The South Coast region covers approximately 8.6 million ha, most of which is classified agricultural. There is also a significant pastoral/rangelands area extending north of Salmon Gums in the region’s east.
Healthy soils support the region’s biodiversity and its land-based primary production, including agriculture and forestry and contribute to sustainable waterways and marine environments by avoiding erosion, nutrient export and sedimentation.
Primary production contributes strongly to the region’s economy and social fabric but faces significant threats if major efforts are not made to develop and manage more sustainable farming systems. Without effective management, soil and water will suffer accelerated decline, which in turn will affect the stability of other South Coast NRM themes.
While agricultural practitioners may desire a short to medium term return from NRM investment, consideration also needs to be given to the medium to long term ramifications of not acting, where the decline of resource conditions is the likely outcome. This intrinsically links all NRM practitioners to have an interest in sustainable land use practices.
Negative impacts of agricultural activities such as sedimentation, acidification, erosion and nitrification, directly or indirectly affect all other South Coast NRM themes, so working and communicating across and between theme areas is essential. The achievements of farmers who actively engage in NRM is applauded and acknowledged. The need for other agricultural practitioners to follow suit is essential to ensure improvements across the landscape.
The link between best practice land management and productivity needs to be continuously promoted across our region. One of the threats to sustainable land use is hydrological change resulting from the clearing of native vegetation and the replacement of deep-rooted perennials with lower water-using (mostly annual) species, which is associated with a significant salinity risk in parts of the region. Hydrological change and salinity are significant threats to biodiversity and to the region’s water resources as well as to agricultural production and are largely a result of past land management practices.
The most effective responses to manage hydrology changes are likely to be through the development and widespread uptake of sustainable primary production practices, together with more specific revegetation and surface water management or drainage where feasible. Salinity mapping for the region is shown in the Western Australian Land Information Service Atlas at www.walis.wa.gov.au Other major risks to the region’s soils are subsurface acidity, water repellence and phosphorous export. Wind erosion, waterlogging, structural decline and subsurface compaction are also risks but are rated lower at a regional scale. This does not imply these risks are not of major significance at a local level in parts of the region.
NRM risk to agricultural production by sub-region
Source: Department of Agriculture and Food WA (2006).
Sub-surface acidity is a significant threat to agricultural land condition because of the depleted buffering capacity and inherently low pH of the sandy top soils. The addition of acidic fertilisers, removal of produce and nitrogen leaching is generally acidifying and occurs extensively.
There is limited information about the significance of the off-site impacts of soil acidity, but these are most likely to include reduced plant growth and increase in the risk of other threats, particularly salinity, wind erosion and phosphorous export. Water repellence is considered to be a high risk to agriculture, especially in areas with sandy topsoils such as the Esperance Sandplain, Albany Hinterland and Fitzgerald Biosphere sub-regions.
Applying clay is the most common and effective treatment for water repellence, but the cost of application rates required to satisfactorily ameliorate water repellent sands can be substantial. New technology such as ‘spading’ or ‘variable rate spreading’ are likely to provide better management opportunities in the region. The impact from water repellence includes reduced water infiltration, which can exacerbate other risks, including nutrient and chemical loss in run-off and water erosion. The increased risk of wind erosion is also an issue, resulting from bare areas created through poor pasture germination and difficulty in managing weeds. Phosphorus export has been assessed as a high risk for soils in the Albany Hinterland and Kent-Frankland sub-regions, largely due to the low relief landscape. Like salinity, phosphorous export is largely a result of land practices rather than an inherent characteristic of the region’s soils and is also associated with significant off-site impacts including eutrophication of waterways and wetlands.
This has been observed at the Wilson and Torbay inlets and Oyster Harbour, all of which have significant levels of eutrophication. Salinity will have a high impact on agricultural production in the Fitzgerald Biosphere as it will develop in a short timeframe with a new equilibrium reached before 2020. A moderate impact of salinity is expected in the Albany Hinterland, Esperance Sandplain, Kent-Frankland and North Stirling Pallinup sub-regions due to a longer timeframe until equilibrium. For the Esperance Mallee sub-region, salinity should have a low impact over a longer timeframe.
The impacts of salinity on water resources and biodiversity is predicted to be significant, particularly for areas of high public and conservation value. High salinity and nutrient levels, impact on the riverine systems flowing from agricultural land into and through conservation reserves. These polluted waters are also likely to have impacts on wetland, estuarine, coastal and marine systems.
