Tim Reinbott, Kerry Clark, Leslie Touzeau
573-884-7945
Reinbottt@Missouri.edu
Jeff Moyer at Rodale
LONG TERM PASTURE NATIVE
WARM SEASON GRASSES
TILLED IN A
CORN/SOYBEAN/WHEAT
ROTATION
No-Till Grain Sorghum Into Hairy Vetch Residue
Tillage Has Destroyed Soil Structure
 Cash Crop All Three
Years?
 Weed Control
Strategies-Using
Cover Crops
 Tillage vs No-Tillage
 Always use a
polyculture cover crop-
legumes, grasses, and
brassicas
 Treatment 1: always
use a crop that is
mowed or i...
 Treatment 2-cover
crops first year (SXS):
cash crops 2nd (grain
sorghum) and 3rd
years.
 Treatments 3 and 4:
no-till-so...
Cover Crops and Weed Control-Both Physical
and Natural Chemical Controls
Cowpea
Weedy plot with
no cover crop
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
buckwheat cowpeas fallow sesbania ss sunn hemp turnip winter
radish
WeedCoverA...
Courtesy of Iowa State
On The Left Cover Crop, Right No Cover CropPlanting Into Standing Cover Crop
After Tillage Radish-No Annual WeedsLight Inhibition From The Cover Crop
>
>
<
Teasdale and Mohler, 2000
From Peachy, et al, 1999
Teasdale, 1996
Early May 1500 lbs Late May 7,000 lbs
Promotes a Bacteria
Dominant Soil Promotes a Fungi
Dominant System
Your text here
From Peachy, et al. 1999
 Weeks After Transplanting
 Treatment 2 4 6 8
 lbs/acre
 Bare Ground 109 2818 13,465 12,376
 Rye-2 WBP 5 120 572 2042...
 As Rye Biomass
Changes From 2,000
lb/acre to 8-10,000
lb/acre Weed
Biomass Decreases
Linearly.
Nord, et al. 2011
WeedBio...
 Delay Cover Crop
Destruction
 Crops that Can Be
Planted Later-
Soybean, Sorghum, Sun
flowers
 Plant Higher Rate of
Cov...
Courtesy of Steve Groff
Lauer, 1996
 1x=100 lb/acre
Oat/legume
 2x=200 lb/acre
Oat/Legume
 3x=300 lb/acre
Oat/Legume
Brennan, et al., 2009
1x
2x
3x
 A Two-Year Rotation
(top) corn/soybean
large number of weeds
 Increasing Length of
Rotation Decreased
Weed Biomass-Midd...
DAY OF DESICCATION
5 DAYS LATER
Flailed Rolled Rolled Flailed
0
10
20
30
40
50
60
70
80
90
100
chop roll chop roll chop roll chop roll
before cc destroyed same day cc destroyed 1 week ...
 Crop Crop Stand Stand
 System 2012 2013 2012 2013
plants/acre
 Corn/soy tilled soybean corn 81,370 20,904
 Corn/GS/so...
Rolled and Then PlantedPlanted Directly and Then Rolled
 Rolled Standing
 Treatment Pop. Pop
plants/acre
 Control 24,347 28,855
 Hairy Vetch 29,563 34,813
 Aust. Winter Pea ...
6,900 lb Cover CropLess Than 4000
lb Cover Crop
 Soybean Yield 2013 Cover Crops Overseeded
into Corn Sept. 2012
 Treatment Yield
 Bu/acre
 Control 29
 Hairy Vetch 24...

 Weed Cover Crop SxS 2013
 System 2012 2013 Biomass Biomass Biomass Grain Yield
 Lbs/acre lbs/acre
 Cover Crop Only ...
 Natural Compounds
 Stems, leaves, roots
 Sorghum, Cereal
Rye, Walnut trees
 Can inhibit
germination and
growth of oth...
Weston et al., 2013
Kelton, et al.,

 Weed Cover Crop SxS 2013
 System 2012 2013 Biomass Biomass Biomass Grain Yield
 Lbs/acre lbs/acre lb/acre lb/acre lb...
 Weed Cover Crop SxS 2013
 System 2012 2013 Biomass Biomass Biomass Grain Yield
 Lbs/acre lbs/acre lb/acre lb/acre lb/a...
 Cover Crops Can Reduce Weed Competition:
 Light Inhibition
 Competition
 Releasing Natural Chemicals-Allelopathy
 Ti...
