A Cardinal number represents an equivalence class of sets between which there is a bijection (one-to-one correspondence). It is the number of elements in any member of the equivalence class. An Ordinal number represents an equivalence class of well-ordered sets between which there is an order-preserving bijection. It is the number of elements in any member of the equivalence class. The difference is only in whether the sets are ordered.
Phosphorous aids in the transfer of energy from one part of the plant to another and is responsible for strong root growth and healthy, hearty blooms. If you need to revitalize a blooming plant, a plant that isn't producing as much fruit as it should or a sparse lawn, a phosphorous rich fertilizer is the best choice.
Many hobbyists recommend a balanced fertilizer, with all three main ingredients, something akin to 20-20-20 or 20-10-10. These numbers refer to the three most common trace elements that all plants need: nitrogen, phosphorus, and potash.herefore, the higher the numbers, the more expensive the fertilizer, per unit, and the less of it you need to treat a given area. The main point is that when someone recommends 20-10-10 and you can find only a 10-5-5 fertilizer, other than perhaps price, there may be no difference.