Near Blue River ca. 1980
Degradation of the resource Fertility loss Organic matter Tilth degradation Water quality Sediment Nutrients Program cost Cheaper to prevent Still expensive Long-term productivity loss Buffalo Co., Wis. Oklahoma, 1935
WATER 3.5 X 10 9 T/yr Waushara, Co. 2009 Fond du Lac, Co. 2010 WIND 1.5 X 10 9 T/yr
SUSPENSION SALTATION CREEP Saltation detaches particles Smaller particles suspended Larger particles creep Sandy and silty soils most susceptible Soil accumulation in ditches and fence rows
Skies actually darkened over Washington, DC causing Congress to pass legislation to control soil erosion
DETACHMENT Detachment Sediment Load Sediment Transport DEPOSITION Soil Sediment Load Deposition Soil
Rill Ephemeral gully
First watershed project in US Vernon Co. between Coon Valley and Chaseburg Early research to evaluate water erosion, 1930 s Promoted contour strip cropping Early information led to the development of models for predicting soil loss
Soil Loss (t/a) = R x K x LS x C x P R = Rainfall intensity and amount K = Soil erosivity Texture Structure LS = Slope length, grade, shape C = Cultural practices Rotation Tillage P = Supporting practices Terraces Contours Buffers
Reduced detachment Hinders overland flow Improved infiltration
USDA-ARS, 1995
Quantity and type of residue Soil condition prior to tillage Presence of compaction or rutting Equipment and time factors Desired final residue cover, distribution, surface roughness, and seedbed condition Planter capability Other management issues (e.g. fertilizer or manure incorporation, conservation programs) Secondary uses for crop residue What s the neighbor doing?
Source: WICCI Soil Conservation Working Group Report, 2010
WDATCP WinTransect Data - Corn Tillage 2000 2005 2010 ----------------------------- % ------------------------------ No-till 11 22 29 Chisel 39 33 58 Moldboard 49 43 5 Other 1 2 8
WDATCP WinTransect Data - Soybean Tillage 2000 2005 2010 ----------------------------- % ------------------------------ No-till 29 46 49 Chisel 39 34 38 Moldboard 22 19 5 Other 10 2 8
Structures: diversions, terraces, waterways Reduce slope length and pitch Slow runoff velocity Divert excess water safely Capture sediment on the land Other: Plantings to reduce detachment and build soil quality
Crop Rotation Changing the crop grown in a field in a planned sequence. Rotations can save cost but most of all this improves soil quality. Planning 1. Maximize cover for best erosion control (e.g. hay) 2. Legume rotate with corn for N use Maintenance 1. Consider herbicide carryover 2. Nitrogen credit
Contour Buffer Strips Buffer strips placed on the contour reduces runoff thus reduces sheet and rill erosion. Planning Grass buffer strips must be at least 15 ft wide and should be harvested. Maintenance 1. Control weeds and fertilizer as needed 2. Keep grass tall in spring to reduce runoff, wildlife
Contour Farming and Strip-cropping Farming on the contour slow runoff. Mixing a small grain or hay crop in a strip with row crop filters sediment because it reduce water flow velocity (runoff). Planning 1. Rotate corn with legume for N use 2. Consider herbicide carryover 3. Strip width will depend on slope Maintenance 1. Keep strips consistent from year to year 2. Establish a small strip of grass between strips to mark areas
Cover Crop Winter cover crops such as rye, oats, winter wheat and etc, protects from wind erosion and provide an opportunity to recover nitrogen. Planning 1. Seed from late Aug. to mid-sept. 2. Consider air seeding prior to harvest Maintenance Spray cover crop in spring
Grass Waterway A natural drainage way that is graded and shaped to make a smooth, shallow channel and then planted to sod-forming grasses. This drainage way will take water from the field thereby reducing erosion. Planning 1. Contact local conservation agency to design (width/depth etc.) 2. Still is a need for soil conservation on the field Maintenance 1. Do not spray 2. Not a road 3. Fertilize and mow as needed 3. Do not till 4.Do not plan end rows along waterway
Grade Stabilization Structure Structure constructed across a gully or grass waterway to drop water to lower elevation will prevent further erosion. Planning 1. Consider cost as this type of structure might be expensive 2. Adequate conservation is necessary upstream Maintenance 1. Remove trees and shrubs within 30 ft of structure 2. Repair cracks in concrete
Water and Sediment Control Basin Pond used to trap water and sediment coming from farm land to protect environment. Water is released slowly via infiltration or suitable outlet, tile or pipe. Planning 1. Consider size of area draining to structure 2. Structure should be of sufficient size to contain a 10-yr 24-hr storm) 3. Consult local conservation agency for assistance in design Maintenance Check basin after large storm and remove sediment a necessary
Critical Area Planting Permanent vegetation planted in gullies, overgrazed hillsides, steep slopes, to prevent soil erosion.
Diversion Used to keep water away from barnyards, feedlots, fields and channel water away from low bottom land. These area should be planted to permanent vegetation. Planning 1. Locate suitable outlet 2. Top should be at least 4 ft wide Maintenance 1. Keep outlet clear of sediment 2. Do not used as road 3. Delay mowing until after July 15
Riparian Buffer Strips of grass, trees or shrubs established along streams, ditches, wetlands or other water bodies to trap sediment, filter nutrient from runoff water and provides wildlife habitat. Planning Work with local conservationist to design and select plants Maintenance 1. Control weeds 2. Delay mowing until July 15 3. Remove sediment
Windbreak Multiple rows of trees planted to protect farmland from erosion and also protect farmstead and feedlots. Planning 1. Plant windbreak for at least north side of area to be protected 2. Avoid planting on south side of road 3. Break will need to be at least 20 to 30 ft tall 4. A mix of conifer and deciduous trees and shrubs make best cover Maintenance 1. Control competing vegetation 2. Fence out livestock