1. Building Soil Quality with No-Till, Crop Rotations & Cover Crops $ $ $ $ $ $ $ $ D. Wayne Reeves J. Phil Campbell Sr. Natural Resource Conservation Center D. Wayne Reeves J. Phil Campbell Sr. Natural Resource Conservation Center

2. “Soil degradation prevents the full use of the soil resource to meet human needs and impacts ecosystem functions.” USDA-ARS Soil Resource Management National Program

3. “Agricultural mismanagement is the most important causative factor of soil degradation.....” Oldeman, 1994 United Nations Environment Programme (UNEP), Global Assessment of Soil Degradtion (GlASOD) Oldeman, 1994 United Nations Environment Programme (UNEP), Global Assessment of Soil Degradtion (GlASOD)

4. “Perhaps the most dominant soil degradative processes are soil erosion and organic matter decline.” B.A. Stewart, R. Lal, and S.A. El-Swaify. Sustaining the Resource Base of an Expanding World Agriculture. In: Soil Management for Sustainability. R. Lal and F.J. Pierce (eds.), 1991.

5. Soil Quality is the Converse of Degradation Environmental Quality Agricultural Productivity Soil Quality Health/Habitation

6. Soil c web from Doran et al., 1993 Total Organic C and N Total Organic C and N Infiltration Soil Strength Bulk Density Water content retention capacity Size Distribution NH and NO, P, K, Ca, Al, CEC NH and NO, P, K, Ca, Al, CEC 3 3 3 3 4 4 4 4 Microbial Biomass C and N Soil Respiration N N Biomass C to TOC ratio Respiration to Biomass ratio mineralized CC Aggregate Stability Soil C is basis of Soil Quality/Productivity

7. Soil c web SOM=SOC (x2) Soil C is the basis of Agricultural Sustainability....

8. Sandor and Eash, 1991 Evidence for Sustainability: SOM from ancient agricultural sites Evidence for Sustainability: SOM from ancient agricultural sites New Mexico 1000-1150 AD New Mexico 1000-1150 AD Peru 400 AD-present Peru 400 AD-present continuous corn diverse rotations, green & animal manures

9. Sandor and Eash, 1991 SOM (%) Evidence for Sustainability: SOM from ancient agricultural sites Evidence for Sustainability: SOM from ancient agricultural sites New Mexico 1000-1150 AD New Mexico 1000-1150 AD 0 0 4 4 3 3 2 2 1 1 Peru 400 AD-present Peru 400 AD-present Continuous Corn Rotation+Manures Cultivated Uncultivated

10. Conservation Tillage! How to increase soil C and improve soil quality?

11. Compass loamy sand Depth (cm) 0 0 5 5 20 15 10 SOM (%) 0 0 1 1 2 2 3 3 4 4 5 5 No-Till Conventional Tillage impact on SOM after 10 y on a sandy soil

12. GA corn erosion pic Conservation tillage alone does not work !

13. Attitude adjustment Attitude Adjustment... Attitude Adjustment... Soil C and crop residues are the key to making conservation tillage work. It’s not “the lack of tillage” but the production & conservation of crop residues which offers the most benefit to productivity. Attitude Adjustment... Attitude Adjustment... Soil C and crop residues are the key to making conservation tillage work. It’s not “the lack of tillage” but the production & conservation of crop residues which offers the most benefit to productivity.

14. USA (%) Adoption 0 0 Brazil Argentina Paraguay Derpsch, 2004 20 40 60 Brazilian Model...

15. Hot Cool Dry Wet Need for Residue Need for crop residues to sustain soil resource as affected by climate. Need for crop residues to sustain soil resource as affected by climate.

16. “The virgin fertility of our soils and the vast amount of unskilled labor have been more of a curse than a blessing to agriculture. This exhaustive system for cultivation, the destruction of forest, the rapid and almost constant decomposition of organic matter, have made our agricultural problem one requiring more brains than that of the North, East or West.” George Washington Carver The Need of Scientific Agriculture in the South George Washington Carver The Need of Scientific Agriculture in the South

17. Conservation tillage – key component... cover crops/residue Conservation tillage – key component... cover crops/residue

18. Effect of cover crop on SOM in no-till corn after 5 years... Effect of cover crop on SOM in no-till corn after 5 years... Reeves and Wood, 1994 Depth (cm) 0-3 6-12 3-6 SOM (%) 0.5 1.5 2.5 3.5 clover fallow

19. Effect of tillage/rye cover crop on SOM after 5 y Depth (cm) 0 0 5 5 20 15 10 25 Decatur silt loam SOM (%) 0 0 1 1 2 2 3 3 4 4 5 5 No-Till w/o cover Conventional w/o cover No-Till w/ cover Fall Paratill w/ cover

20. -Will Rogers, ca. 1931 “Here is my Farm Relief Bill: Every time a Southerner plants nothing on his farm but cotton year after year, and the Northerner nothing but wheat or corn, why, take a hammer and hit him twice right between the eyes. You may dent your hammer, but it will do more real good than all the bills you can pass in a year.” Crop Rotation

