What is a cover crop?
A cover crop is a plant grown primarily to benefit the soil and the ecosystem, rather than for harvest or consumption. These crops are typically grown between main crop seasons to protect and improve the soil’s health.
Why should I plant a cover crop?
- Soil Health Improvement: Cover crops enhance soil structure and fertility by adding organic matter and nutrients.
- Weed Suppression: They outcompete weeds for resources, reducing the need for herbicides.
- Erosion Prevention: Cover crops protect soil from erosion, especially in vulnerable areas like slopes.
- Nutrient Retention: They help prevent nutrient runoff, keeping valuable nutrients in the soil.
- Disease Suppression: Some cover crops can suppress soil-borne diseases, reducing the need for chemical treatments.
- Beneficial Insects: Cover crops attract pollinators and beneficial insects that help control pests.
- Improved Water Management: Their root systems enhance water infiltration and reduce runoff, improving water efficiency.
- Drought Resilience: Deep-rooted cover crops can access water in deeper soil layers, increasing resilience during droughts.
- Biodiversity: Cover crops contribute to biodiversity by providing habitat and food for various organisms.
- Crop Rotation: They can be part of a crop rotation strategy, disrupting pest and disease cycles in the field.
What is the difference between the plants used for cover crops and the plants used for eating?
Although there are some crops you use for both eating and cover crops, there are a couple important differences between what you grow to eat and what you use as a cover crop.
When selecting crops to eat, you are generally selecting based on optimizing yield, taste, appearance, and nutritional content. For cover crops, the emphasis is on maximizing their soil-improving benefits, such as nitrogen fixation, weed suppression, and erosion control.
The most important difference between the two is the harvesting stage. Cover crops must be terminated (cut or tilled into the soil) before they reach maturity and produce seeds. This prevents them from competing with main crops for resources.
How do I decide what cover crops to use?
To decide which cover crop to use in your garden, start by identifying your main goals. Do you want to improve soil fertility, control weeds, or prevent erosion? Next, consider your local climate and the time of year you plan to plant the cover crop. For example, if you’re looking to enrich the soil, consider legumes like clover. Field peas are a great nitrogen fixer. If erosion is a concern, grasses like rye can help. Keep it simple by matching your goals and local conditions when choosing the right cover crop for your garden.
Do you have heavy clay soil like me? Try tillage radish! Tillage radish is a cover crop known for its big roots that help improve soil. These radishes grow fast and have deep roots, which break up hard soil, let water soak in better, and store nutrients for the next crops. They also help stop too many nutrients from washing away and keep weeds in check. During the winter, the above-ground portion of the tillage radish, including its leaves and stems, will typically die off with the onset of freezing temperatures. In spring, as temperatures rise, the taproot also decomposes, adding organic matter to the soil. It’s a favorite for us growers in a northern climate.
When and How Do I Terminate Cover Crop?
To get your field ready for planting crops, it’s a good idea to stop the cover crop about 10-14 days before you plant. This gives it time to break down and not compete with your new crops. But remember, the exact timing can change based on what kind of cover crop you have and your local weather. So, keep an eye on your cover crop’s growth to pick the right time. You want to make sure you terminate before it goes to seed. If you let it go to seed it can quickly get a bit out of control and hard to manage.
- Mowing or Cutting: Use a scythe, sickle, or a mower to cut the cover crop down to ground level. This organic method is effective for most cover crop types and allows the cut cover crop residue to act as natural mulch.
- Tillage: Organic tillage methods, such as plowing or disking, can be used to turn over the cover crop. This helps speed up decomposition and prepares the soil for planting, but it may disrupt soil structure.
- Roller-Crimping: Roller-crimping, using a specialized implement, flattens and crimps the cover crop stems, terminating it effectively. This method is particularly useful for cover crops with tough or fibrous stems.
- Flaming: Organic flaming involves using a propane torch or flame weeder to scorch and kill the cover crop. It’s a chemical-free way to terminate cover crops and is often used in organic farming.
- Cover Crop Smothering: Plant a dense cover crop that can outcompete and smother the previous cover crop. For example, planting a cover crop like buckwheat can effectively suppress and terminate the existing vegetation through competition for light and resources.
How do I know what my soil needs?
In order to know what exactly your soil needs, you will have to get a soil test done. Soil tests tell you exactly how much of each nutrient is in your soil. Once you have the results back, you’ll know what cover crops will benefit you the most.
There are lots of labs that do soil testing. I recommend calling your local extension office and asking who they recommend to do your testing. My local extension office recommended Rock River Laboratory. They have a local drop off location and it was only $9.00. They give you recommendations on what to add based on the crops you tell them you are growing. It took about 8 days to get results back.
We turned over a section of our pasture this year. It has been pasture for over 30 years so the soil is pretty depleted. Based on this plus my super compacted clay soil means for winter I’m covering the whole 5000 square feet with tiller radish. In between tiller radish rows I’m planting field peas/oats mix. I’m also liming my ground to increase the PH. It takes roughly 6 months for the PH change to take effect so over winter is the perfect time to apply.
