February 13, 2012
Mild Winter Could Impact Spring Planting in the United States
The winter of 2011/12 in the United States has been one of the warmers and driest in recent memory. The months of December and January have been the fourth warmest on record with an average temperature 3.8 degrees above average. The amount of snow cover is also much less than average with virtually no snow cover in the northwestern Corn Belt. This mild and open winter may have implications for the early spring planting which will start in just 5-6 weeks.
The driest areas are north and west of Des Moines, Iowa including about half of Iowa, and nearly all of Minnesota, South Dakota, and North Dakota. In the driest areas, it would take about 8 inches of precipitation to fully recharge the topsoil and subsoil back to normal levels and each week that goes by without significant precipitation that number grows. The month of March is usually a rainy month in the Midwest so there is always a possibility that the soil moisture will be recharged, but the odds are increasing that spring planting in the northwestern Corn Belt could be problematic regardless of the type of weather we have between now and when planting begins.
If it continues to stay relatively dry until planting starts, then the concern is that there will not be enough subsoil moisture to sustain the corn crop later in the summer months. The corn crop usually requires more moisture during its lifecycle than what falls as rain during the growing season. The moisture deficit is made up for by the corn plant taping into the subsoil moisture later in the summer. If that subsoil moisture is not available, then the corn yields can be reduced as a result.
If the weather during the late winter and early spring ends up being wetter than normal, then there is a high probability that the soil moisture will be recharged, but the heavy rains that would be required to recharge the soil could also result in planting delays. With normal weather between now and planting, there would probably not be any significant planting delays, but there would probably not be enough moisture to recharge the subsoil.
The bottom line is that we may have a problematic early start to the growing season no matter how the late winter and early spring weather unfolds. If the weather remains dryer than normal, then that would be a problem. If the weather turns wetter than normal, then that is a problem as well. Even if the weather is "just right", that would not provide enough moisture to sufficiently recharge the soil.