Key Term: Sustainability "forms of progress that meet the needs of the present without compromising the ability of future generations to meet their needs.“- World Commission on Environment and Development, 1987

Environmental Impact of primary food production Australia is the driest continent in the world! We have an annual rainfall of less than 500mm. In general, the areas with highest rainfall are associated with higher elevations. In the Otways and south Gippsland, high rainfall can occur at modest elevations because both these areas are frequently exposed to moist air streams.

Agricultural practices that have been used over the last 200 years have negatively impacted on our economy. There is a increase in salinity, acidification and soil erosion as a result of farming practices such as land clearing, irrigation and the misuse of chemicals. Salinity is the saltiness or dissolved salt content of a body of water. It occurs if groundwater (land fed by water ) rises, generally when excess water is added to groundwater supplies- this is called irrigation. As water reaches the surface, water-logging ( soil is so wet where there is insufficient oxygen in the pore supply for plants to respire ) occurs and water and salt emerge through the topsoil, forming salt crusts and kills vegetation and crops.

Managing the use of water Farmers have to irrigate in order to supply sufficient water for orchards, vineyards, vegetable and rice production and pasture for dairy cows and sheep. Australia has the highest water storage system in the world, where 70% is used for irrigation. To support the irrigation systems, the natural landscape is changed, dams and channels are built and paddocks are levelled to move water from natural waterways to agricultural production areas. Pollution and salinty problems threaten hundreds of millions of dollars in agricultural production The high levels of irrigation required to grow rice and cotton crops has led to rising watertables, salinty, the washing of herbicides and pesticides into the water courses downstream, and the potential for nitrates to leach into groundwater and cause contamination.

Salinity Salinity means there is too much salt in the soil and most plants associated with food production will not grow in salty soil. Two main causes of salinity: dry-land salinity and irrigated- land salinity. Preventing the creation of saline land will have a major influence on the long-term sustainability of food- producing land in Australia.

Strategies for sustainable water use Monitoring water quality regularly Using new technologies, to flood paddocks quickly Using only just enough water for maximum growth and good health of the crop or pasture Maintaining and repairing breaks in channels and banks to avoid water loss Enclosing open-channel irrigation systems or using pipe lines to prevent evaporation Using irrigation layouts which reduce water use on a farm Installing sensors to detect when sufficient water has been applied to the soil Catching irrigation water in channels and dams and reusing it

Using your own words make a mind map explaining the concept of a sustainable food supply.

Use of chemicals in primary production Chemical or inorganic fertilisers: nitrogen based, are used in agriculture to improve crop yields. To maintain farming soils nutrient content is to use artificial fertilisers. Herbicides: sprayed on weeds as weeds compete with food crops such as wheat, oats, rice and barley for nutrients in the soil. Biodegradable.

Pesticides: control pests on crops. They have varying toxicity levels and must be used responsibly.

Problems using chemicals? 1. Half of the nitrate in these products is dissolved by rain. The nitrate runs off the fields and can contaminate rivers and groundwater, polluting fresh water systems. 2. Nitrogen is released into the atmosphere and pollutes the air as well as contributing to acid rain. 3. Chemical residue may remain in the food crop and accumulate in the body once the food is eaten

Managing the use of chemicals Aerial spray contractors flying low to the ground to spray the crop accurately and prevent spray drifting onto other paddocks. Ensuring this process is carried out on days where there is little wind to prevent wind drift. Using a GPS system for aerial contractors so they can follow the correct path and apply the correct amount of chemicals. Monitoring crops on a weekly basis

Understanding the text Q Identify how irrigation systems can have a negative impact on the natural environment if they are not managed effectively. 2. Explain how irrigation systems can be used responsibly and provide examples of some strategies. 3. What is ‘salinity’ and why is it a problem for primary producers? 4. Draw a flow chart to show how irrigated-land salinity occurs. 5. explain the four strategies that farmers who rely on irrigation could use to ensure a sustainable water supply. 6. What are three benefits to rice farmers of the development of electromagnetic induction surveys. 7. Explain why the use of chemicals is important in primary production of food. 8. What is the difference between herbicides and pesticides? 9. Outline some of the quality control practices to ensure the food is safe 10. Describe three ways in which sprays used in food production can be applied so they have a minimal impact on the environment.

