U.S. Borax
and the 4Rs

The right source for boron in fertilizers

Successful Fertilization Requires the Right Balance of Nutrients

Agriculture and fertilizer experts are familiar with the 4Rs—the concept that the right fertilizer source, applied at the right rate, in the right time, and in the right place is the best way to increase crop production and profitability while protecting the environment and improving sustainability. But you might not be aware of the key role that the micronutrient boron, when applied in balance, plays in the uptake of other nutrients.

Finding the Right Source

Refined boron from U.S. Borax is sourced from our California deposit. This primarily calcium-free sodium borate is one of the cleanest sources of boron in the world—and our refinement process makes it even cleaner.

Determining the Right Rate

The proper rate of boron supplementation depends on several factors, including region, climate, and crop type. Calculating the correct amount of boron is vital to good results; our online crop guides can help growers diagnose and treat boron deficiencies.

Choosing the Right Time

Application of refined boron at the right point in the growing season is an important part of promoting plant health—and a healthy yield. Timing is key; soil and tissue tests can help growers determine boron levels throughout the growth cycle.

Targeting the Right Place

Distance from the root system, as well as the decision of whether to apply refined boron to the soil (in granular form) or plant leaves (as a foliar spray), are factors that affect the success of boron fertilization. Combining refined boron with other fertilizer can help decrease costs and provide optimal coverage.

U.S. Borax Products

20.8% Boron
Boron for fertilizer manufacturing

This refined U.S. Borax product is made from the dehydration and fusion of borax. Depending on the grade, Anhybor can be used to produce boron-enriched compound fertilizers or to coat different fertilizer products, such as NPK blends with the aid of a binder.

Learn more →

15% Boron |  | OMRI Certified
Optimum product for suspensions

A fine crystalline borate ideal for NPK compound fertilizers and suspensions. Manufactured as free-flowing granules, Fertibor is easily handled and offers superior flow and consistency.

Learn more →

15% Boron |  | OMRI Certified
Made especially for bulk blenders

A pure, 100% water-soluble micronutrient that meets boron demand during the growing season. Made especially for bulk blenders, Granubor helps to ensure uniform distribution in nutritional blends and in the field.

Learn more →

11% Boron (w/w)
Liquid boron from boric acid

The convenience of liquid boron fertilizer straight to your farm with no measuring or mixing required.

Learn more →


20.5% Boron |  | OMRI Certified
Product of choice for foliar applications

A concentrated, highly soluble, and fast dissolving powder that is ideal for foliar and other sprays. With the highest concentration of boron in any approved product, Solubor is an economical choice for nutritional formulations.

Learn more →

10% Boron
Solubor Flow
For fertigation or hydroponic growing

First and only aqueous suspension of sodium borate microcrystals.

Learn more →

14.5% Boron | 29% Zinc
Perfect combination of zinc and boron

Because zinc and boron deficiency are widespread around the world, a product with both nutrients is a good fit in many regions. Zincubor brings these two important micronutrients together in one product.

Learn more →

Helping Growers Feed the World

U.S. Borax is committed to global agriculture and all those who work to feed the world’s growing population. Through our crop guides (which helps growers identify the right approach for treating boron deficiency in specific crops), support for field studies, and expert research and development, we provide the best available refined boron fertilizer.

Calculate your ROI

Boron deficient crops can cost between 1% and 4% annually. Find out what boron deficiency could be costing you.

Step 1: Choose your Crop

Crop Group

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.

Copyright © 2024 Rio Tinto. All Rights Reserved.