Soil Conservation

I. Value A. Everything that lives on land depends on

soil. 1. Plants need soil to grow. 2. Animals eat plants (or other animals that eat

plants) to live. B. Soil is renewable, but it takes a long time to

form. 1. Hundreds of years for a few centimeters.

C. Fertile soil is in limited supply. 1. <1/8 of land has good farming soil.

II. Soil Problems A. Damage

1. When one crop is grown in the same spot year after year, the soil loses nutrients and becomes exhausted.

2. Crop rotation helps fix this problem.

3. Growing peanuts also restores the soil fertility.

a. Discovered by George Washington Carver.

B. Loss 1. Erosion from water and wind can take soil away. 2. 1930’s - farmers plowed the grass on the Great

Plains and removed the sod. 3. A drought occurred and turned the topsoil to

dust. 4. The wind blew the soil away out over the

Atlantic Ocean, lost forever. This was called the Dust Bowl.

III. Conservation A. Contour plowing

1. Plowing fields along the curves of a slope to reduce runoff and washing away of the soil.

B. Conservation plowing 1. Leaves previous year’s crop stubble (dead weeds

and stalks) in the ground, and plants in between them. This disturbs the ground cover as little as possible. Allows the roots to hold the soil in place.