Possible Advantages of Cover Crops Interseeded at V5-V6 Corn Growth Stages in South

Dakota No-Till Production Systems

A.D.Bich*, C.L. Reese, S.A. Clay, D.E. Clay, T. Kahrel, S. Hansen, G. Reicks, P.S. Westhoff

Introduction

• Baling of corn residue for livestock feed has become a common practice in South Dakota (SD).

• Increased from 16% (2007)a to near 50% (2010)b

• Reduces soil surface residue remaining after harvest

• Potentially could increase soil erosion

• Reduces organic matter

• Reduction in grazing opportunities for livestock

• Establishment of cover crops in midseason (corn-post emergence) and after critical weed free period may:

• Provide control of late-emerging weeds

• Reduce dependency on herbicide applications (post-corn emergence)

• Improve soil surface residue remaining after harvest

• Provide a food source for various species (e.g. livestock, pheasants)

Research Objectives

• Objectives of this research project was to determine if interseeding cover crops into corn at the V5-V6 corn growth stages (post-critical weed free period) would:

• Provide a suitable environment for cover crop establishment and growth

• Suppress late-emerging broadleaf and grass weeds

• Be neutral (or increase) corn yield

• Be present after corn harvest to provide soil surface cover and a food source for various animals (e.g. livestock and pheasants).

Research Locations

• Andover, SD (AN) (2010 and 2011)

• Day County, SD

• Trail City, SD (TC) (2011)

• Corson County, SD

• Research Location Farming Practices:

• No-tillage farming systems

• Wheat-corn rotations

• 2 Field Positions per Location

• Summit

• Toeslope

Andover 2010 and 2011 Research Sites

Google Earth 2012

2010 Research Plots

2011 Research Plots

Summit Position

Summit Position

Toeslope Position

Toeslope Position

Trail City 2011 Research Site

Google Earth 2012

Summit Position

Toeslope Position

Research Plot Design

• Randomized Split-Split Design

• Main Treatment: Cover Crops

• A mixture of crimson clover (Trifolium incarnatum), lentil (Lens culinaris), and winter wheat (Triticum aestivum)

• 11 lbs. per acre (lentils)

• $0.99/lb. ($9.90/ac)

• 10 lbs. per acre (winter wheat)

• $0.23/lb. ($2.30/ac)

• 6 lbs. per acre (crimson clover)

• $1.00/lb. ($6.00/ac)

• $18.20/ac (Total Cost)

• Subplots: Cover Crop Planting Procedure

• Drill (DRL)

• Broadcast (BRD)

Research Plot Design

• Plots: 14 rows wide x 90 feet (ft.) long

• 30 inch row spacing

• 5 foot buffer at North and South ends of plots

• Subplots: 6 rows wide x 90 ft. long

• 30 inch row spacing

• Plots were replicated 4 times

• 4 blocks per research site

5 ft. Buffer

5 ft. Buffer

5 ft. Buffer 5 ft. Buffer 5 ft. Buffer

5 ft. Buffer 5 ft. Buffer 5 ft. Buffer

6 R

ow

s B

road

cast

6 R

ow

s B

road

cast

6 R

ow

s D

rill

6 R

ow

s D

rill

Plot Establishment

• Corn Planting (Planted by Farmer)

• AND 2010: 4/21/2010 (96 Day)

• AND 2011: 5/11/2011 (85-89 Day)

• TRL 2011: (Early May)

• Cover Crop Planting At V5-V6

• AND 2010: 6/22/2010**

• AND 2011: 6/28/2011

• TRL 2011: 6/30/2011

**Planted at V6 corn growth Stage

Cover Crop Planting • Critical Weed Free Period (CWFP): is the period in the corn growth

cycle which weeds must be controlled to prevent yield losses (Mahmoodi, S. and Rahimi, A. 2009)

• Corn CWFP: 3rd to 8th leaf (34 days after planting (DAP)) (Ontario 2010)

CWFP

Beckingham, C. 2007

Cover Crop Planting • Only leaves with visible collars (Red Circle) are fully developed and

count as a growth stage.

Larson, E. 2011

Andover and Trail City 2011 Interseeding Stage

Drilled cover crops at Andover, SD 2011

(15 Days After Planting) Broadcast cover crops at Andover, SD 2011

(15 Days After Planting)

Broadcast cover crops at Trail City, SD 2011

(14 Days After Planting) Drilled cover crops at Trail City, SD 2011

(14 Days After Planting)

Cover Crop and Weed Biomass Harvests • Cover crop and weed biomass harvests were completed at corn

maturity prior to corn grain and stover harvests.

