und Forschungsanstalten, Darmstadt, Germany (1997) 8 pp. (in 576 German). 577 [42] A. Mehlich, Determination of cation- and anion exchange properties of soils, Soil Sci. 66 (1948) pp. 429– 578 455. 579 [43] National Environmental Agency, Departament of Hydrometeorology, David Agmashenebeli avn. 150, 580 www.meteo.gov.ge, Climate Data of Stepanzminda 1961-1990. 581 [44] H.-P. Blume, K. Stahr, P. Leinweber, Bodenkundliches Praktikum, 3. ed., Spektrum, Heidelberg (2011) pp. 582 108-109 (in German). 583 [45] I. Keggenhof, T. Keller, E. Elizbarishvili, R. Gobejishvili, L. King, Naturkatastrophen durch Klimawandel 584 im Kaukasus?, Spiegel der Forschung, No. 2/2011, Ju stusMANUSCRIPT Liebig University, Giessen (2011) pp. 16-23 (in 585 German). 586 [46] T. Mansfeldt, Kontamination von Böden in: Blume et al. Handbuch des Bodenschutzes 4 ed., Willey-VCH, 587 Weinheim, 2011, pp. 287-313 (in German). 588 [47] Hygienically assessment of soils of settlements, Ministry of Labour Health and Social Affairs of Georgia, 589 law no. N38/5, 24.01.2003, Tbilisi, 23 pp. 590 [48] Bussmann et al. Wine, Beer, Snuff, Medicine, and Loss of Diversity – Ethnobotanical travels in the 591 Georgian Caucasus, Ethnobotany Research and Applications (2017) Vol. 12, pp. 239-313. 592 [49] H. Hanus, Roggen in: H. Hanus, K.-U. Heyland, E.R. Keller (eds.) Handbuch des Pflanzenbaues: Getreide 593 und Futtergräser. Ulmer, Stuttgart (Hohenheim) (2008) 688 pp. (in German). 594 [50] I. Alsing, A. Fleischmann, H. Friesecke, K. Guthy, Lexikon Landwirtschaft, 3. ed. BLV Verlagsgesellschaft 595 mbH, München, 1995, 767 pp. (in German). 596 [51] B. Honermeier,ACCEPTED Winterroggen und Triticale, in: N. Lütke Entrup, B.C. Schäfer (eds.) Lehrbuch des 597 Pflanzenbaues Band 2: Kulturpflanzen. AgroConcept Verlagsgesellschaft, Bonn (2000) 1036 pp. (in 598 German) 599 [52] M. Akhalkatsi, J. Ekhvaia, Z. Asanidze, Diversity and Genetic Erosion of Ancient Crops and Wild 600 Relatives of Agricultural Cultivars for Food: Implications for Nature Conservation in Georgia (Caucasus) 601 in: Perspectives on Nature Conservation - Patterns, Pressures and Prospects, J. Tiefenbacher (Ed.) (2012), 602 http://www.intechopen.com/books/perspectives-on-nature-conservation-patterns-pressures-and- ACCEPTED MANUSCRIPT 603 prospects/diversity-and-genetic-erosion-of-ancient-crops-and-wild-relatives-of-agricultural-cultivars-for- 604 food 605 [53] Landesforschungsanstalt für Landwirtschaft und Fischerei of Mecklenburg-Vorpommern (n.d.): 606 Anbautelegramm Getreide, Schwerin, 11 pp. (in German). 607 [54] H. Schönberger, U. Kropf, Winter- und Sommergerste, in: Lütke Entrup, N., Schäfer, B.C. (eds.): Lehrbuch 608 des Pflanzenbaues Band 2, AgroConcept Verlagsgesellschaft, Bonn (2000) 1036 pp. (in German). 609 [55] California Department of Conservation Unique Farmland [WWW Document], Important Farml. Categ. 610 (2015) URL www.conservation.ca.gov/dlrp/fmmp/mccu/Pages/map_categories.aspx (accessed 4.29.15). 611 [56] W. Zech, P. Schad, G. Hintermaier-Erhard, Böden der Welt, 2. Ed., Springer Spektrum, Berlin, Heidelberg, 612 (2014) 164 pp. 613 [57] H. Zentgraf, J.-M. Brümmer, Eine kleine Fachkunde der wichtigsten Getreidearten. Vereinigung Getreide-, 614 Markt und Ernährungsforschung, Bonn (2004) 7 pp. (in German). 615 [58] A. Magiera, H. Feilhauer, R. Waldhardt, M. Wiesmair, A. Otte, Mitigating saturation problems in biomass 616 estimation of mountainous grasslands by including a species composition map, Ecol. Indic. (2016) 617 submitted

MANUSCRIPT

ACCEPTED