Sustainable Spraying

Lauren Biegler

Lauren Biegler


It has been a pretty uneventful summer for our soybeans. We had a late start planting with cool, wet weather, but got heat and sunshine as the summer continued. July was warm and dry, but we received a couple of large rains that saved our crop. The soybeans are shorter this year, but that doesn’t necessarily decrease the yield potential. Soybeans are a hard crop to gauge how they will turn out during the growing season, so we’ll have to wait for harvest to see if weather had any effect on yield.

The main activity during the growing season is spraying for weed control. With many of our soybean fields, we have a growing cover crop at the time of planting, so our first application is mainly for the termination of that cover crop. That application will usually give us pretty good weed control for a while, plus the residue from the cover crop controls weeds by blocking the sunlight the weeds need to grow. In fact, we are experimenting this year with part of a field where we cut out one chemical pass to see if the residue would provide enough control itself. Cutting out one pass of spraying would be beneficial to us and to the environment.

We’d prefer to not have to spray, but we do need to control weeds in our fields over the growing season. They compete for resources – such as water and nutrients that our soybeans need to reach their full yield potential. We look at our fields frequently, but we also rely on our agronomist, who scouts our fields weekly, to advise us on when we need to spray. We do not want to spray unless it is absolutely necessary.  After soybeans reach canopy (where you can’t see the ground between the rows anymore), we do not need to spray to control weeds. Sunlight can’t reach the ground and weeds become suppressed naturally.

As far as spraying is concerned, the only thing we have left to think is soybean aphids. We will usually start scouting for aphids in mid-July and do not spray until the number of aphids per plant reaches a certain number. If numbers reach threshold and the soybeans are not too large, we will use our high clearance sprayer to spray for them. If the soybeans are very tall, we will sometimes opt to have our local coop use the crop duster airplanes to apply the insecticide for us.

Our main goal is to get our soybeans to maturity and full yield potential using as little inputs as possible, and our sustainable techniques help us achieve this on our farm.

Spraying our fields is a necessity for soybeans to mature and produce higher yields.


Monitoring where to sprays allows us to apply inputs efficiently and only where needed.