Natural resource management
There have been two major studies of the natural environment at Tocal, they have helped define the important features of the environment, and identified areas for future studies.
The policies identified for the environment are:
- That further ecological studies be undertaken
- That monitoring of ecological processes be undertaken to evaluate the success of environmental programs
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Here we consider each of the natural resources in turn, remembering that they co-exist and interact in a landscape.
Climate
Two climate extremes at Tocal, a flood in 2001 on the left and the 1991 drought on the right
Climate and weather affects all operational decisions at Tocal. Some of the influences are:
- strategic and tactical seasonal decisions take into account climate variability
- stock numbers, pasture management and irrigation frequency are adjusted for seasonal conditions
- seasonal forecasts are used in planning, for example, de-stocking and feeding policies in times of drought
- dry seasons will cause major revegetation plantings to be held over
- flood warnings are used to determine pump removals and stock movements
- shade and shelter is planned for livestock in all paddocks
- ventilation of poultry sheds is designed to take into account weather extremes
- timing and type of cultivation for sowing must take into account the chances of erosive rainfall occurring, especially in summer storms
- a general trend of climatic warming has been recorded at Tocal, which appears to be part of a global phenomenon.
The policy for climate is:
That climate variability and extremes be taken into account in all operational planning in the college land. Seasonal forecasts and reference to the climatic record detailed in the publication 'The Climate of Tocal'.
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More detail on the climate of Tocal is available in the climate section of the e-farm.
Soil
Soil is the basis for agricultural production and vegetation therefore protection and improvement of the soil is our aim. Understanding the nature of the soil allows us to use the land in the best possible way. More detail about the soils on Tocal is available in the soils section of the e-farm.
The first policy for soils is:
- Soil will be kept healthy and fertile by appropriate management.
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The following practices aim to maintain or improve soil health:
- Maintain ground cover at a minimum of 90%
- Fertilise to increase production from and persistence of introduced, productive species and maintain high organic matter levels
- Use land according to its capability and use information such as soil tests to assess each paddock
- Ensure the health of soil microbes and beneficial organisms by reducing compaction and by maintaining soil fertility, an efficient water cycle, suitable pH levels and recycling of nutrients to encourage dung beetles and earthworms
- Ensure the soil structure remains intact by preventing overgrazing, soil compaction and inappropriate cultivation and by preventing erosion that exposes sodic subsoils
- Match the water entering the soil profile with healthy plant growth so waterlogging and soil salinity problems do not emerge
The second policy for soils is:
- Soil problem areas will be identified, mapped and remedied by conservation works or management.
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Existing soil problems or potential problems will be addressed by the following:
- Grade banks protect farm roads from erosion. To remain effective they must be kept in good repair and protected from degradation by stock trampling or vehicle passage.
- Where gully erosion has occurred in the past, farm dams have been constructed to stabilise the area. To ensure they remain effective the areas will be fenced off from stock access as funding allows.
- Soil structure declines through compaction by grazing animals, inappropriate cultivation or overcropping and by overgrazing. Use of minimal tillage cropping in appropriate areas, cropping rotation and careful management of grazing will minimise soil structure decline.
- The coastal soils of Tocal are naturally acidic and acidity increases with the use of introduced pasture species, especially legumes, and the use of fertilisers, especially nitrogen. Soil tests are used to monitor soil acidity levels and fertilisers are carefully chosen to reduce the risk. Lime is applied to paddocks that show levels of lower than pH 5.5 Calcium-chloride (CaCl2)
- Few soils on Tocal show signs of salinity. Healthy perennial pastures with adequate treed areas will help ensure this does not become a problem.
- Some areas around the Tocal Homestead wetland have been identified as Potential Acid Sulphate Soil areas. Currently there is no evidence of acid sulphate, however these areas will be permanently reserved as wetland and managed so they are never drained or excavated to expose the acid sulphate soil problem.
