The role of essential nutrients in plant growth

• Nitrogen (N): Nitrogen is a part of chlorophyll which is responsible for the conversion of light into stored energy in the form of glucose or sugar in the plant. This element is also present in all plant protein molecules which are a component of the cells and enzyme molecules which are responsible for the production of auxins, kinetin and growth-promotion components in the plant. It also has a dominant effect on the uptake of other elements from the nutrient solution.
• Phosphorus (P): Phosphorus is important in the movement and storage of energy within the plant. It has a major role to play in photosynthesis and in respiration as well as in cell division, protein formation, root development and regulation of plant maturity. It is more concentrated in the growing points of the plant and in the seeds.
• Potassium (K): Potassium is vital for cell organisation, salt uptake and permeability into the xylem, the regulation of water uptake and transpiration, and in the metabolism of carbohydrates and nitrogen. It also plays a role in photosynthesis, the control of pH in the cells of the plant, and activates a number of enzymes. It is probably best known for its role in the opening of the stomata in the leaves and hence its role in regulating the rate of transpiration. Potassium improves the plant’s resistance to diseases such as rust and moulds. Large quantities are normally found in the growing points of the plant, in the leaves and in the cell sap.
• Magnesium (Mg): Magnesium is the central atom of the chlorophyll molecule which is responsible for photosynthesis. It is also needed for the activation of certain enzymes and helps the plants utilise phosphorus. It also tends to concentrate in the seeds of the plant.
• Sulfur (S): Sulfur is a constituent of many flavour and odour compounds in plants – the aroma of onions, cabbages, brussel sprouts etc., the stench associated with urine after eating asparagus and the stench of rotting seaweed. More importantly, sulfur is a constituent of the essential amino acids cysteine and methionine, so when sulfur is in short supply, protein production is restricted.
• Calcium (Ca): Calcium is very important for the development of the cell walls which it appears to strengthen and stiffen. It is essential for growth, for cell enlargement, as an activator of certain hormones, and for root functioning. It also helps to balance the effect of excesses of the other elements and stimulates root development. It is very important for the formation of root nodules in legume.
• Iron (Fe): Iron has an important function in photosynthesis, the reduction of nitrates for protein formation and nitrogen fixation in legumes. It is also important for the production of some enzymes.
• Manganese (Mn): Manganese is closely associated with iron in the formation of chlorophyll and also plays a role in the creation of starches and sugars in the leaves of the plant.
• Copper (Cu): Copper assists the functioning of certain enzymes in plants (ascorbic acid, oxidase and pheno-lexidase). It is also active in the formation of chlorophyll.
• Zinc (Zn): Zinc has the major role in the production of auxin, a plant hormone which is responsible for promoting stem elongation and leaf expansion.
• Molybdenum (Mo): Molybdenum’s main function is in the reduction of nitrates prior to the formation of the protein molecules. It also stimulates the nodule bacteria of leguminous plants.
• Boron (B): Boron is important in the movement of sugars, in the structure of the cell walls, and is closely related to some of the functions of calcium.
• Cobalt (Co): Cobalt is only required by some plants. It is essential to the fixing of nitrogen by bacteria and algae.

For more see page 34 of the FloraMax Hydroponics Manual.