Remember late July when everyone was talking about drought and the prolonged dry weather pattern in much of southern Minnesota? Well those days are history, and less than three months later we are worried about the continual rainy weather patterns, extremely wet field conditions, and serious harvest delays in many areas. With a 6-10-day forecast Oct. 15-25 of continued cool, wet weather, it does not look like the situation for improved harvest conditions will be enhanced anytime soon in most areas.
Following extremely dry weather conditions in most areas from late June to early August, rainfall amounts have been considerably above normal in most areas for the months of August, September and October. At the University of Minnesota Research and Outreach Center at Waseca, a total of 19.73 in. of rainfall have been recorded from August 1 through October 15, 2007, which is about double the normal amount of rainfall for that period. Some sections of southeast Minnesota have actually had higher amounts during that period. The result has been extremely wet field conditions in most portions of southern Minnesota. In many areas, the stored soil moisture is at maximum capacity, so any additional rainfall results in very wet soils and standing water. Field conditions are very slow to dry out after October 15, due to no water uptake by plants, low evaporation rates and shortened day length. Growers may be forced to wait until soils freeze in order to harvest very wet portions of fields.
Harvest progress varies greatly throughout the region. In some areas of south-central and southwest Minnesota, soybean harvest was completed by late September, before the latest round of very wet weather occurred. However, in many portions of southeast Minnesota, there is a large percentage of soybeans remaining to be harvested. Very little corn has been harvested in the wettest areas of southern Minnesota, while one-third to two-thirds of the corn is harvested in other areas. As we progress deeper into October, the harvest delays, especially for unharvested soybeans, become a much larger concern. The probability of higher field loss to the mature, unharvested soybeans increases greatly later in the harvest season. There is also some concern with unharvested corn in fields that are susceptible to stalk breakage, due to stalk diseases and corn root damage. Major cold fronts with strong winds are much more likely to occur this time of year, causing crop damage. The frustration for farm operators, especially in eastern south-central and southeast Minnesota, is that they have the potential for good to excellent crop yields on many of the unharvested acres of corn and soybeans. The wet field conditions are also delaying fall tillage, as well as fall manure and fertilizer applications.
Highly variable best describes the 2007 corn and soybean yields in many areas of Southern Minnesota. Growers are reporting corn yield variation of less than 50 bu./acre to over 200 bu./acre in the same field, and wide yield variations in corn and soybeans from field-to-field and farm-to-farm. The yield variation is primarily due to the dry weather pattern from late June to early August, the timeliness of rainfalls, and differences in soil types, with some variation in corn hybrids and soybean varieties.
Many growers in western south-central and southwest Minnesota have been reporting whole farm corn and soybean yields in 2007 that are very close to the long-term average yields of 45-48 bu./acre for soybeans and 160-170 bu./acre for corn; however, the yields have been quite variable. In the eastern portions of south-central Minnesota and southeast Minnesota, whole-farm corn and soybean yields have generally been above long-term averages.
The October 12 USDA Crop Report projects a record corn production for 2007 in the U.S., and much lower 2007 soybean production than in 2006. The record U.S. corn production for 2007 is projected at slightly over 13.3 billion bushels, with a national average yield of 154.7 bu./acre. The 2007 corn production estimate is up significantly from a total U.S. corn production level of just over 10.5 billion bushels in 2006, and is also up from the 11.1 billion bushels in 2005, and the previous record crop of 11.6 billion bushels in 2004. The USDA projected the total 2007 soybean production to be almost 2.6 billion bushels, which is down from the 3.2 billion bushel total production in 2006. The national average soybean yield is projected to be 41.48 bu./acre, which compares to a national average yield of 42.7 bu./acre in 2006. Minnesota is projected to harvest just over 1.2 billion bushels of corn in 2007, with an average yield of 156 bu./acre. The 2007 average Minnesota soybean yield is estimated at 42 bu./acre, resulting in a total soybean production of just over 258 million bushels. Average yields for Minnesota in 2006 were 161 bu./acre for corn and 44 bu./acre for soybeans. The projected average 2007 yields for Iowa are 180 bu./acre for corn and 52 bu./acre for soybeans.
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 kent.thiesse@minnstarbank.com.