RUSLE 2 Wisconsin Website http www wi nrcs

RUSLE 2 Wisconsin Website http: //www. wi. nrcs. us da. gov/technical/cons plan/rusle Judy Derricks-WI RUSLE 2 MANAGER 1

OBJECTIVES • Understand erosion concepts important in RUSLE 2 • Understanding RUSLE 2 updates & installations • Understand the RUSLE 2 factors affecting erosion rates and soil quality • Understand the Application of Erosion Principles to Conservation Planning • Explore Additional Uses and Application for RUSLE 2 2

Visit RUSLE 2 Website 3

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Beyond…RUSLE 2 Sheet & Rill Only…. . No Concentrated Channels 6

Types of Water Erosion Ephemeral Classic Gully Rill / Interill (Sheet & Rill) 7

Why Erosion Is a Concern (What are the impacts of erosion? ) Produces sediment which is a pollutant Produces sediment that carries other pollutants (eg. nutrients, pesticides) Degrades soil resource 1. Reduces soil productivity Causes downstream sedimentation 2. Reduces soil O. M. 3. Removes plant nutrients 8

Erosion Contributing Factors? Climate (R) Soil (K) Topography (LS) Crops (C ) - Management Supporting Practices (P) 9

Erosion Factors – Climate Different geographic areas have different climates. Each climate has a unique pattern of rainfall and storm intensity. The influences of storm energy and volume of water combine to detach soil and transport it. 10

Erosion Factors Climate, Erosivity - R A measure of erosivity of climate at specific locations Las Vegas, NV 8 Phoenix, AZ Denver, CO Syracuse, NY Minneapolis, MN Chicago, IL 22 40 80 110 140 Ashland Dodge Manitowoc Richland Rock 100 130 110 140 150 11

Erosion Factors Soil, Erodibility - K • During mapping, soils are assigned an erodibility factor based on their inherent potential to erode. • Soil erodibility factors assigned to soils usually range from values of 0. 17 to 0. 60. Organics can be as low as. 02. • The higher the erodibility factor, the greater the inherent potential to erode. 12

Erosion Factors Soil, Erodibility - K, Variable over Time • Varies during year • High when rainfall is high • Low when temperature is high • Very low below about 25 o. F 13

Erosion Factors Soil Tolerance to Erosion The “T” Value • Different soils have different tolerances to erosion. • Soil scientists assign a soil loss tolerance “T” value to soil during mapping based on the soil’s properties and potential for the soil to lose productivity over time from erosion. • T values assigned to soils during mapping are 1, 2, 3, 4, or 5 tons per acre per year. • Soils with lower T values are much more quickly damaged from erosion than soil with higher T values. 14

Erosion Factors Topography “The Planning L” Overland flow slope length Soil loss Remote deposition “L” Soil Loss for Planning Sediment yield Complex Slope – Convex/Concave 15

Cover-Management Effects Raindrops intercepted by canopy cover Raindrops not intercepted by canopy cover Canopy cover Ground cover Ridges Random roughness Buried residue Soil consolidation Live roots Dead roots 16

Management – “C” Factors The presence or absence of crop canopy or crop residue is one of the most important factors determining whether erosion will actually occur, even during periods of high EI. 17

Erosion Factors Cover Management Subfactors (Effect of Below Ground Biomass) • Roots mechanically hold the soil • Add organic matter that improves soil quality, reduces erodibility, increases infiltration • Affect rill erosion more than interrill erosion • Effect of buried residue over upper 3 inches, but depth decreases to 1 inch as soil consolidates (e. g. no-till) 18

Erosion Factors Cover Management Subfactors (Soil Consolidation) • Overall, freshly tilled soil is about twice as erodible as a fully consolidated soil. • Erodibility decreases with time > 6 years in Wisconsin 19

Supporting Practices Contour Stripcropping Contour Buffer Strips Terraces 20

Supporting Practices (Contour Farming) • Redirects surface runoff • Effectiveness is determined by ridge height (no ridge height = no contour effect). • Effect is greatest when rows are aligned on the true contour. • Fails on long slope lengths. 21

Supporting Practices (Contour Stripcropping) • Usually equal width strips. • Crops in the strips are rotated through a rotation cycle. • Crops are offset so that strips of close growing crops (small grain, perennial crop) separate strips with more erodible crops row crops (corn, soybeans) 22

Erosion Prediction Conservation Planning Data Needed 1. Locate the “Significant Planning Area” for the field. 2. Length and Steepness of Slopes. 3. Crops grown and sequence of crops. 4. Field Specific Crop Yields. 5. Soil types. 6. Supporting Practices (where appropriate). 23

Significant “Planning Area” 6% @ 200 ft. 25% of area 5% @ 250 ft 15% of Area 8% @ 200 ft. 20% Area 4% @ 250 ft 40% Area 24

KEY CONCEPTS Soil Condition Index (SCI) Soil Tillage Intensity Rating (STIR) Energy Calculator Residue Levels (FLAT RESIDUE) 25

Soil Condition Index Rotation—OM returned to the soil Field Operations—Type, speed & number of passes Erosion Factors THE HIGHER THE NUMBER THE BETTER!! “ 0” Means OM is being maintained (The numbers range from -2. . 0. . +2) 26

ROTATION IS CRITICAL • OM • Canopy Cover • Residue composition 27

HOW CAN I IMPACT SCI? ? High residue crops in rotation Cover crops where it matters Mulch & Manure applications Reduce the tillage Reduce the soil disturbance Minimize the erosion from wind & water Increase crop production/residue levels 28

STIR (Soil Tillage Intensity Rating) Operating speed Tillage type—mechanical disturbance Tillage Depth-Residue incorporation Surface area disturbed as related to consolidation STIR VALUE=0 -200 LOW NUMBER IS GOOD Prefer under 30 29

Improve STIR Value……. . Reduce tillage No Tillage Systems Soil Conserving Crops such as Alfalfa/Grass 30

Next: Computer Application of RUSLE 2 31

Most Common Errors Don’t Capture Enough Information Changing Yields & Residue Levels Not Reviewing Soil Condition Index With Landowners Using Profiles and not keeping common runs under worksheet Not Using Manure Correctly WI First 3 Went Away…Keep Current! Not Using those Yellow Folders Enough 32

veral Profiles Set up Template for county and common soil & Save as “Dane” Change Column Widths 33

Start Here! Add uniqueness La Ste Once & Label Put in notes 34

QUESTIONS? ? 35