Key for identifying categories of vineyard soils in Australia

Transcription

1 Key for identifying categories of vineyard soils in Australia 1 David Maschmedt, 2 Rob Fitzpatrick and 3 Alfred Cass 1 Dept. of Water, Land and Biodiversity Conservation, GPO Box 2834, Adelaide, SA CSIRO Land and Water, Private Bag 2, Glen Osmond, South Australia Alfred Cass & Associates, 1700 Maggie Avenue, Calistoga, CA 94515, USA. Technical Report 30/02, August 2002

2 2002 CSIRO To the extent permitted by law, all rights are reserved and no part of this publication covered by copyright may be reproduced or copied in any form or by any means except with the written permission of CSIRO Land and Water. Important Disclaimer CSIRO Land and Water advises that the information contained in this publication comprises general statements based on scientific research. The reader is advised and needs to be aware that such information may be incomplete or unable to be used in any specific situation. No reliance or actions must therefore be made on that information without seeking prior expert professional, scientific and technical advice. To the extent permitted by law, CSIRO Land and Water (including its employees and consultants) excludes all liability to any person for any consequences, including but not limited to all losses, damages, costs, expenses and any other compensation, arising directly or indirectly from using this publication (in part or in whole) and any information or material contained in it.

3 TABLE OF CONTENTS Summary 1 Rationale for developing the Viticultural Soil Key 1 Characteristics of the Viticultural Soil Key 2 The Viticultural Soil Key and Other Soil Classification Systems 3 Definitions of Morphological Descriptors used in the Viticultural Soil Key 3 Acknowledgments 6 References 6 Table 1 Key for identifying categories and sub-categories of vineyard soils in Australia 8 Table 2 Interpreting Soil Consistence 10 Table 3 Approximate correspondence between categories of vineyard soils in Australia and other soil classification systems 11 Table 4 Colour photographs of sub-categories of vineyard soils in Australia 16

4 Summary A user-friendly soil key was developed to identify soils in vineyards by people who are not experts in soil classification. It is based on a data set of soil properties that have relevance to grape production for most of the Australian rootstock trials across Australia. The soil identification key is an important tool for delivering soil-specific land development and soil management packages to grape growers. It can also help viticulturists select and match grapevine rootstocks to appropriate Australian soils. The soil key provides the means to describe Australian soils in terms of attributes meaningful to viticulture and to correlate these attributes with two local (Isbell 1996, Stace et al. 1968) and three international (Soil Classification Working Group 1991, FAO 1998, Soil Survey Staff 1999) general-purpose soil classification systems. The key uses nontechnical terms to categorise soils in terms of attributes that are important for vine growth. The soil features used in the key are easily recognised in the field by people with limited soil classification experience. The following viticulturally important and mostly visual diagnostic features were used: depth to certain characteristic changes in wetness (waterlogging), consistency, colour, structure, calcareousness in different restrictive layers, cracking, texture trends down profiles (e.g. texture contrast at A/B horizon boundary or duplex character). The key layout is bifurcating, based on the presence or absence of the particular keying property, which is usually a diagnostic property. The soil key consists of a systematic arrangement of soils into 9 broad categories and 36 subdivisions or sub-categories. Rationale for developing the Viticultural Soil Key The soil identification key was developed to provide the viticulture industry with a language to facilitate communication about soils used for wine grape production. The key uses, as far as is possible, non-technical language to categorise soils in terms of attributes that are important for vine growth. The basic philosophy of the key is strongly linked to issues of viticultural soil management (e.g. Cass 1999, Fitzpatrick et al. 1993). However, as a tool for understanding wine production historically within Australia and in other wine-producing countries, the key needs also to correlate with previous and current Australian and international soil classification schemes. Several different soil classification systems have been or are used in Australia (Stace et al. 1968; Northcote 1979; Isbell 1996) and in overseas countries that produce wine (Soil Survey Staff 1999; USDA Soil Taxonomy and Soil Classification Working Group 1991; Soil Classification: A Taxonomic System for South Africa, 1991; FAO World Reference Base for Soil Resources 1998). All these general-purpose classification systems lack user-friendly keys for identifying soil profiles by people who are not experts in soil classification. It was clear from their lack of use in Australia, that the existing general-purpose systems were not suitable because they are too technical or complex. Viticultural information in Australian and overseas literature, based on soils classified using general-purpose soil classification systems could often not be applied correctly to Australian conditions, because there was no means to link these identifiers to local understanding of the nature and properties of soils. Australian and international general-purpose classification systems were found to be too complex for identifying soil profiles in vineyards by people who are not experts in soil classification. The Australian viticulture industry called for the development of a user- Page 1

