Soils - Overview - SA

Summary of Land System / Soil Landscape Mapping Information in South Australia

Introduction

PIRSA's soil landscape mapping programme was undertaken to provide standardized regional scale information about the nature of the land and potential and limitations for agricultural use across the higher rainfall areas of the State. All areas south of the Pastoral Lease boundary, with the exception of a strip of Perpetual Lease land along the western edge of the pastoral country between Morgan and Yunta, have been mapped. Where existing mapping was available, it was used as an additional information source, or else incorporated into the overall coverage.

The maps, at scales of 1:50,000 or 1:100,000 are landscape surveys supplemented by soils information, rather than detailed soil surveys. The main mapping units are Land Systems. These are broad landscape features within which there are recurring patterns of geology, topography, soils and vegetation. They have local geographic names abbreviated to three letters. Each Land System comprises one or more Soil Landscape Units. These are recognizable topographic features formed on a particular geological material or group of materials. They include a limited and defined range of soil classes. They therefore have similar land attributes and land use potential.

The maps and land descriptions were compiled using 1:40,000 scale aerial photography, existing geology and soil maps, and data collected during field investigations. The field work was designed to provide a general indication of the soils and other features of the various landscapes identified by aerial photograph interpretation. The field assessments included morphological descriptions to depths of between 50 and 200 cm, depending on the nature of the soil, and site descriptions in accordance with the standards set out in the Australian Soil and Land Survey Field Handbook (McDonald et al 1990). Soil profiles were classified according to the Australian Soil Classification (Isbell, 1996).

Laboratory determinations of pH and electrical conductivity were made on selected samples from the field survey. More detailed chemical analyses were undertaken on samples from 700 representative sites across the state. The data from these representative sites is available from PIRSA Land Information at the Waite Campus at cost of transfer.

Map themes

Land systems	Large (usually more than 50 km² in area) areas of land with a recognizable and repeating pattern of topography, geology, soils and vegetation.
Soil landscapes	Areas of land (typically 0.5 to 50 km² in area) with recognizable topographic features and a limited range of soil types.

In the PIRSA mapping framework, soil landscapes are nested within land systems.

Scales

Most areas are mapped at 1:100,000 scale. The South East (south of latitude 36o30'), the Mount Lofty Ranges, and Kangaroo Island are mapped at 1:50,000 scale. Maps at both scales are based on the standard map sheet series.

Continuity and extent of data

The area of coverage is shown on the attached map. All coverages join (ie no edge mis-match), including across 1:100,000 / 1:50,000 scale boundaries.

Primary data

Approximately 25,000 site records of profile and land surface descriptions. 730 characterization sites with profile morphology, chemistry and photograph.

Accessory data

Look-up tables are attached to the polygon coverage. These tables contain coded data summarizing a range of soil and landscape attributes which affect land use and land management. The attributes are:

Attributes related to agricultural productivity	Attributes related to land degradation
Waterlogging potential Depth to hard rock / hard pan Water holding capacity Rootzone depth (for five irrigated crops types) Depth to water table Deep drainage Inherent fertility Acidity Alkalinity Carbonates (surface and subsoil) Salinity Toxic elements (Al, B, Na) Surface condition Water repellence Subsoil conditions for root growth Rockiness Exposure Flooding Soil classes (dominant and associated) Surface texture	Water erosion potential Wind erosion potential Salinity Acid sulfate potential Mass movement Gully / tunnel / stream bank erosion Scalding Dry saline land (magnesia) Recharge potential

Attributes related to agricultural productivity

Attributes related to land degradation

Waterlogging potential
Depth to hard rock / hard pan
Water holding capacity
Rootzone depth (for five irrigated crops types)
Depth to water table
Deep drainage
Inherent fertility
Acidity
Alkalinity
Carbonates (surface and subsoil)
Salinity
Toxic elements (Al, B, Na)
Surface condition
Water repellence
Subsoil conditions for root growth
Rockiness
Exposure
Flooding
Soil classes (dominant and associated)
Surface texture

Water erosion potential
Wind erosion potential
Salinity
Acid sulfate potential
Mass movement
Gully / tunnel / stream bank erosion
Scalding
Dry saline land (magnesia)
Recharge potential

Data format

The polygon data are in Arc Info format with linked look up tables.

Crop potential models

Models (or data interpretation rules) have been developed to derive crop potential maps for 20 field crop, horticultural and pasture species.

Click here (2.8 MB) for an example of a map of potential for viticulture in the south-east of SA

Standard outputs

×	Land system / soil landscape maps and reports.
×	Attribute maps (individual attributes, or combinations) and statistics. This category includes soil class maps. Click here (1.2 MB) for an example: a map of susceptibility to water repellence.
×	Crop potential maps and statistics. Click here (2.8 MB) for an example of a map of potential for viticulture in the south-east of SA.

The above are available in electronic as well as hard copy format. Any geographic coverage is possible, provided that the boundaries are on file, or can be added.

Customized outputs

One of the main advantages of GIS based mapping is the capacity to provide non standard or customized products for individual clients. Generally, more than one data set is used to generate such products. Data sets which are commonly used in combination with soil landscape attribute data are rainfall, groundwater resources, native vegetation, roads and cadastre, land use and specific use areas. For example, in a specified Economic Development Region, the area of land with potential for olives can be calculated and mapped, further data can be generated to identify where there is a co-existence of favourable land and groundwater supplies, and how much of this potential area is unsuitable due to constraints such as parks, native vegetation, reserves, specific land use zones etc.

Accessing data and information

Primary data can be made available in electronic format at cost of transfer. Interpreted or customized information, including crop potential maps require consultancy services which are charged accordingly.