Thursday, October 18, 2007

Nutrients are an essential part of healthy plant growth.

For a plant to grow, it requires the correct temperature and humidity, moisture, light, air, certain mineral salts (nutrients) and the absence of pathogens (disease causing organisms).

Plant nutrition is the science which studies what plants eat, or more to the point which nutrients the plant takes from its surroundings, in what amounts, under what conditions and how what the plant takes is used in growth and development. This is of great importance to anyone who is interested in maximizing the genetic potential of his/her plants.

A hydroponic nutrient solution is composed of water, dissolved air and a dozen or so essential elements in their proper proportions. The essential elements, or mineral elements that must be present for proper plant growth and development are nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), calcium (Ca), sulfur (S), iron (Fe), manganese (Mn), boron (B), copper Cu), zinc (Zn), molybdenum (Mo), and chlorine (Cl). The letters in parentheses are the chemical symbols for each element. In addition to these elements, hydrogen (H), oxygen (O2) and carbon (C) are also essential elements which can be found in the air and the water.

The elements that make up a nutrient solution are broken up into two different categories depending upon their relativity to the total make-up of the nutrient solution. Hydrogen, oxygen, carbon, nitrogen, phosphorus, potassium, magnesium, calcium and sulfur are required in relatively large amounts and are so called macroelements (major elements), while iron, manganese, boron, copper, zinc, molybdenum and chlorine are required in relatively small amounts and are so called microelements (minor elements).

Hydroponic nutrients should be complete, containing every essential element, both major and minor, required by all green plants for optimum plant growth. The nutrient should be well balanced containing enough of all essential elements so no deficiency occurs, while not containing too much of any element that might lead to a toxicity. Also the nutrient should be pH balanced and buffered preventing the pH from drifting too high (alkaline) or too low (acid). The last and maybe most important requirement is that the nutrient solution be water soluble with minimal or no residue. The mineral salts used should readily dissociate into elemental ions and not contain any toxic chemicals or elements like heavy metals (lead, mercury or tungsten). This is controlled by the selection and purity of the raw ingredients used.

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