1. Tillage and Cropping Systems to Increase Dryland Crop Production in Southwest Oklahoma by Gary Strickland Extension Educator – OCES Jackson County

2. Team Approach OSU’s IPM Program
Area Extension Staff – Mr. Jerry Goodson (SWREC), Dr. Mark Gregory, Mr. Rick Kochenower, Mr. Terry Pitts, and Daniel Skipper
State Extension Staff – Dr. J.C. Banks, Mr. Shane Osborn, Dr. Jeff Edwards, Dr. Chad Godsey, Dr. Randy Taylor
OAES – Mr. Rocky Thacker and SWREC Crew,
Jackson County OCES Program
Local and Private Industry Sponsors (i.e.; Oklahoma Grain Sorghum Producers, Seed Companies, Coops, etc…)

3. Objectives of the Study
Determine the impact of different cropping systems on resident insect populations
Determine the effect of tillage and cropping management systems on weed species population dynamics
Determine and demonstrate the effects of tillage and crop rotation on the economic components of weed, insect, and yield management in cotton, wheat, and grain sorghum production systems in Southwest Oklahoma
To estimate the effects of tillage and cropping systems on SOM accumulation

4. Study Design Randomized Complete Block with a Split Plot Design
Two Tillage Systems
Three Crops (Cotton, Wheat, Grain Sorghum)
Seven Cropping Systems (C-W-GS, C-W, C-GS, W-DCGS-C, W, C, GS)

6. Summary of Insect Data
To date, no significant differences have been noted between tillage treatments or among cropping systems regarding insect populations or species.
Crop scouting principle has been reinforced in this study
When a buildup of insect pests occurs a corresponding buildup of beneficial insects has occurred

7. Pest and Beneficial Insect Relationship

10. Soil Organic Matter Management - Importance in Dryland Crop Production
Soil Erosion Prevention
Increased Soil Water Storage Capacity
Increased Water Infiltration Rates
Decreased Soil Evaporation Rates
Increase of In-Season Precipitation Use Efficiency
Increased Organic Matter Pool
Increased Cation Exchange Complex (CEC)
Increased Anion Exchange Complex (AEC)
Decrease in Soil Compaction in the Long Term

11. Tillage by Crop Rotation System SOM Comparisons (2002-2008).TS
C-W-GS
C-W
C-GS
W-DCGS-C C W GS
Mean
L.S.D.
(.05) NT
2.00(2)
1.49(6)
1.93(2)
1.63(6)
2.03(2)
1.84(6)
2.08(2)
1.71(6)
2.13(2)
1.94(2)
1.68(6)
2.42(2)
1.79(6)
1.69(6)
NS(2)
NS(6) CT
1.76(2)
1.64(6)
1.87(2)
1.83(6)
1.82(2)
1.70(6)
1.84(2)
1.72(6)
1.79(2)
1.96(2)
1.87(6)
2.06(6)
1.73(6)
0.13(6)(.10)
(2) 2 inch sampling depth; (6) 6 inch sampling depth

14. Organic Matter Summary
The interaction between tillage systems and cropping systems was significant at the .05 probability level therefore comparisons should be primarily between cropping systems within a tillage system.
Soil organic matter accumulation, in general, indicate no significant differences between cropping systems within tillage treatments to date with the exception of the 6 inch sampling depth in the CT cropping systems. But the data does reflect a trend across cropping systems of increasing organic matter content in the top two inches when compared to the six inch depth in both systems, NT systems are 38% higher and the CT systems are 16% higher.
However, a significant difference between the two systems does exist (as indicated by the significant interaction) with the NT systems showing higher levels of SOM across all cropping systems, except for the W only system, at the 2 inch layer.

15. Summary of Weed Data
Only a few significant differences have been noted to date between tillage treatments or among cropping systems
In general the NT systems show higher weed populations than the CT systems
Common weed species that continue to be present in the field include: common purslane, prickly lettuce, winter grasses (bromegrass species primarily), marestail, and henbit
New weed species that have appeared with time include: honeyvine milkweed, morningglory, red stem filaree, and common groundsel.
To date current herbicide programs seem to be working in terms of weed population control with the exception of the Grain Sorghum No-Till Mono-Crop where significant increase in pigweed species occurred and has remained after a glyphosate and two atrazine herbicide applications; and common groundsel in the cotton systems.

16. 2006 Cotton Weed Populations
Treatments
Common Purslane
Prickly Lettuce
Pigweed
C-W (NT)
1.0ψ (P.E.)
0.0 (P.H.)
0.5 (P.E.)
0.5 (P.H.)
C (NT)
4.3 (P.E.)
0.3 (P.E.)
4.0 (P.E.)
C-W (CT)
0.0 (P.E.)
0.7 (P.E.)
C (CT)
Ψ: Weed numbers are from counts taken in 1/1000 of an acre.

18. Post-E Pigweed Counts in 2008 Grain Sorghum Systems
Tillage System
C-GS GS
Mean
L.S.D. (.05) NT
5.8ψ
57.2
31.5
24.2 CT
0.33
0.5
0.42 NS
Ψ: Numbers are counts taken in 1/1000 of an acre

23. Crop Herbicide Systems
Time of Applica-
tion
Mode of Action Group
Crop Use
Crop Rotation Intervals (M)
Broadleaf Tank Mixes
Grazing Restric-tion
(Days)
Roundup
(Glyphosate)
Pre, Post, HA
Inhibition of EPSP Syn. (9)
C, W, GS
All Crops – 0M
Yes
0 Days
Dual
(metolachlor)
Pre & Post
Shoot Inhibitors (15)
GS, C
W-4.5M; C & GS – Next Spring
Do not feed
Maverick
(sulfosulfuron)
Post
ALS Inhibitor
(2) W
C &GS – 12M
Osprey (mesosulfuron-methyl)
C – 3M; GS- 10M
Olympus Flex
C & GS – 12M
Finesse Grass & Broadleaf
ALS Inhibitor (2)
C & GS - Bioassay
7 Days
Axial XL
ACCase Inhibitor (1)
C & GS – 4M
30 Days

24. Crop Herbicide Systems Continued
Time of Applica-tion
Mode of Action Group
Crop Use
Crop Rotation Intervals (M)
Broadleaf Tank Mixes
Grazing Restric-tion
Power Flex
Post
ALS Inhibitor (2) W
C & GS – 9M
Yes
7 Days
MCPA
Synthetic Auxin (4)
After Harvest
Harmony Extra
C & GS – 1.5M NA
Peak
(prosulf-uron)
W & GS
W – 0M
GS – 1M
C – 18M
30 Days
Basagran
(bentazon)
PS II Inhibitor (6) GS
W-0M
C – 0M
Buctril
(bromoxy-nil)
W – 1M
C – 1M
45 Days
Atrazine
PS II Inhibitor (5)
See Label
21 Days

25. Crop Yield and Economic Responses

31. Production Economic Summary for 2003-2009
While not always significant, the NT crop systems have shown a consistent trend for higher return dollars beyond production inputs than the CT systems.
With only a few exceptions the crop rotations have indicated a trend for higher yields and/or returns in the year by year comparisons
When averaged across years the NT C-W and C-GS crop rotation systems are doing significantly better than the mono-crop systems. However C and W only systems (especially within the CT tillage system) have done surprisingly well in comparison as all years are considered. This is somewhat tied to the 2007 elevated crop year yields and commodity prices. When the 2007 crop year is removed from the data then the NT Rotation Systems and CT-CW rotation perform significantly better.