Year 8 Science · Unit 3 · Lesson 26
Apply Worksheet
Learning Goals
Compare three soil types
Complete the table by filling in the correct information for each soil type. Use your lesson notes to help you.
| Feature | Sandy soil | Clay soil | Loam |
|---|---|---|---|
| Particle size | |||
| Drainage (fast / slow) | |||
| Nutrient-holding ability | |||
| Best crops or uses |
Real-world context
A wheat farmer in the Riverina district of NSW has noticed that white salt crystals are forming on the surface of their paddocks after a wet winter. The affected patches of soil no longer grow crops, and the problem seems to be spreading. In some areas the vegetation has died off entirely and the soil surface looks pale and crusty. This is a widespread issue across southern Australia, approximately 2.5 million hectares are affected.
(a) What is this problem called, and what causes the salt to appear at the surface? Explain the role of the water table in your answer.
(b) How did land clearing and irrigation farming contribute to this problem? Use scientific reasoning.
(c) Describe one management strategy the farmer could use to reduce soil salinity on their property. Explain why it would work.
Wrap Up
In one sentence, what was the main idea of this lesson?