5 friendly soil key, which could be used by viticulturists to help select and match grapevine rootstocks to appropriate Australian soils (May 1993, 1994). In both these papers, May states " the choice of the most suitable rootstock may not be possible until we know more about the way in which rootstocks interact with the soil environment on the one hand and with their scion on the other hand". Other uses for the key were foreseen, for example, as a tool to correlate grower knowledge about their soils with other soils classified using these more technical systems. The primary aim of such a user-friendly soil key will be to identify categories of vineyard soils, using soil features that are associated with the main soil types occurring in viticultural regions of Australia. The soil features used in the key should be easily recognised in the field by people with limited soil classification experience. The key layout should be bifurcating, based on the presence or absence of a particular keying property, which is usually a diagnostic property. The concept to be used in the key should be similar to the user-friendly keys compiled for soils in Western Australia (Schoknecht 2001) and Fitzpatrick et al. (1997, 2001, 2002b) to solve practical soil related problems. Characteristics of the Viticultural Soil Key In the system described here, we have developed a simple soil key to assist viticulturists to categorise visual soil properties into a system for naming soils used for wine growing in Australia. In developing the Soil Key we used soil descriptions and soil chemical data contained in the Rootstock Soil Properties Database, which consists of 132 characterised viticulture soils from rootstock trials across Australia (Cass et al. 2002a, b). We focussed on the following viticulturally important and mostly visual diagnostic features: changes in wetness (waterlogging), consistency, colour, structure, calcareousness in different restrictive layers, cracking, texture trends down profiles (e.g. texture contrast at A/B horizon boundary or duplex character). The key layout is bifurcating and based on the presence or absence of the particular keying property, which is usually a diagnostic property (Table 1). Broad groupings (i.e. 9 categories) are made on the basis of general characteristics such as waterlogging, depth different restrictive layers (e.g. shallowness and stoniness), presence of cracking and slickensides, texture trends down profiles (e.g. texture contrast at A/B horizon boundary or duplex character) and calcareousness. Subdivisions (i.e. 36 sub-categories) are made on the basis of more detailed differences in specific properties (consistency, colour, structure, calcareousness). Between 1997 and 2002, this key went through several stages of development (e.g. Fitzpatrick et al. 2002a) and has been successfully tested on many viticultural soils throughout Australia. The terminology used is a combination of that used by McDonald et al., (1990), Stace et al. (1968), Northcote (1979), Isbell (1996), Soil Survey Division Staff (1993) and summarised in Fitzpatrick et al. (1999). This reflects common usage in Australia where soil might be referred to as either "texture contrast" (duplex, with abrupt change from a coarse to medium textured surface layer to a more clayey subsurface layer, "uniform" (little change in texture down the profile) or "gradational" (gradual increase in texture down the profile), cracking clay, and/or calcareous. These terms have been found to be useful in field applications. In particular, in the key we have paid attention to identifying "potential soil constraints", such as easily identifiable restrictive soil layers that might limit effective root depth (Table 1). We also use observations of depth to certain characteristic changes in waterlogging (mottles or watertables), consistency, colour, Page 2

6 texture and structure in different restrictive layers. Each soil category is provided with a listing of possible qualifiers in a priority sequence. The process of identifying soils in the field is facilitated by providing colour photographs of most of the 36 soil sub-categories in the soil key (Table 4). In conjunction with this key the "broadscale" soil maps of the viticultural regions of Australia could also be used to help with the identification of viticultural soil types (Fitzpatrick et al. 1993). A more extensive period of validation will occur over the next few years. The Viticultural Soil Key and Other Soil Classification Systems One of the main objectives in developing practical attributes was to build the key in such a way that it uses knowledge and experience of many soil scientists in Australia and from all over the world. In Table 3 we have identified as closely as possible, corresponding classes in the following systems: The Australian Soil Classification System (Isbell 1996). Great Soil Group Classification (Stace et al. 1968). Soil Taxonomy (Soil Survey Staff 1999). A Taxonomic System for South Africa (Soil Classification Working Group 1991). World Reference Base for Soil Resources (FAO 1998). Definitions of Morphological Descriptors used in the Viticultural Soil Key Morphological descriptors are used for assessing soil conditions. These are: 1. Presence of a ground water table: free water at a particular depth in the soil. 2. Colour: This is the most readily identified morphological characteristic. While the presence and form of iron oxides (red and yellow) and organic matter (dark colours) are the main features determining a soil's colour, it can also be influenced by other minerals such as calcium carbonate (pale colours). Colour is often used to identify horizon changes down a profile. It can also provide an indicator of the soil's organic matter content and fertility levels, as well as redox condition, which relates to soil aeration (drainage). Dark brown or black colours typically result from high organic matter content. High chroma red and yellow colours are usually found where iron minerals are present in oxidizing conditions. Properties influenced by coloured iron oxides include retention of anions such as phosphate. Uniform bright red colours usually indicate good drainage. Pale colours indicate the absence of iron oxide, often due to its removal through leaching or reduction. Mottles - spots, blotches, or streaks of colour subdominant to the matrix colour commonly indicate impeded drainage. Patches of red, orange or yellow in a pale matrix are concentrations of iron oxides formed by redistribution during periodic waterlogging. 3. Gley (bluish or greenish grey) colours (low chroma) are often found in severely waterlogged conditions where reduction is almost complete. Gleyed - a soil condition resulting from prolonged soil saturation, which is manifested by the presence of grey or bluish or greenish pigmentation through the soil mass or in mottles (spots or streaks). Gleying occurs under reducing conditions in which iron is reduced predominantly to the ferrous state. Page 3

