Soil Erosionand Conservation

Developed 9/15/2000 by:

Brian Matchett

Sara Moyer

1/32 OF THE WORLD REPRESENTS THE SOIL WHICH WE ALL DEPEND ON FOR

FOOD PRODUCTION

What is the most destructive natural

phenomenon that causes us to lose this soil?

What is Soil Erosion?

• The movement of soil particles from one place to another under the influence of water or wind.

What influences soil erosion?

1. Climate

2. Topography

3. Nature of the soil

Two types of soil erosion

1. Water Erosion

2. Wind Erosion

WATER EROSION

• Is a process in which organic matter and finer soil particles are removed first, thus rapidly destroying the land’s productivity.

Water Erosion Process

1. Decrease in soil particle size

2. Soil particles are washed away

3. Land is plowed, bringing up new topsoil

4. Process is repeated over again

Results: Soil is less productive

Water Erosion Process

With no protective cover, raindrops can splash soil particles up to three feet away. Residue cover cushions the fall of raindrops and reduces or

eliminates splash erosion.

Soil particles and aggregates that have been detached by raindrops

are transported down the slope by runoff.

Types of Water Erosion

• Splash

• Sheet

• Rill

• Gully

SPLASH Erosion

• Detaches soil

• Destroys granulation

• Causes movement of soil

SHEET Erosion

• Uniform removal of soil in thin layers

• Requires smooth soil surface

• Slow process

RILL Erosion

• Forms shallow trenches

• Uniform in soil removal

• Is often combined with sheet erosion

GULLY Erosion

• Water accumulates in narrow channels

• Causes soil removal from considerable depths

• Very apparent on the landscape

WIND EROSION

• Erodes land by removing top soil. Most common in dry areas with very sandy soils, or organic soils that are clear of vegetation and have high wind velocity.

Wind Erosion Process

1. Wind moves organic matter

2. Sand/coarse materials are left behind

Results: Soil is less productive

Wind Erosion Process

Results of Erosion

• Loss of topsoil

• Reduction of crop yields

• Increase need for fertilizers

• Production of lower nutrient crops

• Formation of gullies

• Covering of rich bottomlands

• Destruction of roads/bridges

Results of Erosion cont.

• Water contamination

• Increased flood hazard

• Decreased soil water content

• Increased cost of production

Factors of Controlling Erosion

• Plant cover on soil

• Intensity, duration, distribution of rainfall

• Topography of the land

• Soil’s physical properties

• Erosion control practices

Soil Conservation Practices

• Sod crops• Cover and green manure crops• Contour cultivation• Strip Cropping• Terraces• Crop rotation• Conservation tillage• Wind breaks

Sod Covers

• Strips of grass sod

• Controls water runoff

• Used with contours and terraces

Cover and Green Manure Crops

• Plant grasses or legumes

• Add organic matter/fix nitrogen

• Plow under green plants

Contour Cultivation

• Plant/cultivate following land contours

• Use with strip cropping or terracing

Strip Cropping

• Plant crops in alternating strips

• Plant on lines of contour

• Used to conserve both soil and water

Terraces

• Remove runoff safely

• Construct embankments or ridges

• Help guide water

• Costly

Crop Rotation

• Grow selected crops in a regular order

• Good rotations secure nutrients and decrease erosion

Conservation Tillage

• No tillage - most effective

• All crop residue is left

• Saves soil, oil and toil

Wind Breaks

• Strip of vegetation that blocks wind

• Conserves moisture

1. Agricultural and Biological Engineering Purdue University. http://abe.www.ecn.purdue.edu

2. T.A. James and R.L. Croissant. “Controlling Soil Erosion from Wind.” Colorado State University Cooperative Extension. Dec. 2, 1999.

http://gopher.colostate.edu/Depts/CoopExt/PUBS/CROPS/00518.html

3. Elbert C. Dickey. “Residue Management for Soil Erosion Control. NebGuide. June 1997. http://ianrwww.unl.edu/pubs/fieldcrops/g544.htm

PICTURE SOURCES

4. Ohio State University Agriculture Extension Office. “Erosion Project.” http://topaz.kenyon.edu/projects/farmschool/nature/eropro.htm

PICTURE SOURCES