Science -----------Chapter 5 lesson 2- Soil------Test------- Friday, Jan. 8, 2016
Vocabulary
1.
2.
3.
4.
Soil- a mixture of bits of rock and once living things.
Soil horizon- any of the layers of soil from the surface to the bedrock.
Humus- decayed plant or animal material in soil.
Topsoil- the dark, top layer of soil, rich in humus and minerals, in which
organisms live and most plants grow.
5. Pollution- the addition of harmful materials to soil, air, or water
6. Conservation- the preservation or protection of natural resources.
Notes
1. The horizon is the layer of soil that contains the most living organisms. This
layer contains the most oxygen.
2. The word soil comes from the latin word solum which means “floor or
ground”.
3. The word humus comes from the Latin prefix ghom- which means “earth or
ground”.
4. The word topsoil is a compound word. Top means that it is above other
parts.
5. There are several things that can happen to soil to make it less useful to
grow plants. The soil can become polluted from the addition of harmful
materials and it can be eroded by water and wind.
6. There are some products that are useful to plant growth but can also
pollute the soil. Examples of these products are pesticides and fertilizers.
9 Methods of Soil Conservation
1. Fertilization- fertilizer containing one or more nutrients can be added to
soil to replace the nutrients used by previous crops.
2. Crop rotation- farmers can alternate the type of crops they plant from one
year to the next.
3. Strip farming- plant roots help prevent soil from being washed or blown
away. For this reason, farmers may plant grasses between rows of other
crops.
4. Contour plowing- Instead of plowing up and down the slope of the hill,
farmers plow furrows across the slope. This will slow the speed of water
flowing down the hill.
5. Terracing – Terraces are flat shelves that are cut into a hillside. Crops are
planted along each terrace. This also slows the speed of water flowing
down a slope.
6. Wind Breaks- Farmers plant tall trees along the edges of farmland to slow
the speed of wind across the ground. Where there are trees, the wind is
less likely to blow away topsoil.
7. Laws- Governments may pass laws to stop the pollution of soil.
8. Individual Efforts- You can avoid polluting soil with trash and help clean up
land that has already been polluted.
9. Education- You can help inform people of the value of soil and how to
conserve it.