How deep should you plant corn?

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Farm Forum

How deep are you planting your corn?

Many factors are needed to be considered while planting a corn crop. One of those factors is planting seed at the right depth.

A common principle of planting depth is to place a seed deep enough in the soil to reach adequate moisture for germination and emergence.

The most common corn planting depth is 1.5 to 2 inches. The depth can be slightly increased if the soil is abnormally dry and warm, however, it is not generally advised to place seed deeper than three inches.

Planting deeper than normal results in slower emergence with the increased likelihood of problems such as crust formation after rainfall before the plant has emerged from the ground.

Modern cultivating equipment allow much better control on planting depths and are equipped with better closing systems than older machinery. This makes it appealing for growers to try shallower planting depths.

Corn fields planted at shallower depth usually result in poor and uneven emergence, which can have potential negative effects on grain yield.

Earlier planting may be appropriate for shallower seed depth because the soil warms-up faster on the surface.

Surface residue can also play a role in deciding the seeding depth. If the field has good residue cover, the depth can be shallower than normal as the soil warms up slower in high residue and no till systems.

In any case reducing seeding depth below 1.25 inches is not recommended. Seeds that are planted shallower than recommended form nodal roots that are very close to the surface and may not develop proper root growth later in the season causing severe stress on the growing plant.

Even though optimal seeding depth can be somewhat dependent on soil type, available soil moisture and rain forecast, planting at 2 inches deep will facilitate germination and allow plant to develop proper root system.

During planting corn, producers should also be aware of natural field-to-field variability and check their seeding depth at each field by planting a short stretch to start with.

More information on corn planting is available at: http://pubstorage.sdstate.edu/AgBio_Publications/articles/ec929.03.pdf.