7 4. Segregations: discrete accumulations of material by chemical or biological processes (e.g. carbonate, ironstone and gypsum). 5. Coarse (rock) fragments: comprise all strongly cemented soil materials, including rock fragments and hard segregations, which are sized greater than 2 mm. They are subdivided into fine gravels (2 to 6 mm), medium gravels (6 to 20 mm), coarse gravels (20 to 60 mm), cobbles (60 to 200 mm), stones (200 to 600 mm) and boulders (>600 mm). High amounts of coarse fragments in the soil may impose severe limitations on its capacity to supply water and nutrients by reducing volume of soil available for root activity. They can also have an adverse impact on soil workability, being highly abrasive to tillage implements. On the other hand, surface gravel may reduce erosion, act as a mulch to reduce evaporation from the soil, and store heat for re-radiation during the night. 6. Soil consistence - is a measure of the strength and coherence of a soil. Soil consistence is also called rupture resistance and is a very readily observed feature in the field. In viticulture, this morphological attribute gives an indication of potential for root impedance. Factors that influence consistence include soil texture, mechanical compaction, aggregation, organic matter content and cementing agents. Soil consistence can be very readily measured in the field by determining the magnitude of finger, foot or hammer force needed to cause disruption or distortion to a 25 to 30 mm block of soil. See simplified definitions and tables in Fitzpatrick et al (1999). The depth of likely root penetration in soils can be estimated in the field by measuring changes in soil consistence progressively down the soil profile from the soil surface (e.g. Tables 1 and 2 in Fitzpatrick et al 1999). The very hard and rigid classes are often indicative of reduced permeability as well. Classes of consistence are defined in Table 2 in Fitzpatrick et al The table is re-presented in this paper, also as Table Soil texture - relative proportions of sand, silt and clay in the soil. Soil texture (field method) - is determined in the field by the following procedure: Take a sample of soil sufficient to fit comfortably into the palm of the hand (separate out gravel and stones). Moisten soil with water, a little at a time, and work until it just sticks to your fingers and is not mushy. This is when its water content is approximately at "field capacity". Continue moistening and working until there is no apparent change in the ball (bolus) of soil. This usually takes 1-2 minutes. Make a ribbon by progressively shearing the ball between thumb and forefinger. The behaviour of the worked soil and the length of the ribbon produced by pressing out between thumb and forefinger characterises 15 soil texture grades as shown in (McDonald et. al., 1990). 8. Texture Groups (according to Northcote, 1979): The Sands = sand (S), loamy sand (LS), clayey sand (CS). The Sandy Loams = sandy loam (SL). The Loams = Loam (L); sandy clay loam (SCL); Silty loam (ZL). The Clay Loams = Clay loam (CL). The Light Clays = light clay (LC). The Medium-Heavy Clays = Medium clay (MC), Heavy clay (HC). 9. "Duplex" texture: contrast in texture between the topsoil and subsoil that is greater than 1 ½ the Texture Groups defined under Texture Groups above, e.g.: Sand/clay Sand/sandy clay loam Loam/clay Loam/clay loam/medium or heavy clay. Page 4

8 10. Uniform texture: very little contrast in texture between layers in the profile, e.g.: Sand/sand/sand Clay loam/clay loam/clay loam Clay/clay/clay. 11. Gradational texture: steady increase in clay down the soil profile, e.g.: Sand/loamy sand/sandy loam Loam/clay loam/clay Clay loam/clay/medium clay. 12. Soil Structure - relates to the way soil particles are arranged and bound together. It can be described from the visible appearance of in-situ soil in a dry to slightly moist state. The size, shape and nature of soil aggregates play a major role in determining profile hydrology and the ease of root penetration. Where soil particles are bound together in natural forming aggregates (peds) separated by irregular spaces, the soil is described as having structure. The degree and nature of structure development is largely determined by clay mineralogy and organic matter content. Where peds are absent, the soil is described as being uniform or structureless. In a single-grained material, the soil is loose and incoherent. In a massive material, it is structureless and coherent. Soils that are single-grained or have moderately to strongly developed small peds, tend to be well aerated and freely drained. Plant roots grow easily through these soils and water infiltrates readily. Where the soil is composed of accommodated (ie close-fitting) peds, there are often restrictions to penetration of roots, air and water, and drainage may be poor. Similar problems can be experienced in massive soils, depending on the soil texture and consistence. 13. Blocky, prismatic, columnar structure: distinct structural character with clear planes of weakness between each ped and with equi-dimensional, sharp angled, accommodating sides (blocky) or vertical dimensions greater than horizontal but with rounded tops (columnar) or flat tops (prismatic). 14. Well structured: consistence that is firm or weaker in moderately moist condition and does not have columnar, prismatic or course blocky structure but rather more spherical, non-accommodating peds. 15. Slickensides: Natural shiny surfaces found on soil aggregates formed by the parallel orientation of clay particles during swelling and shrinking cycles. Refers to polished or grooved surfaces within soils resulting from part of the mass sliding or moving against adjacent material along a plane that defines the extent of the slickensides. In soils, they only occur in clay rich materials with high swelling clay content. 16. Topsoil: the surface layer of the soil, generally but not always darkened by accumulation of organic matter. 17. Subsoil: the subsurface layer, lacking in organic matter and generally coloured by secondary accumulations of iron, clay, carbonate, etc. 18. Calcareous: reaction of the soil to a drop of hydrochloric or other acid (indicates the presence and possibly amount of free carbonate present). 19. Rippable vs. non-rippable rock: rock which can be ripped has potential for supporting some root growth. This characteristic is particularly important in shallow soils. 20. Calcrete (calc-rock): hard, rigid limestone or carbonate-rich soil material. 21. Restrictive layer: layer, which impedes root growth. Includes non-rippable rock or hardpan, clayey material with prismatic, columnar or coarse blocky structure, or waterlogged soil, as indicated by gley or dull grey colours. Page 5

