SEEDING DIVERSE COVER CROP MIXES: DRILLING

Diversity is key for building soil health, and with diversity comes complexity. This new world of seeding complex cover crop mixes includes drilling, seeding with air delivery systems, and broadcast (either by airplane or drone)—and it requires special effort to get the seeding rate right.

People often ask, "How should I set up my drill for cocktail mixtures? Should I set it for the largest seed in the mix?" Before calibrating your drill, consider:

Seeding Rate Per Acre

Mixes with lower seeding rates (25-30 lbs/acre or fewer) are usually comprised of small seeds that typically can flow through the grass-seed attachment box on the drill. Examples include our ValueMax (CC2), BrassicaMax (CC4), MultiMax (CC7), Cultivation Max (CC8), Plowdown Blend (CC9) , and Corn Builder (CC12).

Mixes calling for higher seeding rates (30 lbs/acre or more) include some large-seeded species, such as rye, peas, or buckwheat. Seed these through the large seed box. Examples include our NitroMax (CC1), Winter Max (CC3), AerialMax (CC5), SummerMax (CC6), DiverseMax (CC10), FixNMax (CC11), and Pollinator Max (CC13).

Range Of Seed Sizes In The Mix

Seed size Influences seeding depth. We suggest you seed at a depth ideal for the mid-sized seeds in your mix. This may plant some small seed a bit deep and some large seed a bit shallow.

Mixes including small seed tend to sort in the box, with small, dense seeds dropping to the bottom. Throughout seeding, either partially fill the box at each "refill" or periodically stop and remix the seed within the box.

CALIBRATION: GETTING STARTED

Drill settings on seeding rate charts are calibrated for single species. Using these settings as a starting point, there are ways to make adjustments and determine the best setting for a diverse cover crop mix.

Find the setting for the largest-sized seed in your mix— for example, peas—to deliver the seeding rate (e.g. 50 lbs/A). Since smaller seeds in your mix will readily flow out of the metered openings, resulting in MORE than 50 lbs/A delivered, you’ll need to make an adjustment. Cut that seeding rate back by 1/3 to 1/2 for a first calibration run.

For example, if you want to deliver 50 lbs/A of cover crop mix including peas, note the pea setting for 50 lbs/A and cut back to a setting to deliver 25 to 37 lbs/A.

At this point, there is a series of "trial runs" needed to zero in on the actual drill setting to deliver the 50 lbs/A of your mix.

CALIBRATION: GETTING IT DONE

For more details on three methods of calibrating your drill to deliver your target seeding rate, visit our website.

Reminder: As with any crop, you may want to purchase an extra bag or two of your premixed or custom cover crop mix, (depending on your acres to be planted) to allow for calibration and potential overplanting.