how does grass prevent soil erosion?

How Does Grass Prevent Soil Erosion

This PowerPoint is part of the Science Projects Series

Abstract

What Is Grass?

• Grass in the most common name for the Gramineae family of plants

• There are more than 9,000 species of this plant in the world.

• Grass is one of the only

flowering plants that do not have colorful petals

Where is Grass?

• Grass can be found in almost any terrain around the world

• Grass is found in forests, tundra’s, deserts, jungles, etc.

Ins and Outs of Grass

• Generally grass is green because of the green pigments inside of it, known as chlorophyll

• Through the process of photosynthesis, the chlorophyll helps convert sunlight into energy

Ins and Outs of Grass

• At the base of grass are its roots. The roots grow beneath the ground

• Grass roots are fibrous (thread-like)

• They gather nutrients and water to feed the plant as well secure it in place

Ins and Outs of Grass

• Next are the culms, also known as grass stems

• Culms are normally hollow until you reach the node – solid joints connecting stem section together

Ins and Outs of Grass

• Each grass leaf is made of two parts: the upper part is the blade and the lower part is the sheath

• The blade is made up of growth tissue; therefore, if it is cut it will continue to grow

• The sheath supports the blade and wraps around the stem

Ins and Outs of Grass

• There are two main types of stems: stolons and rhizomes

• Stolons grow above the ground and rhizomes grow below the ground

• New grass grows from stolons and rhizomes, which nurture the new plant until it is strong enough to survive on its own

Why is Grass Important?

• Grass is a major food source for people and animals – Rice and corn both grow from grass plants

• In some parts of the world, grass plants, such as bamboo, play an important role in construction

• Grass is also used to make products such as sugar, bread, and plastic

Erosion Prevention

• Erosion is when Earth’s substances are broken down and carried away by means of wind or water

• Fibrous roots are what help to hold soil together so that wind and water do not easily erode the soil

PurposeTo determine how grass affects soil erosion

Materials

• Six 12-ounce paper cups• Soil • One marker• Tap water• One pencil• Two 6x2 inch pieces of

corrugated cardboard• Shallow cookie tray (or

plastic serving tray)• Grass clippings

Procedure

Procedure

1. Fill two paper cups with soil

2. Fill three of the paper cups with water

3. With the pencil, make six small holes in the bottom of one of the remaining paper cups – use the marker to label the cup A

4. Position the cookie tray on a flat surface outdoors

Procedure

5. Place the piece of cardboard in the cookie tray so that the narrow ends of the cardboard are on the edge of the tray

6. Pour one of the cups of soil on the cardboard and spread it into a thin layer

7. Hold up cup A approximately 6 inches above the soil on the cardboard – while in this position pour water from one of the cups into cup and move cup A back and forth across the soil as if mimicking rain

Procedure

8. Once the water has stopped running off the soil covered cardboard, examine how much soil in the tray

9. Now remove the cardboard and use a second cup of water to wash the soil out of the tray

10.Repeat step 4, 5, and 6, covering the cardboard with the other cup of soil

Procedure

11. Cover the soil on the cardboard with a thick layer of grass clippings

12. Repeat steps 7 and 8

Results

• The dirt was washed off the cardboard into the pan

• More soil is washed away from the uncovered dirt layer than from the layer of soil with grass covering it

Conclusion

• The falling water from the cup acted as rain, which in real life erodes soil by moving it from one place to another

• When the soil is covered with a layer of grass clippings, less soil is eroded

• The grass clippings act like grass blades, which actually provide a protective cover for soil

Additional Info

• This experiment can also be substituted with wind instead of water by using a normal or handheld fan

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