1. Effects of Soil Compaction and Macropores on Water Infiltration Rates By Lanre Adekola

2. Problems Soil becomes hard like concrete when construction equipment is driven repeatedly over soil There is a decrease in vegetative growth Poor infiltration rates lead to runoff – Nitrates – Phosphates – Oils and greases – Salts from ice removal

3. Study Site: Lake Minnetonka Regional Park

4. Methods: Infiltration Rates Modified Philip-Dunne Infiltrometer (MPD)

5. Methods: Laying out Study Area

6. Goals: Compaction Study To determine the soil type at the study site

7. Methods Determining Soil Type

8. Methods Determining Soil Type

9. Methods Determining Soil Type CaCO 3 Content

10. Results for Soil Type Sandy Loam – Brown, R. B. "Soil Texture." Electronic Data Information Source. 2008. University of Florida. 6 Oct. 2008.

11. Goals: Compaction Study To determine the soil type at the study site To measure infiltration rates of the compacted soil

12. Results: Infiltration vs. Frequency

13. Results: Infiltration Rates

14. Comparison with Rain Garden Infiltration

15. Lake Minnetonka has 3.5 times worse infiltration Rates

16. Goals: Compaction Study To determine the soil type at the study site To measure infiltration rates of the compacted soil To determine how water infiltration is affected by bulk density

17. Methods: Bulk Density

18. Methods: Soil Sampling Positions

19. Methods: Bulk Density Samples

20. Results: Bulk Density

21. Comparison of Compaction Levels vs. Soil Type (Shestak et al. 2005) Shestak, C. J. and M. D. Busse. "Compaction Alters Physical but not Biological ices of Soil Health." Soil Society of America (2005): 236-46.

22. Comparison of Compaction Levels vs. Soil Type (Shestak et al. 2005) Shestak, C. J. and M. D. Busse. "Compaction Alters Physical but not Biological ices of Soil Health." Soil Society of America (2005): 236-46.

23. Comparison of Compaction Levels vs. Soil Type (Shestak et al. 2005) Shestak, C. J. and M. D. Busse. "Compaction Alters Physical but not Biological ices of Soil Health." Soil Society of America (2005): 236-46. Minnetonka Regional Park = 1.477 g/cm 3

24. Definition of Macropore Pockets of air found in soil that may influence infiltration Caused by earthworms and hollowed tree roots – Jury, W. A. and Horton, R. Soil Physics. 6th ed. John Wiley & Sons, Inc: Hobeken, New Jersey, 2004

25. Goals: Macropore Study Design and create macropore simulators

26. Methods: Macropore Simulator

27. Goals: Macropore Study Design and create macropore simulators Determine how number of macropores affects infiltration rates

28. Methods: Devices Used for Macropores 5 cm diameter MPDMinidisk InfiltrometerMoisture Content Device

29. Results: Macropore Averages

31. Limitations Presence of rocks and macropores in soil at Lake Minnetonka may have affected infiltration Presence of small trees and shaded areas affected infiltration Time between macropore flood tests varied, affecting drying rate of soil Size and number of macropores may have produced unreliable results

32. Conclusion Soil compaction is directly related to poor water infiltration Poor infiltration is leading to runoff In the absence of macropores, infiltration rates at Lake Minnetonka could be even worse

33. Future Work Tilling/aerating Composting Testing water for chemical content, before and after tilling/aerating and composting

34. Acknowledgments Dr. Gulliver Nick Olsen Greta Schmalle Science Research Class Mrs. Fruen

35. Effects of Soil Compaction and Macropores on Water Infiltration Rates By Lanre Adekola

36. Results for Soil Type Sandy Loam http://edis.ifas.ufl.edu/ss169