environmental issues australia’s rivers and landscapes are under threat from rising salinity. many...
TRANSCRIPT
Environmental issues • Australia’s rivers and landscapes
are under threat from rising salinity.
• Many people feel that salinity is the most serious environmental threat to productive land and waterways
• CSIRO Fact sheet salinity October 2008
• http://www.csiro.au/files/files/pmyj.pdf
© Glenis Heath and Laurel Tully 2011
CSIRO Land and w
ater
The impact of salinity on land for primary production
© Glenis Heath and Laurel Tully 2011
CSIRO Land and waterSalinity and its impact biodiversity
© Glenis Heath and Laurel Tully 2011
CSIRO Land and waterImpact of salinity on the health of rivers and streams – may become too salty for humans and animals to drink
© Glenis Heath and Laurel Tully 2011
Land degradation : soil erosion Severe wind storms blow the top soil from the paddock removing the nutrient rich layer and reducing the productivity of the soil.
© Glenis Heath and Laurel Tully 2011
Managing soil erosion: planting wind breaks
Farmers can plant wind breaks to reduce soil erosion. These trees also protect stock from extreme weather conditions.
© Glenis Heath and Laurel Tully 2011
Managing soil erosion: no-till farming techniques No-till farming techniques retain crop stubble after harvest reducing wind and soil erosion. Direct drilling of seed is used to plant the next year’s crop so that the top soil is not disturbed exposing it to wind erosion.
© Glenis Heath and Laurel Tully 2011
Managing the use of chemicalsAerial spraying is used to spay herbicides and pesticides on broad acre crops such as wheat.
© Glenis Heath and Laurel Tully 2011
Managing the use of chemicalsThe run-off and drift from aerial spraying can contaminate rivers causing the development of blue-green algae.
© Glenis Heath and Laurel Tully 2011
Locusts swarm in the mallee Insect pests such as locusts devastate crops. Farmers may be forced to use chemical sprays to eradicate these pests and protect their crops.
© Glenis Heath and Laurel Tully 2011
locusts destroy cropsReduce chemical use by monitoring crops to determine whether spraying is required to reduce insect pests such as locusts
© Glenis Heath and Laurel Tully 2011
Organic farming • Natural systems include:• Pest management
– Natural insect predators including ladybird to eat insect pests
• Companion planting– Garlic planted between tomatoes to
ward off pests
• Fertilisers – Use of natural, non-synthetic, organic
fertilisers – animal manures – Organic fertilisers may be produced
from organic materials on the farm
© Glenis Heath and Laurel Tully 2011
Organic farming • The following links explain
organic farming methods • The Organic Farming Tour
Australia is available from:www.overlander.tvStarting point: 48.07Downloadable for $11.95
• The Chambers family of Fernleigh Farms near Daylesford who farm organic vegetables, beef and grazing pigs
(we will look at this in class)
© Glenis Heath and Laurel Tully 2011