It is known that mineral fertilizers for vegetable garden differ from organic much higher concentration of nutrients. Depending on the composition, they can be divided into simple, with one substance and complex, containing several compounds. Since each substance contains the basic microelement, which the plant needs, its share in the fertilizer should be expressed as a percentage. In each substance the proportion of trace element is different. For example, ammonium sulfate contains 20.5% nitrogen, in ammonium nitrate – 35%, and even more (up to 46%) – in urea. The conditional formulas of the active substances are as follows: nitrogen – N, phosphorus – P2O5, potassium – K2O.
To calculate the amount of mineral fertilizer needed to treat a particular crop, you need to know the optimal dose of the active ingredient for this plant, multiply by 100 and divide by the% content of the active ingredient in the fertilizing.