Soil Erosion and 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 T.A. James and R.L. Croissant. “Controlling Soil Erosion from Wind.” Colorado State University Cooperative Extension. Dec. 2, html 3. Elbert C. Dickey. “Residue Management for Soil Erosion Control. NebGuide. June PICTURE SOURCES
4. Ohio State University Agriculture Extension Office. “Erosion Project.” PICTURE SOURCES