Annual Ryegrass as a Winter Cover Crop

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Annual Ryegrass as a Winter Cover Crop

• By James J. Hoorman
• Water Quality/Grants
• Extension Educator
• Ohio State University Extension Center at Lima

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Current Farm Situation

• With high fuel prices,
• farmers want to do less
• tillage.
• With high fertilizer
• prices (N), farmers
• Want to recycle nutrients.

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Why Annual Ryegrass (ARG)?

• 1) Great Scavenger of N
• 2) Extensive Root System
• 3) ARG does not go dormant in Winter
• 4) Grows Well on Heavy Clay soils
• 5) Tolerates Flooding
• 6) Prevents Soil Erosion
• 7) Weed and Pest Suppression

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Nitrogen Losses

• Winter cover crops can temporarily immobilize
  nutrients, especially N, and prevent NO3-N
  leaching losses and reduce winter soil erosion
  during the winter rainfall period (Power and
  Doran, 1988). Most of the NO3-N leaching occurs
  during the fall and early spring months when the
  soil is fallow in the typical corn-soybean
  rotation of the U.S. Midwest (Owens et al, 1995).

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Nitrogen Requirements Efficiency

• Corn has a high N requirement and is
  relatively inefficient, recovering only 30-70 of
  an annual fertilizer N input (Sims et al., 1995).
  Vegetative covers provided a 55-85 reduction in
  nitrogen losses, whereas slow-release fertilizers
  and multiple split applications were associated
  with more modest improvements in nitrogen
  efficiency (Drinkwater et al., in press).

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Characteristics of ARG

• 1) Extensive Root System
• in top 18-24 of soil.
• 2) Roots can penetrate down
• 6 feet deep.
• 3) Fast Emergence, Little top
• growth.
• 4) Scavenges for N P
• (300-700 N).
• 5) Elevates Nutrients from subsoil
• into the topsoil.
• 6) 80-90 of root growth by
• April 1st.

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Planting ARG

• 1) Plant after wheat, corn
• silage, or soybeans.
• 2) Planting Date 9/1-10/10
• 3) Seeding Rate 15-30/A.
• 4) Seeding depth .25 to .75 inch
• 5) Needs 60 days of growth
• Or 2-4 inches before frozen soil.
• 6) Seeding Method Airplane,
• Broadcast, light tillage, drill.

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September 15 seeded ryegrass as of Nov. 4
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ARG Reduces Soil Compaction

• 1) ARG roots typically
• penetrate 20-25 first year.
• 2)Second year 25- 30
• 3) Third year 30-40
• 4) Fourth to Sixth Year 40-50
• 5) Corn and Soybeans Roots
• follow ARG Roots for greater
• moisture levels.

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20 To 23
37 to 43
23 to 28
46 to 50
6 years cover crops and no-till effects on corn
root development
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Conventional tillage
No-till with cover crops
3-7 VS
23-27
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ARG Management in Spring

• 1) Kill 3 weeks prior to planting
• or by April 1st.
• 2) Avoid Green Bridge with
• Microbes.
• 3) Expect 6-9 inches Spring
• Growth.
• 4) Makes excellent forage
• (28 CP).

Fall no-till annual ryegrass On April 1st.
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Ryegrass roots April 9th at 12 depth third
year of ryegrass cover
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Herbicides to Kill ARG.

• 1) Touchdown (10) (1 Qt)
• 2) Roundup (1 Qt) Acidic Acid (9)
• 3) Roundup (1 Qt) 2-4, D (1 Qt) (9)
• 4) Roundup (1 Qt) Princep (1 QT)
• in separate applications. (9)

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Warnings on ARG Herbicide Applications

• 1) Avoid Roundup Resistance
• 2) Avoid Herbicide Applications when ARG is
• bolting. About a 3 week period after May 1st
• when is is difficult to kill.
• 3) Easy to kill again after it flowers (End May
  to June)

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Availability of N from ARG

• Soil N from ARG killed April 1st should be
  available same year.
• Soil N from ARG killed after May will be tied up
  in soil OM and slowly released over several
  years.

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Drought Resistance with ARG
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Corn root mass under ryegrass cover crop in
drought year
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Drought Resistance with ARG
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ARG Reduces Soil Compaction

• ARG roots with deep penetration
• into subsoil gives 4-6 inches extra
• water.
• Corn roots in compacted
• conventional tillage typically only
• have 7-12 inches of root depth.
• With ARG, we may be able to
• reduce fall tillage.

Corn roots showing soil tilth from an annual
ryegrass cover crop.
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Crop Rotations

• Corn-Soybean-ARG
• Corn-Soybean-Wheat-ARG
• Corn-ARG-Corn
• Corn Silage-ARG
• Takes 5-7 years to change to No-till.
• With ARG as cover crop, that time
• can be cut in half.

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Diploid versus Tetraploid Varieties

• Italian ryegrass (Spirit) is
• a double cross (tetraploid).
• Used for forages and has
• more winter hardiness. Cost
• 1.50 to 2.00/pound
• Regular ARG is a diploid,
• used as a cover crop, and a
• little less winter hardy. Cost .50
• to .85/pound

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ARG vs Cereal Rye vs Perennial Ryegrass
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Soybean Cyst Nematode Suppression

• Conventional Land 5,000 cyst/g
• Cereal ryegrass 800 cyst/g
• ARG 100 cyst/g
• ARG activated the Soybean cyst in the fall and
  they died in winter due to lack of food.

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Possible Wild Mold suppression

• In Wisconsin, seen white
• mold suppression where
• ARG planted vs
• continuous soybeans.
• Micro-environment effect.

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Winter Annual Weed Suppression

• If ARG is planted in the
• Fall and gets established,
• We see suppression of
• winter annuals (henbit,
• dandelion, purple nettle)

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ARG Water Quality Benefits

• Reduces nutrient and pesticide
• runoff by 50 or more.
• Decreases Soil Erosion by 90
• Reduces Sediment Loading by 75
• Reduces Pathogen Loading by 60
• May decrease flooding potential by
• increasing infiltration.

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ARG Potential Problems

• Round up Resistance ???
• Winter kill ??
• May turn into a weed. Avoid
• planting into or near wheat. Do
• not let seed heads form.

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ARG Test Plots (2005-2006)

• Ten Manure Test Plots with ARG
• ARG vs CR vs Bare Cropland
• Three rates manure (0, 6K, 12K)
• Two Variety Test Plots for Winter
• Hardiness.
• Two Manure test plots with
• variable N application.

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Summary

• ARG has potential as a winter cover crop to
  decrease soil compaction.
• ARG has potential to recycle soil nutrients.
• ARG has potential to improve water quality.
• ARG has potential to save farmers money through
  decreased fertilizer bills, decreased fuel bills
  for tillage, and possibly increased yields on
  no-till crops.