Renewable Farming

Clean soybean fields… without herbicides

Non-chemical weed control takes a lot more management than back in the “see ’em, spray ’em” days before resistant weeds. But organic growers are showing it’s possible to raise good soybean yields, herbicide-free. Research results indicate that a few weed escapes don’t have as much impact on yield as they probably do on the grower’s pride in a clean field.

June 7, 2018 — Soybeans can stand a pretty aggressive spring-tine weeder at around the first pair of trifoliate leaves — IF they have vigorous, deep roots. Indiana grower Hal Brown sent these photos from an organic field today. The second photo below was shot from the tractor cab at full harrowing speed. Small weeds just ready to emerge or barely emerged are dislodged, but you can see there’s very little reduction in bean population. 

Thick, deep roots which had a lot of help from
in-furrow biological feeding for a rapid start

Those massive soybean roots in the close-up photo resulted at least in part from an in-furrow biological blend which Hal brews fresh every season, just for beans. He calls the formulation “bean soup.” It’s an in-furrow approach he has worked with many years, using varied organisms and nutrients. We’ll have to admit — those roots are deeper, thicker and more fibrous than our experimental bean roots were this spring. They’ll anchor the bean plant against the tine of a rod weeder. 

Timing is essential, and of course the weather doesn’t always cooperate. This spring, Hal’s part of Indiana has been on the dry side as you can see in the photo. A slurry of “bean soup” trickled on top of the beans with the planter can help the beans begin absorbing moisture and trigger germination. (Several years ago a central Nebraska grower showed us with yield data that adding 3 ounces of WakeUP Spring to his in-furrow mix enhanced performance of the biological and nutrient blend.)

Earlier this spring, we watched a presentation at an AgriEnergy Resources seminar in Des Moines where Nebraska grower Paul Heunefeldt described organic weed control measures. It isn’t no-till. But it isn’t tillage more than a couple of inches deep, either. No disturbing of the deeper soil profile where mycorrhizae can remain intact season after season.

Below: A full-screen photo of Hal’s heavy-duty rod weeder in action. Several manufacturers are offering an array of such weeders, which are generally more aggressive than a rotary hoe. Even in somewhat trashy corn residue, the spring-tooth weeders seldom clog up and drag out beans. Notice that the tines work deep enough to leave small furrows, making it tough on weeds. 

This kind of “ground truth” travels a lot faster than it did 40 years ago!


Update June 8  By Jerry Carlson —  Hal Brown just sent a “perspective” photo of the 60-foot tine weeder shown from the tractor cab in the photo above. We inserted this updated photo below:

60-foot flexible tine weeder, Windy Lane Farms, Indiana

That will cover a lot of acres per day!  Organic production isn’t constrained to smaller farmers anymore. The larger, well-capitalized growers can do a good job with organics, using upscale technology. 

The photo below shows how it looks folded. This is an Austrian-built harrow built by Hatzenbichler.  Aggressiveness of the tines can be adjusted on each flexible gang (hydraulically or with a lever, depending on the model) to meet changing crop size and field conditions.  The harrow shown here is a 3-point mount, but the company also builds a pull-type version. Visit the website linked in this paragraph to see a wide array of models and field operation.