• AND 2010: (Mid September)

• AND 2011: 8/22/2011

• TRL 2011: 9/14/2011

• Harvesting Procedure

• 3 x 1/10th m2 per subplot

• Samples were separated by:

• Cover crop and weeds

• Broadleaf and grass

• Individually bagged and labeled

• Dried at 86°F

• Weighed and data collected

• Analyzed

Broadcast Treatment at Harvest

Andover 2010: Cover Crop Establishment

Cover Crop Species

Summit Toeslope

BRD V6 DRL V6 BRD V6 DRL V6

-----lbs. per acre----- -----lbs. per acre-----

Crimson C. 107.64 105.42 20.09 35.7

Winter W. 7.81 26.77 0 1.1

Total Biomass 115.45 132.19 20.09 36.8

0

20

40

60

80

100

120

140

BRD V6 DRL V6 BRD V6 DRL V6

Summit Toeslope

Co

ver

Cro

p B

iom

ass

(lb

s. p

er

acre

)

Winter W.

Crimson C.

Andover 2011: Cover Crop Establishment

Cover Crop Species

Summit Toeslope

BRD DRL BRD DRL

-----lbs. per acre----- -----lbs. per acre-----

Winter W. 5.73 43.88 9.04 222.26

Crimson C. 4.41 10.36 1.32 40.57

Total Biomass 10.14 54.24 10.36 262.83

0

50

100

150

200

250

300

BRD DRL BRD DRL

Summit Toeslope

Co

ver

Cro

p B

iom

ass

(lb

s. p

er

acre

)

Crimson C.

Winter W.

Trail City 2011: Cover Crop Establishment

Cover Crop Species

Summit Toeslope

BRD DRL BRD DRL

-----lbs. per acre----- -----lbs. per acre-----

Crimson C. 1.10 24.04 105.84 273.64

Winter W. 0 13.89 0 13.67

Total Biomass 1.10 37.93 105.84 287.31

0

50

100

150

200

250

300

BRD DRL BRD DRL

Summit Toeslope

Co

ver

Cro

p B

iom

ass

(lb

s. p

er

acre

)

Winter W.

Crimson C.

Cover Crop Establishment Conclusion

• Drilling (DRL) resulted in better establishment of cover crops when compared to broadcast (BRD).

• At the AND 2010, AND 2011, and TRL 2011 summit positions, drilled treatments had a 13, 82, and 97% higher establishment when compared to the broadcast treatments

• At the AND 2010, AND 2011, and TRL 2011 toeslope positions, drilled treatments had a 45, 96, and 63% higher establishment when compared to the broadcast treatments

Cover Crop Establishment Conclusion Cont.

• All cover crops were established during the growing season, however, at harvest, only crimson clover and winter wheat remained.

• AND 2010

• Crimson clover was the dominant species remaining at the summit and toeslope field positions at harvest.

• AND 2011

• Winter wheat was the dominant species remaining at the summit and toeslope positions at harvest.

• TRL 2011

• Crimson clover was the dominant species remaining at the summit and toeslope field positions at harvest.

Cover Crop Biomass Cont.

Andover 2011: 10/27/2011

Andover 2010: Cover Crops vs. Grass Weeds

Cover Crop Application

Summit Toeslope

-----lbs. per acre-----

BRD 142.88 105.83

DRL 106.08 91.13

CONTROL 539.21 157.46

P-Value 0.0061 0.0068

• Grass weed biomass was reduced by 74% (BRD) and 80% (DRL) at the summit position.

• Grass weed biomass was reduced by 33% (BRD) and 42% (DRL) at the toeslope position.

Andover 2011: Cover Crops vs. Grass Weeds

Cover Crop Application

Summit Toeslope

-----lbs. per acre-----

BRD 60.99 76.95

DRL 44.85 18.65

CONTROL 60.97 77.62

P-Value NS 0.059

• Cover crops had no significant effect on grass weed biomass at the summit position.

• Grass weed biomass was reduced slightly (BRD) and 76% (DRL) at the toeslope position.

Trail City 2011: Cover Crops vs. Grass Weeds

Cover Crop Application

Summit Toeslope

-----lbs. per acre-----

BRD 29.92 3.84

DRL 2.05 11.1

CONTROL 37.02 27.18

P-Value 0.12 0.12

• Grass weed biomass was reduced by 18% (BRD) and 94% (DRL) at the summit position.

