Water-Caused Soil Erosion This presentation is from Virginia Tech and has not been edited by the Georgia Curriculum Office

Objectives Explain how land capability classes relate to wise soil use Explain how land capability classes relate to wise soil use Describe main vegetative methods used to control water caused soil erosion Describe main vegetative methods used to control water caused soil erosion Describe main mechanical methods used to control erosion Describe main mechanical methods used to control erosion Design proper control strategies Design proper control strategies

Land Capability Classes Range from Class I to Class VIII Range from Class I to Class VIII Classes I–IV are suitable for row crop production Classes I–IV are suitable for row crop production  Class I is the best. Nearly flat with little erosion  Class IV has moderate slopes and is prone to high levels of erosion  Should be covered with vegetation continuously

Class I

Class III

Classes V & VI Class V is very nearly level but it may be too wet or rocky for crop production Class V is very nearly level but it may be too wet or rocky for crop production Class VI is very rocky and steep with very shallow topsoil Class VI is very rocky and steep with very shallow topsoil Good for permanent grazing and forests Good for permanent grazing and forests Overgrazing should be avoided Overgrazing should be avoided

Class VI

Classes VII & VIII Almost impassible Almost impassible Limited grazing and forest production Limited grazing and forest production Class VIII is not suitable for any farming Class VIII is not suitable for any farming

Class VIII

Class exercise classify the land in the following pictures classify the land in the following pictures 1

2 3

4 5

Control Measures Vegetative Vegetative Mechanical Mechanical

Vegetative Control Cover crops Cover crops Crop rotation Crop rotation Strip cropping Strip cropping Grassed waterways Grassed waterways

Cover Crops Close growing crop grown on the field when the cash crop isn’t growing Close growing crop grown on the field when the cash crop isn’t growing Winter wheat, rye, vetch, etc Winter wheat, rye, vetch, etc Reduce erosion, improve soils organic matter, and improve soil tilth (workability) Reduce erosion, improve soils organic matter, and improve soil tilth (workability)

Crop Rotation Orderly and repeated sequence of different crops grown on the same field Orderly and repeated sequence of different crops grown on the same field Example: 3–year rotation using corn, soybeans, wheat Example: 3–year rotation using corn, soybeans, wheat Advantages Advantages  Soil tilth is better  Improves water absorption  Reduces erosion  Increases organic matter  Improves moisture storing capacity

Strip Cropping Alternating bands of different crops Alternating bands of different crops Laid out on the contour or across a prevailing slope Laid out on the contour or across a prevailing slope Hay strip, corn strip, hay strip Hay strip, corn strip, hay strip Hay strips increase water absorption, holds the soil in place, reduces gullying, & slows down running water Hay strips increase water absorption, holds the soil in place, reduces gullying, & slows down running water

Grassed Waterways Natural drainageway permanently covered by vegetation Natural drainageway permanently covered by vegetation Used widely to prevent gullying in natural draws Used widely to prevent gullying in natural draws Types Types  Trapezoidal  V–bottomed  Saucer–most common Perrenial grasses such as fescue or bluegrass are typically used Perrenial grasses such as fescue or bluegrass are typically used Quickly establish sod (overseed, fertilize, mulch) Quickly establish sod (overseed, fertilize, mulch)

Mechanical Control Conservation Tillage Conservation Tillage Contour Farming Contour Farming Terraces Terraces Fencing Fencing

Conservation Tillage Tillage system that is economically practical for crop production and aids in soil and water conservation Tillage system that is economically practical for crop production and aids in soil and water conservation Crop residue from previous crop helps protect soil Crop residue from previous crop helps protect soil Common methods include minimum till, no till stubble plant and strip tilling Common methods include minimum till, no till stubble plant and strip tilling Advantages Advantages  Less energy and time are require  Soil moisture levels increase w/ increase in soil organic-matter levels  Reduces soil erosion

Disadvantages Disadvantages  Increase in weed, insect, and disease problems  Crop residue ties up nitrogen thus requiring more fertilization

Contour Farming Plowing around the hill instead of up and down it Plowing around the hill instead of up and down it Prevents runoff from moving straight down the hill Prevents runoff from moving straight down the hill

Terraces Larger surface channels constructed on a contour with a controlled rate of fall Larger surface channels constructed on a contour with a controlled rate of fall Terraces are needed if slope exceeds about 2% Terraces are needed if slope exceeds about 2% Should be designed by Soil Conservation Service Should be designed by Soil Conservation Service Example: waterbreaks in old logging road Example: waterbreaks in old logging road

Fencing Fencing cattle away from creeks and ponds Fencing cattle away from creeks and ponds Greatly reduce creek bank erosion Greatly reduce creek bank erosion Reduces cattle waste from directly entering the water source Reduces cattle waste from directly entering the water source

Developing Control Strategies

A logging crew is moving to this area. The crew plans to clearcut the forest. What suggestions can you provide the crew to minimize soil erosion.