Harvest Season Progressing Slowly in Many Areas

October 8, 2018


Continued wet, rainy weather has slowed harvest progress in many areas of the Upper Midwest. Harvest progress across the region varies considerably, depending on the amount of rainfall received during September and early October, and the level of soil saturation that existed in given locations. Generally, soybean harvest progress was more advanced in West Central and Northwest Minnesota, as compared to most of Southern Minnesota and Northern Iowa.

Rainfall amounts during the month of September really varied across Minnesota. The University of Minnesota Research and Outreach Center at Waseca recorded 10.54 inches of precipitation during September, which is nearly three times the normal precipitation amount for the month. Some areas of South Central Minnesota had even higher amounts of total rainfall for the month, with some locations now exceeding 50-60 inches of rainfall since May 1 of this year. The U of M Research Center at Lamberton received 6.59 inches of precipitation during September, which is over three inches above the long-term average for the month. By comparison, the U of M Research Center at Morris in West Central Minnesota only received 1.84 inches of rainfall during September.

Above normal temperatures during the month of September in the Upper Midwest allowed most the 2018 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 reached physiological maturity, and have been drying down in the field, as weather conditions have permitted. Most soybeans are ready to harvest, with full-scale soybean harvest ready to proceed across the region, once weather and field conditions are conducive for harvest.

The U of M Research Center at Waseca recorded the first freezing temperature of 32 degrees on October 1. The 2018 growing season ended with a total of 2,775 growing degree units (GDU), which was 12 percent, or 305 GDU’s, above the normal GDU accumulation in a growing season. Four of the past five growing seasons have featured above normal GDU accumulation. The higher than normal GDU accumulation in 2018, especially later in the growing season, greatly enhanced the maturity process for the 2018 corn and soybean crop, even on the later planted crops in the region.

The early yield reports from the soybean harvest across the region have been better than expected, especially considering the weather challenges during the 2018 growing season. There have been many yield monitor, weigh-wagon, and test plot soybean yields of 60 bushels per acre or higher reported in Southern Minnesota. 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. When using this yield calculation, whole field yields of 50-60 bushels per acre have been more common, with lower yields in areas that were hardest hit by excessive moisture earlier in the 2018 growing season.

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 region, 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 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 20-24 percent moisture, with the drying process continuing to occur. 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 2018 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, could 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 could result in additional corn lodging.

Early reports of corn yields across many areas of Southern Minnesota have generally been quite disappointing, with some farmers reporting their lowest corn yields in many years. Whole-field yield reports have ranged from less than 140 bushels per acre to around 200 bushels per acre, with yields near 200 bushels per acre being more of the exception. Whole farm yields of 150-175 bushels per acre have been typical on many high-quality farms in South Central and Southwest Minnesota, which is 20-30 percent below long-term average yields for many producers. Similar to soybeans, there are much lower corn yields in some of the areas that received the greatest impact from this year’s weather events.

Fall tillage and manure applications could also be challenging in many locations 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 Fall applications of nitrogen fertilizer for the 2019 crop year, in order to avoid significant losses. Soil temperatures at Waseca were still near 60 degrees F. in early October.


Note — For additional information contact Kent Thiesse, Farm Management Analyst and Senior

Vice President, MinnStar Bank, Lake Crystal, MN. (Phone — (507) 381-7960);

E-mail — kent.thiesse@minnstarbank.com)


Blog Focus on Ag
Previous Next