Land use and planning
The majority of agricultural land is cropped, for wheat, canola and other grains, or under pasture. In recent times more than 162,000 ha of timber plantation and around 4,000 ha of viticulture and various forms of horticulture have been planted. Beef production occurs in the region’s south and there are a number of dairy farms in the Albany Hinterland and Kent-Frankland. A small but growing number of diverse enterprises are beginning to appear, including inland aquaculture, cut flowers and native seed production, venison farms, tourism ventures and experimental truffle production. There is also a noted increase in organic and biodynamic farming enterprises - ranging from grains to beef, dairy, poultry and vegetable production.
The establishment of tree crops over the past decade, particularly in the higher rainfall areas, has marked a significant change in the region’s land use, with the largest areas being turned over to blue gum (Eucalyptus globulus) plantation. A woodchip plant at Mirambeena north of Albany and export facilities at the Port of Albany are now significant contributors to the region’s economy. The global financial crisis and its impact on the paper industry has seen a decrease in the establishment of tree plantations and the community’s confidence in them as a sustainable industry has been adversely affected. A recent land use trend within the region’s medium rainfall zones is the establishment of tree plantations for carbon sequestration.
This industry is likely to continue to grow over the coming years. Currently, these plantations are large scale monoculture plantings of species such as oil mallee and sugar gums with a timeframe of 75 plus years in the ground. While this land use has the potential to deliver many positive NRM outcomes such as reduced recharge, wind erosion control and improve the connectivity and resilience of native habitats, there is the possibility of negative environmental and social impacts. These may include the decline of small rural towns due to people selling their land and leaving the region; the loss of productive agricultural land for food; an increase in feral animals and weeds within plantations and an increased risk of fire.
To avoid these negative impacts and gain the largest benefit from this land use, adequate planning controls need to be put in place. It is important that complementary outcomes such as biodiversity and the strengthening of ecological links are achieved. A commercial wood pellet manufacturing operation was successfully established in Albany in 2008-09. This operation adds value to the Great Southern’s timber industry by using residue from harvested plantations and creating small wood pellets for use in overseas energy markets. A proposed green power station is still progressing through the planning stage for construction in the Albany area. This system would also take the residues from plantations; wood processing and municipal and agricultural green waste products. Plantings of Monterey pine (Pinus radiate) began in 1987 and there are now around 3,500 ha established within an 80 km radius of Albany.
Maritime pine (Pinus pinaster) plantings commenced in 1997 and there are now 2,500 ha established within 120 km of Albany and 2,000 ha within 160 km of Esperance. Some of these plantations were harvested in 2005 and contribute to the export of soft timber saw logs through the Albany Port Authority. In 1999, the planting of sandalwood (Santalum spicatum) as a long term viable industry, commenced. Research into sandalwood establishment techniques has been undertaken by scientists working with South Coast NRM, Greening Australia, the Centre for Excellence in NRM and the Department of Agriculture and Food WA. Incentives for land managers to establish sandalwood for commercial and biodiversity outcomes have been available under our Southern Incentives devolved grant and are being further developed and applied by Greening Australia through the Gondwana Link program.
Integrated Farm Forestry makes a positive contribution to rural and regional landscapes, environments and communities, by helping to control the rising water table which threatens biodiversity, water supplies, agricultural land and infrastructure assets. When farm forestry is integrated successfully with agricultural practices, it provides business diversification and employment in rural areas.
Appropriately placed trees are assets that provide shelter for stock, crops and pasture. Local planning strategies and town planning schemes administered by local government and the Western Australian Planning Commission (WAPC) have the potential to be powerful mechanisms for achieving regional natural resource outcomes if integrated with NRM goals. Active participation and advocacy is essential to ensure planning tools deliver long term NRM outcomes for the broader community. Planning for the peri-urban interface needs to be carefully managed to prevent loss of prime agricultural land and to reduce conflict between land uses. Equally, planning for biosecurity, climate change adaptation and NRM innovation will become increasingly important.
