# Seed Drill Calibration

Getting the correct amount of seed planted with a grain drill requires calibrating the drill before planting begins. Jim Johnson, Noble Research Institute soils and crops consultant, demonstrates step-by-step how to perform this calibration and the calculations required to determine accurate seed output.

Resources needed to perform the calibration are a vehicle jack, a tape measure, a roll of adhesive tape, five lightweight cups (e.g., Styrofoam coffee cups), a scale that measures in grams, a calculator, and one or two assistants to help catch seed in the cups.

To determine the correct amount of seed to catch in the cups, perform the following three-step calculation:

• Step one Take the circumference of the tire in feet x the row spacing in feet x the number of times you turn the drive wheel = the size of your test area.
• Step two Take the answer from step one x the pounds of seed desired per acre ÷ 43,560 (the number of square feet in 1 acre) = pounds of seed to catch per row.
• Step three Take the answer from step two x 454 (the number of grams in 1 pound) = grams of seed to catch per row.

This video is part of the DIY Agriculture educational series produced by Noble Research Institute.

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Jim Johnson serves as a senior soils and crops consultant at Noble Research Institute, where he has worked since 1999. After receiving a bachelor’s degree in soil science from the University of Illinois and a master’s degree in agronomy from Oklahoma State University, he worked in various plant breeding programs in Nebraska, Texas and Oklahoma. His interests are cover crops and soil health.