Recap and resources from RAFFL’s Basic Cover Crop Strategies for Soil Health and Seed Production workshop in partnership with NOFA-VT. Thanks to Clear Brook Farm’s owner Andrw Knafel and NOFA-VT’s Willie Gibson for hosting the night and sharing information. Note that at the bottom of this post are resources and links for more info! Main theme from the workshop – Cover crops are an art and take some experimenting to figure out how to best manage the crops with your specific land’s needs. Here are some beginning questions to ask yourself before planting cover crops:
1. What are you trying to accomplish with your cover crop—increase nitrogen in your soil, decrease nitrogen, fight weeds, simply add organic material to your soil? This will determine what crops you plant, when you plant them, and how you manage the plants.
2. Speaking of which, how will you manage the end products of cover crops? Plan ahead!
3. How will you incorporate cover crops into your growing schedule and—subsequently—how will you manage this added time commitment with your already busy farming life?
Andrew began the workshop by introducing his crop cover schedule and recommendations for varieties. He reminded folks that this is what works for his land and may or may not work for yours. He heavily plants cover crops in the fall and then plants less in spring.
Spring 1. Pea/Triticale-Fast growing cover crop and fixes nitrogen 2. Oats – Easy to manage, can plant any time, cheap cover crop ($15/50lb bag). If the oat crop fails, this is a great cover crop to incorporate organic material into your soil, so it's not a total failure. Don't harvest oats when it's too green--it will be a pain.
Summer 1. Sudangrass – plants in late June/early July. Do NOT let it go to seed-has potential to become a major weed problem. When it gets over three feet it can be tough to deal with. 2. Millet – Also do not let this one go to seed as it’s a “nightmare of a weed” if mismanaged. This one is good for potatoes and before planting blueberries. Andrew highly recommends millet!
Fall 1. Winter rye – This cover crop is easy to seed, forgiving, has little winter kill, and you can plant as late as Oct 20 (at least for Andrew’s land in Shaftsbury, VT), but seed it thick if you wait that long. Andrew also harvests rye to make into biodiesel fuel. The longer you wait to harvest rye and the more in dries out on the stalk, the bigger the weather issue becomes. 2. Oats with vetch, especially hairy vetch – Andrew uses a mixture of 140 lbs of oats to 40 lbs vetch per acre. The oats will be winter killed but the vetch still comes. This is a good mixture for restoring nitrogen into the soil. Hairy vetch is around $75/50lb bag but Andrew thinks it’s worth it. Other thoughts about cover crops - Buckwheat: Seed is expensive and Andrew doesn’t think it adds much organic material to the soil. If you let it go to seed it will become a weed nightmare.
- Cover crops to eliminate weeds: This is a big debate within cover cropping right now. Andrew doesn’t think cover crops help that much with weeds. His experience is that weeds stay dormant under the crops and then will re-appear once the cover crop is gone.
- Home gardeners: You can plant oats or pea/triticale because it winter kills and will help build soil. Machinery is a big topic when it comes to cover crops. How will you plant seeds? How will you harvest the end produce or till up the plants to incorporate organic matter into soil? Andrew has two seeders—one that seeds in rows and another cone seeder that uses a spinner to cover the ground evenly with seeds. If you have five acres or less you can use a hand-held seeder instead of investing in machinery. For frost seeding, he recommends going in two directions to get good coverage.
Andrew also has a used Massey Harris combined. He recommends checking out craigslist and other classified ads for used equipment. Since most VT farms are small, he encourages farmers to think about sharing equipment instead of making large investments by themselves and going into too much debt. He shares equipment with another farmer down the road to save money. For Andrew’s combine, he uses an 8 foot head, which is on the smaller side compared to Midwest farms but all he needs for his fields. Andrew’s #1 tip for using a combine is to harvest seeds by driving slowly to prevent clogging. If the machine gets clogged, it’s a pain in the a$$.
For harvesting cover crop seeds, remember to figure out the logistics beforehand. How are you going to store the seeds so they stay dry and in good condition? How will they stay cool? How will you deal with rodents? You need ambient air to be flowing throughout their storage spot to prevent mold.
The workshop ended with a discussion of how plants and cover crops can be planted together. A few folks in the audience had luck with this; for instance, some said they had success planting squash over winter rye or New Zealand clover. Andrew experimented with clover under his corn. One year of this was good and the other was bad. Andrew warned that if you have cover crops with your regular crops you need to think about air flow. Having to much cover crops around your vegetables can create high-moisture conditions that are perfect for molds to develop. Cover crops can work well with crops that are strong and higher off the ground, like corn or broccoli. Crops like spinach or kale probably should not be planted with cover crops.
Resources Lakeview Organic Grain – Andrew recommends this seed company. They can be expensive if you just need one 50lb bag, so he recommends putting together large orders (like a whole palette) in cooperation with other farmers in your area. He really likes their seed. (http://www.lakevieworganicgrain.com/)
Vermont Vegetable and Berry Growers – Vern has great advice! (http://www.uvm.edu/vtvegandberry/)
Northern Grain Growers Association – For anyone thinking about harvesting their cover crops, this is a good group to be in tune with. (http://northerngraingrowers.org/)
Farm Agronomic Practices Program (FAP) through the Vermont Agency of Agriculture – Provides financial incentives for planting cover crops (www.vermontagriculture.com/ARMES/awq/FAP.html)
For information about any of the below details, please e-mail Kris at firstname.lastname@example.org.