Hi,
Plants and animals collect elements and weave them into their fabric. They build proteins and enzymes to perform various functions, build structure, consume food and eject toxic waste. Here is a summary of the most important elements in order of their importance;
1. Carbon - Chemical symbol C - Used as a food source in a hydrated form called Carbohydrates. Carbon also is used to build the basic structure of plants. Carbon can only be assimilated by uptake of Carbon Dioxide (Chemical Symbol CO2).
2. Nitrogen - Chemical symbol N - Used with Carbon as a fundamental building block for Chlorophyll, a pigment molecule used to convert light into chemical energy for growth. Nitrogen is also used in the construction of something called a Nucleobase which are then used as basic building blocks of DNA and RNA. Nitrogen is assimilated typically by uptake of Ammonium (NH4) or Nitrate (NO3).
3. Phosphorous - Chemical symbol P - Used primarily in combination with Carbon and Nitrogen to build an important enzyme called Adinosine Triphosphate (ATP). This enzyme is like a battery. Every cell in your body and in a plant can only carry out it's function by using the energy of ATP to power the cell. In the natural world if there would be a currency, then that currency would be ATP. It's the currency of energy.
Phosphorous in the form of phosphate (PO4) is also used as the backbone of the double helix in DNA/RNA. In this image of the helix flattened out, you can see that there are alternating pattern of PO4 molecules which link and hold the spiral. The nitrogenous bases can also be seen as the "steps" of the double helix ladder.
4. Potassium - Chemical symbol K - Used primarily to activate enzyme activity. It is not usually found as part of the structure but many activities are directly controlled by K. It controls water movement into and out of cells and even controls the uptake of other nutrients. Think of K as the "Bloodstream" of plants. K can be assimilated in any salt that contains it such as Potassium Phosphate (KH2PO4), Potassium Sulfate (K2SO4), Potassium Carbonate (KCO3), or Potassium Chloride (KCl). More on Potassium in the thread =>
Lack of Potassium
5. Iron - Chemical Symbol Fe - Used primarily in enzymes relating to the Redox reactions in photosynthesis, most notably in the agent Ferrodoxin. Method of assimilation , most forms of trace element mixes in which Fe is the principle ingredient.
6. Remaining Trace Elements - Manganese, Zinc, Magnesium (see
About Magnesium), Calcium, Sulfur, Boron, Molybdenum and Copper. These all have various roles in enzyme activity and are only required in small trace amounts in the same way we need vitamins. The are all found in the various trace mixes and are normally available in tap water to a greater or lesser extent.
Please visit the Tutorial section of the forum for specifics techniques applicable to plant husbandry.
Cheers,