Common vetch
A member of the Fabaceae family, common vetch is an annual that does not survive the winter. Because it is easy to use, it is now included in our Vitali-T mixes. Hairy vetch is a biennial legume that often overwinters if established early in the season. As a seasonal
plant, hairy vetch may grow back if moved.
Common vetch grows well in sandy soils and is drought-tolerant once established. Seeded in a mix with a grass or a cruciferous species, its growth may be limited by the other species, particularly when combined with an application of liquid manure. Don’t be deceived by the top growth - the roots of this plant develop rapidly,
and it is worth digging up a specimen to appreciate its potential. Without a doubt one of my favourites for the summer!
Crimson clover
Crimson clover is a biennial plant that tends to behave as an annual in our growing conditions. Termination is rarely required the following spring. For fall planting, Crimson clover is preferred over perennial clovers as it establishes more rapidly. Although broadcast seeding is not ideal, it is more tolerant of this system than are other varieties. As a low-growing plant, it is not a champion in terms of aboveground biomass.
Crimson clover supplies approximately 50 units of nitrogen, a substantial contribution. With a much finer root system than other legumes, this clover complements the root growth of other crops.
Oats
Although all spring cereals can be used as cover crops, oats are more tolerant to wetter and more acid soils. Oats establish quickly, providing some control over weeds and protecting against soil erosion.
With an upright form that covers a small surface area, a higher seeding rate is recommended if the growing season is short. As the plant matures, its carbon content increases accordingly, which in turn increases the stable organic matter content of the soil.
Annual ryegrass
Ryegrass has an extremely dense and fibrous root system that is known for its beneficial effect on soil structure. This dense root system can become an inconvenience, however, when preparing the seedbed in the spring. Ryegrass is a nitrogen-loving grass that requires fertilizing to reach its full potential. Hence, ryegrass helps limit nitrogen losses due to leaching and competes well with weeds that have similar nitrogen requirements. Ryegrass prefers fine to medium-textured soils and establishes best under moist conditions. Although ryegrass is an annual, it may overwinter if well established. If this is the case, the crop will need to be controlled in the spring.
Intercropped with corn, ryegrass tolerates both shade and competition. Its growth is limited during the summer, but explodes after the silage harvest. Its greatest advantage is that it improves the weight-bearing capacity of the soil for farm equipment in the fall when harvest conditions are not always ideal.
White or yellow mustard
White mustard grows well in cooler conditions, reaching 24 inches in height at maturity. Although tolerant to mild frost, it does not overwinter. Mustard is a low-cost option, but requires adequate fertilization for good growth. It
readily captures nitrogen and makes good use of fall manure applications. Flowering occurs 50 to 60 days after seeding.
To avoid problems, mustard must be terminated before it sets seed.
Brown or oriental mustard
With agronomic characteristics comparable to those of white mustard, brown mustard is used as a biofumigant. Brown mustard has a high glucosinolate content. As the plant decomposes, this compound changes into isothiocyanates, which are volatile and toxic for some soil organisms.
To ensure that this process is successful, some conditions must be respected. The crop should be plowed under when plants are in full bloom, as the glucosinolate content drops considerably at seed set. Avoid plowing down in hot sunny conditions; morning or evening incorporation is recommended. The fumigant effect is lessened if the crop is plowed down at temperatures below 10°C. The crop should be crushed and incorporated immediately into the first 6 inches of soil.
For vegetable production, irrigation may be required if soil conditions are dry. Lastly, the fumigant effect will be greater if the crop is plowed under when pests are present in the soil.
Phacelia
A very popular plant in Europe, phacelia is still underused in Eastern Canada, mainly because it is costly and sometimes used inappropriately. Extra care must be taken when seeding. Phacelia is photosensitive, which means it does not germinate when exposed to light. Because germination is temperamental and shallow seeding is required, broadcast seeding is not recommended. To ensure a firm seedbed, rolling before or after seeding is highly recommended.
Because phacelia develops slowly in the first three weeks, it is best to avoid dense seeding and competition with other fastestablishing species. Once established, however, its abundant foliage is competitive and will suppress weed growth. In addition to a taproot, phacelia has a fine, well-developed secondary root system that enhances soil structure in the top inch or so all soil. In trials conducted last fall, phacelia had the highest nitrogen content following a liquid manure application. Phacelia also has the ability to absorb potassium from the soil and restore it to the crop the following year, making it an excellent candidate for recycling nutrients. Phacelia is also considered to be a nematicidal plant and is useful for controlling aphids by attracting the insect’s predators. An excellent melliferous plant, phacelia begins to flower about 8 weeks after seeding.