Science at key stage 3 (Year 9)
Unit 9G: Environmental chemistry
Section 1: How are soils different from each other?
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Objectives |
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- that different soils have different characteristics, including pH ranges, and that this affects the plants that grow in them
- to locate information about plants and preferred soil types in secondary sources
- to use knowledge about acids, alkalis and neutralisation to suggest ways of reducing the acidity of soils
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Activities |
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Outcomes |
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Children: |
- Use secondary sources,
eg photographs, video clips, to remind pupils about sedimentation and ask them what else they think plays a role in soil formation. Establish that vegetation and soil animals are also important.
- Present pupils with information about different soils and show them soil-testing kits. Ask them to use secondary sources to find out why soils are acidic or alkaline, and to identify problems that this might cause and suggest possible cures.
- Ask pupils to use the kits to test local and other soils. Use secondary sources to identify plants often found in particular soil types,
eg in the locality of the school, the implications of soil type for agriculture and effects on some plants,
eg hydrangea colour. Help pupils to summarise what they have found out in a database and use this to produce an information sheet.
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- identify a range of differences between soils
- use the results from work with soil-testing kits to rank soils in terms of acidity
- identify and make a record of plants that are likely to grow well in a particular soil,
eg in the locality of the school, and some that are not
- suggest suitable methods of reducing acidity or alkalinity of soils
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Points to note |
- In key stage 2 pupils are likely to have investigated some aspects of different soils, and animals and plants that are found in these. They are not likely to have considered the pH of soils. Soils could be tested with pH paper of an appropriate range rather than soil-testing kits.
- See
unit 3D 'Rocks and soils' and
unit 6A 'Interdependence and adaptation' in the key stage 2 scheme of work. Unit 8G 'Rocks and weathering' covers the formation of sediment. The pH scale is introduced in unit 7E 'Acids and alkalis'.
- It is important to make sure that pupils do not attribute all acidity in soils to acid rain. Contact with vegetation (roots) amplifies acidity.
- Extension: pupils could survey wild flowers found in their immediate locality, relating this to preferred soil type, and exchange information with other schools via e-mail or the internet.
Safety
- if soils collected locally are used, check they are not contaminated with dog faeces. Wash hands after handling soils
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This unit is divided into sections. Each section contains a sequence of
activities with related objectives and outcomes. You can view this unit by
moving through the sections or print/download the whole unit.
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