• Grass weed biomass was reduced by 86% (BRD) and 59% (DRL) at the toeslope position.

Cover Crops vs. Broadleaf Weeds

• Cover crops overall had no significant effect on broadleaf weed biomass at the Andover 2010, Andover 2011, and Trail City 2011 research locations

• *At the summit, only 1 block of the DRL treatment had broadleaf weeds, therefore, the presences of broadleaf weeds is not consistent among all the blocks in the study for the DRL treatment.

Cover Crop Application

AND 2010 (SUM)

AND 2010 (TOE)

AND 2011 (SUM)

AND 2011 (TOE)

TRL 2011 (SUM)

TRL 2011 (TOE)

--------------------lbs. per acre-------------------- BRD 122.8 0 0 0 86.6 237.3

DRL 180.8 4.5 *18.2 0.5 43.9 181.2

CONTROL 8.9 15.6 0 0 46.4 195.6

P-Value NS NS 0.0043 NS NS NS

Cover Crops vs. Corn Yield

Cover Crop Application

Andover 2010 Andover 2011 Trail City 2011

Summit Toeslope Summit Toeslope Summit Toeslope

-----bushels/acre----- -----bushels/acre----- -----bushels/acre-----

BRD 203 a 208 a 154 ab 203 ab 79 a 160 a

DRL 198 a 209 a 158 ab 207 ab 73 a 158 a

Control 214 a 198 a 175 a 205 ab 72 a 144 a

• Cover crops had no significant effect on corn grain yield at either field positions at Andover in 2010 and 2011 and Trail City in 2011.

Conclusion

• Establishment of cover crops at the V5 and V6 stage was successful.

• Drilling resulted in better establishment than broadcasting.

• Increased soil surface residue and grazing opportunities.

• Crimson clover (AND 2010 and TRL 2011) and winter wheat (AND 2011) were the most prolific cover crop species remaining at harvest.

• Provided approximately 20% ground cover (visual estimation).

• $8.30 per acre to apply a mixture of crimson clover and winter wheat

• Cover crops had no influence on broadleaf weed biomass.

• Cover crops reduced grass weed biomass by 59-94% (DRL) and slight to 86% (BRD).

• Cover crops had no influence on yield.

Acknowledgements • Natural Resource Conservation Service

• Conservation Innovation Grants

• CIG Grant: Agreement Number: 9-148

• Roger and Grant Rix (Farmer Cooperation)

• Rick Bieber (Farmer Cooperation)

• South Dakota Wheat Commision

• South Dakota Corn Utilization Council

• South Dakota Soybean Research and Promotion Council

• South Dakota State University

• South Dakota Agricultural Experiment Station

References USDA-NASS. 2012. Quick Stats: U.S. & All States County Data: Crops (South Dakota). http://www.nass.usda.gov/QuickStats/PullData_US_CNTY.jsp

USDA-NASS2. 2011. 2010 State Agriculture Overview: South Dakota. http://www.nass.usda.gov/Statistics_by_State/Ag_Overview/AgOverview_SD.pdf NASS. 2011. Agricultural Chemical Use Database (South Dakota). http://www.pestmanagement.info/nass/act_dsp_bar.cfm USDA-NASS3. 2011. U.S. & All States Data: Chemical Usage Field Crops (South Dakota). http://www.nass.usda.gov/QuickStats/PullData_US.jsp Janssen, L., N.Klien, G. Taylor, E. Opoku, and M. Holbeck. 2008. Conservation reserve resource program in South Dakota. South Dakota State University Economics Research Report 2008-1.

Mamani-Pati, F., D.E. Clay, C.G. Carlson , S.A. Clay, G. Reicks, and K. Kim. 2010b. Nitrogen rate, landscape position, and harvest corn stover impacts on energy gains and carbon budgets of corn grown in South Dakota. Agronomy Journal. 102:1535-1541 Google Earth. 2012

Larson, E. 2011. How to Determine Growth Stages of Young Corn Sorghum. http://www.mississippi-crops.com/2011/04/21/how-to-determine-growth-stages-of-young-corn-or-sorghum Ontario. 2010. Principles of Integrated Weed Management: Critical Period of Weed Control. http://www.omafra.gov.on.ca/english/crops/pub75/1critica.htm#field

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