Micronutrients Can Maximize Crop Performance: Micronutrient Spotlight – Boron (Part 2 in series)

Jul 18, 2022 | Latest news

Andrea Rice, Director of Research, Education, and Outreach, Missouri Fertilizer Control Board

Boron (B) is one of the eight micronutrients essential for plant growth.  Soils deficient in boron are not uncommon in North America.  Globally, boron is second to zinc in the list of most widespread micronutrient deficiencies.

How is boron used by the plant?
Boron is necessary for cell wall formation and rapid growing points within the plant, including reproductive structures.

How should boron be applied?
Careful consideration should be taken when applying boron as the need can vary widely by crop and the line between deficient and toxic amount is more narrow than for any other essential nutrient.

Boron should be used carefully with supervision from a crop adviser or retailer.  Broadcast application will most likely be recommended rather than in-furrow due to a reduced stand count if boron is placed to close to seed.

Is there any information on boron specific to Missouri soils?
MU Extension completed a network of experiments measuring response to boron in soybeans and corn on farmer fields in all areas of Missouri between 2000 and 2002.

The average yield response to B was extremely low, nearly zero, in research conducted by the University of Missouri from 2000-2002.  Research showed Mississippi River bottom soils may have a higher response to B than other Missouri soils.

See the complete reports: Soybean (PDF) and Corn (PDF).

Is boron useful in forage production?
Alfalfa has a high-response rate to boron.  Purdue Extension recommends applying 2-4 pounds of B per acre for alfalfa and ½ to 1 pound per acre on less-responsive crops such as corn.  Foliar sprays can be used but the amount per acre should be decreased to prevent toxicity problems.