The Importance of Corn Planting Date and Depth

At the Latham Premier Agronomy Center, we have many demonstrations including different corn planting dates and planting depths to show how these two important factors influence yield year after year. Research shows that 50 to 75% of corn yield increases during the past 70 years came from genetic advancements, which leaves 25 to 50% of that yield increase to changes we’ve made to our farming practices.

Planting date and planting depth are cultural practices that have led to increased corn yield. Fifty years ago, farmers were talking about planting earlier than mid-May. Today we talk about planting earlier than April 15!

Our adapted hybrids produce the best yields when planted in the first week to 10 days of May. This is usually due to disease, stand loss or slow growth early in the corn life cycle. This is something we know well, and it’s why Latham Hi-Tech Seeds includes emergence and early vigor scores in our product guide.

Matching the right hybrid to the right field and planting it at the right time can lead to outstanding yields – but only if you also plant at the proper depth. Planting corn at the proper depth allows the crown to establish approximately three-fourths of an inch below the soil surface.

Why is crown development so crucial? If the crown is pushed to the soil surface due to shallow planting, at least one set of nodal roots typically establishes above ground. We want nodal roots to develop below ground to anchor the plant and to also increase the corn plant’s drought tolerance. Corn should be planted about 2.5 inches deep, which allows it to establish the crown just below the soil surface. Shallow planting depth causes issues with germination due to dry soils. If you notice spindly corn plants in your field with very small ears or no ears, that seed was likely planted shallow, causing the seedling to emerge late because of dry soil conditions.

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We look forward to harvesting our demo plots at Latham’s Premier Agronomy Center and sharing results with you throughout the fall and winter. Have a safe harvest season!