1. Impact of Cover Crops on Soil Physical Properties Newell R. Kitchen Matt Volkmann Newell R. Kitchen Matt Volkmann October 21, 2009

2. Why do we do cover crops?

3. Cover: blanket, canopy, cloak, hood, layer, shield, overlay, veil, cap

4. On May 1, 1917 in Columbia, MO the first erosion plot research in the US was initiated. WHY Columbia?

6. Historical Loss of Soil from Erosion Average 5 inches of soil loss over the whole field Extreme Loss > 16 inches of soil loss in localized areas Over 150 years…. between 5 and 6 tons/year

7.  Lost topsoil from erosion  Lost organic matter  Lost soil structure  Lower fertility  Lost topsoil from erosion  Lost organic matter  Lost soil structure  Lower fertility What good is “cover” when you’ve lost 60-90% of the function of that original soil?

8. These degraded soils have lost so much of their original function……in many ways they are nearly dead and in need of life support!

9. What are the Hidden (i.e., below ground) Impacts Of Cover Crops?

10. Summit Side Foot

11. Mulch tillage, Corn-soybean rotation (MTCS) No-till, Corn-soybean-wheat rotation (NTCSW cover)

13. b a a a How about Soil Hydraulic Conductivity?

14. NT CS MT CS NT CSWcover How about Infiltration?

15. Do All Cover Crops Provide Equal Benefit?

16. Permanent grass management 2 Conservation Reserve Program (CRP) systems: No inputs Species: Tall fescue, orchard grass, red clover or warm season grasses Hay: Hay crop, N 90 kg/ha, Lime, P, and K by soil test Hay: Hay crop, N 90 kg/ha, Lime, P, and K by soil test Species: White clover, orchard grass, Canadian wildrye, big bluestem. HAY CRP HAY CRP

17. CRP (cool) CRP (warm) hay (cool & warm)

18. How about Soil Aggregate Stability?

19. How about Soil Strength?

20. Soil depth, m How about Total Soil Organic Carbon and Nitrogen?

22. 2005, 2007, 2009 Wheat Cover

23. 2006 Cereal Rye/Red Clover

24. 2007 Sudex (following wheat)

25. 2008 Rye Grass

26. 2009 Brassica Mix (following wheat)

27. What benefits are we noticing?

28. Results – Temporal Differences in SQIs Highlighted items are significantly different between samplings

29. Results – Temporal Differences in SQIs

38. Typical Positive Impacts from Cover Crops on Soil Physical Properties Increased soil organic matter Enhanced infiltration Enhanced infiltration Enhanced aeration Enhanced aeration Improved soil structure/aggregation Improved soil structure/aggregation Decreased soil strength** Decreased soil strength** Preventive of soil compaction Preventive of soil compaction Reduced evaporation potential Reduced evaporation potential