Producers usually start to wonder if they should make any soybean management changes as they move into June planting such as changing relative maturity, row spacing, and seeding rates. As the next weather systems move in today and tomorrow bringing more chances for rain, I have 4 things for growers to consider for late-planted soybeans:
Stick with your normal MG or relative maturity (RM) ratings as planned for now. A 2003-2004 study in Lincoln looked at the average response of 14 varieties ranging from a 3.0 to 3.9 relative maturity. The study found that due to soybeans being photoperiod sensitive, flowering and maturity was similar among plantings dates. For example, an end-of-May planted soybean only matured 1 to 3 days sooner than mid-June planted soybean crop.
A 2013 variety trial conducted in southeast South Dakota on 55 varieties showed that by reducing the relative maturity by 1 unit from a 2.8 to 1.8 RM, we only reduced the days to maturity by 5. If planting is delayed past June 15, you may want to consider reducing your relative maturity by 0.5 at that point on normal full season beans.
Regional studies show that narrow row soybeans yield 3-4 bushels/acre better. If your operation does not own a narrow row planter or drill, you have a strong consideration for looking into someone custom planting some acres for you.
We are losing about 5/8 of a bushels per acre per day and having an extra planter with narrow rows could help you finish a week early given the recent rainfall patterns. This equates to picking up an extra 7-8 bushels per acre in added yield between narrow row spacing and an earlier planting date, well worth a custom planting rate of $20/acre.
As for seeding rates, most growers are have higher seeding rates than what the University of Nebraska currently recommends to achieve a final stand of 100,000 plants per acre. In the case with some drills, seed spacing can be a problem and you may want to increase your seeding rate on drilled soybeans to hasten canopy cover.
- Don’t switch varieties for earlier maturing varieties just yet
- Narrow rows are better
- Have someone custom plant acres for you
- Increasing seeding rates may not be needed