The Indiana Certified Crop Adviser panel includes Betsy Bower, Purdue Extension senior research associate, West Lafayette; Abby Horlacher, Nickel Plate Consulting, Sheridan; and Brian Mitchem, Farmer 1st Agronomy Consulting Services, Decatur.

 

I sat through a presentation this past winter about how foliar application of micronutrients can guarantee a small yield boost in soybeans. Is it worth it to apply them this year? What should I apply? How should I apply them? 

 

Bower: I am skeptical of any micronutrient being applied that guarantees even a small yield boost. There are just too many yield-limiting situations that can occur each season that could limit or erase the potential yield boost following a foliar micronutrient application. 

 

But yes, there can be situations where timing of the application, stage of the crop, potential deficiency in the soil or temporary deficiency in the crops can certainly stack the deck in your favor for getting a yield response. But it takes working with products on your own farm. 

 

In a year like this one, you could lightly start playing with a foliar-applied micronutrient. Mix up a batch and apply it in strips across a field or three to get a feel for the product across different soil types, soybean varieties and growth stages. Do some research on how boron, manganese and zinc function in plants and during what growth stage they work, and reach out to your advisers for their opinions and to do a little testing. 

 

Horlacher: No application in farming is ever guaranteed to provide a return. However, I believe every year growers should evaluate a few acres to better understand how different management practices perform on their specific farm. While this season has been economically challenging, that does not mean new practices should be completely removed from consideration. 

 

Consider testing a small portion of acres by applying a foliar boron or foliar zinc treatment around the R3 growth stage and evaluating how the crop responds. Multiple studies have shown the potential for a positive return on investment, though results are never guaranteed and can vary by environment and management conditions. To help reduce application costs, foliar nutrients can also be included with a fungicide pass.

 

Mitchem: Micronutrient management is an important part of a sound fertility program. The chemical nutritional element that is at a deficit level in a plant will limit yield, regardless of being a macro, secondary or micronutrient. 

 

All sound fertility programs start with regular soil testing, evaluation and applications. The first place to start is to look at your soil test results and see where soil factors such as pH, organic matter and nutrient levels are on your fields. If you are well balanced and have been managing soils well, yield response is potentially less. Soil pH has a major impact on nutrient uptake, and if it is out of the desired range of 6 to 7, then an application is more likely to have response. 

 

Micronutrients are typically applied along with the first in-crop herbicide pass for convenience and just before reproduction starts in the plant. Boron and molybdenum can also be applied along with fungicide at R2 or R3 if there is a need. 

 

I believe it’s best to apply only the nutrients needed that may impact yield, rather than a micronutrient combination product that contains three or more elements that are each at low levels when you need a single element at a higher concentration.