Even though the 2012 harvest season is rapidly drawing to a close, most areas of southern and western Minnesota remain in severe to extreme drought, with conditions worsening in the past couple of months. The latest U.S. Drought Index places all of south-central and southwest Minnesota in an extreme drought category. Approximately 85% of the major corn- and soybean-producing areas in the U.S. are currently experiencing some level of drought, including most of the Western Corn Belt States and nearly all of the Plains states.
According to precipitation data at the University of Minnesota Southern Research and Outreach Center at Waseca, the region has been in drought-like conditions for the past 14 months. From Aug. 1, 2011, to Sept. 30, 2012, Waseca received only 62% of their normal rainfall, receiving over 16 in. of total rainfall less than normal. For the three-month period from July 1 to Sept. 30, 2012, Waseca received only 4.49 in. of total rainfall, compared to a normal amount of 12.24 in., which is 37% of normal. Some areas of western south-central Minnesota and southwestern Minnesota have received even less rainfall than Waseca during that period.
The only two months in 2012 that Waseca received significantly above-normal precipitation were June with +1.81 in. and February with +1.29 in., with nearly 2 in. coming as rainfall on Feb. 29. Those two months helped replenish depleted stored soil moisture supplies, which ultimately helped lead to the better-than-expected 2012 corn and soybean yields in many areas of southern Minnesota, even though the later growing season was extremely dry.
The continued drought across the region is certainly a concern as we look forward to the 2013 growing season. Stored soil moisture levels across the region are at historically low levels. Most reporting stations have only 1-2 in. of stored soil moisture in the top 5 ft. of soil, compared to normal levels of six to seven inches of stored soil moisture in early October. The ongoing drought conditions are also highly visible with the extremely low levels of lakes, rivers and streams across southern Minnesota.
The fall harvest season has been almost unbelievable in the Upper Midwest during September and early October, with almost perfect fall harvest weather conditions. In fact, the long string of very warm, sunny days with very low humidity and virtually no precipitation has been almost too perfect. These very unusual 2012 harvest conditions have led to corn and soybeans drying down too fast, poor fall tillage conditions, and a very high danger for field fires. The extremely warm, dry weather pattern has resulted in a rapid completion of both soybean and corn harvest in most areas.
As of Oct. 8, soybean harvest was virtually completed in most portions of southern and western Minnesota, except for some areas with later-planted soybeans. Overall, most reported soybean yields for 2012 were average to slightly below average, with yields in the eastern portions of south-central Minnesota and in southeast Minnesota being slightly higher. The whole-field yields in most other areas were better than expected, given the ongoing drought conditions during the 2012 growing season, but were generally slightly below long-term average yields. Locations that received some timely rainfalls during late July and early August had some better soybean yields.
Corn harvest has also progressed rapidly in most portions of southern Minnesota, with nearly 80-90% of the corn harvested at many locations, as of Oct. 8. Corn yields across the region have been highly variable in 2012, as a result of the widespread rainfall events at various locations during the growing season. There have been isolated whole-field yield reports of over 200 bu./acre; however, there have also been yield reports of 120-130 bu. in the same general area, with even lower yields in some locations. Differences in planting date, corn hybrid, crop rotation, soil type and storm damage have also helped account for some of this yield variation. When the 2012 corn harvest is completed, farm operators in southern Minnesota will likely end up with yields that range from near average to 20-25% below average, depending on field conditions.
The good news for all producers regarding the 2012 corn harvest is the low harvest moisture of the corn coming out of the field, and the high quality of the corn. Most of the corn being harvested in south-central Minnesota in the past few weeks has been at 13-17% moisture, meaning it can go directly to farm grain bins without additional drying, or can be hauled to grain purchasers with very little price dockage for excess kernel moisture. The rapid field drydown of the corn is saving most farmers $25-30/acre in anticipated corn drying costs. Most of the corn being harvested has a test weight that is at or above the standard test weight for corn of 56 lbs./bu.
The rapid drydown of the soybeans this fall has led to some hidden costs for farm operators. Many of the soybeans this year were harvested at a field moisture content of 8-10%, which is well below the desired harvest moisture content of 12-14%. Harvest losses during combining increase significantly at those very low moisture contents, with harvest losses of 2-4 bu./acre not unusual when harvesting below 10% moisture.
The biggest soybean harvest loss may occur when the soybeans are sold at grain elevators. Soybeans are priced on the basis of 13% moisture. When soybeans are sold below that level, the farmer loses the value of the extra weight that is lost. For example, selling soybeans at 8-9% moisture compared to 13% moisture results in a loss of approximately 70-80¢/bu. at a soybean price of $16/bu.
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.