 Planting Later and Using A Shorter Season
Cultivar Maybe Best to Help Reduce Weeds.
 Small Seeded Vegetables Have a Har...
67
Kristen Veum and Robert Kremer
 SOM is derived from
 Plant residue (both
litter and roots)
 Animal remains and
excreta
 Living soil microbes
(microbi...
 Loss of Organic
Matter
 Soil structure
 Soil microbial
biomass
 Release of CO2
 Soil Erosion
 Why Till?
 Weed Cont...
3000
3500
4000
4500
5000
5500
6000
6500
7000
7500
80001900
1910
1920
1930
1940
1950
1960
1970
1980
1990
Year
SoilC(gm-2)
C...
 20 – 40% of SOM is lost on cultivation
 Management effects on SOM
 Tillage (disturbance) 
 Chemical Fertilization 
...
73
Slake Test
Fungi Hyphae
LONG TERM PASTURE
TILLED IN A
CORN/SOYBEAN/WHEAT
ROTATION
0
500
1000
1500
2000
2500
3000
Biomass(mg/g)
Cropping Type
PLFA Analysis at Bradford Research Center
Bacteria
Actinomycete...
0
50
100
150
200
250
300
350
400
450
500
Soybean Switchgrass NT Corn Hedgerow/fescue Fescue field
Biomass(mg/g)
Cropping S...
Scientists describe 3 pools of soil organic matter
**really is a continuum of decomposition
Passive SOM
500 – 5000 yrs
C/N...
Results are read in a spectrometer in lab or
field or from a color card
Potassium
Permanganate Test
KMnO4 oxidizes active ...
Table 3. PLFA concentrations
Treatment Total Gram+ Gram− Actino Fungi AM Fungi Protozoa
Bare 15.07 DE 4.45 CD 3.94 DE 2.17...
Doug Peterson
140°
F
130°
F
100°
F
70° F
Soil bacteria die
100% moisture lost through
evaporation & transpiration
15% moisture is used f...
Surface crust impedes infiltration.
Open, granular surface structure
enhances infiltration.
Biopores (earthworm channel)
e...
From Steve Groff
Cover Crop No Cover Crop
No-Till With Cover Crop Took Several Hours For
Water To Run-Off
 Biggest challenge in No-Till Organic is
producing enough biomass to control weeds
 9,000 lbs is needed
 Sorghum X Suda...
 Continuous cover
crops during can
increase soil active
carbon and soil health
leading to better
water infiltration
 Huge Kill-Off
 Often highest yield
following
 Take Advantage Of This
 Small Grain-Mow
afterward and plant
cover crops...
 Coming from a tilled
conventional grain field
 Were Weeds
Controlled?-cover crops
and no-till cash crops
 If not: Thre...
 Cover Crops
 Use for weed
smothering with
transplants
 Direct Seeding-lightly
till
 Smother Crops
During Times of Non...
 Lengthen Rotation-
including hay crops
 Early Maturing Cultivars
 Planting Later-Take
Advantage of Cover Crop
Biomass ...
Reinbottt@Missouri.edu
573-884-7945
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
Weed Control and Soil Health During Transitioning To Organic
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  • SOM is NOT just from crop residues! Plant roots are very important to SOM production. Living plants (i.e, cover crops) help retain and PRODUCE SOM.
