Alkalinity

Dataset Number1079
Dataset TitleAlkalinity
CustodianData Authority: Department for Environment and Water
Data Provider: Department for Environment and Water

Description

DescriptionSoil pH is alkaline when there is an excess of negatively charged hydroxyl ions in the solution of a soil layer. Alkaline soils (generally confined to <400 mm annual rainfall areas) can cause problems for plant growth due to reduced availability of phosphorous and essential trace elements (zinc, manganese, iron). This effect becomes more pronounced as the proportion of fine carbonate particles increases. Plant species and varieties have varying tolerance to alkaline conditions. Soils made alkaline by calcium carbonate alone rarely have pH >8.3 (in water). Where fine calcium carbonate is present in the soil matrix these soils are termed 'calcareous'. Alkaline soils with pH >8.3 usually have significant exchangeable sodium (sodic soils) or carbonates and bicarbonates of sodium. The alkalinity of each component of each Soil Landscape Map Unit (LANSLU) is assessed. All land that is known to be alkaline, or is similar to land known to be alkaline, is classified accordingly. Eight Alkalinity attribute (or 'analysis data') classes have been supplied (see I1_1, I1_2, etc in table below, including not applicable) as percentage (areal extent) values of each LANSLU. Note: the sum of all percentage values for each map unit totals 100%. The analysis data is to be used for the calculation of spatial data statistics. Alkalinity attribute classes account for both surface (0-10cm) and subsoil (30-80cm) alkalinity. Respective pH values for soil alkalinity classes are: 'Strongly alkaline': pHCaCl2 >8.5 or pHH2O >9.2SELECT 1 FROM DUAL; 'Alkaline': pHCaCl2 7.0-8.5 or pHH2O 8.0-9.2SELECT 1 FROM DUAL; 'Non-alkaline': pHCaCl2 <7.0 or pHH2O <8.0. For map display purposes, LANSLUs are categorised INTO 9 legend categories (ALKALINE), including not applicable, designed to highlight the component(s) exhibiting the highest, most limiting alkalinity class, provided this accounts for at least 30% of the map unit. Map units with limited occurrences of alkaline soils (10-30% of area) are shown as an additional legend category.
UsageLink to Soil Attribute Descriptions. This dataset has been derived from the Soil Landscape Map Units spatial dataset to be used for map creation or the calculation of spatial data statistics. Used to supply Government, community groups, industry and the general public with up to date regional, subregional and catchment level land and soil attribute information for southern South Australia. The aim is to produce maps, statistics and reports displaying and describing: Land and soil attributes within southern South AustraliaSELECT 1 FROM DUAL; Land surface features affecting land use, land management and productivitySELECT 1 FROM DUAL; Limitations / suitability of land and soil for a range of agricultural and other uses. Independent professional advice should be sought before using this in commercial decisions. Further information: soil and land attributes. Alkalinity dataset can be viewed at NatureMaps (>Soils>Soil Chemistry Attributes). Spatial data downloads are available from Data SA.

Data Quality

LineageThe dataset is based on an interpretation of 1:40,000 stereo colour aerial photography and limited field inspection of landscapes and soils by soil scientists. Soil Landscape Map Unit boundaries were determined after an integration of field observations and recordingsSELECT 1 FROM DUAL; laboratory analysesSELECT 1 FROM DUAL; stereoscopic examination of aerial photographsSELECT 1 FROM DUAL; understanding of regional landscape processes and stratigraphySELECT 1 FROM DUAL; existing soil and geological mapping data. To avoid inconsistencies and confusion, any updates to the Soil and Land Attribute mapping are to be managed by DEWNR Soil and Land Program. This data has been released under a Creative Commons licence. Where products are derived from this data, DEWNR are to be acknowledged, and any changes to the original data should be indicated.
CompletenessComplete. The spatial data is subject to amendment as and when more data become available.
Positional AccuracyThe accuracy is to the scale of mapping (50 metres at 1:50,000 and 300 metres at 1:100,000 mapping scale). The spatial data are to be used at the regional, subregional and catchment-level, and can be used to provide property overviewsSELECT 1 FROM DUAL; however, they cannot to be used at the paddock level. South East, Kangaroo Island, Mount Lofty Ranges and the 'bottom' of Yorke Peninsula have been mapped at 1:50,000. Eyre Peninsula, the main part of Yorke Peninsula, Murray Mallee and Northern Agricultural Districts have been mapped at 1:100,000.

Geographic Extent

Extent NameAgricultural Region - South Australia
Min Easting or Longitude132.25
Min Northing or Latitude-38
Max Easting or Longitude141
Max Northing or Latitude-32.25

Dataset Status

Initially Acquired01-JAN-2000
Last Updated01-JUL-2009
Update FrequencyAs required
Maintenance MethodAs required
LicenseingCC BY (Attribution)

Attributes

TableNameField AliasData TypeDescription
Landscape.SALAD_pH_AlkalinityLANSLU CharacterSoil Landscape Map Unit
Landscape.SALAD_pH_AlkalinityALKALINE CharacterSURFACE (0 - 10 cm) / SUBSOIL (30 - 80 cm) ALKALINITY (Legend category. See layer file for descriptions). Map units are categorised according to the most alkaline component, provided it accounts for at least 30% of the area. Limited occurrences of alkaline surface soils (10 - 30% of the area) are also shown. Legend categories take account of both surface and subsoil (ie deeper than 30 cm) alkalinity.
Landscape.SALAD_pH_AlkalinityI1_1 NumberPercentage of map unit which has non alkaline surface soils and non alkaline subsoil.
Landscape.SALAD_pH_AlkalinityI1_2 NumberPercentage of map unit which has non alkaline surface soils and alkaline subsoil.
Landscape.SALAD_pH_AlkalinityI1_3 NumberPercentage of map unit which has non alkaline surface soils and strongly alkaline subsoil.
Landscape.SALAD_pH_AlkalinityI2_2 NumberPercentage of map unit which has alkaline surface soils and alkaline subsoil.
Landscape.SALAD_pH_AlkalinityI2_3 NumberPercentage of map unit which has alkaline surface soils and strongly alkaline subsoil.
Landscape.SALAD_pH_AlkalinityI3_3 NumberPercentage of map unit which has strongly alkaline surface soils (10 - 30 cm) and strongly alkaline subsoil.
Landscape.SALAD_pH_AlkalinityI4_3 NumberPercentage of map unit which has strongly alkaline surface soils (0 - 10 cm) and strongly alkaline subsoil.
Landscape.SALAD_pH_AlkalinityIX NumberPercentage of map unit which is not applicable.

Contact Information

OrganisationDepartment for Environment and Water
Science Monitoring and Knowledge
Postal AddressGPO Box 1047

ADELAIDE
5001
EmailDEWNR.CustomerServiceCentre@sa.gov.au