Remember late September when everyone was talking about drought and the prolonged dry-weather pattern in much of Minnesota? Well those days are history, and less than a month later we are worried about the continual cool, rainy weather patterns; extremely wet field conditions; and serious harvest delays in many areas. With a six-to-10-day forecast from Oct. 20-30 calling for continued cool, wet weather, it doesn’t look like the situation for improved harvest conditions will be enhanced anytime soon in most areas. Fortunately the weather pattern was broken briefly this past weekend, allowing for soybean harvest in many areas.

Following extremely dry weather conditions from late May through September, precipitation amounts have been considerably above normal during the first three weeks of October in most areas of Minnesota. At the University of Minnesota Southern Research and Outreach Center at Waseca, a total of 3.84 in. of precipitation, including 2.7 in. of snowfall, have been recorded from October 1 to 15, 2009, which is more than double the normal amount of precipitation for that period. Some sections of southern Minnesota have received higher amounts of rainfall and snow during that period. The result has been extremely wet field conditions in most portions of Upper Midwest. Field conditions are very slow to dry in late October and beyond, 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 the very wet fields.

Soybean harvest progress varies greatly throughout southern and western Minnesota. In some areas, where soybean harvest started in late September before the past three weeks of wet weather, two-thirds or more of the harvest is complete. However, in many portions of the region, less than one-third of the soybeans have been harvested. According to USDA’s weekly crop update, only 26% of Minnesota’s soybeans had been harvested as of Oct. 11, compared to a five-year average of 66% by that date.

Very little corn has been harvested in most areas of Minnesota due to wet field conditions and high moisture content of the corn. Most growers across southern and western Minnesota are reporting moisture readings of 25-35%. Corn needs to be dried to 15-16% moisture for safe storage in on-farm grain bins until next spring or summer. If the moisture content of the corn does not come down soon, producers will have a very high cost to dry corn down before placing it in storage.

Ideally producers like to start harvesting corn at 20-25% moisture or below to minimize drying costs. In 2009, it took above-normal temperatures during the entire month of September to allow much of the corn to reach maturity, following below-normal growing degree units (GDUs) throughout most of the growing season. Since Oct. 1, temperatures in the Upper Midwest have been among the coolest on record, which along with the lack of sunshine, has not allowed for any significant natural drydown of corn in the field.

As we progress further into October and early November, 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 that is 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 is 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.

2009 Yields Variable
Highly variable best describes the 2009 soybean yields in many areas of southern Minnesota. Growers are reporting wide yield variations in soybeans from field to field and farm to farm. The yield variation is primarily due to the dry-weather pattern from late June to September in much of the region, the timeliness of rainfalls, differences in soil types and soybean varieties and the incidence of soybean diseases. Many growers in the region have been reporting whole farm soybean yields that are very close to the long-term average yields of 45-50 bu./acre, with a few portions of extreme southern Minnesota that received more rainfall during the growing season reporting slightly higher yields. Some areas farther north and west that received less rainfall during the growing season are reporting lower-than-average soybean yields.

It is a bit early yet to get a handle on 2009 corn yields. Early indication is that corn yields in many areas will be above average; however moisture content is quite high and some reported test weights are low. Of course, potential field losses with the poor harvest conditions in many areas could also impact final corn yield figures in some locations.

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.