A long tape measure marked in 0.1 inch or in centimeters, a piece of paper and a pencil - the classic approach. New planter last year with all of the bells and whistles. Decision driven by data. But "even" spacing, uniform emergence and up to 30% barren/missing stalks at harvest. Need to figure out why. Two potential causes - seedling inhibition (34.5k seed/a or 6" spacing on 30" rows) and stunted growth from wheel track compaction. Should not be difficult to sort out but it takes a lot more data than we have time/resources to collect. Hence interest in image analysis.

Check out article by Ruen in Feb. 2018 Corn and Soybean Digest, pg 24&26. Seedling inhibition goes up as spacing falls under 6".