1. WIND EROSION • Text page 144: 3 problem areas • Large Continental Wheat Growing Regions line the Great Plains in US • Dune areas along coastlines • Intensively Farmed Organic Soils • What are the characteristics of these areas that promote wind erosion?

2. Wind Erosion • What are the two basic processes that together make up soil erosion? • How would these two processes compare in wind erosion vs water erosion?

3. TYPES OF MOVEMENT

4. Wind Erosion • The text discusses 3 types of soil movement in wind erosion. • How would these compare between wind erosion and water erosion?

5. SALTATION • Saltation: (most within 1 foot of the surface) • Typical size from 0.1 to 0.5 mm. • 65 to 90% of all wind erosion

6. CREEP • Creep: Roll on the surface • Typical size from 0.5 to 20mm. • 7 to 25% of all wind erosion

7. SUSPENSION • Suspended particles: Dust clouds • Typical size <0.1 mm • 3 to 10 % of all wind erosion.

8. To be moved by wind erosion, a soil particle must: • Be light weight enough to be moved. • Be sticking up into the wind • Be free to move (not held in place)

9. WIND EROSION Wind Erosion generally requires a wind speed of at least 10 mph at a height of 1 foot above the surface.

10. WIND EROSION EQUATION • E = f(I, K, C, L, V) • I = Soil Erodibility Index - Related to Cloddiness • K = Surface roughness • C = Climatic Factor - wind velocity and soil moisture • L = Field Length Factor • V = Vegetative Cover Factor

11. Compare the following erosion control methods between wind and water erosion. • Vegetative Cover • Crop Residue • Field Length • Strip Cropping • Contour Farming • Moisture Conservation • Surface Roughness

12. FACTORS MOST RESPONSIBLE FOR WIND EROSION IN IOWA • 1. Fall plowing, especially soybean stubble • 2. Dry fall and winter months followed by high winds in March and April • 3. High speed, multi-bottom plowing which turns most residue under • 4. Large cultivated fields, especially soybeans