Ohio Farmer

Planting considerations for corn, soybeans

Consider soil temperatures, planting depth and seeding rate.

May 19, 2023

2 Min Read
 Case IH planter
PLANTING: Planting corn and soybeans after soil temperatures reach 50 degrees F is recommended.Jennifer Kiel

May is here, and the planting season will speed up with better weather in the coming days and weeks. Planting dates can bring advantages and disadvantages for both corn and soybeans.

Following the OSU Agronomy Guide recommendations, below is a list of key reminders and considerations for planting season this year:

Soil temperatures

  • Planting corn and soybeans after soil temperatures reach 50 degrees F is recommended.

  • Measure a half-inch to 2 inches below the soil surface in the early morning.

  • Generally, early planting comes with the risk of late-spring frost, insect or disease losses, and slug damage. However, timely planting is important to maximize yield. In Ohio, we have measured a 0.5 bushels-per-acre reduction in yield for each day soybeans were planted after the end of April. Similarly, grain yield can decrease to 1.75 bushels per acre per day for corn if planted after the end of April.

Planting depth for soybeans

  • Plant soybeans 1 to 1.5 inches deep where tillage practices are being used.

  • If in no-till fields, three-quarters to 1 inch deep is recommended.

  • Shallow planting may emerge more quickly, but early planting may have a higher risk of herbicide exposure.

  • There is a higher risk of losses from soil crusting at greater planting depths if soil crusting is a concern.

  • Check planting depth consistency.

Planting depth for corn

  • Plant corn 1.5 to 2 inches deep.

  • Adjust depth for field and weather conditions as needed.

  • Greater planting depths may delay emergence.

  • Shallower depths may cause poor root development, with nodal roots not developing properly and potentially leading to “floppy” or “rootless” corn.

  • Check planting depth consistency.

Seeding rate for soybeans

  • For May planting dates, 100,000 to 120,000 plants per acre is recommended as the target plant population in soybean.

  • The seeding rate in soybean is recommended to be about 25% higher than the target plant population.

  • It is recommended to factor in crop value and seed cost to determine the optimal economic seeding rate.

Seeding rate for corn

  • Depending on the hybrid and production environment, recommended plant populations (or final stand) have ranged from 24,000 to 34,000 plants per acre.

  • Adjusting the seeding rate to factor in germination and emergence losses is necessary.

  • To calculate the planting rate (seeding rate) in corn, consider the following formula:

Planting Rate = Desired population per acre / (germination x expected survival)

For other agronomic crop updates, visit the Ohio State Agronomy YouTube channel.

Source: OSU

Subscribe to receive top agriculture news
Be informed daily with these free e-newsletters

You May Also Like