9 In addition to the above attributes a set of modifiers can be used to further refine soil classes. Modifiers are properties that cannot be determined in the field but require laboratory intervention. The modifiers are determined on samples taken from soil layers within the soil profile. They are used to designate any soil category as, say, Saline or Sodic or Acid (Cass et al. 1996). Morphological descriptors combined with modifiers are useful in assessing soil conditions because they assist in diagnosing possible constraints to vine growth and they can be used in research to evaluate causes for variation in soil condition induced by land management, hydrology and weather conditions. The principle modifiers used in this key are: Soil reaction: the ph of a 1:5 soil to water extract. Salinity: the amount of salt in the soil as measured by electrical conductivity of a 1:5 soil to water extract. Sodicity: the relative proportion of sodium to calcium and magnesium in a 1:5 soil to water extract. Acknowledgements This research was partly supported with contributions from Grape and Wine Research and Development Corporation Project CRS 95/1. The authors are grateful to the following members of the respective state departments of agriculture and other organisations for providing access to and help and information on the Australian rootstock trials: South Australia: Mr. P. Nicholas and Dr. M. McCarthy; Victoria: Mr. John Whiting; New South Wales: Mr. T. Somers and Mr. H. Creasey; Western Australia: Mr. J. Campbell-Clause; Other experimental sites: Dr. R. Walker (of CSIRO Plant Industries) in South Australia and Victoria and Mr. P. Sinclair in New South Wales. References Cass A. (1999). What soil factors really determine water availability to vines. The Australian Grapegrower and Winemaker, Annual Technical Issue, pages Cass Alfred, Robert Fitzpatrick, Karin Thompson, Andrew Dowley and Susan Van Goor (2002a). Rootstock Trial Soil Properties. In: Alfred Cass (ed) Sustainable viticultural production: Optimising soil resources. Final report (CRS 95/1) to Grape and Wine Research and Development Corporation (GWRDC). Cass Alfred, Robert Fitzpatrick, David Maschmedt, Karin Thomson, Andrew Dowley and Susan Van Goor. (2002b). Soils of the Australian Rootstock Trials. The Australian and New Zealand Grapegrower & Winemaker (Annual Technical issue). vol. 461A. p Cass A., R.R. Walker and R.W. Fitzpatrick (1996). Vineyard soil degradation by salt accumulation and the effect on the performance of the vine. p In: C.S. Stockley, R.S. Johnstone and T.H. Lee (eds.). Proceedings of the 9th Australian wine industry technical conference; July, 1995; Adelaide, South Australia. Winetitles. FAO (1998). The world reference base for soil resources (WRB) World Soil Resources Report No. 84. Food and Agriculture Organisation for the United Nations (FAO)/ISSS/AISS/IBG/ISRIC, Rome, Fitzpatrick R.W., J.W. Cox, and J. Bourne (1997). Managing waterlogged and saline catchments in the Mt. Lofty Ranges, South Australia: A soil-landscape and vegetation key with on-farm management options. Catchment Management Series. CRC for Soil and Land Management. CSIRO Publishing, Melbourne, Australia, 36 pp. ISBN Page 6

10 Fitzpatrick Robert, David Maschmedt and Alfred Cass (2002a). Australian Viticultural Soil Key. In: Alfred Cass (ed) Sustainable viticultural production: Optimising soil resources. Final report (CRS 95/1) to Grape and Wine Research and Development Corporation (GWRDC). Fitzpatrick R.W., J.W Cox, B. Munday, and J. Bourne (2002b). Development of soillandscape and vegetation indicators for managing waterlogged and saline catchments. Australian Journal of Experimental Agriculture: Special Issue featuring papers on Application of Sustainability Indicators (In press). Fitzpatrick R.W., N.J. McKenzie and D. Maschmedt (1999). Soil morphological indicators and their importance to soil fertility. p In K. Peverell,, L.A. Sparrow and D.J. Reuter (ed.) In Soil Analysis: an Interpretation Manual. CSIRO Publishing, Melbourne, Australia. Fitzpatrick R.W., P.M. Slade, and P. Hazelton (2001). Chapter 3 - Soil-related engineering problems: identification and remedial measures. p In V. A. Gostin (ed.) Gondwana to Greenhouse: Australian Environmental geoscience. Geological Society of Australia Special Publication 21. GSA, Australia. Fitzpatrick R.W., M.J. Wright and R.M. Stevens (1993). Drainage, sodicity and related problems of vineyard soils. p In: C.S. Stockley, R.S. Johnstone, P.A. Leske and T.H. Lee (eds.). Proceedings of the 8th Australian wine industry technical conference; October, 1992; Melbourne, Victoria. Winetitles. Isbell R.F. (1996) The Australian soil classification system. CSIRO, Publishing, Melbourne, Australia. May P. (1993) Review of rootstock use in Australia. In Vineyard development and redevelopment. Proceedings of a seminar organised by the Australian Society of Viticulture and Oenology, Inc. and held on 23 rd July, Mildura, Victoria. Ed Peter Hayes. Pages and continued on page 48. May P. (1994). Using grapevine rootstocks: the Australian perspective. Winetitles, Adelaide, South Australia. McDonald, R.C., Isbell, R.F., Speight, J.G., Walker, J. and M.S. Hopkins, (1990). Australian soil and land survey field handbook. 2nd Edition, Inkata Press, Melbourne. Northcote, K.H. (1979). A Factual Key for the Recognition of Australian Soils. 4th Ed. (Rellim: Adelaide). Schoknecht, N.R. (ed.) (2001). Soil Groups of Western Australia. Resource Management Technical Report 193. Agriculture Western Australia, Australia. Soil Survey Staff (1999). Soil Taxonomy: A Basic System of Soil Classification for Making and Interpreting Soil Surveys. 2nd edition. Agriculture Handbook No United States Department of Agriculture, Natural Resources Conservation Service, Washington. pp 869. Soil Survey Division Staff (1993). Soil Survey Manual. United States Department of Agriculture Handbook No. 18. (U.S. Government Printing Office, Washington, DC). Soil Classification Working Group (1991) Soil Classification: A Taxonomic System for South Africa. Memoirs on the Agricultural Natural Resources of South Africa No. 15. pp Stace, H.C.T., G.D. Hubble, R. Brewer, K.H Northcote,. J.R. Sleeman, M.J. Mulcahy, and E.G. Hallsworth, (1968). A Handbook of Australian Soils. Rellim: Glenside, South Australia. Page 7

