Cash Crops
Silage Corn: Row intercrops are most suited to corn silage operations. In this scenario, the silage is removed in early fall, opening up the potential for a fall harvest of the cover crop for forage.
Grain Corn: Choose an early maturing variety (96 to 100 day). It is important that the corn tassels before the cover crop is large enough to compete for water and nutrients.
Some farmers increase in-row seeding rates by 50-100% — the equivalent of 68,000 seeds per acre based on a 30-inch row setting.
Anticipate at least a 5% to 7% yield reduction per acre, or greater.
Crop & Row Arrangement
Plant crops in either a 30-60 30-60 row spacing or straight 60-inch rows with cover crop between each of the 60-inch rows.
The 60-inch rows are formed by simply disengaging every other row unit on a 30-inch planter, so no special equipment is required.
Seeding Recommendation
Seed cover crop in early to mid-June (approximately at the V4 growth stage). Depending on available equipment, cover crop can be drilled with an interseeder or broadcast and lightly incorporated.
The ideal species for row intercrops are cool season, drought and shade tolerant and are relatively easy to establish.
Try a multi-species mix containing
- Orchardgrass - 10 lb/acre
- Berseem Clover - 4 lb/acre
- White Cover - 4 lb/acre
- Radish - 1 lb/acre
A mix of annual ryegrass (20 lbs/acre) and crimson clover (5 lbs/acre) is also a good shade tolerant option.
Pros
- Great at reducing erosion during the growing season and improving soil health; can provide a sizable double crop of forage
Cons
- Yield reduction of cash crop
- Increased weed pressure
Bottom line
- Typically only worthwhile if you are harvesting the cover crop for feed in the late fall or if soil health gains are a primary cropping goal.
Interseeding Cover Crops
An interseeder is a specialized seed drill designed to sow cover crops in standing row crops. The cover crop grows under the standing corn crop until harvest.
Timing
Interseeding generally occurs when corn is between the V3 and V7 stage; cover crop interseeded into V4 to V5 corn is typically the most successful.
At this stage, the potential for injury from short residual pre-emergence herbicides is reduced and the timing is good for sidedressed nitrogen. Furthermore, post-emergent glyphosate or glufosinate could also be applied at this time, if necessary, to control escaped weeds prior to cover crop emergence.
Expert Tip... Grain Corn Only
“This practice is typically recommended for grain corn fields where a fall seeding window is often limited. For corn silage fields, a better cover crop stand is usually achieved by drilling post harvest.”
— Lisa Blazure Soil Health Coordinator, Stroud Water Research Center
Equipment
Interseeding requires a specialized drill that sows cover crop into standing corn rows. Interseeders are typically designed to sow 2 to 3 rows of cover crop between 30 inch corn rows.
Cost to purchase a new interseeder ranges from $12,000 to $45,000 depending on width and capacity.
Most equipment can be used to drill cover crops after harvest, as well. Some equipment will simultaneously apply a post-emergent herbicide and/or fertilizer.
Seeding Recommendation
The ideal cover crop species for interseeding are those that are cool season, somewhat drought and shade tolerant, and relatively easy to establish. A low cost option is 20 lb/acre annual rye grass.
For greater soil health gains consider the following mix:
- 10 lb/acre Orchard grass
- 5 lb/acre Cereal Rye
- 5 lb/acre Crimson Clover
- 5 lb/acre Daikon Radish
Expert Tip... Orchardgrass
“Although not typically used as a cover crop, orchardgrass tolerates shade and looks great.”
— Jim Hershey Pennsylvania No-Till Alliance President Hershey Farms, Elizabethtown, Pa.
Pros
- Cover crop protects against erosion between crop rows in growing season
Cons
- Expensive equipment required
- Typically poor cover crop coverage post harvest
Interseeding with High-Clearance Sprayers
Modified high-clearance sprayers can broadcast cover crops between corn & soybean rows. The cover crops grow under the standing cash crop until harvest in mid-fall.
Timing
Farmers can use high clearance sprayers to broadcast seed through corn in V4 to V5 vegetative growth stages (early summer) or corn and soybeans during the end of their reproductive stages (early fall).
Early summer application causes less crop damage but is generally not recommended. Broadcast cover crop seeds in the summer will struggle to germinate; those that do will be shaded-out by the surrounding corn canopy.
Early fall application is optimal but requires highly specialized equipment that is not available in many regions. Aim to seed soybean fields when the first yellow appear and corn fields after tasselling.
Equipment
High-clearance sprayers, also called Highboys, can be modified to plant cover crop. Cover crop interseeders allow applicators to convert high clearance rigs for cover crop seeding.
Most producers tend to hire custom operators to seed cover crops using a high clearance sprayer.
Farmers should anticipate substantial crop damage in headlands. A level field will have substantially less damage.
Seeding Recommendation
Grasses are more adapted to germinate on the soil surface. Their young roots are smaller than those of legumes, so they can penetrate the surface crust easier. Small seeded brassicas will also establish well so long as soil temperatures are greater than 45° F.
Expert Recommendation
- 10 lb/acre ryegrass
- 5 lb/acre crimson clover
- 5 lb/acre daikon radish
Pros
- Lowest cost option to establish cover crop in standing corn and beans
- More exact placement than aerial
Cons
- Requires access to very specialized equipment
- Potential for larger amount of crop damage, especially in soybeans.
No-Till Farmer's "Getting Started With No-Till Farming" is brought to you courtesy of Calmer Corn Heads.
Farmer Invented. Farmer Tested. Farmer Proven.® Calmer boasts this motto proudly as it references our farmer-first mentality and state-of-the art technology.
Calmer offers a custom experience, suited to your farm’s needs. Whether its talking with our experienced sales team or directly with the folks who designed and built your corn head, we are committed to providing you top-notch service without the red tape of a big corporation. Calmer specializes in products suited to benefit your no-till operation including the patented BT Chopper® Stalk Rolls, versatile Corn Head Upgrade Kit for harvest efficiency and residue management, and the High-Performance Concave Upgrade Kit.
We know Calmer products work because we run them on our own farms; that’s why we offer a 100% Satisfaction or Your Money Back Guarantee!
