The record high corn yields achieved by many Ohio farmers in recent years have generated considerable interest in what can be done to sustain and push yields even higher. Many Ohio growers are achieving 200-bu./acre corn. According to some agronomists and crop specialists, we have entered a new era in corn production characterized by higher annual rates of yield improvement. These higher rates are attributed to several factors, including genetic technologies that allow for greater expression of corn genetic yield potential by withstanding various crop stresses.
In the quest for high yields, considerable attention has been given to increasing various inputs, including seeding rates and fertilizers, narrowing row spacing and making preventative applications of foliar fungicides, growth regulators and biological stimulants. However, the additional costs of some of these practices and inputs may prohibit their use except perhaps for those growers interested in participating in corn yield contests on high yielding sites.
A more practical and economic approach to achieving high yields is to follow proven cultural practices that enhance corn performance. Not only are these practices the foundation for successful corn production but they will also help exploit the yield potential offered by new technologies.
- 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 is potential for the western cornrootworm damage.
- Follow pest 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 or 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 – average of 175 bu./acre or more – final stands of 32,000 plants/acre or more may be required to maximize yields.
- Supply the most economical rate of N. Use an application method that will minimize the potential loss of N (incorporation/injection, consider stabilizers under high risk applications, etc.).
- Utilize soil testing to adjust pH and guide P and 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.