Published on Tuesday, March 14, 2017
We are midway through March and have experienced some above average temperatures that have left many of us feeling as though our corn planters should be running. We have actually heard a few reports of corn being planted around the state, but I believe it is in your best interest to be patient and postpone your planting operations for just a little bit longer.
One key motivator for delaying corn planting in Missouri is crop insurance. The below map details the initial planting date windows by county for Missouri crop insurance. As you can see from this map, these dates vary across the state, but April 1 to April 5 covers the majority of our Missouri acres.
Although these dates are based on historical planting trends, there is agronomic data to support these planting windows. According to the three-year data from our Southern Illinois Practical Farm Research (PFR)® site, April 1 to April 15 is the ideal planting timeframe fo corn.
The reason I chose to include the information from our Effingham, IL site is because the planting conditions and soil types at that site closely resemble what many farmers here is Missouri face when planting their corn acres. It’s important to note that there isn’t a large statistical gap between the late March timing through mid-April. In 2016, that yield gap kept with the trend. However, when you consider the overall stand-loss from the March 23 planting date compared to the April 5 planting date, it becomes clear that the earlier planting is not always ideal.
While there are many factors that can influence the ideal planting date for corn, two of the most important are soil temperature and the extended weather forecast. When taking soil temperature readings from your fields, take measurements from multiple areas to ensure that your including any low areas or northern slopes as those tend to be cooler. The “magic number” you are looking for in this situation is a daily average soil temperature of 50°F. It is important to note that soils tend to take much more time to warm than they do to cool, so night-time low temperatures will dictate your daily average.
For example, using the University of Missouri’s Bradford Research and Extension Center weather station outside Columbia, the average daily soil temperature at two inches has been about 46°F since March 1, 2016.
This is the point where the extended forecast comes into play. If your daily average soil temperature has reached that 50°F mark but the air temperature is forecasted to drop over the next few days, it is probably in your best interest to hold off on planting.
As you can see from the graph above, the temperatures throughout the rest of March are expected to gradually warm up, so the soil temperatures should as well. Expect to see the soil temperatures to be much closer to where we like to see them once we hit that April 1 planting window.
I hope you have a safe and productive planting season in 2017! And remember, just because the weather feels good, doesn’t mean it will to your corn!
Author: Alex Long
Categories: Agronomy, Missouri
Tags: Practical Farm Research, Beck's Agronomy, Missouri Agronomy, PFR, Planting Date, Alex Long, Crop Insurance, Soil Temperatures, Forecast