1. Phosphorus occurs in most plants in concentrations between 0.1 and 0.4%.
2. Plants absorb either H2 PO2- or H + PO42- ortho PO4 ions Absorption of H2 PO2- is greatest at low pH values, where as uptake of HPO4- is greater at higher values of soil pH, plant uptake of HPO4- is much slower than H2 PO4-.
Functions of Phosphorus
- It has a greater role in energy storage and transfer.
- It is a constituent of nucleic acid, phytin and phospholipids.
- It is essential for cell division and development .
- P compounds act as energy currency within plants. The most common P energy currency is that found in ADP and ATP. Transfer of the energy rich PO4 molecules from ATP to energy requiring substances in the plant is known as “Phosphorylation”. It stimulates early root development and growth and there by helps to establish seedlings quickly.
- It gives rapid and vigorous start to plants strengthen’s straw and decreasess lodging tendency.
- It is essential for seed formation because larger quantities of P is found in seed and fruit- phytic acid is the principle storage from of phosphorus in seeds.
- It increases the activity of Rhizobia and increases the formation of root nodules.