  • Weed Control and Soil Health During Transitioning To Organic

    1. 1. Tim Reinbott, Kerry Clark, Leslie Touzeau 573-884-7945 Reinbottt@Missouri.edu
    2. 2. Jeff Moyer at Rodale
    3. 3. LONG TERM PASTURE NATIVE WARM SEASON GRASSES TILLED IN A CORN/SOYBEAN/WHEAT ROTATION
    4. 4. No-Till Grain Sorghum Into Hairy Vetch Residue Tillage Has Destroyed Soil Structure
    5. 5.  Cash Crop All Three Years?  Weed Control Strategies-Using Cover Crops  Tillage vs No-Tillage
    6. 6.  Always use a polyculture cover crop- legumes, grasses, and brassicas  Treatment 1: always use a crop that is mowed or incorporated into the soil-no cash crop-includes sorghum x sudangrass (SXS)
    7. 7.  Treatment 2-cover crops first year (SXS): cash crops 2nd (grain sorghum) and 3rd years.  Treatments 3 and 4: no-till-soybean/grain sorghum or soybean/corn rotation  Treatments 5 and 6- same as treatments 3 and 4 except tilled  Treatment 7: tilled sorghum x sudan first year followed by wheat/soybean/corn
    8. 8. Cover Crops and Weed Control-Both Physical and Natural Chemical Controls Cowpea Weedy plot with no cover crop
    9. 9. 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% buckwheat cowpeas fallow sesbania ss sunn hemp turnip winter radish WeedCoverAsPercentageOfTotalLandArea Cover Crop Weed Control In Summer Cover Crops Clark and Reinbott, 2012
    10. 10. Courtesy of Iowa State
    11. 11. On The Left Cover Crop, Right No Cover CropPlanting Into Standing Cover Crop
    12. 12. After Tillage Radish-No Annual WeedsLight Inhibition From The Cover Crop
    13. 13. > > < Teasdale and Mohler, 2000
    14. 14. From Peachy, et al, 1999
    15. 15. Teasdale, 1996
    16. 16. Early May 1500 lbs Late May 7,000 lbs Promotes a Bacteria Dominant Soil Promotes a Fungi Dominant System
    17. 17. Your text here From Peachy, et al. 1999
    18. 18.  Weeks After Transplanting  Treatment 2 4 6 8  lbs/acre  Bare Ground 109 2818 13,465 12,376  Rye-2 WBP 5 120 572 2042  Rye-1 WBP 3 28 320 1556 WBP=Weeks Before Planting-how many weeks prior to Tomato Transplanting was cover crop terminated Smeda and Weller, 1996
    19. 19.  As Rye Biomass Changes From 2,000 lb/acre to 8-10,000 lb/acre Weed Biomass Decreases Linearly. Nord, et al. 2011 WeedBiomass,lbs/acre 2008 2009 0 6,000 0 6,000
    20. 20.  Delay Cover Crop Destruction  Crops that Can Be Planted Later- Soybean, Sorghum, Sun flowers  Plant Higher Rate of Cover Crops  Earlier Maturing Corn  -so we can plant later  Plant cover crop in fall earlier
    21. 21. Courtesy of Steve Groff
    22. 22. Lauer, 1996
    23. 23.  1x=100 lb/acre Oat/legume  2x=200 lb/acre Oat/Legume  3x=300 lb/acre Oat/Legume Brennan, et al., 2009 1x 2x 3x
    24. 24.  A Two-Year Rotation (top) corn/soybean large number of weeds  Increasing Length of Rotation Decreased Weed Biomass-Middle and Bottom  Including Hay for two years (bottom) In Rotation Decreased Weeds-Bottom open symbols Teasdale, et al, 2004 Two-Year Rotation Three Year Four-year
    25. 25. DAY OF DESICCATION 5 DAYS LATER Flailed Rolled Rolled Flailed
    26. 26. 0 10 20 30 40 50 60 70 80 90 100 chop roll chop roll chop roll chop roll before cc destroyed same day cc destroyed 1 week after cc destroyed 2 weeks after cc destroyed Plantcountper10feet Corn germination when planted into rye cover crop
    27. 27.  Crop Crop Stand Stand  System 2012 2013 2012 2013 plants/acre  Corn/soy tilled soybean corn 81,370 20,904  Corn/GS/soy soybean GS 86,771 47,034  Corn/soy no-till soybean corn 61,492 22,646  GS/Soybean no-tillsoybean GS 66,196 29,614  GS=Grain Sorghum
    28. 28. Rolled and Then PlantedPlanted Directly and Then Rolled
    29. 29.  Rolled Standing  Treatment Pop. Pop plants/acre  Control 24,347 28,855  Hairy Vetch 29,563 34,813  Aust. Winter Pea 23,884 26,926  Cereal Rye 25,774 24,315 
    30. 30. 6,900 lb Cover CropLess Than 4000 lb Cover Crop
    31. 31.  Soybean Yield 2013 Cover Crops Overseeded into Corn Sept. 2012  Treatment Yield  Bu/acre  Control 29  Hairy Vetch 24  Crimson Clover 28  Radish 27  Cereal Rye 36 Reinbott, 2013
