Summary:
Sustainable agriculture can only be attained through efficient land use, increased productivity and yield, research and planning.
1.1. Apply the Australian land capabilities system to the local area in order to compare existing land use to that suggested by a land capability assessment to ensure sustainable land use.
To decrease land degradation farmers and planners have developed land capability classification systems to help land users decide what their land is most suitable for. Management recommendations are made for each land capability class to ensure sustainable practices.
The 8 point land capability assessment measures the capability of the land for grazing and cultivation.
The School Dairy System has a capability of one and in some places two. Very few limitations occur with this capability and the land can be used for a variety of uses. Most of Sydney areas are flat and are used for urban areas. Places with small pockets of rural land including Windsor and Richmond with capability of one and two. The dominant activity here is turf farms, vegetables and dairies.
For a sustainable farm, the area needs to be used according to its capability. This allows it to be productive over the long term. As sustainability is the profitable production of quality food and fibre, whilst ensuring resources and other sectors of the environment are maintained or enhanced for future generations and other sectors of the community.
Although capability is major measured by slope other factors influence it such as soil characteristics, physical limitations, existing erosion etc.
Land Capability Classifications
Land capability one- Land is suitable for a variety of uses. Where soil are fertile, this is land with highest potential for agriculture and may be cultivated for vegetable and fruit production, cereal and other grain.
Land capability two- usually gently sloped, with potential for production of crops on fertile soils. Prime agricultural land
Land Capability three- Generally used for the production of the same type of crops as one, but productivity will vary depending upon soil fertility. Generally fair to good agricultural land, as soil erosion is often a problem.
Land capability four- limitations such as slope, erosion, rocks, climate or a combination of these. Generally grazing land.
Land capability five- Not suitable for cultivation n regular basis due to same limitations as four.
Land capability six- Productivity will vary due to the soil depth and fertility. Less productive land, used by hobby farmers.
Land capability seven- generally steep slops, shallow soils and or rock outcrop. Minimum grazing, with high levels of tree cover is recommended.
Land capability eight- unusable land for agriculture such as cliffs, lakes or swamps. These can be used for wildlife refugees, national and state parks and scenic areas.
1.2 Discuss the effects of soil degradation on agricultural productivity and sustainability
AGRICULTURE PRODUCTIVITY:
Reduced Productivity. In Victoria and NSW 12-19% of irrigated land is affected by salinity. This is reducing the amount of land available for agriculture as it is hard to work in land with high salt levels.
Reduced Profitability. Erosion is estimated to cause a loss of $300 million per year in lost agricultural production. Acidity levels are also estimated t be same due to lost production.
Increase levels of inputs and costs.
For salinity to be fixed areas need to be fenced off, trees replanted and purchase of salt tolerant plants. While this is improving there is loss of production as stock and crop can not access land. there is a need to alter irrigation practices.
For erosion, fencing off areas, replanting tees and vegetation need to be incorporated. While this occurs there is a loss of production, increased herbicide cost and machinery changes are needed. Management needs to change.
For acidity, high levels of lime need to be added, tolerant species, fencing off areas, fertilizer application evaluation, soil testing all needs to occur. there is reduced profit due to lowered production and management need to change.
SUSTAINABILITY:
Sustainable agricultural practices have been designed to lessen the effects of agriculture and halt repair or maintain the level of soil degradation. Past management of land has led to its degradation including erosion, acidity, salinity, soil structural decline and decreased water quality. An increasing amount of farmers are adapting to sustainable farming practises. Some of these adaptations are occurring after soil degradation, though some are learning from others mistakes and embracing sustainability. Despite the increased cost and decreased yield initially many farmers now value the long term advantages of sustainable farming. I.e. the effect of soil degradation is making more people aware of sustainability.
1.3 discuss the issues related to water quality, supply and regulations
Water is an important component of agriculture and a number of processes require water to function efficiently. To obtain and maintain the sustainability of this recourse the amount used, the manner in which it is used and the quality of returning water must be considered.
Factors effecting water quality include
Cultivation
Fertilizer application
Pesticides and herbicides
Bare fallowing and erosion
Drought
Chemical dumps
Factors effecting water supply include
Irrigation
Growing crops with high water needs
Drought
On farms, water can be conserved to increase sustainability. Damming water for personal use, the use of contour banks so water can be collected and use of absorption areas all add to preserve water. Often a grassed area designed to allow water to seep into the soil for future plant use is both a short term and long term effect for profitable production.
Regulation of water supplies is necessary on farms as part of the Total Catchment Management Concept. This involves looking at water catchment areas as a state, rather than individual farming areas. Regulation of these areas is needed for:
Equitable distribution of a scarce resource
Reducing salinity, erosion
Ensuring natural resources and ecosystems are not damaged
For greater wellbeing of surrounding communities.