In 2008 an internet NRM-local government planning support tool was launched to support the integration of natural resource management principles into local land use planning (www.eksa.com.au/scnrm-planningtool). While this website receives multiple hits, the online tool needs to grow to accommodate new land use planning modules and options for various levels of community in the region. Soils have been extensively mapped at the landscape level at varying scales to assist with regional planning - these range from 1:50,000 to 1:250,000. The information is supported by a comprehensive map unit database comprising more than 200 attributed units and some 20,000 data/profile observation points.
Some soil-landscape mapping areas were mapped in finer detail during the Southern Prospects 2004-2009 investment phase. Additional sampling points and aggregated data have also been placed on community websites such as www.soilquality.org.au for easy comparison of soil qualities across the region. While soil-landscape mapping is still at a level unsuitable for paddock-scale planning, the mapping and associated database has assisted in providing information for analysing the risk of potential on-site land degradation to soils and agricultural land assets.
These risks are reported on the basis of Agro-ecological Zones (AeZs) in the NRM sub-regions which are based on common soil, hydrological, geological, geomorphological, climate, biological and vegetation differences. Radiometric digital landscape mapping has allowed for the creation of better detailed maps of some existing broadscale land resource surveys in priority or strategic areas. This will assist in improving base information and our understanding of on and off-site land degradation issues.
Rapid Catchment Appraisals (RCA) or focus catchment studies have been carried out by inter-disciplinary study groups. RCA reports include catchment analysis - climate, geology, soils and landforms, hydrogeology and salinity risks, as well as information on appropriate management options for the catchments. Many of the publications released between 2002 and 2005 are likely to require revision. The Bremer Strategic Catchment aligns with one of the RCA study areas and a snapshot review of this area is currently being prepared to show the effects of NRM investment.
Salinity and groundwater
The former State Salinity Strategy framework recognised the over-arching management goals of recovery, containment, and adaptation. It also recognised the appropriate areas for these approaches needed to be based on an analysis of public and private assets and the threats, as well as an assessment of the technical and economic feasibility of management.
The Government of Western Australia endorsed principles developed by the State Salinity Council for the strategic investment of public funds into managing salinity and these were incorporated in the development of the Salinity Investment Framework (SIF). State of the environment reporting indicates salinisation is still a significant issue, with about 1.1 million ha in the south-west land division affected and more than 14,000 ha of land lost from production each year. Suggested responses include a continued implementation of the State Salinity Strategy and monitoring to determine the extent and changes to salinisation levels. Hydrological balance investigations have been undertaken for each of the strategic catchments – the Fitzgerald, Frankland-Gordon, Kalgan, middle Pallinup and West rivers, Lake Warden and the Stokes, Torbay and Wilson inlets.
The analysis identified priority sub-catchment and perennial planting areas where actions would be most likely to achieve recharge reduction and contain groundwater rise. While the monitoring timeframe remains too short to draw any firm conclusions, review of 2009 bore data from the Bremer River Strategic Catchment suggests the increase in perennial pasture plantings across since 2004 have assisted in lowering the groundwater table in some areas. This is a successful outcome of promoting perennials as one tool for reducing recharge, containing rising water tables and addressing waterlogged soils.
Waterlogging, water and wind erosion, structural decline and subsurface compaction have all been assessed as posing a moderate to low risk at a sub-regional scale, although these issues may pose higher risks to agricultural production at a property or local level.
Management options to address the main risks to soil health in the south-west were identified and their effectiveness evaluated in 2008. These options and their implications are similar for most of the South Coast region and farmers have already adopting many of them The management of acidity in agriculture is largely dependent on soil testing, appropriate fertiliser use and the application of lime or dolomite.
While incentive schemes have increased the application of lime within the region in recent years, its use is still less than what is considered optimal for agricultural production. Regional studies undertaken in 2008 and 2009 compared the soil acidity condition for WA’s northern and southern agricultural regions. This investigation suggests that due to the cost and limited availability of lime, acidification could only be reduced by between 5-30 per cent. This is mostly due to nitrate leaching exacerbating acidity levels in high rainfall areas.
However, steps can be taken to reduce acidification rates including the selection of non-acidifying nitrogen fertilisers and the reduction of leaching through split-nitrogen applications.
These activities are not likely to remove the need for lime application to soils that require remediation. There are social and environmental issues associated with the supply of appropriate quality lime for agriculture, as well as issues of competition with the mining and construction industries. The Department of Industry and Resources is working towards a State lime supply strategy. Issues of supply and demand need to be addressed and included in planning for the region to ensure the conservation values of supply areas are not compromised.