11 Table 1: Key for identifying categories and sub-categories of vineyard soils in Australia Does the soil have one of the Soil Category Sub-category following diagnostic features? a water table within 50 cm of the 1: Wet Soil Can soil be drained? 1 surface for three months of the year. NO? or Un-drainable wet soil grey subsoil layers that may have yellow and/or reddish mottles. YES? YES? Wet drainable - continue below NO? is less than 15 cm deep (or <25 cm if sandy) over non-rippable rock. YES? 2: Very shallow non-rippable soil Very shallow non-rippable soil 2 NO? is non calcareous and overlies loose stones, semi-hard rock or calcareous pan (all rippable) within 15 cm. YES? NO? is non calcareous and has a uniform clay content or gradual increase in clay content with depth over hard rock, hard pan or calcrete within 50 cm of the surface. YES? NO? is clayey to at least 50 cm, cracks on drying. and has slickensides within 50 cm. YES? NO? 3: Very shallow or stony rippable soil 4: Shallow soil 5: Cracking Clay Deep stony soil Soil has more than 75 % loose coarse fragments in upper 100 cm Very shallow soil over rock Rippable non-calcareous rock within 15 cm. Very shallow sandy soil over calc-rock Sandy over rippable calcareous rock or calcrete. Very shallow loamy/clayey soil over calc-rock Loamy to clayey over rippable calcareous rock or calcrete. Shallow sandy soil Sandy over hard rock or hard pan between 25 and 50 cm Shallow loamy soil over calc-rock Loamy to clay loamy over calcareous rock or calcrete between 15 and 50 cm. Shallow loamy soil over rock/pan Loamy to clay loamy over non- calcareous hard rock or hard pan between 15 and 50 cm. Shallow clay over calc-rock Clayey, non-cracking over calcareous rock or calcrete between 15 and 50 cm. Shallow cracking clay over calc-rock Clayey, cracking over calcareous rock or calcrete between 15 and 50cm. Poorly structured cracking clay Hard setting coarse blocky or massive surface. Well structured over restrictive cracking clay Well structured within 80 cm of surface over restrictive layer (coarse blocky structure or wet/grey subsoil layers). Well structured throughout cracking clay Well structured surface, no coarse blocky structure within 80 cm of surface Page 8

12 Continued Table 1. Key for identifying categories and sub-categories of vineyard soils in Australia Diagnostic features Soil Category Sub-category Restrictive duplex soil with thin well structured 6.1 topsoil Topsoil is not hard and thinner than 30 cm. has a sandy, loamy or clay loamy topsoil <80 cm thick abruptly (with sharp, abrupt or clear boundary) overlying a hard more clayey subsoil with prismatic, columnar or coarse blocky structure and/or dull grey colours within the depth specified in the Sub-category. YES? NO? has a sandy, loamy or clay loamy topsoil <80 cm thick abruptly (with sharp, abrupt or clear boundary) overlying a more clayey subsoil which does not have prismatic, columnar or coarse blocky structure and/or dull grey colours within the depth specified in the Sub-category. YES? NO? is calcareous throughout or at least below 20 cm. YES- NO? has a uniform clay content or gradual increase in clay content. A hard restrictive layer may occur anywhere in the profile. YES? 6: Duplex soil with restrictive sub-soil 7: Duplex soil with nonrestrictive sub-soil 8: Calcareous soil 9: Uniform or gradational soil (termed unigrad if both allowable in same subcategory) Restrictive duplex soil with thick well structured topsoil Topsoil is not hard and between 30 and 80 cm thick. Restrictive duplex soil with thin hard topsoil Topsoil is hard and thinner than 30 cm. Restrictive duplex soil with thick hard topsoil Topsoil is hard and between 30 and 80 cm thick. Non-restrictive duplex soil with thin well structured topsoil Topsoil is not hard and thinner than 30 cm. Non-restrictive duplex soil with thick well structured topsoil Topsoil is not hard and between 30 and 80 cm thick. Non-restrictive duplex soil with thin hard topsoil Topsoil is hard and thinner than 30 cm. Non-restrictive duplex soil with thick hard topsoil Topsoil is hard and between 30 and 80 cm thick. Sandy calcareous soil Sandy to at least 80 cm Shallow calcareous restrictive soil Soil over non-rippable calcareous rock or calcrete pan between 15 and 50 cm. Shallow calcareous non-restrictive soil Soil over rippable calcareous rock or calcrete pan between 15 and 50 cm. Rubbly calcareous soil Soil has a layer with more than 30% carbonate rubble at least 20 cm thick Clayey calcareous soil Clayey (> light clay) over carbonate layer within 80 cm Loamy calcareous soil Loamy, clay loamy or light clayey over carbonate layer within 80 cm. Deep sandy uniform soil Sandy to at least 50 cm. Deep sandy gradational soil Sandy topsoil over loam to clay within 50 cm Deep loamy calcareous unigrad soil Sandy loam to loam topsoil with calcareous subsoil Deep clayey calcareous unigrad soil Clay loam to clay topsoil with calcareous subsoil Deep hard loamy unigrad soil Firm to hard sandy loam to loam topsoil Deep well structured loamy unigrad soil Sandy loam to loam topsoil well structured to at least 50 cm Deep hard clayey unigrad soil Firm to hard clay loam to clay topsoil Deep well structured clayey unigrad soil Clay loam to clay topsoil well structured to at least 50 cm Page 9

