Tillage and Cropping Systems to Increase Dryland Crop Production in - PowerPoint PPT Presentation

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

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…)

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

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)

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

Pest and Beneficial Insect Relationship Table 5. Wheat Insects 2002/2003 ∞ ‡ Greenbug Treatment Parasitized Greenbugs Beneficials Weekly Counts † 6 7 7 8 9 10 6 7 8 9 10 4. W-DCGS-C (NT) 2.7 2.7 75 46 5.7 3.3 64 13 28 6.3 7.0 6. W (NT) 1.7 0.3 61 15 10 5.0 70 16 15 6.0 13 11. W-DCGS-C (CT) 5.3 0.3 80 12 5.0 6.3 84 13 9.3 7.0 5.0 13. W (CT) 1.7 0.7 63 7.7 4.0 4.3 64 9.0 6.7 5.3 8.0

IPM PRINCIPLE REINFORCED - 2002/2003 WHEAT 90 Numbers of Total Insects from both Sweep and Linear 80 70 60 W-DCGS-C (NT) Foot of Row Counts 50 W (NT) 40 W-DCGS-C (CT) 30 W (CT) 20 10 0 Insect and Week Count: Greenbug (GB); Parasitized Greebug (PGB); Beneficial (B)

IPM Principle Reinforced 2007 Cotton Crop Numbers of Total Insects from both sweeps and linear row 35 30 25 foot counts 20 15 Aphids Beneficials 10 5 0 NT - Week 6 CT - Week 6 NT - Week 7 CT - Week 7 NT - Week 8 CT - Week 8 Weeks of Insect Buildup and Decline

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

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

Water content, g g -1 Soil resistance, kPa 0 1000 2000 3000 4000 5000 6000 7000 0.12 0.15 0.18 0.21 0.24 0.27 0 Table of significance A Rotation / Tillage 5 *** / *** *** / ns 10 15 *** / * 20 *** / *** 25 *** / *** * / *** 30 35 ns / *** 40 Soil depth, cm 45 0 B Rotations 5 C-W-GS C-W 10 C-GS W-DCGS-C 15 C W 20 GS 25 30 35 40 45

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.

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.

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

Post-E Pigweed Counts in 2008 Grain Sorghum Systems Tillage C-GS GS Mean L.S.D. System (.05) 5.8 ψ NT 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

Grain Sorghum Crop System Average Weed Population (Pre-Harvest) 2002-2008 30000 25000 20000 Weeds/A 15000 10000 5000 0 Cropping Systems by Tillage Treatment

2009 Cotton Weed Counts 160000 140000 120000 Plants - Thousand/Acre 100000 C-W-NT C-GS-NT 80000 C-NT C-WCT 60000 C-GS-CT C-CT 40000 20000 0 Pigweed (PE) Groundsel (PH) Weed Species by Tillage and Cropping System

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

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

Crop Yield and Economic Responses

Average Cotton Yields 2003-2008 700 640 600 557 554 552 538 486 500 Lint Yield (Lbs./A ) 425 371 400 364 300 169 200 100 0 Cropping Systems by Tillage Treatment

Wheat Yields 2003-2008 80 74 70 64 63 59 60 49 50 Yield (Bu./A ) 42 40 37 30 20 15 10 0 Cropping Systems by Tillage Treatment

Grain Sorghum Yields 2003-2008 3000 2831 2690 2500 1932 2000 1743 1649 Yield (Lbs./A ) 1500 1000 500 0 0 0 0 Cropping Systems by Tillage Treatment