The mapping of acid sulphate soils has improved, but many gaps in our knowledge and priority areas remain and need detailed assessment to confirm the presence, or degree of acid sulphate soils.
From regional reconnaissance, the incidence of acid sulphate soils is low and generally restricted to the lower coastal plains and estuarine areas. Where these soils do exist, disturbance and exposure to air has a high risk of release of acid and pollutants, such as heavy metals. Outcomes from a statewide project resulted in a number of useful publications discussing the protocols for appropriate management of acid sulphate soils for agricultural practices in the region. Soil fertility and organic carbon content decline were not assessed for the region in the previous investment phase because of the inadequate information base.
However, baseline and benchmarking surveys for soil organic carbon content for representative South Coast soils has been underway since 2007 by the Australian Farming Future Climate Change (Better Soil Management) Research Program.
This has assisted with the detailed investigation of large studies at Esperance-Condingup; Woogenellup-South Stirling and Kojonup. This activity between the Australian Government’s Department of Agriculture, Fisheries and Forestry, UWA and DAFWA measures ‘actual’ carbon content and models ‘potential’ carbon for key soils by land use in these three study areas. This information will allow for the development of management options to store carbon and assist in mitigating the potential impacts of climate change.
Best practice management
Two of the most beneficial practices employed to improve the sustainable management of land are whole of farm planning, including careful matching of land uses and practices to land capability and the more widespread use of perennial species. Most of the region is ideally suited to perennial species due to the high probability of summer rainfall. The use of perennial species, including trees and pastures, to restore or maintain hydrological balance has been identified as a preferred option for managing salinity, but can also assist in reducing or avoiding nutrient export, subsurface compaction, water repellence, waterlogging and wind and water erosion. There is also likely to be increasing pressure for primary production industries to demonstrate their production methods are sustainable and are using best management practices as part of accredited production systems.
Environmental Management Systems (EMS) and land condition monitoring is being promoted in the region by the Best Farms project team. A number of EMS workshops have been delivered with the target audience being mostly semi-rural land holders.
About 48 properties are operating as organic farming businesses producing beef, mixed vegetables, wine, olives and grains, with 20 of these being certified under recognised organic standards. The range of agricultural data from the Australian Bureau of Statistics provides information on the level of soil ameliorants usage and can be used to infer regional soil conditions and trends. However, these are insufficient to establish definitive benchmarks on land condition in high risk areas. A 2010 statewide survey measured changes in farming practices between 2009 and 2010 and prior years to 2007.
It showed landholders were increasing soil sampling and monitoring of soil conditions, such as compaction, acidity and water repellence and concluded:
- Forty-five per cent of South Coast rural landholders regularly monitor their water table levels compared to 24 per cent in 2009.
- Sixty per cent of South Coast NRM region landholders increased the implementation of non-irrigated perennial pastures, compared to 46 per cent in 2008/2009 as a tool to recover or contain groundwater level rise, while also seeking to adapt to the region’s climate variability by increasing groundcover and ‘green-pick’ pasture leading into dry seasons. These actions are helping to reduce the risk of wind erosion and to better use excess soil moisture to reduce seasonal waterlogging.
- In pastoral areas there was an increase to 58 per cent of landholders excluding their stock from areas impacted by land degradation in 2009/2010, compared to 43 per cent in 2009.
- Approximately 50 per cent of landholders test their topsoil annually However as there is no regional database of the results, there is no clear evidence for the trends in soil fertility and other factors. Anecdotal evidence remains the only source of soil testing results, provided through follow-up workshops where some landholders are willing to share their analytical results.
Climate change and seasonal variability
IN 2008, the Commonwealth Scientific and Industrial Research Organisation (CSIRO) projections for primary production in the south-west of WA, stated some agricultural crops may benefit from higher Co2 concentration, but protein content of grains is likely to decline by between 4 - 14 per cent, assuming there are no management adaptations.
Frost-sensitive crops, such as wheat, may respond well to some warming, but increased hot days and less rainfall may reduce yields. Adverse effects for agriculture include reduced stone fruit yields in warmer winters, livestock stress and an increased prevalence of plant diseases, weeds and pests. Unfortunately, there are likely to be knock-on effects to NRM assets caused by the uncertainty and reduced production in agricultural areas.
