Australian farmers and soil scientists are striving to develop more cost-effective, sustainable ways to improve soil quality, replenish depleted soils, rebalance acidic soils, and prevent erosion and loss of topsoil.
Key challenges include:
- the relative fragility of many Australian soils combined with a harsh, highly variable climate
- the relatively low nutrient and carbon status of most native soils (ie prior to any agricultural use)
- scarcity of arable land (much of the most fertile farmland in higher rain fall areas has been or is being lost to development),
- erosion and loss of topsoil due to land clearing, overgrazing, woody weeds and animal pests,
- soils depleted of carbon,
- acidic soils,
- soils polluted by chemicals,
- sandy soils that repel water.
Soil degradation and erosion, acidification, clearing of vegetation and loss of soil carbon all impact sustainability and future productivity. Monitoring and improving soil quality and replenishing carbon stocks, preventing erosion, and working to counter acidification are critical to maintaining healthy, fertile lands.
Strategies for protecting and improving soil include
- strategic planting of native trees and grasses to provide protection from erosion
- controlling weeds and locked stands of woody vegetation that compete with grasses and other beneficial ground cover.
- adopting better livestock rotation systems to avoid overgrazing
- managing crop rotation so as to minimise depletion of soils and restore nutrients (eg rotating with nitrogen fixing crops);
- controlling burrow-digging, soil-eroding animal pests such as rabbits and wombats,
- employing sensor technology that enables accurate monitoring of soil characteristics,
- managing soil moisture and temperature to prevent loss of organic carbon and soil flora and fauna (eg by retaining stubble for shade)
- Minimising the use of chemical fertilisers, pesticides, herbicides and fungicides,
- employing farming practises that replenish soils
- increasing soil carbon with supplements such as biochar
Improving Australia's soils has been recognised as a priority for many decades, resulting in significant public and private investment by State and Federal agencies, CSIRO, all major universities, the Landcare movement and farmers themselves.
The Australian Government’s National Soil Research, Development and Extension Strategy, based on the Stocktake, is intended to make soil RD&E more collaborative and better targeted. It provides information and tools to help farmers better manage their soils.
Australian Government Department of Agriculture, Fisheries and Forestry (DAFF) Soil Carbon Research Program investigates soil carbon and its sequestration in Australia; Filling the Research Gap and Action on the Ground programs support research into and implementation of, abatement technologies and management practices to improve soil carbon and reduce greenhouse gas emissions from the land while supporting sustainable agricultural practices.
The Department also sponsors soil RD&E conferences and symposiums including the:
- Soil Change Matters Workshop
- 5th World Congress on Conservation Agriculture
- Australian Soil Information Symposium
- 3rd Sustainable Phosphorus Summit
- 5th Joint SSA and NZSSS Soil Science Conference
- 19th World Congress of Soil Science
Improving soils data and information
DAFF’s Sustainable Resource Management Division (SRM) contributes to The Australian Collaborative Land Evaluation Program (ACLEP), an initiative jointly funded by the government and CSIRO to “improve the collection, management and dissemination of nationally consistent data and information on soil and land resources”.
The federal government’s Stocktake of Australia also examined currently-available information about soils in Australia. Appendix 5 of the stocktake, the National soil information base, includes a soils mapping overview, soil profile data and a soils archive.
Improving soils management
The Department of Agriculture supports several projects aimed at improving agricultural land management practices and encouraging innovation in soil management in areas such as reducing soil loss through wind and water erosion, improving groundcover, reducing the risks of soil acidification; and improving farm productivity and profitability.
Monitoring soil condition
Prepared by CSIRO with state and territory agencies, the National Soil Condition Monitoring for Soil pH and soil carbon: Objectives, Design, Protocols, Governance and Reporting outlines a 20-year project monitoring long-term changes in soil pH and soil carbon through time.
The Australian Bureau of Statistics (ABS) Water Account Australia (WAA) for 2011-2012 aggregated a broad range of information on water use from standing stocks such as rivers, groundwater and dams, but failed to include measurements of soil water as recommended in international water accounting standards.
The United Nations’ System of Environmental-Economic Accounts – Water (SEEA-W) defines soil water as “water suspended in the uppermost belt of soil, or in the zone of aeration near the ground surface, that can be discharged into the atmosphere by evapotranspiration”.
Soil water is a significant water resource, accounting for more than 325,000 GL in 2011-12, Its use impacts standing water supplies, reducing run-off into dams and rivers, percolation into groundwater resources, and biodiversity for native species. Soil water estimates will be included in the ABS’s 2012-13 WAA, due for release in late 2014.
Soil water is described in both the SEEA-W and SEEA 2012. The ABS’s method prefers the SEEA 2012 framework for measuring soil water abstraction, which excludes evaporation and water retained in the soil.
Soils, grazing and vegetation
Through SRM and ABARES, the Department of Agriculture is working with state/territory agencies and CSIRO to develop national monitoring of groundcover in the rangelands in the grazing industry and ascertain whether changing land-management practices help improve soil condition.
CSIRO projects underway include planting legumes for their non-nitrogenous, break-crop effects; and using revegetated saltland as grazing land. CSIRO researchers are also investigating the role nitrogen-fixing soil bacteria on plant roots may play in improving soil and plant productivity.
Australian Government Department of Environment’s soil policy (on soil degradation and erosion, acidification, clearing of vegetation and loss of soil carbon) http://www.environment.gov.au/science/soe/2011-inbrief/land#ib5
Commonwealth Environmental Water Office
Australian Government Department of Environment on water
United Nations’ System of Environmental-Economic Accounts – Water (SEEA-W)
Australian Bureau of Statistics (ABS) Water Account Australia (WAA) 2011-2012
Stocktake of Australia’s investment in soils research, development and extension – a snapshot for 2010–11
National Soil Research, Development and Extension Strategy
The Australian Collaborative Land Evaluation Program (ACLEP)
CSIRO water-use projects