    32. 32.   Weed Cover Crop SxS 2013  System 2012 2013 Biomass Biomass Biomass Grain Yield  Lbs/acre lbs/acre  Cover Crop Only SxS SxS 83 4891 41,384  Modified Cover Crop SXS GS 2279 4112 20  Modified Conv. Till SXS wheat 209 28  Corn/soy tilled soybean corn 2299 5490 77  Corn/sorg/soy soybean GS 2788 7071 13  Corn/soy no-til soybean corn 3143 8712 49  Sorghum/Soybean soybean GS 3129 6268 4 Clark and Reinbott, 2013
    33. 33.  Natural Compounds  Stems, leaves, roots  Sorghum, Cereal Rye, Walnut trees  Can inhibit germination and growth of other plants
    34. 34. Weston et al., 2013
    35. 35. Kelton, et al.,
    36. 36.   Weed Cover Crop SxS 2013  System 2012 2013 Biomass Biomass Biomass Grain Yield  Lbs/acre lbs/acre lb/acre lb/acre lb/acre bu/acre  Cover Crop Only SxS SxS 83 4891 41,384  Modified Cover Crop SXS GS 2279 4112 20  Modified Conv. Till SXS wheat 209 28  Corn/soy tilled soybean corn 2299 5490 77  Corn/sorg/soy soybean GS 2788 7071 13  Corn/soy no-til soybean corn 3143 8712 49  Sorghum/Soybean soybean GS 3129 6268 4  SxS=Sorghum x Sudan  GS=Grain Sorghum
    37. 37.  Weed Cover Crop SxS 2013  System 2012 2013 Biomass Biomass Biomass Grain Yield  Lbs/acre lbs/acre lb/acre lb/acre lb/acre bu/acre  Cover Crop Only SxS SxS 83 4891 41,384  Modified Cover Crop SXS GS 2279 4112 20  Modified Conv. Till SXS wheat 209 28  Corn/soy tilled soybean corn 2299 5490 77  Corn/sorg/soy soybean GS 2788 7071 13  Corn/soy no-til soybean corn 3143 8712 49  Sorghum/Soybean soybean GS 3129 6268 4  SxS=Sorghum x Sudan  GS=Grain Sorghum
    38. 38.  Cover Crops Can Reduce Weed Competition:  Light Inhibition  Competition  Releasing Natural Chemicals-Allelopathy  Tillage Increases Weed Germination and Competition With Heavy Weed Pressure Year Around Cover Crops May Need to Be Utilized. Forgoing a Cash Crop
    39. 39.  Planting Later and Using A Shorter Season Cultivar Maybe Best to Help Reduce Weeds.  Small Seeded Vegetables Have a Hard Time In No-Till Cover Crops  Incomplete Cover Crop Kill Can Inhibit Vegetable Yield
    40. 40. 67 Kristen Veum and Robert Kremer
    41. 41.  SOM is derived from  Plant residue (both litter and roots)  Animal remains and excreta  Living soil microbes (microbial biomass)  Over time fresh organic material is transformed into soil organic matter Crop Residues Bacteria Fungi Actinobacteria SOM 68
    42. 42.  Loss of Organic Matter  Soil structure  Soil microbial biomass  Release of CO2  Soil Erosion  Why Till?  Weed Control
    43. 43. 3000 3500 4000 4500 5000 5500 6000 6500 7000 7500 80001900 1910 1920 1930 1940 1950 1960 1970 1980 1990 Year SoilC(gm-2) Conventional Tillage Reduced Tillage 53% of 1907 61% of 1907 71
    44. 44.  20 – 40% of SOM is lost on cultivation  Management effects on SOM  Tillage (disturbance)   Chemical Fertilization   Manure   Residue Retention   Crop   Crop Rotation   Cover Crop  72 Decline in SOC from Sanborn Field Plots showing increase following the return of residues beginning in 1950
    45. 45. 73
    46. 46. Slake Test Fungi Hyphae
    47. 47. LONG TERM PASTURE TILLED IN A CORN/SOYBEAN/WHEAT ROTATION
    48. 48. 0 500 1000 1500 2000 2500 3000 Biomass(mg/g) Cropping Type PLFA Analysis at Bradford Research Center Bacteria Actinomycetes Fungi Protozoa No Protozoa in Corn/Soybean Rotations. Micro Organism biomass highest in perennial cover Bradford Research Center, 2012
    49. 49. 0 50 100 150 200 250 300 350 400 450 500 Soybean Switchgrass NT Corn Hedgerow/fescue Fescue field Biomass(mg/g) Cropping System PLFA Sub-categories at Bradford Rhizobia Arbuscular Mycorrhizal Saprophytes Soybean-Conventional-had no Mycorrihizae or Rhizobia
    50. 50. Scientists describe 3 pools of soil organic matter **really is a continuum of decomposition Passive SOM 500 – 5000 yrs C/N ratio 7 – 10 Active SOM 1 – 2 yrs C/N ratio 15 – 30 Slow SOM 15 – 100 yrs C/N ratio 10 – 25 •Recently deposited organic material •Rapid decomposition •10 – 20% of SOM •Intermediate age organic material •Slow decomposition •10 – 20% of SOM •Very stable organic material •Extremely slow decomposition •60 – 80% of SOM 82
    51. 51. Results are read in a spectrometer in lab or field or from a color card Potassium Permanganate Test KMnO4 oxidizes active carbon. The purple color of the chemical changes to pink the more active carbon there is in a soil sample.
