Phosphorus is a chemical element with symbol P and atomic number 15. As an element, phosphorus exists in two major forms—white phosphorus and red phosphorus—but due to its high reactivity, phosphorus is never found as a free element on Earth. Instead phosphorus-containing minerals are almost always present in their maximally oxidised state, as inorganic phosphate rocks.
Sources of phosphorus
- Soil organic matter e.g. crop residues.
- Weathering of rocks that contain phosphate e.g. Tororo Rock.
- Organic manures e.g. farm yard manure and from artificial fertilizers.
Importance of phosphates
- It stimulates root development and Nidule formation legumes.
- Promotes respiration in plant cells, accelerates the breakdown of carbohydrates as well as other metabolic processes.
- It helps information of proteins and fats.
- It is necessary in reproductive process e.g. flowering food and seed formation etc.
- It promotes cell division and early plant maturity.
- It encourages leaf formation and the development of mono shoots.
- It impacts disease resistance to certain crops.
- It makes straw in cereal crops strong therefore prevents lodging of crops.
- It improves crop quality especially the vegetables.
Ways through which phosphorus can be lost from the soil.
- It can be taken up by crops which are later harvested.
- Fixed by iron and aluminum oxided and this very common in clay soils.
- In very acidic soils phosphorus becomes unavailable to plants.
Deficiency symptoms of phosphorus.
- Stunted growth
- Lack f branching in roots and stems.
- Leaves especially maize become purpled and fall off prematurely.
- Low yield of grain fruits and food crops and delayed maturity.
Excessive symptoms of phosphorus.
Excess phosphorus induces iron deficiency of iron.
Practical control of phosphate availability.
- Phosporus is not very soluble in water so only about 5-20% of the phosphorus.
- Addition of agriculture lime to keep the PH between 6 & 6.5 this will prevent phosphorus being fixed.
- Crop residues should be in cooperated in the soil and organic manure added.
- Phosporus fertilizers should applied as pellets to reduce its reaction with soil.
THIS VIDEO EXPLAINS MORE ABOUT PHOSPHORUS