Above-normal temperatures during the month of September in most of Minnesota have allowed the 2013 corn and soybean crop in many areas to either reach maturity, or be very close to maturity, by month’s end. Most of the early-planted corn hybrids have now reached physiological maturity and are drying down, while some later-planted corn may need a bit more time to reach desired kernel moisture content for harvest. Most soybeans are now turning color and dropping leaves, with full-scale soybean harvest beginning in portions of southern and western Minnesota.
The early reports from the soybean harvest across south-central Minnesota have been quite surprising, considering the extremely dry weather late in the growing season. Many yield monitor and weigh-wagon soybean yields of 50-60 bushels per acre, or higher, have been reported across the region. 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. This means that any drowned out areas of the field, or other acres that are not harvestable, need to be factored in to the final yield calculation. In some cases this will significantly lower the final whole field yields. There were also numerous soybean fields that were not planted until late June in portions of southeast and eastern south-central Minnesota, which will also reduce soybean yields in some areas. Most experts expect a wide variation in final soybean yields once harvest is completed.
Corn harvest has also been initiated in many areas, as most corn in southwest and western south-central Minnesota has now reached physiological maturity, or black-layer. Once the corn reaches maturity, it is at about 30-32% moisture, and then begins to dry down naturally in the field. Some early harvested corn was at a moisture content of 23-25% kernel moisture in late September; however, most corn is still at 25-30% moisture or higher. Ideally, corn needs to be dried down to about 15-16% moisture for safe storage in on-farm grain bins until next spring or summer. It is likely that producers will have to use more supplemental drying for corn in 2013, as compared to 2011 or 2012, which will add some extra corn drying expense this year.
Stalk quality and strength has been a major concern with the 2013 corn crop in many areas of southern and western Minnesota, with significant stalk breakage and ear droppage already occurring in some fields. The very warm late growing season and rapid maturity process for corn has likely lead to weakening of corn stalks in some corn hybrids across the region. There was also corn damaged by strong winds in recent weeks, which has lead to weaker stalks and late-season development of stalk rots. Growers in affected areas are adjusting their 2013 harvest schedule accordingly.
Fall tillage could also be a bit challenging in many areas, due the extremely dry top soil conditions. This type of soil situation makes it difficult for quality tillage, and requires more fuel for tillage operations. If the dry soil conditions persist through October, it will make for very poor soil conditions for Fall applications of anhydrous ammonia fertilizer, due to potential nitrogen losses. A few inches of rain in the next several weeks would be welcomed by most farmers to address the dry soil conditions.
The University of Minnesota Ag Research Center at Waseca had accumulated a total 2,518 growing degree units from May 1 through Sept. 30, which is right on target with the long-term average GDU accumulation of 2,468 GDUs by the end of September. The higher than normal GDU accumulation during late August, and September greatly enhanced the maturity process for the 2013 corn and soybean crop, which was planted much later than normal in many parts of the state.
Rainfall totals in most of Minnesota have been well below normal during July, August and September; however, there has been a lot of variation around the state. Total September rainfall at U of M Ag Research Center at Waseca was 1.92 inches, compared to a normal rainfall for September of 3.19 inches. The total rainfall at Waseca for July through September 2013, was 9.28 inches, which is 76% of the normal average precipitation amount of 12.24 inches for those three months. By comparison, the U of M Ag Research Center at Lamberton has received only 3.33 inches of rainfall from July 1 through September 23, which is only about 34 percent of the normal average precipitation of 9.75 inches for July through September.