Protect our soils
Sapphire proclaimed a town
Soils perform four important functions. They:
- provide a structure and medium for plant growth
- store, purify and release water
- modify the atmosphere
- are habitat for organisms that decompose organic waste and create nutrients and habitat for other organisms.
Soils are a valuable and finite resource. Good quality soils support high value agricultural industries. As well as supporting their own ecology (soil microbes, fungi etc.), soils are the foundation on which plants and animals grow. Healthy soils are fundamental to supporting the region’s ecosystems and agricultural industries. Soils supported traditional Indigenous lifestyles, and today they continue to provide important social, cultural and recreational resources.
The Soils fact sheet gives an overview of the current state and trends of this regional asset.
Mapping the key values and identifying areas that are at risk is an important tool for managing these assets effectively. The mapping tool below allows stakeholders to access specific data that can be used as a basis for sound decision making. If you are using an iPad or iPhone to access the CQSS:2030 website, please click on the mapping application button below to access it.
Full more complete and detailed geographical data, or if you are using an iPad or iPhone, please visit the detailed map application by clicking the link below. You will be taken from the CQSS:2030 website to a powerful mapping application that draws on a richer data set.
In central Queensland
The region’s soils are diverse, and like elsewhere, they reflect the geology and landforms in which they are found. The Fitzroy Basin is a large, lowland basin surrounded by a highland rim. The geology is dominated by large sedimentary basins: the Bowen Basin in the north and the Surat Basin in the south, and the metamorphic New England Fold Belt in the east.
Soil types and properties that support particular agricultural industries in the region include:
- dryland cropping on soils with high water-holding capacity
- irrigated broad acre and horticultural crops on soils with good drainage
- peanuts on friable soils with gravel-free surfaces
- grazing on a wide range of soil types, and beef cattle finishing on soils with higher fertility.
Grazing occurs on 78 per cent of the catchment area and cropping on a further 5 per cent. Both rely on healthy and productive soils. The preservation of good quality agricultural land is an important issue for the region, with competition for land use between the expanding resources and energy industries and agricultural land uses.
Soil erosion is a natural process where wind and rain dislodge soil particles that can move across the landscape and to waterways. Poor land management practices, across all sectors, can result in greatly accelerated erosion processes. With a climate that regularly provides extended droughts, often followed by high intensity rainfall events and floods, maintaining healthy soils and groundcover is important to minimise erosion. An estimated 4 million tonnes of sediment are exported to Keppel Bay and the Great Barrier Reef lagoon annually.
Groundcover is organic material such as crops, grass or leaf litter on the soil surface. Managing groundcover through, for example, long-term sustainable stocking rates and zero-till cropping, are ways to manage soil health and erosion risk.
Salinity, from land use changes such as tree clearing or inappropriate irrigation practices, is an issue in the region. Approximately 70 salinity outbreaks have been identified in the region. Salinity can reduce productivity, damage infrastructure and degrade water quality.
Acid sulfate soils are marine soils that leach acid if exposed to the air. Acid sulfate soils are an issue when low-lying coastal soils are disturbed by development through activities such as excavation and dredging.
Soil fertility decline is an issue in the more fertile and productive brigalow soil types. The natural high fertility of these soils has declined under cropping and grazing systems. Other soil properties that are important elements of soil health and productivity are soil structure, water holding capacity, pH (acidity), nutrients, biology and soil carbon. Land management practices influence these at the local scale.
As well as issues associated with grazing and agriculture, soil can be disturbed and contaminated by industrial, infrastructure or mining activities.
Groundcover responds to seasonal conditions as well as management practices. Average and above-average rainfall in recent years has caused high groundcover levels across most of the catchment, with 84 per cent average late dry season groundcover recorded in 2012 and 2013.
Salinity outbreaks also respond to recent seasonal conditions, as well as land management practices. Soil fertility declines continue to be a significant issue.
Soil erosion and its impacts on the downstream marine environment will continue to be an important issue for central Queensland. Intensification of land use brings with it greater risks to soils. Open-cut mining operations often involve substantial modification of local landforms and soil properties. Intensive animal industries, urban, suburban, industrial and infrastructure development can all impact and contaminate soils. Climate change, with increasing temperatures and changes to the frequency and intensity of extreme weather events, will impact soil health and land management systems.
Soils are a finite and valuable resource and face increasing pressure from a growing population, changes and intensification of land use and climate change. Three strategies are proposed.
First, to protect and maintain the productive soils that support high-value agricultural industries. Maintaining and increasing agricultural productivity into the future relies on the health of these soils.
Second, we must tackle the degraded soils that we have, and ensure we manage soils that are at risk of degradation.
Finally, maintaining groundcover is the most effective way of managing soil erosion risk in the grazing and cropping lands that cover most of the catchment.
A wide variety of soil mapping reports and spatial information is available from the Queensland Department of Natural Resources and Mines.
Modelling of salinity risk has been completed for the region (NRM, 2007).
The Reef Report Card provides annual reporting of the adoption of improved agricultural practices (for water quality benefits) and groundcover, as well as other measures relevant to the health of the Great Barrier Reef.
The Central Queensland Regional Plan (DSDIP, 2013) seeks to resolve land use conflicts between agriculture and resource industries by identifying good quality agricultural land and regional towns’ growth envelopes.
The Queensland Agricultural Land Audit identifies land important to current and future production and constraints to development across the state.
Catchment health indicators
Groundcover is proposed as a generic indicator of soil health and soil management practices. Groundcover is associated with erosion risk and other soil health properties e.g. organic matter, soil structure etc.