Corn

Damage to corn leaves.
Figure 1. Damage to corn leaves.

Description

Family

  • Annual grass

Cover Crop Use

  • after early harvested crops, when soil moisture and nitrogen available
  • Use discarded or old seed

Growth Habits

Germination

  • A relatively large seed, it requires some moisture to get going
  • Needs warm soils, temperature greater than 10 C for germination and growth

Top Growth

  • When planted as a cover crop will behave more like a grass like sorghum sudan

Root System

  • Fibrous

Overwintering

  • Winterkills

Site Suitability

  • Tolerant of most soil types, germination and emergence in mid to late summer on heavy clay soils challenging

Control Options

  • Tillage, frost and burndown herbicides can be used for control

Sensitivity to Herbicides: Weed Control

  • There are many herbicides registered for use in corn but good weed control for a cover crop should not be expensive and may not be needed. Use narrow rows and a high enough plant population to establish a vigorous crop canopy as soon as possible.

Benefits and Concerns

Patchy field of corn cover crop.
Figure 2. Patchy field of corn cover crop.

Corn can make an inexpensive and effective cover crop if seeded early. However it is very sensitive to frost. If seeding a fragile, erosion prone area, mix with a cover crop like rye or wheat to ensure that the cover is stable.

Nutrient Management

  • high uptake of soil nitrogen once past 3 to 4 leaf stage

Pest Management

  • some concern about harbouring corn pests like armyworm in late summer

Organic Matter

  • best used as a green manure crop
  • biomass return highly dependent upon planting date, seeding rate and first frost

Erosion Control

  • not a good option

Getting Started

Establishment

  • plant similar to sorghum sudan
  • use drill rather than rows to get fastest cover possible
  • seed heavy to get fast cover and to compensate for low seed viability

Cost and Availability

  • if discard seed available locally – seed should be inexpensive or free

Fescues

  • often used in erosion control projects to stabilize banks and provide cover on buffer strips or grassed waterways
  • also used for sod strips in orchard production
  • low growing varieties greatly reduce the need for mowing

Triticale

Description

Family

  • Grass - Triticeae

Cover Crop Use

  • similar to other spring cereals is using spring triticale
  • winter triticale - overall ground cover after harvest, will establish late into the season
  • as a forage crop

Growth Habits

Germination and Emergence

  • Will germinate in cold temperatures –1 to 2°C but vegetative growth requires 4°C

Top Growth

  • Taller than wheat, mature crop 120 to 150 cm in height;
  • Warm wet weather in spring can cause rapid growth from 15 cm to 1 m in a short period of time
  • Long day plant – will flower when daylight hours exceed 14 hours and temperatures average 5 to 10°C
  • When flowering starts – vegetative growth stops

Root System

  • Fibrous
  • Extensive - can cover 1 m radius and 2 m depth of soil

Overwintering

  • Does not winter kill
  • As living tissue, there is greater resistant to sand abrasion over winter
  • Resumes growth in spring faster than wheat

Site suitability

  • More drought tolerant than wheat or oats
  • Tolerates a wide range of soil conditions but does best in well drained light soils – sands, loamy sands, sandy loams and gravelly soils

Control Options

  • Can be harder to kill than other cereals – timing and control options are critical
  • Mow when crop goes into flowering stage (vegetative growth has stopped) for non-chemical control
  • Requires careful management of chemical control in the spring
  • Low rates of glyphosate can kill the plant – but leave it standing. This prolongs protective features longer. High rates of glyphosate will knock the crop down leaving less wind protection.

Sensitivity to Herbicides: Weed Control

  • There are many herbicides registered for use in wheat but good weed control for a cover crop should not be expensive and may not be needed.
  • Establish a vigorous crop canopy to smother out weeds.

Benefits and Concerns

Nutrient Management

  • Best cool season cereal crop for taking up leftover nitrogen from previous manure application(s);
  • Can tie up nitrogen in spring when needed by following crop;
  • Rye may help to increase the concentration of potassium at the surface due to its extensive root system

Pest Management

  • Competitive growth habits – good for suppressing weeds;
  • Allelopathic effect – prevents weed germination and growth, but can have allelopathic effect on other grass-like crops e.g. corn

Organic Matter

  • Large volumes of plant biomass returned to soil

Erosion Control

  • Wind abatement strips;
  • On tomato beds;
  • As strips in tobacco or vegetable fields;
  • Preferred because it does not winterkill and is resilient to sand blasting

Soil Moisture

  • More drought tolerant than wheat or oats

Getting Started

Establishment

  • Shade tolerant – can be overseeded into a standing crop of corn before leaf drop;
  • Only cover crop that can be planted in the late fall and still provide some soil cover, although the protection may not be highly effective until early spring;
  • Cold tolerant - established rye can withstand temperatures of –35° C

Cost & Availability

  • Seed is relatively inexpensive and readily available