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Cover Crops: Red Clover
Table of Contents
- Description: Family
- Cover Crop Use
- Growth Habits
- Control Options
- Sensitivity to Herbicides
- Weed Control
- Benefits and Cautions
- Getting Started
- Related Links
Description
Figure 1. Red clover in flower
Figure 2. Red clover as a cover crop
after wheat
Figure 3. Red clover seedlings at the
first unifoliate stage. Note the cotyledon leaf is still visible.
Figure 4. Dense stand red clover.
Figure 5. The red clover root system
in combination with wheat in rotation builds better soil structure
and enhances soil life.
Family
- Leguminosae
- Species Trifolium pratense L.
Cover Crop Use
- Frost seeded/underseeded in a cereal crop
- Inerseeded in a standing crop
Growth Habits
Two general types of red clover grown in Ontario
- Dougle cut or "medium" red clover
- flowers in seeding year
- vigorous regrowth after cutting
- Single-cut or "mammoth" red clover
- slower growing, matures about 2 weeks later than double-cut
- requires vernalization to flower, does not flower in seeding
year
- more drought tolerant
Germination
- Innoculate with Rhizobium trifolii
- Plant shallow
Top Growth
- 20 to 60 cm height growth
- Best growth in moist, cool conditions
- Usually flowers within 65 days of planting - will continue
to flower every 30 to 35 days after harvest once established
Root System
- Thick tap root that grows 60 to 90 cm per year
- Lateral roots are found mostly in top 12 cm of soil
Overwintering
- Short-lived perennial
- Will overwinter
Site suitability
- Will grow on a wide variety of soil conditions - including
slightly acidic pH
- Shade tolerant
- Short lived perennial, persists 1 to 2 years in southern Ontario,
2 to 3 years in northern Ontario
- Best growth with soil pH 6.0 to 7.0
Figure 6. The tap root of Red Clover
can grow 60+ cm/year
Figure 7. Red clover root systems for
single cut and double cut crop
Control Options
- Systemic herbicides
- Tillage
Sensitivity to Herbicides
- Red clover is sensitive to the soil residues of atrazine and
some Group 2 herbicides.
Weed Control
- Red Clover is frequently underseeded into a cereal crop and
any weed control herbicide program must be:
- safe to the cereal crop
- effective on the weeds
- safe to the cover crop
- Usually the major weed control problems will be with winter
annuals in fall seeded crops and with annual broadleaf weeds in
spring cereals. Sometimes the herbicide needed to control the
weed is not safe on the cover crop.
The safest formulation of MCPA is the sodium salt form but MCPA
is only safe at low rates. Higher rates may give better weed control
but frequently it will stunt the clover or kill it. 2,4-D will
injure red clover.
- See Publication
75, Guide to Weed Control for herbicide recommendations for
use on "Winter Wheat and Fall Rye Underseeded to Clovers"
(Achieve, Buctril M, MCPA, MCPA/MCPB) or on "Spring Wheat,
Oats, Barley Underseeded to Forage Crops" ( Avenge, Achieve,
MCPA Sodium, or MCPA/MCPB).
Benefits and Cautions
Nutrient Management
- Efficient nitrogen-fixer - 45 kg/ha for plowdown clover (40cm
in height)
Pest Management
- Host to several insects, nematodes and diseases
- Host to root-lesion and root-knot nematodes
- Will stimulate soybean cyst nematode cyst hatching - and if
a proper host is not present - will reduce population
Organic Matter
- Adds considerable biomass
- Improves conditions for soil microbial life
Erosion Control
- Once established, extensive soil protection provided
- Improves soil infiltration and structural strength
Soil Moisture
- Improves water holding capacity, infiltration and permeability
rates
Getting Started
Establishment
- Seed 11 kg/ha, lower if seeded with a forage grass like timothy
- Usually frost seeded, but can be drilled or broadcast shallowly
- Slow growing at the beginning, more easily established than
alfalfa
- Use a clover type inoculant if clover has not been grown recently
Cost & Availability
- Seed readily available - 2 kinds available, single (late blooming)and
double cut (early blooming, usually more expensive seed)
Related Links
For more information:
Toll Free: 1-877-424-1300
E-mail: ag.info.omafra@ontario.ca
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