Phosphorus is second most essential nutrient next to nitrogen needed by plants. It plays as a key role in photosynthesis, respiration, energy storage and transfer, cell division, cell enlargement and genetic reproduction. Plants must have phosphorus for normal growth and maturity. A plant must have phosphorus to complete its normal production cycle.
· Function of phosphorus:
1. Used in numerous process such as photophosphorylation (creation of stored energy in plants),
2. genetic transfer,
3. transportation of nutrient,
4. phospholipid cell membranes,
5. component of RNA that reads DNA genetic code to build proteins and other compounds essential for plant structure, seed yield and genetic transfer.
6. Phosphorus is a vital component of ATP, the ‘energy unit’ of plants. ATP forms during photosynthesis, has phosphorus in its structure, and processes from beginning of seedling, growth through to the formation of grain and maturity.
Deficiency of phosphorus can done by visual inspection of the plant. Darker green leaves and purplish or red pigment can indicate a deficiency in phosphorus. This method however can be unclear diagnosis because other plant environment factors can result in similar discoloration symptoms. Scientific testing can be do to get more accurate nutrient data of the plant. The most prominent method of checking phosphorus levels is by soil testing. The testing is viable but has tendencies to be more accurate in known geographical areas.
Symptoms of deficiency:
Phosphorus is more difficult to diagnose than a deficiency of nitrogen or potassium. Crops usually display no obvious symptoms of phosphorus deficiency other than a general stunting of the plant during early growth. By the time a visual deficiency is recognized, it may be too late to correct in annual crops. Phosphorus is highly mobile in plants, and when deficient, it may be translocation from old plant tissue to young, actively growing areas. Consequently, early vegetative responses to phosphorus are often observed. As a plant matures, phosphorus is translocation into the fruiting areas of the plant, where high-energy requirements are needed for the formation of seeds and fruit. Phosphorus deficiencies late in the growing season affect both seed development and normal crop maturity. The percentage of the total amount of each nutrient taken up is higher for phosphorus late in the growing season than for either nitrogen or potassium.
- Application of ammonium forms of nitrogen with phosphorus increases phosphorus uptake from a fertilizer as compared to applying the phosphorus fertilizer alone.
- Sulfur = sources of phosphorus on neutral / basic soils.
- Apply phosphorus into soil before planting will lead more efficient utilization of fertilizer phosphorus.