    52. 52. Table 3. PLFA concentrations Treatment Total Gram+ Gram− Actino Fungi AM Fungi Protozoa Bare 15.07 DE 4.45 CD 3.94 DE 2.17 BC 0.42 BC 0.58 DE 0.07 B Black Poly 13.27 E 4.10 D 3.28 E 1.87 C 0.36 C 0.48 E 0.04 B White Poly 15.49 CDE 4.61 BCD 4.04 DE 2.20 BC 0.45 BC 0.59 CDE 0.08 AB Rye 19.33 AB 5.48 AB 5.58 AB 2.69 A 0.61 AB 0.85 A 0.18 AB Rye Roots 18.39 ABC 5.26 ABC 5.16 ABC 2.53 AB 0.60 AB 0.73 ABC 0.14 AB Rye Shoots 16.72 BCD 4.90 BCD 4.51 CD 2.41 AB 0.44 BC 0.66 BCD 0.11 AB Vetch 20.38 A 5.82 A 5.76 A 2.71 A 0.73 A 0.81 AB 0.20 AB Vetch Roots 19.04 AB 5.47 AB 5.36 ABC 2.59 AB 0.54 BC 0.72 ABCD 0.27 A Vetch Shoots 17.39 BCD 5.05 BC 4.77 BCD 2.46 AB 0.55 ABC 0.71 ABCD 0.13 AB  Plastic Has Much Less Than Cover Crops!! Buyer, et al, 2010
    53. 53. Doug Peterson
    54. 54. 140° F 130° F 100° F 70° F Soil bacteria die 100% moisture lost through evaporation & transpiration 15% moisture is used for growth 85% moisture lost through evaporation & transpiration 100% moisture is used for growth J.J. McEntre, USDA SCS, Kerrville, TX, 1956
    55. 55. Surface crust impedes infiltration. Open, granular surface structure enhances infiltration. Biopores (earthworm channel) enhance infiltration. Conventionally tilled field No-till field 92
    56. 56. From Steve Groff Cover Crop No Cover Crop
    57. 57. No-Till With Cover Crop Took Several Hours For Water To Run-Off
    58. 58.  Biggest challenge in No-Till Organic is producing enough biomass to control weeds  9,000 lbs is needed  Sorghum X Sudan can reduce weeds  harvest  During transition three years of continuous cover crops is desired.  Can be harvested-for livestock and kill emerged weeds
    59. 59.  Continuous cover crops during can increase soil active carbon and soil health leading to better water infiltration
    60. 60.  Huge Kill-Off  Often highest yield following  Take Advantage Of This  Small Grain-Mow afterward and plant cover crops  Suppress Volunteer pasture grasses  Cover Crop  Summer
    61. 61.  Coming from a tilled conventional grain field  Were Weeds Controlled?-cover crops and no-till cash crops  If not: Three year cover crops  -winter/summer  Graze or hay?  Need Cash?-plant small grain and follow with summer cover crop
    62. 62.  Cover Crops  Use for weed smothering with transplants  Direct Seeding-lightly till  Smother Crops During Times of Non Cash Crop  Avoid Using Plastic Mulch
    63. 63.  Lengthen Rotation- including hay crops  Early Maturing Cultivars  Planting Later-Take Advantage of Cover Crop Biomass Production  Grow Cover Crops Year Around Including Those That You Can Harvest For Sale
    64. 64. Reinbottt@Missouri.edu 573-884-7945

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