How do you know if your planter did a good job of singulation and spacing corn kernels? If you have a Precision Planting 20/20 Seed Sense monitor or similar type monitor from someone else, you should know singulation and have a pretty good idea of whether you spaced correctly before you ever left the field – in fact round by round after round. Of course, the real proof is when the stand emerges.
Even Bob Nielsen, Purdue University Extension corn specialist, gives leeway for some errors and kernels not emerging or turning into seedlings for various reasons.
In the first place, 95% emerge listed as warm germ on many seed tags means that if you plant 32,000 kernels, in theory under the best of conditions 300, 400 will emerge. That's one reason why he says a standard deviation of 2.0 is about the best you can hope to achieve in terms of plant spacing.
Standard deviation refers to the amount of variation if you measure distance between plants in one/one-thousandth acre in several parts of the field.
According to the Purdue University Corn & Soybean Field Guide, here is what spacing between plants should be at various row widths and population goals. For 30,000 seeds per acre in 30-inch rows, the expected spacing is 7.0 inches per plant. At 34,000 kernel drop, it's 6.1, and at 32,000 it's 6.5 inches.
If you go narrower, row spacing between plants within the row increases. At 32,000 plants per acre in 20-inch rows, for example, it's 9.8 inches per row. If you're in 15-inch rows and at 32,000 plants per acre, the spacing should be 13.1 inches between plants.
Note that the number for spacing in 15-inch rows is basically double the spacing between plants within a 30-inch row. You are spreading plants out within the row and making the row spacing narrower.
From the corn hybrid you select to the seeding rate and row width you choose, every decision you make influences the size and scope for corn yields. Download our FREE report: Maximizing Your Corn Yield.