Keep the soil covered
Late summer and early fall are important windows to establish cover crops after vegetables, potatoes, and other annual crops are harvested. Leaving soil bare can increase the risk of erosion, nutrient loss, weed growth, and degradation of soil structure.
Cover crops help keep the soil covered, capture unused nutrients, improve biological activity, suppress weeds, and build soil organic matter. They can also improve water infiltration and water-holding capacity, helping soils become more resilient to variable weather, drought, and heavy rainfall.
Start with your farm goals
There is no single cover crop or mixture that is best for every farm. The right choice depends on your soil, crop rotation, planting date, available equipment, and what you want the crop to accomplish.
Before choosing a species, consider whether your main goal is to build organic matter, fix nitrogen, capture nutrients, suppress weeds, reduce compaction, protect the soil from erosion, or simply keep the soil covered until the next crop.
Option 1: A cover crop that will winter-kill
If you want the cover crop to be naturally terminated by winter, consider a mixture such as oats + tillage radish + crimson clover.
Oats establish quickly and provide ground cover and biomass, while tillage radish develops a deep root system and can help capture nutrients and create biological channels in the soil. Crimson clover adds nitrogen fixation and biomass.
Crimson clover is killed by winter in most years, but in some years, it may survive the winter.
Option 2: Keep living roots through winter and into spring
If your goal is to maintain living roots over winter and continue growing the cover crop into spring or later, cereal rye is one of the most reliable choices. Cereal rye can be planted alone or combined with a legume to provide additional benefits.
Some options include:
- Cereal rye + single-cut red clover
- Cereal rye + double-cut red clover
- Cereal rye + hairy vetch
- Ceral rye + Austrian winter peas
Winter rye provides strong soil cover and biomass, while red clover or hairy vetch can contribute nitrogen and additional biomass. These winter-hardy species will require a planned termination strategy, such as herbicide, mowing, tillage, grazing, or a combination of these methods, depending on the crop and production/rotation system.
If you are planting late in the fall, cereal rye would generally be the main option. Winter wheat and triticale are also winter-hardy options. However, planting dates are very important, and the best choice will depend on your location and how late you are planting. Winter wheat can serve not only as a cover crop but also as a valuable cash crop, giving growers the opportunity to produce a marketable crop while providing soil-cover benefits over the winter.
Planting method and seeding rate matter
Good establishment is one of the most important factors determining crop success. Choose the planting method based on the equipment you have available or can borrow. This could include a no-till drill, conventional seed drill, air seeder, or broadcasting. The important thing is to achieve good seed-to-soil contact and establish an even stand.
Drilling generally provides more consistent seed placement and establishment. Broadcasting can also work, but seed-to-soil contact and moisture become especially important. If you are broadcasting, you will generally need 20–50% more seed than the recommended drilled seeding rate.
Additionally, the seeding rate will depend on whether you are planting a single species or a mixture. For example, if cereal rye is normally seeded at 110 lb/ac when broadcast, a mixture with hairy vetch could use approximately 55 lb/ac of cereal rye + 20 lb/ac of hairy vetch. These rates are only examples; the appropriate seeding rate will depend on the planting date, planting method, species, and your specific goals.
Atlantic Canada is not one growing environment
This is especially important for growers who are new to cover crops. Weather conditions can vary considerably across Nova Scotia and the Atlantic provinces. Temperatures, rainfall, frost dates, and growing conditions can be very different between northern and southern areas, as well as between eastern and western locations. They also vary from year to year.
Because of these differences, species selection and planting date are very important. A mixture that works well when planted in August in one area may not establish the same way when planted later or in a different location.
Plan now for next spring
A cover crop should be selected not only for what it does this fall, but also for how it will fit into next year's crop. Consider when the next crop will be planted, how the cover crop will be terminated, how much residue it will produce, and whether the field will be tilled or managed with reduced tillage.
Planning the termination strategy before planting can prevent problems in the spring.
In the photos, you will see some vegetable crops, an air seeder, and cover crops. Some of the photos were provided by Lawrence Levesque.
Need help choosing a cover crop?
Every farm and field is different. My goal is to help growers succeed with cover crops—not simply plant a cover crop and hope it works. Species selection, planting date, seeding rate, and planting method are all important, especially for growers who are new to cover crops.
If you are unsure what to plant, please feel free to contact me before deciding on your farm. I would be happy to discuss your crop rotation, location, planting date, goals, and available equipment and help you select an appropriate species or mixture and seeding rate.
The goal is to choose a cover crop that works for your farm—not simply to plant a cover crop for the sake of planting one.
Manphool Fageria, PhD, P.Ag.
Vegetable Specialist | Agricultural Services
Perennia Food and Agriculture Corporation
Email mfageria@perennia.ca
Mobile 902-890-7716
6-28 Aberdeen Street, Kentville, NS B4N 2N1
