Editor’s note: This is the final of a two-part series on corn production.

Achieving 90 to 95 percent light interception at or close to silking (R1) is affected by seeding rate, row spacing, planting date, hybrid maturity, adequate nutrients and proper weed management. Current UK recommendations will accomplish maximum light interception close to silking. Those recommendations include seeding rates between 22,000 and 30,000 seeds per acre, a row spacing of 30 inches, timely planting, hybrid maturities of 113 to 117 days and good early season weed control. The ability of corn in 30-inch rows to achieve 90 to 95 percent light interception at silking is one of the reasons that we normally do not see yield increases from narrow rows.

Providing adequate nutrients, water and air to the soil to complete plant growth and seed fill includes adjusting soil pH, precipitation, water infiltration and water availability and adding the proper amount of nitrogen, phosphorus, potassium and zinc. A soil test is required for accurate adjustments of most soil nutrients. Soil type and previous crop determine the range of nitrogen necessary for high yields.

While no one can control the amount of rainfall (except by irrigation), water infiltration and water availability can be managed by conserving soil organic matter and reducing soil compaction. Soil compaction will limit water infiltration, reduce water availability and reduce air availability to the plant. Reduced tillage and no-tillage are two methods that conserve soil organic matter and typically reduce soil compaction.

There are at least 10 practices that will allow a farmer to optimize the five keys to high corn yield.

• Know which fields should be planted with corn.

• Rotate crops.

• Tillage (as little as possible): deep ripping, if necessary; no-till where possible.

• Select a high-yielding hybrid.

• Fertilize according to soil test.

• Timely planting.

• Nitrogen application: timely and adequate.

• Higher seeding rates on better soils; but not too high.

• Effective, timely pest management control.

• Monitor the crop to handle problems this year and learn for next year.

These 10 practices are not always easy to accomplish. The window for optimal planting in Kentucky is about 10 days, and many farm operations would have great difficulty getting all corn planted in 10 days. So, while these 10 points will optimize the five keys to high yields, real life often makes achieving these practices difficult. The important factor is to know what they are and try to attain as many as possible.

These 10 practices and five keys are not necessarily new, but they are a reminder of the basics behind corn production. By keeping these in mind when considering how to manage inputs, each farmer can determine how to maximize returns in his or her operation.

For more information on corn production, contact the Boyle County Cooperative Extension Service.

Jerry Little, County Extension Agent for Agriculture/Natural Resources