As of Sunday May 22, corn was 11% planted in Ohio, which was 76% behind last year and 69% behind the five-year average (http://www.nass.usda.gov/). Given the saturated soil conditions of many Ohio fields and the potential for more rain this week, it’s likely much of the crop acreage will be planted in June. Ohio State University Extension has developed a decision aid, Estimated Yield and Profit by Planting Date – Corn, Soybeans or Preventative Planting Crop Insurance, to assist producers in exploring the option of late-planted corn, switching to soybeans or accept preventative-plant payments. It allows farmers to enter their own production information to determine which choice might be best for their operation.
If switching to soybeans and preventative-plant crop insurance are not options, farmers need to reconsider their production practices and focus on those that will generate the greatest profits in a late-planting production environment. What optimizes yield when corn is planted early doesn’t always have the same effect when corn is planted in June. Given the shorter growing season, the response of a late-planted corn crop to certain inputs may be limited compared to responses of a corn crop planted on normal planting dates. Moreover some management adjustments will facilitate more rapid crop establishment and thereby limit further yield losses associated with planting delays.
Consider the following management alternatives so that planting is not further delayed when favorable planting conditions occur and economic returns from various inputs are optimized.
- Avoid high-end range nitrogen (N) rates on corn following soybean. OSU research has shown that N rates can be decreased by 10-15% with minimal impact on productivity when corn is planted in early June.
- Side-dress anhydrous N (or UAN liquid solutions) and apply a minimum of 30 lbs./N broadcast or banded to stimulate early seedling growth. If you do not have the capability to apply N with your planter, a surface application of UAN as a herbicide carrier can be a way to carry your corn crop until sidedress N is applied.
- Place starter applications of P and K in bands 2 in. to the side and 2 in. below the seed. Remember application of P and K is only necessary with the starter if they are deficient in the soil, and the greatest probability of yield response from P and K starter is in a no-till situation.
- Keep time expended on tillage passes and other preparatory operations to a minimum. Such work will provide minimal benefits if it results in further planting delays. No-till offers the best option for planting on time this year. Field seedbed preparation should be limited to leveling ruts that may have been left by the previous year’s harvest; disk or field cultivate very lightly to level. Most newer planters provide relatively good seed placement in "trashy" or crusted seedbeds.
- Switch to an adapted short-season hybrid. Although a full-season hybrid may still have a yield advantage over shorter-season hybrids planted in early June, it could have significantly higher grain moisture at maturity than earlier maturing hybrids if it dries down slowly. Moreover, recent evaluations indicate there are some 100-104 day relative maturity hybrids with excellent yield potential. However performance data for such early hybrids is limited compared to late maturities. For more information on selecting corn hybrids for delayed planting, download the pdf "Delayed Planting & Hybrid Maturity Decisions." (Consult Table 4. Approximate “safe” relative hybrid maturities for delayed plantings throughout Ohio.)
- Reassess seeding rates. Soil temperatures are usually warmer in late-planted fields, and as a result germination and emergence should be more rapid and uniform. So, as planting is delayed, seeding rates may be lowered (decreased to 3-5% higher than the desired harvest population) in anticipation of a higher percentage of seedlings emerging. Past university research indicates that optimal plant populations for early (mid- to late April) and late-planted (late May to early June) corn are similar. However, recent OSU studies suggest little benefit from increasing plant populations above 30,000 plants/acre in June. This lack of response to final stands over 30,000 plants/acre was associated with greater stalk lodging for hybrids planted during June compared to May.