Micronutrients 101: Going Back to Basics

This article first appeared in the LIFT newsletter, a publication of CHS Agronomy. Read the entire article.

As growers finalize planting preparations and plan in-season fertilizer and sidedress applications, they may be looking for solutions for micronutrients deficiencies identified by soil or tissue sampling on their most productive acres. What are the most essential micronutrients and what products can help with yield and profitability?

The essential micronutrients include Zinc (Zn), Iron (Fe), Boron (B), Copper (Cu), Molybdenum (Mo) and Manganese (Mn).

  • They are considered micros because they are needed in smaller amounts compared to macronutrients by the plant.
  • Many micronutrients hold the key to how well the other nutrients are used; attribute to how well the plant develops and effects the total yield it will produce come harvest.
  • They also help feed the microorganisms in the soil to perform important steps in various nutrient cycles of the growing process.

But what specifically do they do?

chart explaining what micronutrients do

What crops and soils are prone to deficiency?

Crops and soil are prone to micronutrient deficiency in various ways. Soybeans deficient in iron can develop iron deficiency chlorosis (IDC). Alfalfa commonly experiences boron deficiencies. Wheat may be deficient in copper, and high-pH/sandy soils may be more prone to zinc deficiencies. For more information on micronutrients, check out “Role of Micronutrients in Efficient Crop Production,” by Purdue University.

soybean field
Soybeans treated with Soygreen (left) and untreated iron deficient soybeans (right).

Since all the essential nutrients work together, it’s important to consider the importance of each of them as individuals as well as how they relate to each other. If you find your crops experiencing a possible deficiency, a recommendation is to take plant and soil samples from both the affected and unaffected areas. A comparison of the results can then help to develop a clear and concise report of what is deficient and what actions are needed.

A good resource is the 4Rs of Nutrient Stewardship by the International Plant Nutrition Institute (IPNI). This decision-making guide uses the 4Rs method of: determining the Right Source, applying the Right Rate, applying at the Right Time, and applying in the Right Place.

It’s extremely beneficial to have a comprehensive nutrient plan in place to ensure growers are getting the best return on their investment and utilizing the most effective application and use of nutrients throughout their plants’ growth cycle to get the best yield from the crop.