Enterprise suitability maps can assist farmers and prospective investors to analyse potential crop or enterprise options for a property or district. The information is intended as a guide to the further on-farm investigations and business analysis required before making investment decisions.
What are Enterprise Suitability Maps?
Enterprise Suitability Maps are derived from a combination of new digital soil mapping, localised climate data and crop rules. Via the power of Geographic Information Systems, climate and soil information can be used to match the known soil and climate requirements of a range of crops to a given area. This process allows a farmer or investor to short-list potential crops or enterprises for further investigation. The likely risks or impediments to growing the crops can also be identified.
Importantly at the regional or district level, the tool can help determine the wider potential for new crops, as a guide to the viability of a new enterprise at a state or regional scale.
Enterprise Suitability Maps are currently available state-wide for twenty different crops. Users can view the maps, zoom into specific locations, and also overlay other useful data sets. The suitability maps cover the following crops: barley; blueberries; carrots: carrot seed; cherries; hazelnuts; industrial hemp; linseed; lucerne; olives; onions; poppies; potatoes; pyrethrum; raspberries; rye grass for dairy; strawberries; wheat and wine grapes (pinot noir and chardonnay). Also included on this page is information on the appropriate crop rules and site suitability fact sheets.
As at July 2017 further work is underway for a further sixteen crops to be investigated. These include five perennial grasses, three perennial legumes, three seed crops (grass seed, clover seed, seed potato) and three tree species and supplementary feed crops (fodder beet and maize).
The enterprise suitability mapping data, and the consolidated soil and climate data is also available from DPIPWE for professional advisers and consultants under a standard data sharing agreement. Behind the enterprise suitability mapping sits extensive digital soil attribute modelling, soil profile sampling, and 12-months of continuous on-farm temperature and climate sampling correlated against historical weather state records.
Crop Rules to Guide Suitability
Many plants require particular climatic and land characteristics for best performance. Frost, winter chilling, summer heat, drainage, slope and salinity are some of these characteristics. For each enterprise land and climate criteria, or "crop rules" distinguish suitable from less suitable areas. These rules define the boundaries between the different classes of the enterprise suitability maps. Refer the Enterprise Suitability Maps page for the relevant crop rule.
Digital Soil Mapping (DSM): Applying new technologies to soil science
Soil mapping in Tasmania was not at the scale, format or quality to allow for a detailed assessment of land suitability, for example 1:50,000 or better. Digital Soil Mapping (DSM) - or predictive soil mapping - can now be used to generate soil property surfaces. When compared to traditional soil mapping, these techniques can produce more realistic three dimensional and continuous soil property surfaces, while requiring fewer field sites and associated resources. Importantly, DSM also has the ability to derive information on the reliability (or uncertainty) of mapping produced by the modelling process.
Modelling is Based on Soil Sampling
The DSM approach was initially being trialled in the Meander East irrigation district. In order to inform a statistically sound soil sampling design, an initial desk-top analysis was undertaken using existing soils and landscape data including existing 1:100,000 soil mapping. Physical sampling was then undertaken for 200 sites using a "Conditioned Latin Hypercube" sampling design, which is a randomised sampling approach that ensures the entire landscape is effectively sampled, (Minasny & McBratney, 2005). Soil cores were sub-sampled according to soil horizon, with samples undergoing Mid Infra Red and Near Infra Red scanning, and chemical calibration analysis.
Ground-based gamma radiometric mapping was also undertaken to help predict soil properties where no such data existed. Spatial soil surfaces (pH, EC, Clay %, Soil Depth, Stone %, Drainage), are now being generated using various modelling techniques (using data such as geology, existing soil maps, radiometrics, and terrain characteristics), to inform the enterprise suitability model for poppies, blueberries, carrots, barley, hazelnuts, pyrethrum and hemp crops.
Soil surfaces generated are validated by sampling further sites to compare modelled to actual soil information.
This methodology has now been validated and will be used to generate crop suitability and soil characteristic maps for the Tasmanian agricultural areas as part of the Water for Profit program.
For further information on Digital Soil Mapping contact Darren Kidd, Senior Land Resource Analyst (refer contact details below).