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Objective

Recommendation

Key issues

What has been achieved 1998-2003

Tasmania Together

Related Issue Reports

Objective

To manage and reduce the adverse impacts from soil erosion and structural decline.

Recommendation

It is recommended that:

• monitoring of key soil reference sites and water quality in identified high risk areas is undertaken to provide indications of change in soil condition;
   
• research and development is undertaken to identify appropriate land management practices to reduce the risks of soil degradation; and
   
• monitoring of the extent of uptake of 'Soil Management Guidelines' (Hamlett 2002) by the farming community is undertaken to assess improvements in land management practices over time and the extent to which the farming community is accepting the principles.
   

Key issues

Sustaining the productive capacity of soils occurs where the level of intensity of land use is matched with appropriate crops for any given soil type. It is also based on optimum crop rotations and verifiable environmental management systems. Where agricultural practices shift to cropping regimes, land should be used within its capability rating with appropriate management systems that maintain or enhance soil structure (e.g. reduced tillage, green manuring).

The following are some brief extracts from relevant Issue Reports within the Land Chapter. Links are provided to these Issue Reports for further detail.

• Soil Condition: Recent work by Cotching et. al. (in prep) indicates that most soils used for cropping in Tasmania are in good condition. However, Grice (1995) estimated that approximately 15% (317,000 ha) of private land in Tasmania has been affected by moderate to severe soil structure decline. A more recent comprehensive assessment of the condition of Tasmanian soils has not been undertaken.
   
• Soil Structure Decline and Compaction: Soil structural impacts is an issue for land under production forestry. Monitoring of soil structural condition is undertaken in the Warra Long-Term Ecological Research Site in the Southern Forests. Soil survey data is not available broadly for State Forest, although visual assessment of soil condition in Tasmanian forests is undertaken in Forest Practices Board audits.
   
• Soil Erosion: Based on the most recent, broad-scale soil erosion survey of private land in Tasmania (Grice 1995), sheet and rill erosion hazard are not appreciable or only occur at a moderate level. Private land gully erosion hazard is generally not appreciable or only occurs at a minor level. Tunnel erosion is the most limited form of land degradation in Tasmania estimated to be affecting 5% of private land. Severe to extreme sheet and rill erosion occurs in the vegetable cropping areas of the northern coast (e.g. between Devonport and Wynyard), and on the heavily grazed drier hills of the Southern Midlands and Derwent Valley.
   

What has been achieved 1998-2003

The following is a summary of a few of the key achievements in maintaining land productivity in Tasmania. Further information is contained in the relevant Issue Reports within the Land Chapter.

• A set of Soil Management Guidelines has been prepared and published by the DPIWE and the Tasmanian Farmers and Graziers Association (Hamlett 2002). These voluntary guidelines are a broad set of best management practices relating to the use of soils for agriculture and include details on planning, maintaining soil structure and organic matter, reducing soil erosion, managing soil salinity, avoiding soil contamination, and managing riparian land. The guidelines complement a number of technical documents relating to land management published by the DPIWE, including 'Managing Tasmania's Cropping Soils' (Chilvers 1996).
   
• Within forestry areas, the main soil types have been defined and keys for their identification developed. The Forest Practices Act 1985, through the Forest Practices Code, requires that management of forests (e.g. use of machinery, cultivation procedures, slope limits for harvest) is modified to take into account soil factors like erodibility. New (January 2003) guidelines have specified increased soil protection next to headwater streams in the forestry estate and these are being trialled.
   
• A Natural Heritage Trust supported project entitled 'Minimising Land Degradation and Salinity Risk using Resource Information' is investigating the degradation risks, including soil structure decline, of intensified land use on soil types in three pilot areas around the State. Each area receives less than 800 mm rainfall per annum and is currently experiencing, or will experience in the near future, a significant land use change away from traditional grazing enterprises to more intensive cropping activities, such as irrigated cropping.
   
• There have been a number of research studies of soil compaction on forest soils at the Warra Long-Term Ecological Research Site.
   

Tasmania Together

Relevant Tasmania Together goals and standards for 'Land' are listed in the linked file. The Tasmania Together Progress Board reported on progress toward targets for benchmarks set (Tasmania Together Progress Board 2003). Indicators, targets and baseline data are available in the latest Progress Report June 2003. Further information, including progress report updates, is available from Tasmania Together.

Related Issue Reports