A nutrient, usually in the parts per million range, used by plants in small amounts, less than 1 part per million (boron, chlorine, copper, iron, manganese, molybdenum, zinc, and nickel). Related Images:

Chlorine plays a very important part in photosynthesis, particularly in helping to control the hydrolysis process. It also aids in the process of cation balance as well as the transport of ions and nutrients throughout the plant system.

The majority of the micronutrients are not mobile in the plant. Deficiency symptoms are usually found on new growth. Their availability in the soil is highly dependent upon the pH and the presence of other ions.

Cobalt is one of the elements which is classified as an essential element, although it does classify as a micronutrient because of the fact that it is not required in as high of a concentration as opposed to a macronutrient like phosphorous.

In the past, nickel (Ni) was not considered an important element for plant growth, but research has concluded that it is an essential element for plant growth. The normal range for nickel in most plant tissue is between 0.05-5 ppm.

Boron is concentrated on Earth by the water-solubility of its more common naturally occurring compounds, the borate minerals. These are mined industrially as evaporates, such as borax and kernite. The largest proven boron deposits are in Turkey, which is the also the largest producer of boron minerals.

Manganese also functions in the oxygen-evolving complex of photosynthetic plants. The element is a required trace mineral for all known living organisms.

Molybdenum-containing enzymes are by far the most common catalysts used by some bacteria to break the chemical bond in atmospheric molecular nitrogen, allowing biological nitrogen fixation.

The most common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral. The largest mineable amounts are found in Australia, Asia, and the United States. Zinc production includes froth flotation of the ore, roasting, and final extraction using electricity (electrowinning).

Copper is essential to all living organisms as a trace dietary mineral because it is a key constituent of the respiratory enzyme complex cytochrome c oxidase.