13 Table 2. Interpreting Soil Consistence (figures in parentheses are the force needed for failure in newtons) Class No Consistence Classes Australian/ B USDA/ B USDA Rupture resistance on a mm fragment of dry soil (newtons) B Consistence test inferred from Excavation Difficulty Environment indication B Dry B Moist 1 Loose Loose Loose Block-like piece not obtainable. Only individual sand grains can be picked up between thumb and forefinger (0) 2 Very Soft Friable Fails (i.e. crumbles) under slight force weak to applied between thumb and forefinger weak (<8 20) 3 Firm to very firm 4 Strong to very strong Firm Firm Fails under moderate to strong force applied between thumb and forefinger (20 80) Very hard Very firm Cannot be ruptured between thumb and forefinger but can be by applying full body weight under foot. (80 800) 5 Rigid Rigid Rigid Cannot be ruptured by blow with hammer. (> 800) Can be excavated with a spade using armapplied pressure. Neither application of impact energy nor application of pressure with the foot to a spade is necessary. Arm-applied pressure to a spade is insufficient. Excavation can be accomplished quite easily by application of impact energy with spade or by foot pressure to spade. Excavation with spade can be accomplished, but with difficulty. Excavation is easily possible with a full length pick using an overthe-head swing. Excavation with a full length pick using an over-the-head swing is moderately to markedly difficult. Excavation is possible in a reasonable period of time with a backhoe mounted on a KW (50-80 hp) tractor. Excavation is impossible with a full length pick using an over-the-head arm swing or with reasonable time period with a backhoe mounted on a KW (50-80 hp) tractor. No restriction on root growth for annuals and perennials. No restriction on water movement. Root growth of annuals and perennials is not restricted. Slight restriction on water movement; soil water is usually available to most crops and trees. Water flow may sometimes be restricted contributing to periodic waterlogging. Root growth of most species is restricted. Water flow may be restricted. Root growth of most species is severely restricted. Water flow is normally restricted. Note: Two systems are used to describe soil consistence. The Australian system ( A McDonald et al. 1990), uses the concept of soil strength and is measured on a 20 mm piece of soil. The class names are the same for all moisture contents but soil water status must be recorded. The USDA system ( B Soil Survey Division Staff 1993) uses fragments of soil about mm in size and has different class names for different moisture contents (dry and moist). Table 2 approximately correlates the two systems by using five classes with corresponding field tests and environmental indications. The force (expressed in newtons) required to fail a fragment of soil is calculated from the weight required to crush the fragment (expressed as in kg force) multiplied by 9.81, the gravitational factor. Page 10

14 Table 3 Approximate correspondence between categories of vineyard soils in Australia and other soil classification systems Key for identifying "categories of vineyard soils" in Australia Isbell 1996 Great soil group Stace et al Soil Taxonomy Soil Classification: A Taxonomic System for South World Reference Soil Base for Soil Resources (WRB) 1: Un-drainable wet soil Hydrosol Grey clay Humic gley Neutral to alkaline peat Acid peat Lithosol 2: Very shallow nonrippable soil 3: Very shallow or stony rippable soil Lithic Rudosol (very shallow) Lithic Tenosol (very shallow) Petrocalcic Rudosol / Tenosol (very shallow) Rudosol Tenosol 3.1 Deep stony soil Clastic Rudosol Clastic Tenosol 3.2 Very shallow soil over Paralithic Rudosol rock Paralithic / Petroferric Tenosol 3.3 Very shallow sandy soil over calc-rock 3.4 Very shallow loamy/ clayey soil over calc-rock (all very shallow) Petrocalcic Tenosol Petrocalcic Tenosol Petrocalcic Dermosol Lithosol Lithosol Alluvial soil Lithosol Terra rossa Lithosol Terra rossa Lithosol Terra rossa Lithosol Terra rossa Rendzina Aqualfs Salids Aquents Fibrists Saprists Hemists Aquepts Aquolls Aquox Aquod Auults Aquerts Entosols Salic aridisols Entosols Salic aridisols Inceptisols Entosols Salic aridisols Entosols Salic aridisols Entosols Salic aridisols Inceptisols Entosols Lithic Calcixerepts Africa (1991) Champagne Katspruit Pinedene Bloemdal Rensburg Mispah Knersvlakte Dresden Coega As above Mispah Mispah Knersvlakte Dresden Coega Coega (1998) EndogleyicHistosols Epigleyic Histosols Rheic Histosols Endogleyic Gleysols Epigleyic Gleysols Plinthic Gleysols Sodic Gleysols Umbric Gleysols Mollic Gleysols Arenic Gleysols Calcic Gleysols Haplic Gleysols Lithic Leptosols Lithic Calcisols Paralithic Leptosols Hyperskelectric Leptosols Lithic Leptosols Paralithic Leptosols Paralithic Leptosols Hyperskelectric Leptosols Lithic Calcisols Epileptic Calcisols Arenic Durisols Lithic Calcisols Petrocalcic Calcisols Renzic Leptosols Rhodic Calcisols Page 11

