Controlling Erosion on the Farm

1. Controlling Erosion on the Farm Soils Ag I

2. Objectives* • Explain how land capability classes relate to wise soil use • Describe the main vegetation methods farmers use to control water-caused erosion • Describe the main mechanical methods farmers use to control water-caused erosion • Describe the control measures farmers use to control wind-caused erosion • Explain why soil erosion control should be important to every farmer

3. Land Capability and Land Use

4. Review of Land Capability Classes • I-IV suitable for cultivation • V-VIII considered not usable for cultivation

5. Control Measures for Water Caused Erosion

6. Vegetative Control • Cover crops • Close growing • Improve organic matter content, structure and tilth of the soil • Green-manure crops • Cover crops that have been tilled under • Close growing grasses and clovers work best for both cover and green-manure crops

7. Crop Rotation • Orderly and repeated sequence of different crops grown on the same field • 3 year rotation- Corn, soybeans, wheat • 4 year rotation corn, cotton, oats, hay or pasture • Sequence is repeated every 3-4 years • Many possible rotations to use with success

8. Advantages of Crop Rotation • Soil tilth is better maintained • Soil water absorption is improved • Erosion danger is lessened • Organic matter content is increased • If a legume is included, nitrogen fixation helps supply that costly plant nutrient • Soil tillability is improved • Moisture storing capacity of the soil is improved

9. Strip Cropping • The production of alternating bands of different crops • Used to control both wind and water erosion • Sloping lands • Strips are laid out either on the contour or across the prevailing slope • Typical strip cropping scheme alternates row crop, hay, row crop • Example- 3 year rotation of corn-soybeans-hay the strips of hay would make up 1/3 of the field while the corn or soybeans would make up the other 2/3. Strips would be alternated annually

10. Permanent Strip Cropping • Variation is permanent strips of cover crop, pasture, or hay alternated with a row crop with or without a crop rotation system • Effect is to provide bands of heavier vegetation alternated with row-cropped bands. • Heavier vegetation • Increases the rate of water absorption • Holds the soil in place better • Cuts down on gullying • Improves soil tilth in the band • Also serves the slow down run-off to lessen its cutting power

11. Grassed Waterways • Widely used throughout the world • Best used in a fields natural draws and drainageways • In terraced or contour fields used as a release for the water from the row or terrace

12. Construction of Grassed Waterways • 3 shapes • Trapezoidal • Triangular • Saucer • Most common is saucer shaped

13. Grassed Waterway Shapes

14. Best Grasses for Grassed Waterways • Fescue • Bermuda • Bluegrass • When planting the grasses the seedbed should be seeded at 2 to 3 times the normal rate

15. Mechanical Erosion Control

16. Conservation Tillage • Any tillage system that is economically practical for crop production and aids in soil and water conservation • Techniques differ across the country • Common techniques • Minimum tillage • No till • Zero till • Stubble plant • Chisel plowing • Lot planting • Strip tilling

17. Advantages • Less energy and time are required as the amount of tillage is decreased • Soil moisture levels increase with the increased soil organic-matter level • Soil erosion is better controlled

18. Disadvantages • Increase in weed, insects and disease problems • Heavier fertilization may be required due to crop residues tying up soil nitrogen • Increased herbicide use is needed to kill weeds • Exsisting equipment may not be well suited to conservation tillage

19. Contour Farming • Plowing “around” the field • Rows act like small damns to slow run-off • Rows should not be laid out straight across the slope, they should run downhill slightly to allow runoff to be conducted in the desired direction • Also works to control wind erosion if rows are plowed across the prevailing winds, then each row of crop acts as a mini shelterbelt

20. Terraces • Larger surface channels constructed on the contour with a controlled rate of fall • Designed to accept runoff and conduct it across the slope to some protected area • Needed on slopes that exceed 2% and where the slope is over a few hundred feet long

21. Terraces

22. Controlling Wind Erosion

23. Windbreaks • Trees or shrubs planted across the prevailing winds • Reduce the cost of heating and cooling the home • Help keep soil moisture from evaporating as rapidly

24. Shelterbelts • Planted to provide protection to crops and livestock • Consists of trees and shrubs • Height and density determine effectiveness • Reduce the effects of high wind up to 20 times the windbreak height

25. Conservation Tillage • Conserves soil moisture • Reduces surface wind speed • Holds loose soil particles in place • One exception- • In areas of low wind erosion danger farmers will sometimes cultivate the surface of the soil into a loose, sandy layer to conserve soil moisture

26. Summary* • Best erosion control is to use the land according to it capability • Vegetative controls for water erosion include-cover crops, crop rotation, strip cropping, grassed waterways • Mechanical controls for water erosion include conservation tillage, contour farming and terraces • Wind-caused erosion controls include windbreaks, shelterbelts, conservation tillage and contour farming