Phosphorus (P) is vital to the growth and health of plants. It assists in converting the sun's energy and other elements, such as nitrogen, into usable food for plants. It functions as one of the major players in the process of nutrient transport and energy transfer.
role in growth
- "The orthophosphates, (H2PO4-) and (HPO42-), are the primary forms of phosphorus taken up by plants" (University of Hawaii).
- "When the soil pH is less than 7.0, (H2PO4-) is the predominate form in the soil" (University of Hawaii).
"Phosphorus is involved in many plant processes, including:
Energy transfer reactions, Development of reproductive structures, Crop maturity, Root growth and Protein synthesis (University of Hawaii).
- "Management of cover crops and potentially enhanced arbuscular mycorrhizal fungi colonization from organic production practices can increase the availability of soil P pool (both organic and inorganic) by stimulating microbial activity and release of root exudates" (HortTechnology).
- "Phosphorus is a component of the complex nucleic acid structure of plants, which regulates protein synthesis. Phosphorus is, therefore, important in cell division and development of new tissue. Phosphorus is also associated with complex energy transformations in the plant" (Plant & Soil Sciences eLibrary).
"The function of phosphorus as a component of macromolecular structures is most prominent in nucleic acids, which, as components of DNA, are the carriers of genetic information and, as units of RNA, are the structures responsible for the translation of the genetic information. In both DNA and RNA, phosphate forms a bridge between ribonucleoside units to form macromolecules" (H. Marschner, 2012)
"Plants deficient in phosphorus are stunted in growth and often have an abnormal dark-green color. Sugars can accumulate and cause anthocyanin pigments to develop, producing a reddish-purple color. These symptoms usually only persist on extremely low phosphorus soils. It should be noted that these are severe phosphorus deficiency symptoms and crops may respond well to phosphorus fertilization without showing characteristic deficiencies. In addition, the reddish-purple color does not always indicate phosphorus deficiency but may be a normal plant characteristic" (Plant & Soil Sciences eLibrary).
- "Phosphorus deficiencies may even look somewhat similar to nitrogen deficiency when plants are small. Yellow, unthrifty plants may be phosphorus deficient due to cold temperatures which affect root extension and soil phosphorus uptake. When the soil warms deficiencies may disappear" (Plant & Soil Sciences eLibrary).
- "Compared with shoot growth, root growth is less inhibited under P deficiency, leading to a typical decrease in shoot/root ratio. This decrease in shoot/root ratio is due to the increase in partitioning of carbohydrates towards the roots, indicated by a strong increase particularly in sucrose concentration of the roots of P-deficient plants" (H. Marschner, 2012).
sources of phosphorus
H. Marschner, 2012. Mineral Nutrition of Higher Plants.