1. Conservation Tillage in Cotton: A Mississippi Delta Perspective
Bill Pettigrew
USDA-ARS (retired)
Crop Production Systems Research Unit
Stoneville, MS

2. 1997-98 Study Conventional vs. No-till comparison Wheat cover crop
Six varieties
Planted first week of May
Hand harvested
W.T. Pettigrew and M.A. Jones, Agron. J. 93:
Pettigrew and Jones, 2001

3. Pettigrew and Jones, 2001

4. Pettigrew and Jones, 2001

5. Pettigrew and Jones, 2001

6. Tillage System Effects on Cotton Lint Yield and Yield Components During 1997 and 1998.
Boll
Year
System
Yield
Number
Size
Percent
lbs acre-1
bolls m-2
g boll-1 %
1997
Conventional
1226 94
3.93
37.2
No-till
1075 87
2.79
36.2
LSD 0.05 72 5
0.12
0.7
1998
683 67
3.30
34.5
619 60
3.33
34.4
70 (ns) 6
0.10 (ns)
0.7 (ns)
Pettigrew and Jones, 2001

7. Tillage System Effects on Cotton Fiber Quality Traits During 1997 and 1998.
2.5%
Fiber
Year
System
Span Length
Strength
Micronaire
inches
kN m kg-1
1997
Conventional
1.16
210
4.12
No-till
209
3.94
LSD 0.05
0.01 (ns)
4 (ns)
0.12
1998
207
4.01
1.15
203
4.30 3
Pettigrew and Jones, 2001

8. 2004-2007 Study Conventional vs. Minimum-till comparison No cover crop
Four varieties
Planted first week of April and first week of May
Machine harvested
W.T. Pettigrew, W.T. Molin and S.R. Stetina, Agron. J. 101:
Pettigrew et al., 2009

9. Tillage System Effects on Cotton Lint Yield Production During 2004 through 2007.
2005
2006
2007
lbs acre-1
Conventional
870
1054
1300
1057
Minimum-till
779
987
1097
947
LSD 0.05
233 (ns)
140 (ns)
169
121 (ns)
Pettigrew et al., 2009

10. Planting Date Effects on Cotton Lint Yield Production During 2004 through 2007.
2005
2006
2007
lbs acre-1
Early
908
1054
1177
1100
Normal
741
987
1217
904
LSD 0.05
233 (ns)
140 (ns)
169 (ns)
121
Pettigrew et al., 2009

11. Tillage System Effects on Cotton Leaf Water Potential and Root Hydraulic Conductance Averaged Across 2005 through 2007.
Tillage
Water
Osmotic
Turgor
Hydraulic
System
Potential
Conductance
MPa
kg s-1 MPa-1
Conventional
-1.47
-1.67
0.20
5.4 x 10-5
Minimum-till
-1.49
-1.70
0.22
5.2 x 10-5
LSD 0.05
0.10 (ns)
0.09 (ns)
0.04 (ns)
8.7 x 10-6 (ns)
Pettigrew et al., 2009

12. Study
Starter fertilizer ( ) vs. no starter fertilizer comparison under early planted no-till production
Wheat cover crop
Seven varieties
Planted first week of April
Machine harvested
W.T. Pettigrew and W.T. Molin, Crop Management DOI /CM RS
Pettigrew and Molin, 2013

13. Starter Fertilizer Effects on No-till Cotton Plant Stand Counts During 2008 through 2010.
Fertility
Program
2008
2009
2010
plants m-2
No Starter
8.5
9.3
7.9
Plus Starter
6.7
6.5
7.0
LSD 0.05
0.5
0.3
Pettigrew and Molin, 2013

14. Starter Fertilizer Effects on No-till Cotton Lint Yield Production During 2008 through 2010.
Fertility
Program
2008
2009
2010
lbs acre-1
No Starter
1341
1192
1123
Plus Starter
1391
1242
LSD 0.05 39 38
35 (ns)
Pettigrew and Molin, 2013

15. Advantages Reduced soil erosion Improved soil structure
Increased rain infiltration
Clearer runoff
Similar yields

16. Disadvantages Cooler soil temperature at planting
More complicated weed control
Stand establishment issues?
Delayed maturity and development
Early season insect issues?

17. Tips and Issues Use a cover crop
Let cover crop grow as tall as possible before termination
Rotate crops on a field
Furrow irrigation issues
Make sure the seed furrow closes
Wet harvest season could rut up the field