Corn Production

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Corn leaves

Soil Fertility

The target soil pH for mineral soils for corn production is 6.0. Total Nitrogen for corn crop should be 120-160 lbs. of N. Rate can be an adjusted depending on soil type and expected yield potential. For irrigated corn, you may need to increase nitrogen rates 10-15%, particularly if plant population is increased. If no soil test is available, 30 to 50 lbs. of P2O5/acre and 80 to 100 lbs. K2O should be applied.

Utilization of a starter fertilizer has shown to increase yields. This fertilizer should be placed 2 – 3 inches away from the seed and 2 – 3 inches deep. The blend should supply 20-30 lbs./acre of actual N and phosphorous (P).

Planting Decisions

Hybrid is the most important decision in reaching high yield or avoiding severe yield loss due to drought. For more information, visit ncovt.com.

Corn should be planted when soil temperatures reach 55oF at a 2-inch depth and the weather forecast shows a good chance of warm temperatures over the next few days. Seed depth could be planted 1.5 – 2.5 inches depending on soil and residue conditions. For cool, wet soil, plant 1 to 1.5 inches and for dry soil or heavy residue, plant 1.5 – 2.5 inches.

On soils with good to excellent soil moisture holding capacity, growers should seek to obtain a maximum of 32,000 plants/acre. Seldom is there a need to seed dryland corn at final stands exceeding 28,000 plants/acre in our area. On soils with average water holding capacity, they should plant to obtain a final stand between 22,000 and 26,000 plants/acre, and on soils with poor water holding capacity, final stands should not exceed 20,000 plants/acre.

Planter speed is critical in obtaining optimal seeding rates in conventional and no-till corn production systems. Most planter types function best at 4 ½ miles per hour. Excessive planter speed will manifest itself in erratic stands, poor weed control, and low yields. Corn growers must recognize that planter performance has the greatest influence on their ability to produce uniform stands of the desired density. The potential yield for a given field is highest when corn plants are evenly distributed. Row widths and seeding rates that combine to distribute plants uniformly across a field, ensure that individual plants have maximum access to available light, nutrients and soil moisture.

Weed Control

Weed control in corn is important. Weeds and corn are competing for all the same nutrients, water, sunlight, and more. It’s important to start clean whether you are in conventional tillage, strip tillage, or no till, and use pre-emergence herbicides for residual control. There are many great burndown options for Corn. When making a burndown choice, it’s important to know the plant back restrictions on timing and rainfall. Remember that the label is the law to follow all label requirements.

Also, for more information on weed control, you can view the 2018 North Carolina Agricultural Chemicals Manual online. If you have questions, please contact Lance Grimes at the Martin County Extension Center at 789-4370.