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© Boardworks Ltd 2004 1 of 9 This icon indicates that detailed teacher’s notes are available in the Notes Page. To use this presentation click on View,

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Presentation on theme: "© Boardworks Ltd 2004 1 of 9 This icon indicates that detailed teacher’s notes are available in the Notes Page. To use this presentation click on View,"— Presentation transcript:

1 © Boardworks Ltd 2004 1 of 9 This icon indicates that detailed teacher’s notes are available in the Notes Page. To use this presentation click on View, Slide Show. This icon indicates the slide contains activities created in Flash. These activities are not editable. Environmental Impacts of Farming

2 © Boardworks Ltd 2004 1 of 9 Habitat losses in the UK since 1949 95% of lowland grassland 40% of lowland heaths on acid soils 30-50% of ancient lowland woods Some 140,000 miles of hedgerow removed by 1974 Farming – habitat loss

3 © Boardworks Ltd 2004 1 of 9 Farming – hedgerows Why are hedgerows important? They provide a habitat (home) for animals and birds. They reduce soil erosion. They act as a windshield which helps stop the wind blowing away the topsoil. The roots of the hedgerow bind the soil together.

4 © Boardworks Ltd 2004 1 of 9 How has food production been increased? 2.5 million tonnes of artificial fertilizers and pesticides are used every year globally. The use of mineral fertilizers and pesticides have vastly increased global agricultural yields.

5 © Boardworks Ltd 2004 1 of 9 Fertilizers and pesticides But what are artificial (or mineral) fertilizers? Fertilizers generally encourage plant growth. They come in salt form, which is easily soluble in water, or in liquid form. This is important as then the plant will be able to absorb the weak solution of fertilizer. Prepared fertilizers are balanced to contain all the elements necessary for the type of plant for which they are designed. However, different plants need different fertilizers. For example, a plant grown mainly for its leaves will use a fertilizer more heavily concentrated in nitrogen.

6 © Boardworks Ltd 2004 1 of 9 Fertilizers and pesticides But what are pesticides? A pesticide is any substance or mixture of substances intended to prevent, destroy or repel a pest. The pests you want to control could be insects, mice and other animals, unwanted plants (weeds), fungi or micro- organisms (bacteria or viruses). Insecticides kill insects while fungicides kill fungi (mildews, molds, and rusts).

7 © Boardworks Ltd 2004 1 of 9 Producing artificial fertilizers uses fossil fuels. Energy is also used by the machinery spraying the pesticides. Today, it now takes about 1.2 barrels of oil to produce a single ton of grain in more developed countries. This is some 7 times greater than in 1950! Problems of using artificial fertilizers and pesticides So if using artificial fertilizers and pesticides increases crop yields, why shouldn’t we use more of them?

8 © Boardworks Ltd 2004 1 of 9 Problems of using artificial fertilizers and pesticides An overuse of these fertilizers and pesticides can result in them being washed into rivers and lakes causing eutrophication. These chemicals can also end up in our water supply. It costs Britain £121 million each year to monitor and remove pesticides from the water supply. In Germany a water company has found it cheaper to pay farmers to go organic than clean pesticide from the water supply.

9 © Boardworks Ltd 2004 1 of 9 Eutrophication


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