Spring Application Tips for Boron Fertilization

:: Wednesday, January 22, 2020
The 2019 crop season in North America was one for the books; no one in agriculture was sad to see it come to an end. Looking forward, 2019 will have carryover effects on the 2020 cropping season. How producers align their management practices heading into the growing season can make the difference between a successful crop and lagging yields.
Boron deficiency varies based on soil type and structure. Sandy soils with low organic matter will likely be boron deficient, as will soils with less-than-optimal pH. To mitigate the risks of yield lag, boron is a micronutrient that should be on your radar when assessing your soil and tissue tests. Testing for boron deficiencies in the major field crops is the best way to manage the challenge of having sufficient boron in the plant.
Deficiency symptoms are something you should be watching for throughout the growing season—paying special attention to those crops showing signs of:
  • Impaired root growth
  • Misshapen, thick, brittle and small leaves
  • Weak or dead growing points
  • Shortened internodes

Bulk boron application

Thanks to delayed harvest and continued wet conditions in 2019, much of the boron application in 2020 should be in bulk applications, applied in combination with macronutrients. With all of the leaching that occurred in the last growing season, there will be virtually no remaining available boron for the new crop.
Keep in mind that considerations for any applied fertilizers, spring or otherwise, should always include the 4Rs of nutrient management: The right source, rate, time, and place. For spring-applied boron: Three of the Rs are pretty self-explanatory … but the fourth—the “right source” —may be more challenging when looking at boron fertilizers available on the market.
As agricultural production input costs continue to rise, it’s important to minimize both your time and cost in applications while maximizing resources available for a developing crop—think of the 4Rs’ rate, time, and place.
Boron can be applied in bulk fertilizer applications with other macro- and micronutrient application. But because boron application rates are low when compared to macronutrients, you must assess the product spreadability in order to achieve uniform field application.
Granubor® is designed to be bulk blended with other nutrients—matching particle size in the fertilizer blend closely to spread evenly in a bulk application. Results from New Leader’s granular product spreadability testing show that Granubor offers consistent and even spread across all bulk fertilizer blends tested for spreadability. Granubor is a low inclusion and high potency product. Remember, a smaller particle size simply means less product to handle…not less coverage!

Crop’s boron demand

In addition to spreadability, growers need to evaluate the demand curve of their crops. The boron fertilizer product you select should ensure that nutrient resource availability is maximized during your crop’s peak demand curve.
Peak consumption of boron by crops occurs during the reproductive growth and seed production stages. Some plant species produce significant amounts of polyol (eg sorbitol), making boron mobile in the phloem due to the formation and transport of boron sorbitol complexes. This mobility requires a constant, regulated supply of boron throughout the growing season to prevent toxicity in older leaves and deficiency in new, young leaves (Oertli, 1994).
Granubor is the only pure, 100% water soluble micronutrient that is engineered to meet crops’ boron demands during the growing season. Granubor is optimal for season-long fertilization in pre-plant or pre-emergence applications and after the last tillage pass in operations using tillage practices. Other products and minerals with a lower water solubility fail to meet these demands.
All things considered, there are a lot of unknowns heading into 2020’s growing season, don’t let boron deficiency be one of them. Reach out to your regional U.S. Borax team member to learn more about how we can help boost yields and maintain a healthy, viable soil profile in your fields.



U.S. Borax, part of Rio Tinto, is a global leader in the supply and science of borates—naturally-occurring minerals containing boron and other elements. We are 1,000 people serving 650 customers with more than 1,800 delivery locations globally. We supply around 30% of the world’s need for refined borates from our world-class mine in Boron, California, about 100 miles northeast of Los Angeles. Learn more about Rio Tinto.

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