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Uses of Metals In Agriculture

Plants and animals are living organisms, and so require various nutrients from their environment to grow and prosper. These nutrients include many metals, especially as the periodic table of elements divides most elements into metals, metalloids and non-metals. The metal group is the largest of these. Farmers can also use metals for other purposes apart from feeding plants and animals as they can have biological effects on other organisms.

Fertilizer
- Crops may require additional fertilization on top of the natural soil nutrient content to thrive. Each plant needs inorganic nutrients such as metals, which are divided into macronutrients (of which the plant needs a lot), and micronutrients (of which the plant only needs a trace amount). Examples of macronutrients include the metals potassium, calcium and magnesium. Essential micronutrients include iron, manganese, zinc, molybdenum and copper. In nature, plants gets these nutrients primarily from decomposing organic sources such as dead plant material, but in agriculture the farmer may need to boost the natural levels for the soil to support commercially viable crop yields, so he applies fertilizers that contain these nutrients on the soil. Different crops preferentially take different metals from the soil, so the farmer must tailor his metal fertilization to the plant. For example, corn and soybeans strip zinc more than some other crops.
Supplements
- Animals also require metals for essential biological functions. For example, a cow needs a trace amount of copper in its diet for its enzymes to function correctly, and if it cannot take in the necessary copper, it will become anemic and have a weak immune system. Calves which do not get enough manganese have bones that grow abnormally, and a lack of cobalt results in issues such as weight loss. Farmers can ensure their cattle, or other animals, receive enough of these metallic nutrients if they give the animals a source of supplementation such as a salt lick which allows them to ingest enough of the nutrients as they like.
Pesticides
- Certain pesticides use a metal to keep diseases at bay. For example, a copper-based pesticide can control mildew on grapes. Different forms of copper compounds can also kill bacteria or fungi. They can also tackle algae problems in water sources.
Antiseptics
- Metals in their natural form, or metal compounds, can act on microbial populations as an antiseptic. Silver, for example, according to the Merck Veterinary Manual, kills bacteria at a 0.1 percent concentration. Silver, therefore, may be present in some eyedrops for veterinary conditions or as an antiseptic for wounds. Mercury compounds are also antiseptic but as the metal can persist in soil as a health risk it is not in common usage.

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