Why healthy soils are important
Healthy soils provide habitat for plants and animals, and support ecosystems and the primary production of food and resources. Soils make a significant contribution to the economic and ecological prosperity of New South Wales.
Soil health is assessed by describing the extent of change or soil degradation that has occurred. Soil degradation is the decline in soil quality caused by its improper use, usually for agricultural, industrial or urban purposes. Australian soils are among the oldest and most fragile in the world.
Soil health indicators
There are 7 important indicators of soil health:
- soil pH (the measure of acidity or alkalinity in soils)
- soil organic matter and soil organic carbon (i.e. the amount of carbon stored in the soil, including plant and animal materials in the soil that are in various stages of decay)
- soil structure (i.e. the arrangement of soil into units called soil aggregates or peds, which have both solid and open pore spaces)
- soil stability (unstable soils collapse when wet)
- soil salinity (the salt content in soil)
- depth of topsoil (this is usually 5 to 8 centimetres but sometimes only 1 to 2 centimetres, or it could be absent from erosion)
- soil contamination.
Soil degradation is measured by recording changes in soil characteristics over time.
It is essential that soils are managed with careful consideration of their individual characteristics, landscapes and climate.
Soil is essentially a non-renewable resource. It takes a very long time to form. One millimetre of soil can take up to 1,000 years to develop. Australian soils are among the most ancient and fragile in the world. Therefore, in order to maintain productivity and ecosystem services, soils must be managed sustainably.
The effects of most types of soil degradation are long-term and may be permanent or difficult and costly to repair. While some other forms of degradation, such as soil nutrient decline and surface soil acidification, may be fixed if addressed early, it’s often expensive. In agricultural landscapes, using best management practices can prevent or even reverse some lower levels of soil degradation.
At the regional level, land management priorities are undertaken by Local Land Services (LLS). Each LLS plans and coordinates land management and natural resource priorities through a community-based strategic planning process.
SoilWatch is a soil health monitoring program which works in partnership with NSW Local Land Services to measure changes in soil condition.
OEH is the lead agency in the Monitoring, Evaluation and Reporting program which monitors land and soil condition across New South Wales.
The Soil Conservation Act 1938 provides for the conservation of soil and farm water resources and the mitigation of erosion. Parts 2A, 3 and 4 of the Act provide for the management of:
- land degradation and erosion
- the management of areas of erosion hazard
- management of the impact of erosion on waterways.
Contaminated soils are covered by the Contaminated Land Management Act 1997. This policy is for investigating and restoring contaminated land.