If you ask someone how much corn is planted, or how much spring fieldwork has occurred in your area, the response is likely to be quite different, depending on where the person resides. Frequent heavy rainfall events throughout most of late April and the first half of May in much of Minnesota has caused significant delays in corn and soybean planting in many areas of south-central, east-central and southeast Minnesota.

The best news for enhancing planting was a warm-up in soil temperatures over this past weekend, which should help alleviate many of the cold soil concerns that have existed throughout the spring. Prior to recent days, the soil temperatures in most areas at the 2-4-inch planting depth had remained near or below 50° F, which is considered the minimal desirable temperature for good corn planting conditions. At the University of Minnesota Research Center at Waseca the 24-hour average soil temperature at the 2-inch level was only 47° F on May 14, before rebounding to the mid to upper 50s this past weekend.

In the very wet areas, the soil temperature should now be favorable for good planting conditions, once the fields dry out adequately for corn and soybean planting. Most growers will move immediately into soybean planting once corn planting is completed. The warmer soil temperatures, along with adequate top soil moisture, should provide some good conditions for rapid seed germination and early growth of the newly planted corn and soybeans. Research shows that 50% corn emergence will occur in about 20 days at an average soil temperature of 50° Fahrenheit, which is reduced to only 10 days at an average temperature of 60° F.

Agronomists are advising growers to stick with planting full-season corn hybrids for about another week, probably until around May 25, before moving to earlier corn hybrids, or switching major acreage to soybeans. Research from 2009 to 2011 at the U of M Research Centers at Waseca, Lamberton and Morris showed that corn planted on May 25 averaged 93% of the yield of corn that was planted from April 25 to May 10. The average yield dropped to 89% of maximum for corn planted on May 30, and yield potential begins to decline quite rapidly for corn planted after June 1.

The planting window for soybeans is significantly wider than it is for corn. In southern Minnesota, full-season varieties of soybeans can be planted until late May or early June, with only minimal reductions in yield potential. Weather conditions in the next 10 days to two weeks will determine how serious the planting delays in many areas of Minnesota become. This could have a major economic impact of farm operators in that region, especially with lower crop prices in 2014, as compared to recent years.

Planting dates and crop insurance

The final planting date for corn in the southern two-thirds of Minnesota, as well as in all of Iowa, and Wisconsin is May 31, in order to receive full crop insurance coverage for 2014. The late planting period for corn is June 1-25, with a reduction in the insurance coverage level of 1% for each day that corn planting is delayed past May 31. In northern Minnesota, the final date for corn planting with full insurance coverage is May 25. For soybeans, the final planting date is June 10 in Minnesota and the northern two-thirds of Wisconsin, and June 15 in Iowa and the southern one-third of Wisconsin, with the final planting date extending for 25 days until July 5 in Minnesota and northern Wisconsin, and until July 10 in Iowa and southern Wisconsin. For crops planted after the final dates for the late planting period, crop insurance coverage is set at a maximum of 60% of the original insurance guarantee, which is the same as the prevented planting insurance coverage.

It is important to pay close attention to the final planting dates and the late planting oeriod when making late planting or prevented planting crop insurance decisions. Producers should contact their crop insurance agent for more details on final planting dates and prevented planting options with various crop insurance policies.

There are also some good fact sheets available on the USDA Risk Management Agency (RMA) website. I have also prepared an information sheet, Prevented Planting Options For 2014, which contains details on prevented planting requirements and considerations, as well as tables comparing the options of late planting or prevented planting with normal production for corn and soybeans. To receive a copy of the prevented planting information sheet, please send an e-mail.