Spring fieldwork has been slow to begin in most areas of Minnesota in 2014, with conditions in many areas very similar to last year. Very cool temperatures have existed across the region during most of the month of April, resulting in cold soil temperatures and soil conditions, which have not been conducive to the initiation of corn planting in Minnesota and northern Iowa. In addition, heavy rainfall in late April across large areas of the Upper Midwest has added to the planting delays in most of the region. Farm operators were able to plant peas and small grain crops in some locations from April 20 to 26, and there was some corn planted in southwest Minnesota and northwest Iowa; however, in most areas, soil conditions have remained too cold and wet to begin full-scale spring fieldwork.
At the U of M Research and Outreach Center at Waseca, Minn., the average soil temperature on April 24 was only about 43° F at the 2-4 inch level, which is too cold for good corn planting conditions. At the U of M Research Center at Lamberton, the average soil temperatures on April 24 at the 2-4 inch depth were a bit warmer at 47° F, still a bit cold for corn planting. The long-term average soil temperatures on April 28 at Waseca are 52.8° F at the 4-inch level, and 53.1° F at the 2-inch level, which are just above the minimally desirable daily average soil temperature for corn planting of 50° F at the 2-4 inch level. Research shows that 50% corn emergence will occur in 20 days at an average soil temperature of 50° F, which is reduced to only 10 days at an average temperature of 60° F.
Most university and private agronomists are encouraging producers to be patient with the initiation of corn planting in 2014, and to wait until soil conditions are conducive for good corn planting and seed germination. Given the high cost per acre of seed corn, and the limited availability of some of the best yielding corn hybrids in 2014, most growers do not want to take the risk of planting corn into poor soil conditions. Normally, in early May, the soil temperatures warm up quite rapidly, so concern over cool soil temperatures becomes less of an issue. It is expected that most farm operators in southern Minnesota and northern Iowa will begin full-scale corn planting as soon as the field conditions dry out, and are fit for planting.
According to University of Minnesota and private seed company research, the “ideal time window” to plant corn in southern Minnesota in order to achieve optimum yields is April 20 to about May 5. Even though spring planting is off to very slow start, compared to recent years, the good news is that there are still opportunities for timely corn planting. Based on long-term research, the reduction in optimum corn yield potential with planting dates from May 5-15 in southern Minnesota is usually very minimal. Even corn planted from May 15-25 has a good chance of producing 90-95% of optimum yield potential, assuming that we get some favorable growing conditions in 2014. Hopefully, planting conditions will improve in the next couple of weeks, which would still allow for getting a significant amount of corn in southern Minnesota and northern Iowa planted on a fairly timely basis in 2014.