Adaptation strategies can reduce the impacts of climate change. In 2007, the Australian Bureau of Agricultural and Resource Economics estimated that adaptation measures can reduce the economic impacts of climate change on agricultural production by approximately half. CSIRO provided an overview of the impacts, options and priorities of adaptations to climate change in Australian primary industries, with adaptations issues classified according to industry and region. Issues such as the need for climate data and monitoring and the acceptance of uncertainty, are common across industries.
Impacts of climatic change on primary production for the Mediterranean agro-climatic zone
Cropping: Potentially, large reductions in rainfall will reduce yields markedly, leading to flow-on effects to regional communities and businesses. Cropping will become more challenging at the current dry margins but may expand into areas which are currently generally too wet for regular cropping. There may be a reduction in the risk of dryland salinity. A range of adaptations, particularly aimed at improving crop water management may be required.
Viticulture: Seasonal shifts to wine grape vines may result in ripening in a warmer part of the season. Quality will be affected. Grapevine variety suitability will change and planting of longer season varieties to fit the warmer climate will reduce any negative impact. Water may become a limiting factor for grape production in these regions.
Horticulture: Timing of crop cycles for annual horticulture crops may be hastened requiring crop scheduling and marketing responses. Reduction in chilling over winter, may affect suitability for growing of some perennial fruit crops. Increased frequency of extreme temperature events resulting in undesirable physiological responses must be managed. Water availability and security of supply is essential, especially for perennial horticulture.
Forestry: Bioclimatic analysis should be used to identify particularly vulnerable E. globulus, Pinus radiata, Pinus pinaster and oil mallee plantings so these can be monitored to provide early warning of any problems. Many eucalypts in native forests have narrow climatic ranges and may be particularly vulnerable to climate change.
Intensive livestock: Irrigated dairy is likely to be impacted by reduced water allocation and increased temperatures. Landscape rehydration through wetland creation is a priority. Heat stress issues for livestock. Increased energy demands for cooling production sheds, increased demand for new energy efficient designs or retrofitting of existing sheds.
Water resources: Median runoff projections are for moderate decreases for the south-west. Increased demand and reduced supply is a substantial issue. Catchment risk score is moderate to very high.
Invasive species: Invasive species not currently widespread may become more common under conditions created by climate change. ‘Sleeper’ species need to be monitored to ensure they can be managed to prevent ‘break out’. Under climate change condition, native species or ecosystems under stressful conditions may be replaced by invasive species.
Climate Change adaptation options in agriculture and forestry
Cropping and horticulture
Alter the variety or species planted to those with more appropriate thermal, time and vernalisation requirements and/or with increased resistance to heat, frosts or drought.
Alter application times and amount of fertiliser or irrigated water to maintain growth and quality.
Change timing and location of cropping activities.
Enhance water efficiency by using zero tillage, retaining crop residues and changing planting patterns.
In lower rainfall areas, enhance water management by implementing or expanding water harvesting technologies and acting to conserve soil moisture; in higher rainfall area, improve water management to prevent waterlogging, erosion and nutrient leaching.
Enhance pest, disease and weed management practices through integrated pest and pathogen management and using more pest and disease resistant varieties.
Reduce potential for soil erosion by retaining stubble, reducing fallow times etc.
Adapt annual production cycle to better match feed production.
Change pasture rotations and modify grazing times.
Alter forage and animal species or breeds.
Provide supplementary feeding.
Provide alternative housing infrastructure – for example winter housing or increased shading.
Change or improve feed concentrates.
Change management intensity, harvesting patterns and rotation periods as appropriate.
Select a variety of species.
Manage landscape to reduce fire risk.
Undertake prescribed burning of native vegetation to reduce vulnerability of native and planted vegetation to fire damage.
Introduce practices which ensure conservation and wise use of water resources.
Use seasonal forecasting to reduce production risk.
Diversify farm income by integrating other farming activities or increasing off-farm income.
Move to alternative income sources outside of agriculture.
Minimise high input costs in high risk area or time periods.
Have emergency response plans in place for fire, flood, hail and heavy rain etc.
Offset increased costs of managing climate change by reducing other costs.
Use financial risk management tools or options to manage risk – for example futures contracts, water trading, carbon offsets, income stabilisation, and insurance.
Spread risk through multiple holdings in different climatic regions.
Increase resilience of land systems through land care and stewardship initiatives.