21. No legume/no N (1, 6) Winter legumes (2,3, 8) 120 lbs. N/acre/yr (13) Cotton every year Cotton-corn rotation Winter legume (4,7) Winter legume + 120 lbs. N/acre/yr (5,9) 3-year rotation Cotton (legumes)-Corn (small grain for grain)soybean (10,11,12) Old Rotation Experiment

22. 250250 100100 00 Yield Increase (%) 200200 5050 CotCot Cot(Leg)Cot(Leg) Cot/Corn (Leg) Cot/Corn (Leg+134 kg N/ha/yr) 150150 1986-19951986-1995 “Old Rotation” cotton yield increase from first ten years (1896-1905) “Old Rotation” cotton yield increase from first ten years (1896-1905) 1996-20051996-2005

23. 400400 200200 Yield Increase (%) 600600 300300 5005001986-19951986-1995 Corn/Cot (Leg) Cot/Corn (Leg +134 kg N/ha/yr) Cot/Corn/Wht-Soy (Leg +60 kg N/ha on wheat) 1996-20051996-2005 “Old Rotation” corn yield increase from first ten years (1896-1905) “Old Rotation” corn yield increase from first ten years (1896-1905)

24. Conservation Tillage-constraints… Cooler, Wetter Soils Conservation Tillage-constraints… Cooler, Wetter Soils

25. MAY 1 65 o F @ 8:00 a.m. Manage constraints... 50 DD60’s

26. MAY 50 -55 o F @ 8:00 a.m. Manage constraints... 2800 GDD

27. Conservation Tillage-constraints… Poor Seed-Soil Contact Conservation Tillage-constraints… Poor Seed-Soil Contact

28. Conservation Tillage-constraints… Soil Compaction/Crusting Conservation Tillage-constraints… Soil Compaction/Crusting

29. Manage compaction...

30. Manage residue...

31. Manage compaction... Non-Inversion Tillage

32. Timing Non-inversion Tillage

33. No-tillage resists compaction by equipment Conventional Tillage Conventional Tillage No-Tillage Seed cotton (kg/ha) a a b b a a a a 0 0 400 800 1200 1600 2000 2400 Traffic No Traffic

34. Conservation tillage – key components... Manage soil compaction Conservation tillage – key components... Manage soil compaction Cover Crops/ Residue

35. Conservation tillage – key components... Manage soil compaction Conservation tillage – key components... Manage soil compaction No Cover Crop or Rotation !

36. Conventional Tillage

37. No-Till w/o Cover Crop

38. No-Till with Cover Crop

39. No-Till with Cover Crop and Fall Paratilling

40. Agricultural Productivity Health/Habitation Environmental Quality Soil Quality Tillage negates cropping system effects!

41. Effect of cropping/tillage system on SOC (0-15 cm) from an eroded Ultisol Effect of cropping/tillage system on SOC (0-15 cm) from an eroded Ultisol Bruce et al., 1995 Soil Carbon (g kg –1 ) 5 5 10 30 25 20 15 1984 1986 1988 1990 Year conversion to conventional till soybean conversion to conventional till soybean Grain sorghum no-till into crimson clover Grain sorghum no-till into crimson clover

42. No-tillage Conventional tillage Top 2-cm of soil after 6 y of corn-soybean with clover cover crop Top 2-cm of soil after 6 y of corn-soybean with clover cover crop

43. Water is key pics THE Water is THE key! $ $ $ $ $ $ $ $

44. Surface soil effects pic Residues/Soil C: Surface soil effects are most critical Residues/Soil C: Surface soil effects are most critical

45. Rainfall sim pic lead-in Rainfall Simulation Study... Tillage Systems 12 yr old +/- residue removed

46. Rainfall (%) 100 80 0 0 60 40 20 No Till w/ residue No Till w/ residue No Till w/o residue No Till w/o residue Conventional Tillage Conventional Tillage Tillage and residue effects on infiltration of a Coastal Plain Soil (50-mm rain event) 3 days 11 days 6 days

47. Conservation Tillage Systems are Site-Specific..... Limestone Valleys – Clay Soils

48. Coastal Plain – Sandy Soils Conservation Tillage Systems are Site-Specific.....

49. The Future: Site Specific Soil Management GPS Guidance System

50. Electrical Conductivity Map -85.8995-85.899-85.8985-85.898-85.8975-85.897-85.8965-85.896-85.8955 32.4245 245.578.5 32.4240 32.4235 32.4230 32.4225 32.4220 32.4215

51. No-tillage improves degraded soils and reduces spatial and temporal yield variablility Conservation Tillage Conventional Tillage (+16 %) (+11%)

52. Conclusions… Soil degradation is the problem...

53. Conservation tillage by itself cannot solve the problem of soil degradation... Conclusions…

54. Soil degradation is the problem... Residue production and conservation is the solution Residue production and conservation is the solution

55. Conclusions… Soil degradation is the problem.... Residue production.... Conservation tillage and cropping intensity are the means to the solution Conservation tillage and cropping intensity are the means to the solution

56. “It is not the stronger of the species that survives, nor the most intelligent, but the one most responsive to change.” Charles Darwin