How Management Effects Nutrient and Sediment Losses

1. How Management Effects Nutrient and Sediment Losses Dennis Frame Fred Madison Directors UW Discovery Farms Program

2. Goals of Discovery Farms • Evaluate farming systems effects on air, water and soil • Understand farming systems - how they operate

3. Goals – Continued • Work with families to identify how to modify farming systems while insuring economic viability • Insure fairness of environmental regulations

4. Questions To Address • How much water really runs off of farm fields? • When does this runoff occur? • What is the magnitude of the losses associated with this runoff? • When do these losses occur?

5. Discovery Farm Locations • Buffalo County • Two paired basin sites (stream) • Iowa County • Up/down stream and one field site • LaFayette County • Three paired basin sites (field) • Kewaunee County • Three paired basin sites (field) • Two tile line sites

6. Discovery Farms • Special Projects • Manitowoc County • Up / down stream sites • One small basin site • One tile site • One large basin site • Waukesha County • One small basin site • Two tile monitoring sites

10. Suspended Sediment Total Dissolved Solids TKN Ammonium Nitrate Total P Dissolved Reactive P Chloride Total Nitrogen Organic Nitrogen Why did we choose these constituents to look at? What is the significance of these constituents? What are we analyzing for?

11. What is a runoff event or storm? • There are two types of runoff events: Those that derive from rainfall on non-frozen ground and those that are the combination of rain and melting snow on frozen ground. • To fully understand the relationships between the landscape and its practices to the water quality, both types of runoff events are important to analyze.

12. Sample Overview - 2004 • At the three sites we had in operation, samples representing 98% of the annual storm volume were collected. • This means, 2% of the annual storm volume was unsampled or “missed” and concentrations were estimated.

13. Sample Overview - 2005 • Samples representing 84% of the total runoff volume were collected in Kewaunee County. • Samples representing 95% of the total runoff volume were collected in Manitowoc County. • There were 524 discrete samples taken so far in Kewaunee County and 695 discrete samples (not including the tile) in Manitowoc County.

15. When does runoff occur? • Runoff during frozen ground periods make up a significant portion of the yearly runoff. • Most studies don’t capture snowmelt.

16. Snowmelt • Snowmelt is labor intensive. • Freezing conditions • State-wide event • Weeks of runoff • Expensive!

17. 13% 4% 13%

20. FY05 Sediment Loss Highlights

21. Surface-Water Nutrient Losses FY04 • A large portion of the total nutrient losses occurred during the period of frozen ground. • Can we assume this is the same for all years?

23. Frozen Ground Comparisons2004 vs. 2005

25. Frozen Ground Comparisons2004 vs. 2005

26. How is phosphorus lost?

27. Phosphorus Losses (Stream) distribution during a storm?

28. Surface-Water Nutrient Losses FY05 • All the nutrient losses are associated with snowmelt. • Some P1 losses are possibly due to wintertime manure applications. • Some P3 losses are possibly due to alfalfa winter kill.

29. Take Home Points Rainfall/Runoff • It doesn’t run off every time it rains. • The landscape plays a role in the surface-water runoff. • Frozen ground runoff is significant in volume and nutrient loss

30. Take Home Points Magnitude/Loss • Sediment loss occurs during non-frozen events • Sediment losses on these farms are much less than “T” • With proper management farmers can achieve very low rates of soil loss

31. Take Home Points Magnitude/Loss • N & P loss is present during both frozen and non-frozen events • Most of the phosphorus loss is in the dissolved form

32. Take Home Points: Manure Management • Manure spread on melting snow (imminent) impacts water quality • Type of manure may or may not matter • Timing of application is important

33. Conclusions • Our sites are well below tolerable soil loss levels. • Farms can achieve tolerable soil loss and be profitable • Phosphorus loss may be different on a farm with significant soil loss • These farms are doing an excellent job of harvesting rain (88 – 96%) • Applications of manure on melting snow result in significant loss of both nitrogen and phosphorus

34. Conclusions • Manure applications in the late winter (when snow melt is eminent) should be done on fields which are internally drained and pose little risk of runoff reaching surface waters

35. Conclusions • Stream data and edge of field data are different. • Soil loss • Nutrient concentrations • We need more data to improve existing models.