Mistakes made during the planting operation are usually irreversible, and can put a “ceiling” on the crop’s yield potential before the plants have even emerged.

The following are some tips that will help get a corn crop off to a good start.

1. Adjust Seeding Depth According to Soil Conditions

Plant corn seed from 1-1/2 to 2 inches deep so as to facilitate adequate root development. In late April and early May, when the soil is usually moist and evaporation rate is low, seed should be planted no deeper than 1-1/2 inches. As the season progresses and evaporation rates increase, deeper planting may be advisable. When soils are warm and dry, corn may be seeded more deeply up to 2 inches on non-crusting soils. One risk associated with shallower planting depths is the possibility of poor development of the permanent (also referred to as secondary or nodal) root system if the crown is at or near the soil surface. Permanent roots may not grow under hot, dry conditions (resulting in the “rootless” and “floppy” corn syndromes). Another potential risk from planting less than 1-1/2 inches is shoot uptake of soil-applied herbicides. Seeding depth should be monitored periodically during the planting operation and adjusted for varying soil conditions. Irregular planting depths contribute to uneven plant emergence, which can reduce yields.

2. Adjust Seeding Rates on a Field-by-Field Basis.

Adjust planting rates by using the yield potential of a site as a major criterion for determining the appropriate plant population. Higher seeding rates are recommended for sites with high-yield potential with high soil-fertility levels and water-holding capacity. On productive soils, with long term average yields of 160 bu/acre or more, final stands of 30,000-33,000 plants/acre or more may be required to maximize yields. Some recent studies conducted under favorable growing conditions on high yielding soils have indicated that final stands as high as 36,000/A were required for optimal yield. However at these higher plant densities the risk for major stalk lodging increases considerably.

Lower seeding rates are preferable when droughty soils or late planting (after June 1) limit yield potential. On soils that average 120 bu/acre or less, final stands of 20,000 to 22,000 plants/acre are adequate for optimal yields. On soils that average about 150 bu/acre, a final stand of 28,000 plants per acre may be needed to optimize yields. Seeding rate can be cut to lower seed costs but this approach typically costs more than it saves. Most research suggests that planting a hybrid at suboptimal seeding rates is more likely to cause yield loss than planting above recommended rates (unless lodging becomes more severe at higher population levels) and harvest delays occur. Under moderate drought stress, high plant populations usually do not cause significant yield reduction on most Ohio soils. When planting occurs in cold soils, usually early planting dates, the seeding rate should be 10-15% higher than the desired harvest population. Follow seed company recommendations to adjust plant population for specific hybrids.

3. Perform Tillage Operations Only When Necessary and Under the Proper Soil Conditions.

Avoid working wet soil and reduce secondary tillage passes. Perform secondary tillage operations only when necessary to prepare an adequate seedbed. Shallow compaction created by excessive secondary tillage can reduce crop yields. Deep tillage should only be used when a compacted zone has been identified and soil is relatively dry. Late summer and fall are the best times of year for deep tillage.