Farmers on the quest for record corn yields this spring may try to push the limits with higher seeding rates, narrower rows, more fertilizer and preventive applications of pesticides, but Peter Thomison, an Ohio State University Extension agronomist, says the best way to optimize yields is to follow proven practices.
"A more practical and economical way to achieve high yields is to follow those practices that we know enhance corn performance," says Thomison. His recommendations include the following:
- Know the yield potential of your fields, their yield history and the soil type and its productivity.
- Choose high-yielding, adapted hybrids. Pick hybrids that have produced consistently high yields across a number of locations or years. Select hybrids with high ratings for foliar and stalk rot diseases when planting no-till or with reduced tillage, especially after corn. Select high-yielding Bt rootworm resistant hybrids where there is potential for corn rootworm damage.
- Follow best management practices that will provide effective, timely pest control – especially weed control.
- Aim to complete planting by May 10. If soil conditions are dry, begin planting before the optimum date but avoid early planting on poorly drained soils. If planting late (after May 25 in central Ohio) plant corn borer resistant Bt hybrids.
- Follow practices that will enhance stand establishment. Adjust seeding depth according to soil conditions and monitor planting depth periodically during the planting operation and adjust for varying soil conditions. Make sure the planter is in good working order. Inspect and adjust the planter to improve stand establishment. Operate planters at speeds that will optimize seed placement. Uneven emergence affects crop performance because late emerging plants cannot compete with larger, early emerging plants.
- Adjust seeding rates on a field-by-field basis. On productive soils, which average 175 bu./acre or more, final stands of 32,000-33,000 plants/acre or more may be required to maximize yields. Check with your seed company representative for optimum planting rates for your hybrids.
- Supply the most economical rate of nitrogen. Use an application method that will minimize the potential loss of N (incorporation or injection, consider stabilizers under high risk applications, etc.).
- Utilize soil testing to adjust pH and guide phosphorus (P) and potassium (K) fertilization. Avoid unnecessary P and K application. High soil tests do not require additional inputs.
- Perform tillage operations only when necessary and under proper soil conditions. Deep tillage should only be performed when a compacted zone is detected and soil conditions are dry (usually late summer).
- Take advantage of crop rotation. Corn grown after soybeans will typically yield 10-15% more than corn grown after corn.
- Monitor fields and troubleshoot yield-limiting factors throughout the season.
"These are by no means the only management practices with which growers need to be concerned, but they are keys to achieving high corn yields." Thomison said.