In-furrow soybean fertilization’s impacts on nodulation and reduction in nitrogen fixation.

Because soybeans are a legume and have the ability to fix nitrogen (N), fertilization with N is not a common practice. Plants don’t begin to fix much nitrogen until after the middle of June, and wet and cool soil conditions further hamper nitrogen fixation.

Many growers are hesitant to apply fertilizer in-furrow either because of salt injury or delaying nodulation. However, if we could discover when to fertilizer soybeans in-furrow and apply nitrogen without inhibiting nitrogen nodulation and fixation—we would be on our way to higher yields.

What started out as a basic fertilization trial in soybeans has yielded some impressive results to date. We planted the trials on May 11. The treatment was 2 gallons (per acre) of Nucleus® HP 8-24-4 in combination with Kickstand® PGR. The components of the PGR enhance early plant development thru cell division, elongation and plant maturation, and increase plant metabolism for improved nutrient uptake and utilization.

On June 23 we evaluated the trials. Remember, June has been a wet, cool and cloudy month and this has resulted in yellow soybeans. The treated plots were at V4 and the plots untreated at V3—a whole growth stage behind.

The results we have seen so far in two trials are faster development, evidenced by an increase in growth stage by 1 and a 30% increase in nodulation. The root mass also increased dramatically resulting in a greener and healthier plant, which should lead to much better stress mitigation under the harsh conditions.

Further checking of the trials has shown the treated plots to be handling the wet conditions better and even increasing their health and size over the untreated. As the summer progresses and we harvest the plots, I will share the final results.