15 Cont. Table 3. Key for identifying "categories of vineyard soils" in Australia 4: Shallow soil Rudosol Tenosol Vertosol 4.1 Shallow sandy soil Rudosol Tenosol 4.2 Shallow loamy over calcrock 4.3 Shallow loamy soil over rock/pan 4.4 Shallow clay over calcrock 4.5 Shallow cracking clay over calc-rock Isbell Great soil group Soil Taxonomy Soil Classification A Taxonomic System for South Africa (1991) Petrocalcic Dermosol / Kandosol Petrocalcic Tenosol Lithic / Petroferric / Silpanic Tenosol Petrocalcic, Black Dermosol Petrocalcic, Black Dermosol Lithosol Shallow black earth Cracking clay Lithosol Red siliceous sand Entosols Inceptisols Verisols Inceptisols Xerepts Udepts Prieska Dundee Arcadia (shallow) Dundee World Reference Soil Base for Soil Resources (WRB) (1998) Leptosols Arenosols Cambisols Terra rossa Calcixerepts Prieska Calcaric Cambisols Red and brown hardpan soil Rendzina Ground water Rendzina Rendzina Ground water Rendzina 5: Cracking Clay Vertosol Black earth Cracking Clay 5.1 Poorly structured cracking clay 5.2 Well structured over restrictive cracking clay 5.3 Well structured throughout cracking clay Durixerepts Prieska Leptic Cambisols Regosols Calcixerepts Prieska Phaeozems Calciaquolls Kastanozems Xerolls Calcixerolls Lithic Argixerolls Calcic Argixerolls Vertisols Immerpan Milkwood Arcadia Rensburg Massive / Epihypersodic Vertosol Sodic Haploxererts Arcadia Rensburg Endohypersodic Vertosol Wiesenboden Aquerts Xererts Calciaquerts Endoaquerts Aquic Haploxererts Self-mulching / Epipedal Vertosol Black earth Calcixererts Chromic Haploxererts Rensburg Arcadia Calcic Vertisol Duric Vertisol Kastanozems Phaeozems Vertisols Mazic Vertisol Hyposodic Vertisol Natric Vertisol Calcic Vertisol Pellic Vertisol Grumic Vertisol Gypsiric Vertisol Natric Vertisol Calcic Vertisol Pellic Vertisol Grumic Vertisol Haplic Vertisol Chromic Vertisol Page 12

16 Cont. Table 3. Key for identifying "categories of vineyard soils" in Australia 6: Duplex soil with restrictive sub-soil 6.1 Restrictive duplex soil with thin well structured topsoil 6.2 Restrictive duplex soil with thick well structured topsoil 6.3 Restrictive duplex soil with thin hard topsoil 6.4 Restrictive duplex soil with thick hard topsoil 7: Duplex soil with nonrestrictive sub-soil 7.1 Non-restrictive duplex soil with thin well structured topsoil Isbell Great soil group Soil Taxonomy Soil Classification A Taxonomic System for South Africa (1991) Sodosol Sodic Chromosol Natric Kurosol Solodized brown soil Solodized solonetz, Solodic Soloth Red-brown earth Gleyed podzolic soil Xeralfs Udalfs Natrixeralfs Kroonstad Longlands Wasbank Estcourt Cartref Westleigh Klapmuts Glencoe Sterkspruit Sepane See above See above See above See above See above See above See above See above See above See above See above See above See above See above See above See above Chromosol Kurosol Red podzolic soil Yellow podzolic Brown podzolic Lateritic podzolic soil Red-brown earth Plintoxeralfs Rhodoxeralfs Palexeralfs Haploxeralfs Rhodustalfs Plinthustalfs Constantia Vilfontes Avalon Klinelbos Swartland Valsrevier Tukulu As above As above As above See above World Reference Soil Base for Soil Resources (WRB) (1998) Gleyic Solonetz Duric Solonetz Calcic Solonetz Magnesic Solonetz Albic Solonetz Stagnic Solonetz Gleyic Planosols Sodic Planosols Albic Planosols Petroferric Planosols Albic Plinthosols Lixisols Alisols Acrisols Luvisols Mollic Planosols Page 13

17 Cont. Table 3. Key for identifying "categories of vineyard soils" in Australia 7.2 Non-restrictive duplex soil with thick well structured topsoil 7.3 Non-restrictive duplex soil with thin hard topsoil 7.4 Non-restrictive duplex Isbell Great soil group Soil Taxonomy Soil Classification A Taxonomic System for South Africa (1991) As above As above As above See above As above As above As above See above As above As above As above See above soil with thick hard topsoil 8: Calcareous Soil Calcarosol Solonized brown soil Calcareous sand Grey-brown calcareous soil Calcareous red earth 8.1 Sandy calcareous soil Calcic Calcarosol Solonized brown soil Calcareous sand Lithic Xerothens Calcixerepts 8.2 Shallow calcareous Petrocalcic / Lithic Calcarosol Solonized brown soil Petrocalcic Etosha restrictive soil Calcareous sand Calcixerepts Gamoep Calcixerepts Trawal 8.3 Shallow calcareous non Petrocalcic / Paralithic Calcarosol Solonized brown soil Lithic Calcixerepts Brandvlei restrictive soil Addo 8.4 Rubbly calcareous soil Supracalcic / Lithocalcic Solonized brown soil Lithic Calcixerepts Brandvlei Calcarosol Addo 8.5 Clayey calcareous soil Hypercalcic Calcarosol Red calcareous Typic Calcixerepts Molopo soil Petrocalcic Oakleaf Solonized brown soil Rhodoxralfs Montagu Terra Rossa Calcic Rhodoxralfs Augrabies 8.6 Loamy calcareous soil Hypercalcic Calcarosol Solonized brown soil Oakleaf Terra Rossa Montagu Desert loam Augrabies Typic Calcixerepts Petrocalcic Rhodoxralfs Calcic Rhodoxralfs World Reference Soil Base for Soil Resources (WRB) (1998) Calcaric Arenosol Arenic Regosol Epipetric Calcisol Calcic Calcisol Hypocalcic Calcisol Skeletic Calcisol Hypocalcic Calcisol Calcisol Endopetric Calcisol Page 14

