Cover crop mixtures are being encouraged more today than previous years, but the challenge is figuring what setting on the drill will drop the desired rate.

Calibrating your grain drill is the only way to avoid over- or under-seeding your fields.

We did this at a field day recently with annual ryegrass and crimson clover. The desired mixture was 10 pounds of each per acre, but when we looked at the grass seed chart on the grain drill (after we mixed the seed) the fastest setting for annual ryegrass was around 12 pounds per acre, but what would it be if we mixed it half and half with crimson clover.

Grain drill calibration is not too difficult and should only take you a half hour or so. What you will need is: a measuring wheel or tape, 2–4 containers, a scale that measures in hundredths of pounds, calculator, pen and paper.

• Start by calculating the width of your drill. Count the number of openers and multiply by the disk spacing.
Ex. 24 openers x 7.5” spacing = 180” or 15.0’.

• Divide 43,560 by 20 to get the number of square feet in a 1/20th of an acre.
Ex. 43,560/20=2,178.

• In order to know how far to drive to collect seed from the drill divide 2,178 (1/20th of an acre) by the width of the drill in feet.
Ex. 2,178/15.0´= 145.2 feet.

• Now that you know how far to drive, measure out the distance and flag or mark the starting and stopping point.