This article was originally written for the “Burrus Buzz.”
Several industry experts have been urging growers to plant soybeans earlier and earlier. There is substantial data and on-farm experience to support this logic, however, one remaining question for many growers is, “Should I change maturities for an earlier planting date?” On a recent Twitter poll posted by ILSoyAdvisor, they asked, “If you are planting soybeans in April, how are you going to choose your maturity group?” Given three possible responses, 33% of respondents chose “Same as for May planting,” 15% selected “Shorter for early harvest,” and 52% opted for “Longer for greater yield.” As you can clearly see, there are differing opinions when it comes to maturity group (MG) selection.
To maximize yield by planting early, my recommendation is the same as when maximizing yield with a normal planting window. In Jacksonville, Ill., we have growers who utilize soybeans from 2.8 – 4.3 MG. Some experts say growers should be able to go a little later (0.1 – 0.2 MG) with an earlier planting (April) than the traditional planting window (May), but not very much. Keep in mind that each 0.1 change in maturity equates to a 1- to 1.5-day difference as to when soybeans will be harvested. In Jacksonville, we recommend using a 3.9 – 4.3 for an April planting timeframe. My recommendations in this article are for the central Illinois region, but can be adapted to your own area as appropriate.
Multi-year data suggests the variety that can finish maturing closest to the first frost would prove to have the highest yield potential. A longer season variety will capitalize on more sunlight and nutrients than a shorter season variety. This isn’t to say that every year the fuller season variety will win, however, in most years they will outcompete a shorter season variety. Ideally, growers should select the latest MG possible without the risk of not finishing before the first frost. If you are not sure the latest MG your area can handle, I recommend running small strip trials on your farm to experiment with different MGs.
Another common question is what maturity to consider for early harvest on a portion of acres. Switching up maturities and planting dates is not only an effective way to mitigate risk, but also to position for a more successful harvest. If you find all your soybeans are becoming ripe at the same time and you have enough acreage that it makes harvest a lengthy process, then varying your harvest windows makes sense.
After soybeans reach full maturity (R8), they aren’t going to get any better sitting out in the field. If we can vary our harvest windows by switching up maturities, it can help us not only capture more yield, but also have better quality grain. In Jacksonville, we commonly have growers switching to a 2.8 – 3.3 for early harvest fields with great success. This is early enough to mitigate risk and to have some acres ready to start harvest sooner, while not sacrificing too much yield.
The third common question around soybean MGs pertains to late planted, replanting or double-crop soybeans. This is a more tricky question. For late planted or replanted soybeans, it greatly depends on how late we are talking. If you are looking at late planted soybeans in June, then my recommendation is to stick around 3.6 – 4.1 MG for the Jacksonville area. However, if we are talking about double-crop soybeans in July, that is a different story. From July 1 – 15, I would stay with the full season end (3.9 – 4.3). Because soybeans are photoperiod driven and we are already after the June 21summer solstice, these soybeans will likely start to flower before they have much height. A fuller season variety planted at a higher density will provide more growth, both shading out the row and putting on more nodes to set pods before flowering starts, compared to a shorter season variety.
There are many options when it comes to selecting soybeans today. We can no longer pick solely on maturity; there are many other considerations as well. The first decision is often focused on herbicide technology. Select a herbicide technology that works well for your specific fields and equipment, if you will be the one spraying it. Once you have selected a herbicide platform, then consider maturities. We need to be careful not to just pick on maturity alone. Growers should stay flexible on their maturity to select the best varieties. For example, growers this past year in Jacksonville were somewhat skeptical about planting DONMARIO™ 28J9X because it was earlier than they were used to planting, but the yield potential in this 2.8 MG was outcompeting the 3.0 – 3.2 MG they had been using. We need to continue to select the best soybean and stay flexible on maturities to help maximize yields.