1. Soil Conservation and Degradation Alex and Diamond and Liz

2. Problems Affecting Soil Productivity Erosion Desertification

3. Erosion People have increased vulnerability of fertile lands to erosion through: – Over cultivating fields through poor planning/ excessive tilling – Overgrazing rangelands with more livestock than can support – Clearing forests on steep slopes or with large clear-cuts

4. Types of Erosion Splash Erosion- raindrops dislodge soil particles that fill gaps between remaining clumps; decrease soil’s ability to absorb water. Sheet Erosion- water flows in thin sheets over broad surfaces, washing topsoil away in uniform layers.

5. Types of Erosion Rill Erosion- water runs along small furrows, deepening and widening them into channels called rills. May eventually merge to form larger channels and eventually gullies. Has greatest potential to move topsoil. Gully Erosion- cuts deeply into soil, leaving large gullies that expand as erosion proceeds.

6. Desertification Degradation of land in arid, semi-arid areas. Causes: – Erosion – Soil Compaction- too many animals compacting the soil; water cannot infiltrate the soil – Forest Removal – Overgrazing – Drought/ Climate Change

7. Desertification 2007 United Nations report stated that Desertification worsened climate change. Industrialized nations should fund restoration projects in dry land areas of the developing world to slow desertification. As a result of desertification, dust storms from China have blown across the Pacific to North America

8. The Dust Bowl Location- Oklahoma, Texas, Kansas, New Mexico, Colorado (Great Plains) Area- 12 million to 100 million acres Biome- Temperate Grassland Time- late 19 th and early 20 th century (1879-1929) Affected- Farmers and their crops such as wheat and farm animals Cause- expanding unstable land, removing of grassland, breaking down soil erosion Effect- soil erosion, drought

9. What happened? – Strong winds and dust storms called “Black Blizzard” Blackened the rain and snow in New York and Vermont Some areas lost 4 inches of topsoil People lived their farmland Some people asked for assistant government

10. Degradation Prevention Crop Rotation- farmers alternate the type of grown in a given field from one season to the next Contour Farming- consists of plowing furrows sideways across hillside, perpendicular to its slope, to help prevent formation of rills Terracing- transform slopes of series of steps like a staircase, enabling farmers to cultivate hilly land without loosing huge amounts of soil to water erosion

11. Degradation Prevention cont… Intercropping- planting different types of crops alternating sands or other spatially mixed arrangements. Shelterbelts- rows of trees or other tall perennial plants that are planted along the edges of the fields to slow the winds. Reduced tillage- practice of minimizing soil disturbance and allowing crop residue subtle on the ground instead of being thrown or incorporated into the soil.

12. Benefits of no-till farming Conserves biodiversity in soil and ecosystems Produces sustainable, high crop yields Heightens environmental awareness among farmers Provides shelter and winter food for animals Reduces irrigation demands by 10-20% Crop residues act as a sink for carbon Reduces fossil fuel use by 40-70% Enhances food security by increasing drought resistance Reduces erosion by 90%

13. Soil Conservation Service Worked closely with farmers to develop conservation plans for individual farms. – Asset land’s resources problems, and opportunities for conservation – Use science to prepare plans for each property – Work with land users to be sure conservation plans harmonize with users objectives – Implement conservation measures on properties to contribute to quality of life in region

14. Erosion Control Practices Farming methods to control erosion uses the principle that maximizing vegetative cover will protect soils. – Stabilize eroding banks along creeks and roadsides by planting plants to anchor soil

15. Erosion Control Practices China initiated the world’s largest tree- planting program to slow soil loss. – This does not produce functional forests because the trees they select are only for fast growth and are planted in monocultures.

16. Benefits arising from erosion reduction Reduces silt deposit in reservoirs Reduces water pollution from chemicals Eliminates dust storms in towns and cities Increases efficiency in use of fertilizer and machinery