Soil Erosion: Causes, Control & Estimation

Soil Erosion: Causes, Control & Estimation

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Soil Erosion: Causes, Control & Estimation

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1. Soil Erosion: Causes, Control & Estimation AGME 1613 - Fundamentals of Agricultural Systems Technology Photos courtesy of NRCS of USDA

2. Objectives • Describe the two causes of soil erosion • Describe the types of soil erosion by water • Estimate the rate (tons/ac) of soil erosion using the RUSLE • Describe common erosion control practices

3. Soil Erosion • The detachment and movement of soil particles by the erosive forces of wind or water.

4. USDA estimates 70% of Soil Lost by Erosion is from Agricultural Land

5. Soil Erosion by Wind Soil erodibility Climate Soil roughness Field length Vegetation Factors Affecting:

6. Interrill Erosion Soil Erosion by Water Raindrop Sheet Rill Erosion Gully Erosion

7. Raindrop Erosion

8. Estimating Soil Erosion • Revised Universal Soil loss Equation (RUSLE) A = R x K x L x S x C x P A = Average annual soil loss (tons/ac/year) R = Rainfall factor (approximately 275 for Fayetteville) K = Soil erodibility factor (p. 221) L = Slope length factor (p. 222) S = Slope gradient factor (p. 222) C = Cropping management factor (p. 223) P = Erosion control practice factor (p. 223)

9. Example RUSLE Problem • Estimate the annual erosion for a field having the following characteristics: • Rainfall factor = 275 • Continuous small grain • Silt loam soil • 1% organic matter • 6% slope with a length of 400-ft. • Farmed up and down the slope • Moderate residue (worked under)

10. Example RUSLE Problem • Rainfall factor = 275 • Continuous small grain • Silt loam soil • 2% organic matter • 6% slope with a length of 400-ft. • Farmed up and down the slope • Moderate residue (worked under) A = R x K x LS x CP

11. Decreasing Erosion by Changing Cropping Practices • Assume same situation as before, except: • We plant on the contour • Assume same situation as before, except: • We plant into residue of previous crop (ROS) • Assume same situation as before, except: • We plant on the contour, and • We plant into residue of previous crop (ROS)

12. Water Erosion Prediction Project(WEPP)

13. Erosion Control Practices • No-Till Farming • Minimum Till Farming • Contour Farming • Strip Cropping • Terracing • Grass Waterways

14. No-Till and Minimum Till Farming • Leave plant residue on soil surface. • Reduce erosion by absorbing energy from falling raindrops, increasing water infiltration, and reducing run-off. • No-Till • Minimum Till

15. Contour Farming

16. Minimum Tillage/Contour Farming

17. Strip Cropping

18. Contour and Strip-Cropping

19. Terraces

20. Terrace after Storm

21. Drop Inlet Terrace

22. Grass Waterways