- Soil tests are used to monitor soil fertility. Fertilisers are only applied according to soil test results, where economic responses can be expected and off-site impacts can be avoided. Soils that are infertile, shallow or not sown to introduced species are not fertilised and grazing of native species is limited and strategic - designed to maintain the natural vegetation cover without losing of degrading species.
More detail on the soils of Tocal is available in the soils section of the e-farm.
Water
Bona Vista lagoon: a stark almost bare landscape in 1981 and right as
it now appears, heavily treed with an abundance of shade in the
adjacent paddocks.
Reliable and high quality stock water is required for each paddock on Tocal. The property is fortunate in having areas of wetland, lagoons, creeks and the Paterson River as natural water resources. These water bodies, however, can be easily degraded by poor management, and the results of past misuse are evident.
In order to protect the natural water resources:
- Water sources will be protected from degradation and managed to maintain high quality water and a stable riparian zone
- A policy of providing alternative water sources in the form of dams and troughs rather than relying on the natural water courses will be implemented
Irrigation water is a vital component of the Tocal dairy. Water is pumped from the Paterson River which is tidal at Tocal. Water quality for irrigation is usually satisfactory, although in times of drought, salinity readings may rise to unacceptable levels.
The policy for irrigation is:
- Irrigation will be applied efficiently: matched to plant and soil type, to ensure that crop and pasture growth is not restricted by lack of supply, and that excessive watering does not add to groundwater supplies.
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Protective works have been carried out on several fragile wetlands, including the Bona Vista lagoon (beginning in 1981), wetlands in Racecourse paddock, and the establishment of an artificial wetland/dam in Railway paddock.
The policies on wetlands are:
- More wetlands are to be protected and rehabilitated through fencing and plantings
- Dam building will incorporate wetland areas
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The health of the waterways on Tocal have a direct effect on the water quality of the Paterson River.
- Major waterways will be progressively fenced off and managed for biodiversity
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The fenced off areas will be managed to reduce weed invasion and planting of native species will be carried out if natural regeneration fails. Alternative arrangements for stock water and shade will be made.
A final policy for protecting water resources is:
- Water problems will be identified, mapped and managed to improve the condition of the water and the surrounding landscape.
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Planning of farm enterprises and site works, as well as drought plans and water conservation plans must ensure there is adequate water available for stock
Water quality issues must also be taken into account including muddy water, saline water, and water contaminated with animal manure or chemicals entering water sources. Protective works on the Tocal wetlands will ensure that they are as efficient as possible at filtering some contaminants; restricting stock access to dams will reduce pollution of dams, as will careful application of fertilisers so the nutrients do not enter the dam; and finally buffer strips around all waterways will improve water quality by preventing erosion, removing stock and filtering the inflow of water.
Vegetation
Progress on Webbers Creek; removal of a stand of Giant reed in 1995 at top; planting out the site in 1996 at centre; and the same view in 2004
Protecting and increasing biodiversity is in every farmer's best interests. Mantaining a wide range of native plants and animals in an agricultural environment maintains the health of an ecosystem meaning it is more resistant to invasion by pests and diseases. A healthier ecosystem is stronger and more productive.
Carefully thought out tree planting can be important to improving biodiversity and pasture and livestock production.
The policy for increasing biodiversity is therefore:
- That tree planting be continued to achieve a more balanced landscape.
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Pasture and grazing management on Tocal identifies areas to be pasture improved, areas for production within the land's natural capacity, while other areas are designated as habitat areas. This approach provides for land with high potential to be improved and grazed as well as for habitat areas within these paddocks. Those areas will also provide shelter for livestock.
The policies for pasture management and grazing are:
- That the best land be improved and maintained at a high level of production.
- The use of artificial fertilisers will be closely monitored and targeted.
- A grazing strategy will be developed for the beef pastures.
- Native pasture areas will be encouraged through strategic burning and grazing, and minimal use of fertiliser in designated areas.
