Cover crops have been used for many years to maintain soil vs growing a crop for sale. They are grown mainly for the benefit of the soil rather than the crop yield. Cover crops are commonly used for weed management, reducing soil erosion, helping build and improve soil fertility and also soil quality, helping reduce crop diseases and pests, and promoting biodiversity.
Let's jump right in and see which cover crops are the best to grow and why.
How Cover Crops Reduce Soil Erosion
Vegetation plays a vital role in controlling erosion by:
Shielding the soil surface from the impact of rainfall.
Holds soil in place.
Prevents crust formation.
Improves the soil’s capacity to absorb water.
Slows the velocity of runoff.
Soaks up water between storms through the plants.
Types of Cover Crops
Soil type, depth, water-holding capacity, and fertility all affect plant growth. Depending on the crop you intend on planting you can increase fertility by growing legumes and incorporating them at the proper time in order to provide nitrogen.
If you have clay or if water penetration is poor in your soil, cover crops with fibrous root systems, such as cereals, can be grown to improve the physical structure of the soil.
Types of Grasses/Grains
Growing grasses or grains as cover crop provides numerous benefits for soil health, erosion control, and overall farm sustainability. Crops, such as rye, oats, and barley, have dense root systems that bind soil particles together, effectively reducing erosion by wind and water. Their extensive root networks also enhance soil structure by increasing organic matter and improving water infiltration, which helps maintain moisture levels in the soil.
Grasses and grains are excellent at finding residual nutrients, particularly nitrogen, from the soil, preventing nutrient leaching and making these nutrients available for future crops. These crops also contribute to weed suppression by outcompeting weeds for light, water, and nutrients, reducing the need for herbicides.
Overall, integrating grasses and grains into crop rotations or as cover crops supports soil conservation, nutrient management, and sustainable farming practices.
Here are a few grasses or grains to try on your farm:
Rye
Wheat
Barley
Oats
Legume Varieties
Growing legume varieties offers numerous benefits, particularly in enhancing soil fertility and supporting sustainable agriculture. Legumes, such as clover, peas, and beans, have a unique ability to fix atmospheric nitrogen through a symbiotic relationship with root-dwelling bacteria. This natural nitrogen fixation reduces the need for synthetic fertilizers, leading to cost savings and minimizing environmental impact.
Additionally, legumes improve soil structure by adding organic matter as they decompose, increasing soil's water-holding capacity and promoting microbial activity. These crops also support biodiversity, providing habitat and food for beneficial insects and pollinators.
By integrating legumes into crop rotations or as cover crops, farmers can boost soil health, reduce input costs, and contribute to more sustainable agricultural systems.
Here are a few legumes to try:
Alfalfa
Red clover
Fava
Vetch
Cowpeas
Brassicas
Growing brassicas as cover crops provide significant agricultural benefits, particularly in improving soil health and pest management. Brassicas, such as radishes, mustards, and turnips, have deep, strong roots that penetrate compacted soil layers, enhancing soil structure and increasing water infiltration. They are also known for their biofumigation properties; certain brassicas release natural compounds that suppress soil-borne pests, nematodes, and diseases, reducing the need for chemical treatments.
Additionally, brassicas efficiently find nutrient resources, especially nitrogen, from deeper soil layers, preventing nutrient leaching and making these nutrients available to subsequent crops. This adds a dual benefit of soil health and pest suppression making brassicas a valuable component to sustainable farming practices.
A few Brassicas to choose from:
Radish
Turnip
Rapeseed
Arugula
Mustard
Broadleaf Cover Crops
Broadleaf cover crops also play a crucial role in carbon sequestration. As they grow, these plants capture atmospheric carbon dioxide and store it in their biomass and the soil. When the cover crops decompose, they add organic matter to the soil, further enhancing its carbon content and contributing to long-term soil health. This process not only improves soil fertility but also helps mitigate climate change by reducing the amount of carbon dioxide in the atmosphere.
A few broadleaf crops to grow are:
Spinach
Flax
Marigold
Buckwheat
Planting Cover Crops
Plant your cover crop strategically in the fall so that it will grow faster than the weeds in the spring. Maximum effects are achieved by planting early in the fall or in the late summer into a prepared seedbed followed by irrigation to increase germination, early growth, and soil cover.
Cover Crop Seedbed Preparation
Regardless of the cover crop species selected, soil preparation for planting is relatively standard. Preparing a well-granulated, soft, friable, and moist seedbed generally works well for virtually any cover crop species.
No-Till versus Till
Whether to till or not is an important consideration when choosing a cover crop strategy. Preventing soil erosion and saving fuel are two benefits of the no-till management strategy. Another benefit is firm footing in wet weather, which can make a tremendous difference, especially if your area receives a high volume of rain. Growers also often report fewer insect and mite pest problems in no-till areas.
What is no-till? No-till planting refers to planting primary crops into actively growing cover crops. This practice can be used when planting a grain crop. The other type of no-till planting involves planting into a bed where the cover crop was killed 2 or 3 weeks before planting.
Seeding Cover Crops
Cover crop seed can be planted with a drill or a broadcast seeder. Drills place the seed with much more precision than broadcast seeders but either can be used. Watering after seeding helps ensure successful germination and establishment of the crop. Once germinated, many cover crop species can survive drought fairly well.
Mowing Cover Crops
Mowing the cover crop can improve cover crop establishment and performance. Mowing removes taller weeds that can shade the cover crop. Mowing also encourages the growth of shoots from the crown of the plant, spreading, and flowering. Many cover crop species are pasture forages that respond well to grazing.
You can use Farmbrite to help manage your soil rotations and cover crops. Give it a try for 14 days free.
Green Manure From Annual Cover Crops
Green manure cover crops are typically planted from roughly September to early December or into the spring. They consist of winter annual grasses, legumes, or flowering plants. If the green manure is used to add nitrogen, legumes are used alone or in combination with non-legumes, usually cereals. These plants store nitrogen in their roots and are tilled/mulched into the soil to decompose and add nutrients to the soil.
How Much Nitrogen For Cover Crops
Research indicates that legume cover crops can fix from 50 to 200 pounds per planted acre of nitrogen. The amount of fixation depends on the cover crop species, soil pH, soil temperature, soil moisture, soil nitrogen status, and inoculation.
Microorganism Benefits
Although invisible to the naked eye, soil microorganisms are an important part of your soil, and are a potentially valuable asset to your next harvest. The value lies in the role they play in the decomposition of organic matter, improvement of soil structure, cycling of nutrients, and as a living reservoir of nutrients. The microbial community is most beneficial to the grower when it is diverse, abundant, and active. Microbial populations play active and passive roles in soil fertility and should be taken into consideration to improve soil health.
The Best Cover Crops
At the end of the day, we could go on and on about cover crops and the numerous benefits of planting them. The best one for your farm will depend on your soil, your environment, your budget, and many other factors. There is no universal cover crop for all agricultural operations. The choice of cover crop systems depends largely on the benefits you hope to gain from the cover crop.
Cover crops should be chosen for their suitability for a production system and the style of farming that the manager wishes to use. The cover crop’s physical stature, water use, and ease of establishment/maintenance are only a few reasons why they should be chosen carefully. That being said, there are a tremendous amount of cover crops to choose from. Start small and experiment to determine which type will most benefit you.