Tillage and Cropping Systems to Increase Dryland Crop Production in Southwest Oklahoma

1. Tillage and Cropping Systems to Increase Dryland Crop Production in Southwest Oklahoma

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)

5. General Approach in each area of objectives • Insects: Define populations and/or dynamics through weekly scouting of plots • Weeds: Define population at beginning of crop cycle and at the end prior to harvest • Crop Production: Maximum economic production efforts for each crop and cropping system • Economics: Develop production input costs and return dollars above production input costs • S.O.M.: Evaluate the buildup of organic matter at the 2 and 6 inch soil depth zones

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). (2) 2 inch sampling depth; (6) 6 inch sampling depth

13. 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.

14. 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 2008 Grain Sorghum No-Till Mono-Crop where significant increase in pigweed species occurred and remained after a glyphosate and two atrazine herbicide applications.

15. 2006 Cotton Weed Populations

16. Post-E Pigweed Counts in 2008 Grain Sorghum Systems

18. Crop Herbicide Systems

19. Crop Herbicide Systems Continued

20. Herbicides • Know the weed species you are trying to control • Be familiar with application timing, label requirements for additives, and GPA requirements • Crop rotations a strong benefit in no-till work in terms of weed control • Sprayer maintenance vital • Calculate the economics • Changing the M.O.A important (again tied to crop rotations

22. Crop Yield and Economic Responses

28. Production Economic Summary for 2003-2008 • 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 • However, when averaged across years the C and W only systems (especially in the CT tillage system) are currently doing as good as all rotation crop systems with the exception of the C-W system. 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.