Fundamental to Life
As one of the 109 elements that make up the planet, it's not surprising that boron is everywhere - in soil and water, plants and animals - in trace amounts. Although scientists refer to levels of "boron," it is important to note that the element boron does not exist by itself in nature. Rather, boron combines with oxygen and other elements to form boric acid, or inorganic salts called borates.
Despite the millions of tons of industrial borates mined, processed and distributed around the world every year, far larger quantities of boron are transferred around the planet by way of natural forces. Rain, volcanic activity, condensation and other atmospheric activities redistribute at least twice as much boron as all commercial practices combined.
Boron in Plant Life
People didn't know about mineral nutrients when they first started growing crops more than 10,000 years ago. In fact, it has only been in the last century that scientists and farmers discovered the seven essential micronutrients that plants need to grow, boron among them.
Boron performs at the cellular level, and is integral to a plant's reproductive cycle; controlling flowering, pollen production, germination, and seed and fruit development. The mineral also acts as a fuel pump, aiding the transmission of sugars from older leaves to new growth areas and root systems.
Boron in Your Diet
Plants get the boron they need from soil and water. In fact, they can't live without it. For humans, experts agree that boron is nutritionally important, and mounting evidence suggests that boron may be an essential element to our diet as well.
Boron in Water
Boron occurs naturally in seawater at an average concentration of five milligrams of boron per liter (mg B/L). The element generally occurs in fresh water lakes, rivers, streams, and groundwater at concentrations well below one mg B/L.
Boron in Soil
Boron is a naturally occurring element in soil originating from boron-containing minerals in the earth's crust. Boron availability and levels in soil are dependent on solubility of boron in the parent rock; the physical and chemical characteristics of the soil; and the availability of water moving through it. The available level of boron ranges from 0.1 to 3 mg/kg of soil. However, most of the boron in soil remains part of insoluble minerals or is firmly attached to other components such as clay or organic matter. The total boron level (soluble and insoluble) in soil can be categorized as low-boron (less than 10 mg B/kg soil) or high-boron (on the order of 100 mg/kg). The average overall concentration of boron in all soil ranges from 10 to 20 mg/kg.
Boron deficiency is more widespread than boron enrichment. Extremely high-boron soils are rare. Existing large deposits were formed over many years encapsulating high concentrations of borates in non-permeable layers of clay. In some areas of the world soil is layered on top of rock with a high boron content. This rock is a source of boron and may result in boron-enriched topsoil and groundwater.
Boron in the Atmosphere
Relatively little information is available about the quantity and form of boron in the atmosphere. Boron has been detected in measurable quantities in evaporation from seawater, rain, snow, and hot springs, and industrial airborne dust. In rain and snow, boron has been reported in concentrations ranging between 0.002 and 0.1 milligrams boron per liter. The major source of boron in the atmosphere appears to be evaporation from seawater. Industrial processes contribute much less. On a global basis, boron moves through the atmosphere at a rate of five to seven million tons per year.