Above normal temperatures during the month of September in the upper Midwest allowed most the 2016 corn and soybean crop to either reach maturity, or be very close to maturity, by month’s end.

Most of the corn hybrids that were planted in late April and the first half of May have now reached physiological maturity and are drying down in the field, while some later planted corn may need a bit more time for field dry-down. Most soybeans are ready to harvest, with full-scale soybean harvest proceeding across the region, as weather and field conditions permit.

Most farm operators took advantage of some very favorable weather during the last week of September and first few days of October to harvest soybeans, and in some cases to begin harvesting corn.

Harvest progress across the region varied considerably, depending on the amount of rainfall received during September, and the level of soil saturation that existed in given locations. Generally, soybean harvest progress was more advanced in west central and southwest Minnesota, as compared to the south central and southeastern portions of the state.

At the University of Minnesota Research and Outreach Center at Waseca, no precipitation was recorded for eight straight days from Sept. 27 through Oct. 4, which was the longest period with no precipitation during the 2016 growing season.

Two rainfall events from Oct.4-7 greatly slowed harvest progress in many areas of southern Minnesota and northern Iowa. Rainfall amounts in many portions of the region totaled 1-2 inches, which was particularly harmful in some of the extremely wet areas of south central and southeast Minnesota, along with adjoining areas of eastern Iowa and western Wisconsin. Some farms in that region have yet to dry out adequately, following the heavy rainfall event on Sept. 21 and 22, for either soybean or corn harvest to begin.

As of Oct. 5, the U of M Ag Research Center at Waseca had accumulated a total 2,919 growing degree units, which only the third time since 1950 that the GDU’s during the growing season at Waseca have topped 2,900 GDU’s. The 2016 GDU’s reported at Waseca are more than 17 percent above the GDU accumulation for a normal growing season. The higher than normal GDU accumulation in 2016, especially later in the growing season, has greatly enhanced the maturity process for the 2016 corn and soybean crop, even on the later planted crops in the region.

The early yield reports from the soybean harvest across southern Minnesota and northern Iowa have been surprisingly good, especially considering some of the weather challenges during the 2016 growing season.

Many yield monitor, weigh-wagon, and test plot soybean yields of 60-70 bushels per acre, or even higher, have been reported across the region, with soybean yields of 50-60 bushels per acre being quite common. Of course, it should be pointed out that “whole field” yields are determined by dividing total bushels harvested by the total acres in a field that were planted last Spring.

There are many farms or fields with significant drowned out areas, or potions of fields that are not harvestable. The crop acres that are not harvestable need to be factored in to the final “whole field” yield calculations. In some cases this will significantly lower the final “whole field” yields.

For example, a soybean field with a weigh wagon yield of 60 bushels per acre, measured in an area with no drown-out damage, would see the “whole field” yield reduced to 48 bushels per acre, if 20 percent of the field is not harvestable. There will be numerous soybean fields across the region that will have 10-20 percent, or more, of the total acres that are not harvestable this year. Most experts expect a wide variation in final soybean yields, once harvest is completed.

Corn harvest has also been initiated in many areas of western Minnesota, now that corn has reached maturity and is drying down in the field. Once corn reaches physiological maturity, or “black-layer”, the corn begins to dry down naturally in the field.

On very warm days, such as occurred in late September and the first few days of October, corn will naturally dry down by nearly one percent moisture per day in the field. Field dry-down rates of one third to one half percent per day are more typical for corn during the first half of October, with normal temperatures.

One piece of good news for farm operators is that the above normal temperatures in the early fall has allowed most corn to dry down naturally in the field to 16-23 percent moisture, with the drying process continuing to occur. This will greatly reduce corn drying costs in 2016, which will be a big plus in a year with very tight profit margins.

Ideally, corn needs to be dried down to about 15-16 percent moisture, either naturally in the field, or with supplemental drying, for safe storage in on-farm grain bins until next Spring or Summer.

Stalk quality and strength has been a major concern with the 2016 corn crop in many areas of the Upper Midwest, with significant stalk breakage and ear droppage already occurring in some fields.

A higher than normal incidence of corn diseases late in the growing season, together with the rapid maturity process for corn, has likely lead to weakening of corn stalks in some corn hybrids. The consistent standing water in some areas in recent weeks is likely to result in weaker stalks, as well as more development of stalk rots, which can also result in additional corn lodging.

Fall tillage and manure applications could also be a bit challenging in many areas this Fall, due the extremely saturated top soil conditions. This type of soil situation makes it difficult for quality tillage, and may require leaving portions of fields without Fall tillage or manure applications.

Producers are also reminded that soil temperatures should be 50 degrees fahrenheit or lower for fFall applications of anhydrous ammonia nitrogen fertilizer for the 2017 crop year, in order to avoid significant losses. Soil temperatures at Waseca were still above 60 degrees F., as recently as Oct.5.