From Bedrock to Soil Ch. 10 Section 3

What is soil? Soil is a loose mixture of small mineral fragments, organic material, water, and air that can support the growth of vegetation.

All soil is different Soil (weathered rock fragments) can be made of many different types of rock. The type of rock that the soil was made from is called parent rock.

Parts of Soil

Bedrock Bedrock is the layer of rock beneath the soil. Some soil is made from bedrock, so it remains above the parent rock.

Humus Humus is the dark, organic material in soil that is formed from decayed remains of plants and animals.

Soil Horizons Soil is usually layered with humus-rich soil on top, sediment below that, and bedrock on bottom.

Think about it! What is the source of mineral fragments in soil? The proportion of different sized particles in soil determines the soil’s A. Texture B. Fertility C. Structure D. Horizon

Think about it! What is the source of mineral fragments in soil? Parent Rock The proportion of different sized particles in soil determines the soil’s A. Texture B. Fertility C. Structure D. Horizon

Soil Conservation Ch. 10, Section 4

Soil Conservation Soil Conservation is a method to maintain the fertility of soil by preventing erosion and the loss of nutrients.

Importance of soil Soil provides nutrients to plant life. If the soil loses these nutrients then the plants will not grow. All animals get energy from plants. How can unhealthy soil effect us?

Housing and Water Soil is also important to providing shelter for animals that live in soil. It also stores water for plants and animals, and helps prevent flooding.

Can you tell which is grown in healthy soil?

Land Degradation When soil is overused it loses its nutrients. How could soil be overused?

Land Degradation When soil is overused it loses its nutrients. This can happen from poor farming techniques or overgrazing. Plants can’t grow in infertile soil. Without plants and moisture the soil can be washed or blown away.

Erosion Erosion is the process by which wind, water, or gravity transport soil and sediment from one location to another. This happens when land is left unprotected. This happened in south Georgia long ago. The result was Providence Canyon. What was once cotton fields is now a 150 ft. deep canyon.

Providence Canyon

Providence Canyon

Providence Canyon

Providence Canyon

Providence Canyon

Soil Conservation There are many ways that farmers help prevent erosion. Contour plowing Terracing No-till farming Cover crops Crop rotation

Contour Plowing

Terracing

No-till farming

Cover crops Cover crops are crops such as soy beans and peanuts that help restore important nutrients to the soil and prevents erosion.

Crop rotation Rotating crops from one year to the next.

Think about it! Why is soil important? How does crop rotation benefit soil?

Think about it! Why is soil important? Soil provides nutrients to plants; provides houses for animals; and stores water. How does crop rotation benefit soil? Crop rotation helps prevent soil nutrients from being depleted. Alternation of crops in the same soil reduces nutrient loss.