Environmental Education Resources Extracts of statistics on the impact of Australian agriculture are provided below. Superphosphate and nitrogenous fertilisers are widely used, particularly on pasture and cereal crops. Australia has an estimated 2,239,000 hectares of land affected by dryland salinity. 156,000 hectares are thought to be affected by irrigation salinity. Erosion rates are thought to have increased 10 to 100 times in the last 100 years within agricultural areas.
Water erosion is the most common form of land degradation in Australia.
The natural distribution of vegetation is mainly regulated by the amount and seasonality of rainfall, temperature and soil fertility. The clearing of native vegetation from 1983 to 1993 has been most pronounced in Queensland and New South Wales, where it is estimated that 300,000 and 150,000 hectares respectively have been cleared annually. Livestock grazing activity, mainly sheep and cattle, is the largest land-user in Australian agriculture. About 2,500 farm chemicals and 2,000 animal health products containing around 400 active ingredients are used in Australia to control over 5,000 economically significant pests. MPCs are set out in Standard A12 of the food standards code.