A water soluble fertilizer is one that may be dissolved in water and then added to the soil in a liquid form. These fertilizers are very convenient because it can be much easier to control the amount of nutrients that each plant needs due to the fact that they are in a measureable liquid form.
Most water soluble fertilizer solutions that are available on the market today will have a particular set of numbers listed on their label. These are known as the N-P-K numbers. N-P-K numbers are an indication of the smallest percentage the water soluble fertilizer has of each element listed. The reason why these numbers appear on many fertilizer labels in this fashion is so that the company’s competitors will not know the exact amount of each element that is in the fertilizer. This prevents fertilizer companies from copying an exact formula from one another.