Case study four of the "NSW Water conservation Strategy" Article shows a comparison between the productivity of furrow and drip irrigation. The Case study took place in the Murrumbidgee irrigation are, on Whitton Farm involving rockmelon crops, with the following results:
DRIP IRRIGATIONFURROW IRRIGATION
Yield (t/ha)4030
Water Use (ML/ha)3.14.8
Gross Return ($ML)45002500
From these results it is clearly evident that drip irrigation is a sustainable water use system, conserving 1.7 ML per hectare. Their are also other advantages of using drip irrigation such as a higher gross return, higher yield as well as being able to irrigate through harvest period, extending that time and a better melon overall quality.
1.4 Examine the cause of soil erosion, dryland salinity, irrigation salinity, soil acidification, and soil structural decline.
SOIL EROSION:
Bare fallowing increases the soils vulnerability to run off and wind exposure. This is leaving the soil with no vegetation or ground cover in between cropping seasons.
Poor cultivation techniques such as conventional soil preparation increases erosion. Cultivation during windy and prior to wet periods is undesirable Removal of soil cover mainly removed by cultivation and grazing increases the possibility of erosion
Poor land drainage and water movement, especially on sloped land can cause erosion.
Stock effects and management with overstocking results in overgrazing which leaves the soil surface bare and open to erosion as a result of denuding the land.
DRYLAND SALINITY:
Tree and pasture clearing of deep rooted vegetation such as deep rooted perennial grasses in upper catchment areas is a major cause of dryland salinity. Dryland salinity occurs when deep rooted vegetation is cleared from areas where large volumes of water can enter the ground water and subsequently loss of water by evapotranspiration is reduced. As water loss decreases the water table rises carrying dissolved salt which maybe deposited in the upper layers of the soil profile in commercial plant root zone
IRRIGATION SALINITY:
Poor irrigation of unsuitable soils, over watering and lack of proper drainage are comment causes of irrigation salinity. In Victoria and NSW 12-19% of irrigated land is affected. It occurs when the water table is raised by adding more water to the land than can be used by a crop or pasture. In addition to increase water the result from clearing native vegetation, there is an increase because some irrigation water drains below the root zone.
SOIL ACIDIFICATION:
fertilizer application and placement such as sulphate of ammonia and superphosphate leave acidic residues.
Adding lime to the soil reduces soil acidity and replaces Hydrogen ions with calcium ions.
SOIL STRUCTURAL DECLINE:
Excessive working of soils breaks down soil aggregates as a result of cultivation and the repeated passage of farm machinery over the soil surface.
Working fragile soils, with poor structure easily break down especially under unfavourable conditions such as working when wet or too dry
Non rotation of crops and continuos cropping destroy structure as there is no real rebuilding.
Exporting potential organic matter such as hay and grain. When this is removed from the system fr sale it is not replaced
Compaction of soil from heavy machinery and hard hoofed animals develops a plough pan
1.5 Explain in detail the processes that have led to one of the types of soil degradation and outlining the extent of this soil degradation problem in Australia, with specific reference to effects on plant and animal production.
PROCESSES LEADING TO IRRIGATION SALINITY:
Irrigation salinity occurs when salt dissolved in soil alter are bought up to the root zone of plants and the concentrations of these salts adversely affect the growth of plants. The processes that lead to irrigation salinity occurs when a crop is irrigated the water percolates down through the soil to the root zone of the plants. The plant uses the water for growth and development. Excess water (water not used by the plant) passes down through the soil to the watertable and as a result this groundwater rises. This rising groundwater is salty from naturally occurring salts present in the soil and rock that re dissolved in the groundwater and from salty irrigation water. As the salty groundwater approaches the soil surface, evaporation further draws water and salt into the root zone of plants and often to the soil surface. Farming practice leading to irrigation salinity include:
Over irrigation, where more water is applied than is used by the crop or pasture
Using water for irrigation that already has a high salt content
The clearing of deep rooted native trees and shrubs.
EXTENT IN AUSTRALIA:
In Victoria and NSW 12-19% of irrigated land is affected by salinity, with 6.5% of Australia's irrigated areas effected from irrigation salinity.
EFFECT ON PLANT PRODUCTION:
With high concentrations of soil within the uppermost soil layer, the soil structure collapses with a decline in populations of soil organisms, the possibility of waterlogging and the loss of the uppermost layers of soil through erosion will all reduce plant productivity. Early signs of salinity problems include patchy growth, slower growth, stunted growth and reduced yields. Excessive levels of salts in soils make it very difficult for plants and trees to take up both water and nutrients, and therefore crop and pasture yields are reduced, plant growth stunted and seed germination is reduced. If salt concentrations are high, trees, shrubs, crops and pastures will die.
EFFECT ON ANIMAL PRODUCTION:
Livestock should be excluded from saline areas so that rehabilitation work can be carried out and therefore less farming land is available to supply feed to animals. Pasture growing on saline soils grow poorly and are less nutritious and therefore grazing animals have less available feed and the feed would be of a poorer quality. As a consequence grazing animals would have reduced growth rates, reduced fertility and greater susceptibility to disease.
- Research Methodology and presentation of research.