18 Cont. Table 3. Key for identifying "categories of vineyard soils" in Australia Isbell Great soil group Soil Taxonomy Soil Classification A Taxonomic System for South Africa (1991) Wide range - see below Wide range - see Wide range - see 9 Uniform or gradational soil below 9.1 Deep sandy uniform soil Arenic Tenosol Red earthy sand Podzol Red siliceous sand 9.2 Deep sandy gradational soil 9.3 Deep loamy calcareous unigrad soil 9.4 Deep clayey calcareous unigrad soil 9.5 Deep hard loamy unigrad soil 9.6 Deep well structured loamy unigrad soil 9.7 Deep hard clayey unigrad soil 9.8 Deep well structured clayey unigrad soil below Psamments Spodosols Kandosol Alfisols Ultisols Calcic Kandosol/Dermosol; Red earth Alfisols loamy Ultisols Calcic Dermosol; clayey Alfisols Ultisols Eutrophic Kandosol; loamy Krasnozem Euchrozem Alfisols Ultisols Eutrophic Dermosol; loamy Alfisols Ultisols Eutrophic Kandosol; clay loamy Krasnozem Alfisols Euchrozem Ultisols Eutrophic Dermosol; clay loamy Krasnozem Euchrozem Alfisols Ultisols Oxisols Fernwood Namib Lamotte Concordia Vilafontes Shortland Klinkelbos Hutton Kimberley Shortlands Swartland Hutton Clovelly Hutton Clovelly Hutton Clovelly Griffin Hutton Kranskop Magwa Inanda World Reference Soil Base for Soil Resources (WRB) (1998) Arenosols Arenic Regosols Arenic Fluvisols Arenic Ferralsols Arenic Ferralsols Plinthic Ferralsols Hypocalcic Calcisol Luvic Calcisol Luvic Calcisol Lixic Ferralsols Lixic Ferralsols Lixic Ferralsols Plinthosols Lixic Ferralsols Plinthosols Alumic Nitosols Lixic Ferralsols Gibbsic Ferralsols Page 15

19 Table 4 Colour photographs of sub-categories of vineyard soils in Australia Un-drainable wet soil 1 Very shallow non-rippable soil 2 Page 16

20 Deep stony soil Soil has more than 75% loose coarse fragments in upper 100cm 3.1 Very shallow soil over rock Rippable non-calcareous rock within 15cm 3.2 No image available Page 17

21 Very shallow sandy soil over calc-rock Sandy over rippable calcareous rock or calcrete. 3.3 Very shallow loamy / clayey soil over calcrock Loamy to clayey over rippable calcareous rock or calcrete. 3.4 Page 18

22 Shallow sandy soil Sandy over hard rock or hard pan between 25 and 50cm 4.1 Shallow loamy soil over calc-rock Loamy to clay loamy over calcareous rock or calcrete between 15 and 50 cm. 4.2 Page 19

23 Shallow loamy soil over rock/pan Loamy to clay loamy over non- calcareous hard rock or hard pan between 15 and 50 cm. 4.3 Shallow clay over calc-rock Clayey, non-cracking over calcareous rock or calcrete between 15 and 50cm. 4.4 Page 20

24 Shallow cracking clay over calc-rock Clayey, cracking over calcareous rock or calcrete between 15 and 50 cm. 4.5 Poorly structured cracking clay Hard setting coarse blocky or massive surface. 5.1 Page 21

25 Well structured over restrictive cracking clay Well structured within 80 cm of surface over restrictive layer (coarse blocky structure or wet/grey subsoil layers). 5.2 Well structured throughout cracking clay Well structured surface, no coarse blocky structure within 80 cm of surface. 5.3 Page 22

26 Restrictive duplex soil with thin well structured topsoil Topsoil is not hard and thinner than 30cm. 6.1 Restrictive duplex soil with thick well structured topsoil Topsoil is not hard and between 30 and 80 cm thick. 6.2 Page 23

27 Restrictive duplex soil with thin hard topsoil Topsoil is hard and thinner than 30 cm. 6.3 Restrictive duplex soil with thick hard topsoil Topsoil is hard and between 30 and 80 cm thick. 6.4 Page 24

28 Non-restrictive duplex soil with thin well structured topsoil Topsoil is not hard and thinner than 30 cm. 7.1 Non-restrictive duplex soil with thick well structured topsoil Topsoil is not hard and between 30 and 80 cm thick. 7.2 Page 25

29 Non-restrictive duplex soil with thin hard topsoil Topsoil is hard and thinner than 30 cm. 7.3 Non-restrictive duplex soil with thick hard topsoil Topsoil is hard and between 30 and 80 cm thick. 7.4 Page 26

30 Sandy calcareous soil Sandy to at least 80 cm. 8.1 Shallow calcareous restrictive soil Soil over non-rippable carbonate pan (calcrete) between 15 and 50 cm. 8.2 Page 27

31 Shallow calcareous non-restrictive soil Soil over rippable carbonate-rich rock or pan between 15 and 50 cm. 8.3 Rubbly calcareous soil Soil has a layer with more than 30% carbonate rubble at least 20 cm thick 8.4 Page 28

32 Clayey calcareous soil Soil has a clayey (> light clay) carbonate layer within 80 cm 8.5 Loamy calcareous soil Soil has a loamy, clay loamy or light clayey carbonate layer within 80 cm. 8.6 Page 29

33 Deep sandy uniform soil Sandy to at least 50 cm 9.1 Deep sandy gradational soil Sandy topsoil over loam to clay within 50 cm 9.2 Page 30

34 Deep loamy calcareous unigrad soil Sandy loam to loam topsoil with calcareous subsoil 9.3 Deep clayey calcareous unigrad soil Clay loam to clay topsoil with calcareous subsoil 9.4 Page 31

35 Deep hard loamy unigrad soil Firm to hard sandy loam to loam topsoil 9.5 Deep well structured loamy unigrad soil Sandy loam to loam topsoil well structured to at least 50 cm 9.6 Page 32

36 Deep hard clayey unigrad soil Firm to hard clay loam to clay topsoil 9.7 Deep well structured clayey unigrad soil Clay loam to clay surface soil well structured to at least 50 cm 9.8 Page 33