Keys To Upping Corn Planting Rates

Increasing plant populations can increase yields, but putting more seed in the ground is just one of the things you have to do right.

Published on: Feb 3, 2012

There's good reason to increase corn planting rates, says Adam Spelhaug, an agronomist with Peterson Farms Seed, Harwood, N.D.

It's the one thing that consistently increases yield.

But there's more to increasing rates than just putting more seed in the ground, Spelhaug says.

Make sure you know your hybrids and their characteristics. Most of the current hybrids on the market today have good stalk and root strength. However, there are some hybrids that have super high yield potential but do need to be managed or watched to maximize those yields. These types of hybrids will work in a high population situation, but may need to be harvested in a timely manner. We learned lessons like this last year with the weekly high winds we received.

More corn plants per acre can mean more bushels per acre --  if you do three other things right.
More corn plants per acre can mean more bushels per acre -- if you do three other things right.

Consider row spacing. In 30-inch rows, an ideal spacing for 32,000 plants is 6.56 inches, while planting 36,000 reduces that spacing to 5.83 inches giving a tighter margin for error. Spacing for 22-inch rows will be about 2 inches more in the row. Corn does not like to compete for resources with its neighbors, so the more even the stand the better production you will receive from each plant. If the spacing is too tight both plants will be reduced leading to poor yields and under-utilizing that higher population.

Plan to apply more fertilizer. The extra plants will need to be fed. Increased nitrogen is a must, but phosphorus, potassium, sulfur, and zinc also need to be considered. These may not have been limiting nutrients when you were planting 28,000 to 30,000 seed per acre, but may show deficiencies with the higher population.

"Raising your population is more than just adding additional kernels to the soil. Make sure you make a plan and adjust your resources to meet the needs of the additional plants," Spelhaug says.