Phosphorus plays an important role in all living organisms and forms an essential component in the nutrition of both plants and animals. It holds a key position in cell metabolism and in the total energy transfer of the plant. It is also a building block of the cell walls, DNA, and all kinds of protein and enzymes.
Phosphate is indispensible for young plants; around 3/4 of the total phosphate uptake occurs before the plant has lived a quarter of her lifecycle! The biggest concentrations of phosphate are also found in the developing parts of the plant such as the roots, growth shoots and vascular tissue.
Phosphorus is a chemical element that belongs to the non-metals and that is not found in pure form in nature because it is highly reactive. It was discovered in 1669 by an alchemist from the evaporation of urine (in an attempt to make gold).
Phosphate compounds in a form which plants can make use of are rarely found in nature. In days gone by, people used ground bones (bone meal) as a fertilizer, and later used sulphuric acid thanks to which the phosphates were made considerably more available. In the second half of the 19th Century, guano, a natural phosphate fertilizer made from accumulated seabird droppings, was quarried on a huge scale for use in agriculture.
These days the basic materials are extracted from natural phosphates, primarily these are phosphate-rich ores extracted from places such as Morocco, Algeria, North and South America. In order to make natural phosphates suitable for agriculture and horticulture they are first acidified and then purified. In alternative agriculture they are finely ground or heated and are available as expanded granules in stores.
Certain symptoms of phosphate deficiency described in the literature should not be confused with nitrogen deficiency. A phosphate deficiency is characterised in cannabis not by a noticeable purple colouration in the stems and leaf veins, but by a small plant with purple-black necrotic leaves that warp and eventually crinkle the leaf.
Its progression in chronological order:
Inorganic phosphates, in ion form, are very easily taken up. As far as is known, plants take up no phosphorus in organic form. However, inorganic phosphates can be released in the decay of organic soil particles. Thanks to the residue effect of phosphates it holds that the older the soil the more phosphate rich it tends to be.
Enriching the soil with phosphate-containing fertilizers after a deficit has been discovered often has very little effect: thanks to precipitation or absorption phosphate hardly penetrates the soil and the disturbances in growth when the plant is young are hard to recover from. For this reason phosphate-fertilizers need to be well worked into the soil.
An excess of phosphate is damaging to the environment and can trigger all kinds of side effects, including zinc, copper or magnesium deficiency.