- Shade and shelter will be provided in all grazing paddocks.
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Substantial areas of existing bushland are found in Ridge, Bush and Top Bush paddocks. These areas are managed to maintain biodiversity and tree cover. Maintenance of tree cover will also retain trees with hollows which are important for many breeding birds and critical habitat for many animals; it will avoid erosion in steep areas; and identify areas where selective thinning can suuply some on farm uses of hardwood species.
The policies for managing tree cover are:
- That there be minimal felling of old growth trees.
- That only selective clearing of fencelines in bushland areas be carried out.
- That current timber resources be classified and managed for both timber production and habitat purposes.
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Management of vegetation on Tocal provides for habitat for animals, birds, insects and fungi. Rotting, hollow timber and dead standing trees and rocks provide important habitat and will only be removed for safety or efficient paddock management. Wildlife also need to move around the property safetly. To this end a network of wildlife corridors are being planted to encourage wildlife to range from riparian zones to the top of ridges. Added benefits are seen in reintroducing understorey species, removal of livestock from creeks and protecting pastures with windbreaks.
The policies for maintaining habitat are:
- That dead trees, fallen timber and rocks be left in place
- That wildlife corridors be constructed of left inact in the grazinfg landscape.
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Fire is an important and useful tool in manageing biodiversity and controlling hazards. More research into the use of fire is needed for a policy to be set. Any burning policy will involve conflicting demands, and will need some compromises to be agreed on.
- A plan for strategic burning of bushland areas will be developed.
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Weeds can cause problems ranging from nuisance value to serious threats to production and biodiversity. Tocal is in a warm temperate area with a wide range of tropical and subtropical weeds. Appropriate grazing management is the key to controllling many weeds in pastures. A weed control strategy will be developed to target weeds in their location as well as annual control measures.
- African Olive (Olea Africana syn. Olea europaea subsp Africana)
- Balloon Vine (Cardiospermum grandiflorum)
- Water hyacinth (Eichornia crassipes)
- Lantana (Lantana camara)
- Green cestrum (Cestrum parqui)
- Fireweed (Senecio madagascariensis)
- Giant Parramatta Grass (Sporolobus indicus var. major)
- Thistes (various).
The policy for weeds is that a weed risk assesment will be completed.
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Organisms
Small family groups of kangaroos are common close to the Homestead and Campus
Other organisms apart from vegetation contribute to the biodiversity of a landscape. They range in scale from wildlife such as kangaroos and dingos to micro-organisms that are vital for soil and plant health. The also vary greatly in their effects: some organisms are toxic to plants (some fungi and bacteria) or feral to the land (foxes and rabbits) while others provide great benefits (earthworms and mycorrhizae or 'friendly fungi').
Encouraging beneficial organisms. Maintaining a range of native animals in the local ecosystem adds to biodiversity. The more diverse the ecosystem, the less susceptible to pests and diseases it is. The populations of birds and small animals that directly control insect numbers contribute directly to grazong production. The place of kangaroos and wallabies is more debatable. Previous studies suggest local kangaroo numbers are fairly stable, and do not pose a threat to grazing productivity. Indeed, their presence adds to the ambience and tourism potential of Tocal.
- The policy for encouraging beneficial organisms is that native wildlife continue to be protected.
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Dealing with problem organisms. At various times feral animals pose a threat to the land and to livestock. The threats include wild dogs (including dingos), pigs, rabbits and foxes. Where necessary, control measures are implemented. Control campaigns are conducted according to strict guidelines, following advice and recommendations from the Rural Lands Protection Board, and safety (warning) signs are displayed at these times.
Other problem organisms may include diseases in plants or animals, insect attacks on pastures or crops or parasites in livestock. None of these poses a major threat, although the risk of exotic diseases is always present for Australian agriculture. The protocols and recommendation of the Department of Primary industries will be followed for the control of any of these organisms, including cooperating and communicating with adjoining landholders.