Will manure spreading bans reduce winter runoff events?


Published on

For more: http://www.extension.org/67684 The Wisconsin Discovery Farms Program was one of the first on-farm evaluation projects to identify the risk of manure applications in the late winter period. Data from several of our farms have shown that manure applied during February and March has an increased risk of running off and contributing to high nutrient losses in surface water. This data has been used to justify the establishment of recommendations, rules and regulations on winter manure spreading. But, do bans on winter manure spreading (spreading on frozen or snow covered ground) actually reduce the risk of manure runoff? A close evaluation of the data indicates that spreading during early winter (November - January) is much different than during late winter when frost can extend deeper and be more solid in the soil profile. Total winter application bans also increase the volume of manure that needs to be stored and increase the risk of runoff during the spring spreading season.

Published in: Education
  • Be the first to comment

  • Be the first to like this

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Will manure spreading bans reduce winter runoff events?

  1. 1. Amber RadatzUW Discovery FarmsApril 3, 2013Will Spreading Bans ReduceWinter Runoff Events?
  2. 2. Key Lessons from DiscoveryFarms Timing, timing, timing Management decisions really do matter Losses can vary greatly year to year based onweather, location and management decisions Sound conservation is still sound conservation
  3. 3. Wintertime runoff On average, 50% of runoff while soil is frozen Can be 100% of total annual runoff dependingon conditions Mostly February and March March: 100% frequency 1/3 of total annual runoff Risk for runoff in April, May and June is similar tothat of January and February
  4. 4. Runoff TimingAverage % ofAnnualRunoffRunoffFrequencyOctober 3% 23%November <1% 15%December 1% 35%January 4% 50%February 16% 58%March 34% 100%April 4% 54%May 12% 38%June 19% 42%July 3% 42%August 3% 19%September <1% 19%Source: Precipitation-Runoff Relations and Water-Quality Characteristics at Edge-of-Field Stations, Discovery Farms and Pioneer Farm, Wisconsin, 2003–8.55% of annual runoff35% of annual runoff
  5. 5. Management Decisions Shorter time between manure application andrunoff event = greater potential for nutrientlosses Liquid dairy and solid beef applications shortlybefore runoff increased nutrient lossOR
  6. 6. Winter unpredictabilityFebruary 2011February 2012
  7. 7. Winter/Spring unpredictabilityMarch 27, 2013
  8. 8. So what about banning spreadingbased on dates? Spreading bans don’t stop runoff events, peopledo Understanding the key factors for runoff is thebest way to reduce nutrient and sediment losses It comes down to: Our job: giving producers the best informationavailable on runoff timing, effects of manureapplication at different times Your job: using that information to make the bestdecisions possible
  9. 9. Key Recommendations Understand factors for runoff and assess thesituation on your farm Winter runoff: Dramatic and rapid warming causing snowmelt Rain on frozen or snow covered ground Spring runoff: Saturated soils Consecutive rain events
  10. 10. Key Recommendations Manage manure storage to avoid high-risktime periods Save some less risky fields for the most riskytime periods Work with local land and water professionalsto identify areas on your farm suitable forstacking or spreading Decide if some amount of storage is right foryou
  11. 11. Amber Radatzaradatz@wisc.eduwww.uwdiscoveryfarms.orgThank you!