Land Degradation Land degradation can be caused through erosion and poor soil health – both nutrient loss and soil acidification

Erosion Occurs when vegetation covering the land and the surface of the land’s crust is damaged, often creating large gullies Main causes: drought, poor land management The topsoil provides nutrients needed for plant growth and when landscape is cleared to grow food crops or plant pasture, the wind and water can remove the top soil. Pollution of waterways: the sediment from the topsoil can be blown and carried into wetlands and streams. This is a problem as it can carry nitrogen and phosphorus that pollutes waterways. Erosion is difficult to overcome as it takes many years to develop and many more decades to redress.

Landcare: This unique partnership between communities, government and organisations are achieving great things such as: Improving farmlands Conserve, rehabilitate and better manage our river systems Improving local coastal and marine environments Planting millions of native trees, shrubs and grasses that will produce better soils, water and air quality Restoring wildlife habitats

Strategies to minimise soil erosion Minimise the amount of tillage Leaving stubble to cover the soil after harvest Planting trees so their roots will hold the soil in place Contour farming: ploughing across a slope following its elevation contour lines. The rows formed slows water run-off during rainstorms to prevent soil erosion and allows the water time to settle into the soil.

Silt traps: slows the flow of water and catches waterborne soil and seeds. The seeds caught germinate and help to slow water movement, resulting in stable soils. Planting windbreaks or shelter belts to reduce soil erosion, stabilise hillsides and waterways

Poor soil health Soil acidification: plants take up nutrients and release acidic waste from their roots. Once soil becomes acidic, crops and pasture do not grow very well and the productivity of the land decreases Using the same soil for crops to grow in, has caused the nutrient level of the soil to gradually decrease

Strategies to improve soil health Undertake regular pH tests on soil to determine the levels of acid present Add lime to the paddocks to help lower the pH level and to counteract high acid levels Retaining crop stubble. Stubble that is retained helps to mulch the soil, which is then able to retain more moisture. It also assists in preventing wind erosion, and nutrients contained in the stubble are returned to the soil. Crop rotation: reduces weed and pest problems and builds up the nutrient levels in the soil

Case study 11.1 Read case study ‘ Growing lentils’ on pg 196 of your text book and answer Q 1-7

Organic Farming Organic food is produced without the use of artificial chemicals They are produced, processed, packaged and transported without the use of herbicides, pesticides, fungicides and fertilisers Not treated with preservatives, hormones, chemicals or other products Cannot use GM organisms in any stage of their production Organic foods are sold through specialist natural food shops and fresh food markets.

Organic certification ‘ Certified organic’ means a product has been produced in accordance with a organic standard established by a certifying agency Annual inspections- a farmer has to show strategies they use for soil management, crop rotations, weed control, pest and disease management, windbreaks, biodiversity, animal health and water management It takes three years to change over from regular farming practices to certified organic production, but farmers are still able to sell their food.

Organic food products Most popular organic products: baby food, organic meat and poultry, eggs, fresh fruit and vegetables and dairy products. Along with some breakfast cereals, wheat flours, chocolate and coffee.

Benefits to the producer Sustainable practices: crop rotation, improve soil fertility, reduces impact of pests and weeds Livestock can be raised in a stress-reduced environment without the use of growth hormones or antibiotics Traditional seed varieties helps to preserve the range of crops for future generations Rigorous audit systems Crop yields can be stabilised and increased

Benefits to the consumer Provide health benefits Tastes better than non-organic produce Provides security that the food is not GM Contains fewer artificial ingredients and lower chemical residues

Benefits to the environment Artificial pesticides and herbicides are prohibited Prevent salination and soil erosion and improve the ability of the soil to take up and retain water are implemented Organic fertilisers and natural methods are used to reduce insect infestation and control weeds Non-renewable resources is minimised so organic fertilisers can be produced from organic waste from the farm Biodiversity is maintained