- 1 Analyse a study of innovative technologies or practices that are assisting with the conservation and efficient use of water in agricultural production systems
See Partial Root zone Drying. - Innovation, ethics and current issues
- 1 Examine and evaluate the current recommended procedures to alleviate the problem studied above with special reference to the physical and biological processes occurring in the soil.
SOIL EROSION:
Maintaining and improving the vegetative cover of the soil by checking stocking rates, checking land slopes when cultivating, tree planting to reduce wind velocity.
Maintaining and improving soil organic matter content and therefore structure by stubble mulching and strip cropping
Reducing the speed of run-off water and preventing its concentration in places where it is likely to cause damage by cultivating along the contour, strip cropping, installation of contour banks, installation of dams, using grassed waterways to move water.
DRYLAND SALINITY:
Re-establishing trees in the catchment areas to reduce the amount of water filtering into the ground water
Fencing off the salt affected areas and planting them with salt tolerant pastures and crops e.g. marsh grass
Using reduced stocking rate on the affected areas what are in keeping with the reduced capability of the land.
IRRIGATION SALINITY:
Installation of drainage systems to reduce further water in the soil
Storing salty water in large water basins and pumping salty water from the water table.
More judicious and efficient use of irrigation water
SOIL ACIDIFICATION:
Application of lime to the soil
Reducing leaching effects by controlling water movement
irrigation.
Judicious and well timed fertilizer application
SOIL STRUCTURAL DECLINE:
Avoid over working and compaction of fragile soils.
Implement minimal till techniques and deep rip the plough pan
Include clop rotations and introduce organic matter and lime into the soil to improve fertility and structure
3.2 Analyse the strategies and innovative activities occurring in programs related to Total Catchment Management, Landcare and whole-farm planning as a means of dealing with sustainability in agriculture.
TOTAL CATCHMENT MANAGEMENT
A catchment is an area with a common major drainage line and as agriculture is both dependant on the threatened by water movement, it provides a natural planning unit. Controlling water movement is usually the primary aim of catchment planning as excess water leads to salinisation and mobilisation of nutrient nutrients which encourages algal growth in water supplies. The important features of TCM that will assist in the sustainable use of resources are:
Corporation between governments, businesses and the community
A coordinated approach to natural resource management
Consideration of the impacts activities have on others
An understanding of the ecosystems within the catchment
LANDCARE:
Landcare is the action by individuals, community groups, government, business and other in carrying for our natural resources, I.e. soil, water, air, vegetation and wildlife. It helps communities understand and find solutions to local problems and manage natural resources more sustainable to avoid problems. Land care is supported by all levels of government however it is the community not the government that leads Landcare. Strategies implemented by Landcare aim to:
Help community members plan ways to improve sustainability
Provides a forum for the interaction of ideas and information
Reduce existing land degradation and manage water resources in an integrated way
Implement Total Catchment Management
These strategies and innovations include
Plant trees
Create more awareness in the community through the production of newsletters and visiting other groups
Improve local skills by a training course such as tree establishment
Financial benefit is given to projects who address important local problems.
Develop sustainable land use practices.
WHOLE FARM PLANNING:
Whole farm planning involves looking at the property from above and designing the farm and its management in a way which preserves the whole farms resources- soil, water and natural resources and the use of the land, its productivity, profitability and lifestyle. It will help deal with land degradation problems such as erosion, salinity and soil structure decline in a way that will not run down the farm assets but steadily improve them.
Whole farm strategies include;
Obtaining an aerial photography of the property
Create overlay details that consist of the property including physical stones, creeks tracks, pipelines, steep land, areas needing further development, unproductive areas and infertile soils. This will help outline the profitability and productivity sets of sustainability.
Create another overlay with existing land use on the property
Create overlay with existing problems such as salt patches
Create and overlay to show land capability
Begin planning the new farm layout using the previous overlays, taking into account the capability, infrastructure and other things noted above.
In this, land capability should determine fencing
Mark on water supply systems,
Mark in tree windbreaks, shade and shelter, soil stabilization, water use to lower water table, reduced water loss by wind drying, firewood.
Management strategies should be emplaced from maps.
- 3 discuss the importance of the attitudes of farmers and the wider community to effectively achieve environmental, economic and social sustainability in agricultural systems.
- 4. Appreciate the role of the government in land and resource management
Government regulations aim to protect environments, and equitably distribute are vital resource for example, The Water Administration Act 1986 gives the Water Administration Ministerial Corporation the right:
To control lakes,
To control rivers
Control water naturally occurring on ground level
Control water below the ground, dams and weirs
They aim to share the water between uses via licences, which cover a variety of circumstances
This policy was amended in 1997 to incorporate ecologically sustainable development, and more recently their has been a bill to for a new water legislation
The government also have economic incentives such as:
Taxation concessions or interest free loans given for land rehabilitation.
Penalties are imposed to discourage unreasonable behaviours such as polluting water ways
Reduced sales tax on agriculture type transport
Governments have educational projects, ongoing funding for research and support Landcare for the purpose of achieving sustainability.
This is the complete article, containing 2,792 words
(approx. 9 pages at 300 words per page).
