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Real Life Experiences in the Uses of Cover Crops

Steve Groff

Cover crops are gaining in popularity due to increased knowledge in the benefits of their use. Right now, all my 175 acres have something growing in them, except 1 acre that was in late broccoli. It is as important to me to get those covers in as it is to get a crop planted! The most influential part to the success of my "Permanent Cover Cropping System", is the use of cover crops. In March, I've seen rye roots 40" deep, while the top was only 5" tall! The use of covers and by not tilling the soil has increased organic matter levels from 2.7% 11 years ago, to 4.3% now. Covers also aid in weed control to varying degrees. But, you don't have to have a system like mine to receive these benefits. At the very least, try and get a cover planted for overwinter erosion protection. Think of how you can strategically place covers on your farm to enhance soil quality.

My System

A cover crop of hairy vetch and rye has proven most conducive to high vegetable yields at Cedar Meadow Farm, where tomatoes, pumpkins, and sweet corn are the top cash crops. I feel the components of the cover crop mix complement each other through different rooting actions and biomass production. Rye has finer roots and it's residue lasts longer into the season. Vetch, which is very succulent, tends to decompose quickly and releases its nitrogen quickly. Rye spreads out its release of N throughout the season.

To reduce pesticides and avoid burndown, I use a rolling stalk chopper to knock down and crimp the cover crop before transplanting vegetables or direct seeding pumpkins and sweet corn. To finish off weeds, I’ll apply a low rate of herbicide if a pollinating or mid-bloom cover crop proves stubborn and small weeds are present.

For a first planting of tomatoes and sweet corn, I usually seed a rye cover alone because the vetch can't gain sufficient growth to suppress weeds or fortify the soil with nutrients. Roundup is the burndown of choice for early rye that is about 18 inches. In mid-May the rye is heading out, while the vetch is beginning to flower. At this stage, the chopper stops growth without killing the cover crop and a contact spray is needed to finish it off. Rye or vetch that is mature can almost be totally controlled with 2 passes of the rolling stalk chopper. Those who don't have a machine like I do, can spray with high booms and roll with a cultipacker, or roll first with a cultipacker, then spray. Roundup is ineffective on vetch unless you use 2 quarts/A. Gramoxone can be used as well. Those who till can incorporate the cover of choice or plow it under.

I use a John Deere 750 drill for no-tilling the cover crops. Spinning on cover crop seeds is fast, but doesn't get the consistency I like. I raise my own rye, vetch, and oats seeds and have been offering those seeds for sale as well.

Benefits

• Erosion control
• Increase organic matter (although this is negated if you aggressively till it in)
• Takes out excessive soil moisture in the spring
• Keeps soil cooler during hot summer if left on top

Challenges

• soil stays cooler in spring
• dries out soil in spring
• hard to find time to establish
• difficult to plant into if you don’t have the proper equipment

The Economics

I've factored in the extra cost for cover cropping and am sure the dividends offset the investment. Seed costs per acre:

• Vetch- $1.50/lb. x 25lb/A = $37.50
• Rye- $5.50/bu x 2 bu/A = $11.00
• Rye/vetch- 30lbs. rye/20lbs. vetch = $32.75

Does it pay to plant cover crops?

• Planting: $10 - $15/A
• Seed costs: $11 - $37.75/A
• TOTAL $21 - $52.50/A

• What is increased organic matter worth?
• What is a ton of topsoil worth?
• What is increased biological activity worth?
• What is better infiltration worth?

Fall/Winter Covers

• Rye
• Vetch
• Spring oats (will winter kill)
• Triticale (spring triticale will winter kill)

Summer Covers

• Sudex
• German Millet

Spring covers

• Spring oats
• Spring triticale
• Field Peas

These are the covers I have found to be useful on our farm. There are many more options out there that might be better for your operation. I prefer 3 bushel of spring oats planted as soon as I can in the spring. I'll even plant into slightly frozen ground as a way to avoid compaction on wet soils. Spring triticale is the spring cover of choice, but since I don't grow that seed myself yet, it is more economical to plant spring oats. Mixing field peas with either spring oats or triticale is better yet to give some added N.

Cover Crop Seeding Rates: Vetch- 25#/A Rye- 2 bu/A Rye/vetch- 30#/ 20#/A Oats- 2-3 bushel/A

Other values: Vetch- Add’s up to 100 lbs. N Rye- N absorber Rye/vetch- Adds 50 lbs. N

Research on Cedar Meadow Farm Effect of covers on soil quality and corn crop yield. (1999 University of Maryland) High quality soil Low quality soil cover 110.4 bu 81.2 bu no cover 107.5 bu 72.1 bu dif. 2.9 bu dif. 9.1 bu

For further research information check out our website

Bio: Steve Groff and his family, farm 175 acres of vegetables and crops on hilly land in Lancaster County, Pennsylvania. He has pioneered the "Permanent Cover Cropping System", which includes: cover crops, permanent mulch, and effective crop rotations as a way to increase profits, increase soil and water quality, and reduce pesticides. He hosts an annual Field Day, which will be held July 26th, 2000 and had produced a video titled, "No Till Vegetables". He has received numerous national, state, and local awards for his soil conservation efforts and travels the US for speaking engagements. Steve is happily married to Cheri and they have 3 children.