20 How much soil is lost?5 Billion Tons, Billion with a “B” lost each year3.5 Billion tons due to Water1.5 Billion tons due to Wind
21 What is average loss?Scientists expect to lose 5 tons per acre per yearThis much can be re-captured through soil formationWater makes up 4.8 tons lostWind makes up 3.3 tons lost8.1 tons is averageTHIS IS TOO MUCH!
22 Lasting effects of erosion Loss of topsoil-loss of productive organismsOrganic matter gone along with N-P-KReduced Root Zone-less water holding capacityGullies make farming difficultPollutes lakes, streams causing harm to wildlifeSediment fills up lakes, streams, and waterwaysLoss of $$$$ due to un-productive soilSediment fills and pollutes a lake
23 What affects erosion #1 Texture and Structure The coarser the texture, the higher infiltration rate, the lower amounts of run-offFine particles detach easier than large particlesSilt erodes faster than sandGood structures resist rain splash and wind lift
24 What affects erosion #2 Slope Length and steepness or grade both need consideredLength accounts for volume of erosionGrade creates water velocityLong fields have snowball effect with windLittle loss at the head end, piles of soil at the bottom end
25 What affects erosion #3 Surface Roughness Rough soil slows water and reduces downhill flowTillage ridges are helpfulTillage across slope prevents erosion, tillage with the slope promotes erosion
26 What affects erosion #4 Surface Cover Surface cover reduces impact from falling water and slows down movement of waterSurface crops’ roots hold soil closelyRow crops need a foliage canopy to help protect soil
27 What affects erosion #5 Climate Dry soils and dry climates promote wind erosionThe drier the soil particles the greater risk of being picked up and moved elsewhereDry weather promotes wind loss
28 Types of erosion #1 Splash Erosion Water hits the soil and can move particles as much as 5 feet!
29 Types of erosion #2 Sheet erosion A thin layer of soil is removed as a sheet.Sheet erosion hides until topsoil is lost and subsoil is exposed.Sheet erosion exposes sub-soil in the circles
30 Types of erosion #3 Rill erosion Many small channels on slopes Running water carves out rillsStill can be filled in by tillage
31 Types of erosion #4 Ephemeral (e fem er al) Large rills Tillage won’t completely fill them inThe next rain will create gullies if not fixed
32 Types of erosion #5 Gully erosion So large equipment cannot cross Begin on steep slopes where water creates enough energy to cut large channels in the earth