Widespread rainfall across the upper Midwest from May 7 to 9 temporarily delayed the rapid pace of corn and soybean planting in southern Minnesota and northern Iowa. Much of the region received an inch or more of rain, which could lead to several days of planting delays in the areas with heavier rainfall amounts. Fortunately, the excellent planting conditions in late April and early May allowed most of the corn across the region to be planted by the first few days of May, which puts the planting dates on target for optimum corn yield potential in 2009. Planting conditions were almost ideal in many parts of the region, and much of the early planted corn has now emerged with very good plant stands.

Soybean planting is also well underway in southern Minnesota and northern Iowa, with about one-third to two-thirds of the soybeans planted, depending on the location. We are right in the heart of the ideal planting window for planting soybeans in the region. University and private research has shown that soybeans in southern Minnesota can be planted up until about May 20, with little or no negative impact on optimum yields. Yield impacts from later planting are fairly minimal until soybean-planting dates extend past June 1.

While the western Corn Belt is generally well ahead of average with corn- and soybean-planting progress, the eastern Corn Belt continues well behind normal progress. Producers in major corn-producing states like Illinois, Indiana and Ohio have struggled with timely corn planting this spring. It has yet to be seen if the significant planting delays in the eastern Corn Belt will lead to any added strength in the corn markets or result in any intended corn acreage being switched over to soybeans for 2009. Usually, corn planted very late due to wet soil conditions has less yield potential and can be more susceptible to drought conditions if it turns extremely hot and dry in July and August.

Have you ever wondered why some corn emerges quickly and other corn takes much longer? Obviously, there can be differences in seed genetics, planting depth, soil compaction, etc. However, assuming those factors are close to equal, the difference in corn emergence time is probably due to the soil temperature at and immediately after planting. If the 24-hour average soil temperature at the 2-in. depth is 50° F, it normally takes about 20 days from the corn planting date for emergence to occur. When the average 2-in. soil temperature increases to 60° F, the corn emergence time is reduced to 10 days after planting; if the average 2-in. soil temperature reaches 70° F, the corn emergence time drops to five days after planting. So, next time it seems like a lot of corn has emerged unusually quick after planting, pay attention to the temperature, especially the nighttime temperature, because that was probably the reason for the rapid start to the corn crop.

Another U of M Ethanol Study
The University of Minnesota (U of M) has released another study related to the ethanol industry that has stirred some controversy. The U of M study, which was released on April 15, 2009, compares the water usage to produce corn-based ethanol on a state-by-state basis. According to the study, corn-based ethanol produced in Iowa used the least water, at 6 gal./gallon of ethanol produced. In Minnesota, water use was calculated at 19 gal./gallon of ethanol produced. The study showed that states with a significant amount of irrigated corn production used much more total water to produce ethanol than states with primarily dryland corn production. For example, the study showed that California used approximately 2,100 gal. of water produce 1 gal. of ethanol, while South Dakota used about 96 gal./gallon of ethanol produced.

Obviously, this data points out why many of the corn-based ethanol plants have been built in the heart of the Corn Belt, which has high levels of corn production, primarily from dryland farming practices. Similar to past university research studies on the ethanol industry, some industry experts criticized the data and analysis of this most recent U of M study. The industry leaders point out that the study does not account for recent industry advances that has modern ethanol production facilities using only 3.5 gal. water/gallon of ethanol produced, compared to approximately 8 gal. a few years ago. According to industry officials, the study does not properly point out that only 4% of the corn used in ethanol production is actually derived from irrigated corn production.

Once again, another university study on the ethanol industry creates some controversy. Sound science is needed to develop our nation’s future for renewable fuels. Hopefully the future science and research that universities conduct can also account for the genetic advances in corn hybrids, as well as the technology and production advances in the ethanol industry.

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.