Last week, I told you some observations about my corn harvest. So this week, I thought I would change gears and give you my insights on our farm’s soybean harvest.
The biggest issue that I notice this year was where I post-applied my glyphosate in Roundup Ready soybeans compared to where I did not post-apply any glyphosate.
My burndown program consists of 3 ounces of Valor XLT along with 12 ounces of 2-4,D E-99 in the spring with a crop-oil concentrate 1 to 2 weeks ahead of planting. The soybean crop was planted from April 22 to May 4, so we actually had a good jump on the calendar this past year.
The crop emerged quickly with plenty of moisture and heat. From mid-May to July 1, we had constant rains that actually slowed the soybeans down, but still a lot of my residual Valor herbicide was holding its own along with the help of a good canopy. With that, I decided not to spray 25% of my soybeans with the post application of glyphosate.
During August, I had some weed escapes, but nothing that I thought would hurt yields too much. I somewhat make a rule of thumb to put away the sprayer after July 1 because I would likely do more harm than good.
To my surprise at harvest, I’m glad I did put away the sprayer. What I saw with the yield monitor was something that really shocked me.
My yields where I sprayed my post application of glyphosate averaged 59 bushels per acre. With the somewhat weedy part of the field in spots right next to where I post applied my glyphosate, my yields averaged 65 bushels per acre! This field was planted the same day with the same variety with the same soil types and same planter.
The question is why the difference? Could it be that the glyphosate post-applied has something to do with the yield reduction? Is this why our soybean yields have not increased dramatically for the past 10 years, but our corn yields have exploded with our superior hybrids. Surely there has been research done for this, or maybe this is just a coincidence. It sure was not due to wheel tracks from the sprayer because my tires were in-between my 15-inch rows where I applied glyphosate at the R2 stage.
Last year, I had a suspicion that something was going on where I noticed a 5- to 8-bushel-per-acre increase in yield where I post-applied Select and Flexstar on my Roundup Ready 2 soybeans in comparison to where I post-applied the glyphosate. Hopefully, you blog readers can give me some insight to this because I am surely not the only one that has noticed this. Your thoughts are appreciated.