The corn crop in southern Minnesota and northern Iowa is being planted in very rapid fashion when soil conditions are fit for planting. During a four-day period from April 24 to 27, nearly ideal planting weather resulted in a large amount of corn being planted in most portions of south-central Minnesota. Crop experts have estimated that as much as 15% of the corn grown in a given area can be planted in one day, when field and soil conditions are at optimal levels. As of April 27, it was estimated that 50-65% of the 2012 corn crop has been planted at many locations in southern Minnesota. Some farmers have finished their corn planting, and are now waiting a bit to begin planting soybeans, hoping for a bit warmer soil temperatures. Soybeans can be planted up until about May 20-25 in order to maintain optimum yield potential. In general, soybean yields are much less sensitive to planting dates than corn.
Some of the early planted corn in south-central Minnesota that was planted around April 11-13 is now emerging, and crop stands look very good. Based on university and seed company research, the ideal window to plant corn in for optimum yield potential in southern Minnesota is April 15-May 5, so most corn in the region will likely be planted in that “window” for the 2012 growing season. Topsoil moisture has been adequate for seed germination and early seedling growth; however, there has been some concern due to periods of very cool soil temperatures in the past couple of weeks.
Even though more frequent rainfall events in the past two months have alleviated dry topsoil concerns for spring planting in most areas, there is a continuing concern over the limited stored soil moisture as we head deeper into the 2012 growing season. Most of south-central and southwest Minnesota, as well as adjoining areas of northern Iowa, remain in a moderate to severe drought as of April 24, according to the NOAA U.S. Drought Monitor Service.
Since Feb. 29, rainfall amounts at the University of Minnesota Research and Outreach Center at Waseca, MN, have been slightly above normal, which has greatly improved the topsoil moisture. However, rainfall amounts during the past two months have varied considerably across the region, with southeast Minnesota generally getting more total precipitation than other areas. Total precipitation during a six to seven month period from late July 2011 to late February 2012, was less than 50% of normal at most locations in the region, which has lead to the continuing drought concerns in many areas for the 2012 growing season.
At the U of M Research and Outreach Center at Lamberton, in southwest Minnesota, the measured stored soil moisture in the top 5 ft. of soil was just over 3 in., as of April 15, 2012, out of a maximum capacity of 10 in. of stored soil moisture. The 2012 amount is less than 50% of normal stored soil moisture for late April at Lamberton, and compares to almost 9 in. of stored soil moisture in late April 2011. The stored soil moisture data at Lamberton shows that most of the stored soil moisture is in the top 6 in. of soil, and at the 3-5-ft. soil depth. There is very little soil moisture from the 6-in. to 3-ft. range in the soil profile. If this pattern continues, we could see drought stress on crops in some areas during extended periods of hot, dry weather this summer.
The month of April featured freezing temperatures in many locations of Minnesota and northern Iowa.
While there was very little frost damage to corn in the region, there was some damage to alfalfa, fruit and vegetable crops. The heaviest economic damage was probably to commercial apple and grape producers in the region. Alfalfa also received moderate damage in some areas.
Editor’s note: Kent Thiesse is a former University of Minnesota Extension educator and now is Vice President of MinnStar Bank, Lake Crystal, MN. You can contact him at 507-726-2137 or via e-mail at firstname.lastname@example.org.