Nitrogen-phosphate-potassium fertilizers (NPK) are a solid granular compound widely used in agricultural practices as a balanced fertilizer with a chemical formula of NPK. It appears as small, colored granules or pellets. NPK fertilizers are essential for plant growth and development as they provide three vital nutrients: nitrogen (N), phosphorus (P), and potassium (K). Nitrogen-phosphorus-potassium (N-P-K) fertilizers are manufactured using ammonium phosphate, to which potassium (usually potassium chloride) and water have been added. Additional nitrogen and other nutrients also can be added.
While all the 3 nutrients work together in a plant, each has some specific jobs. A simple trick for remembering what each component of N-P-K does is "head-arms-legs" for "leaves-flowers or fruit-roots."
Nitrogen (N) gets the growth shown on the road. It's a building block for growing new stems and leaves, plus it is a necessary part of chlorophyll, which makes the leaves green and helps plants photosynthesize.
Phosphorus (P) is needed for developing flowers, fruits, and root systems.
Potassium (K) keeps roots healthy and also aids flowers and fruits. It helps plants tolerate stress, such as drought.
Nitrogen-phosphate-potassium fertilisers are manufactured with potassium ammonium phosphate (usually potassium chloride) and water, to which additional nitrogen and other nutrients can be added. Higher-quality (N-P-K) fertilisers can be prepared by reacting potassium hydroxide with phosphoric acid made at the furnace level and then adding nitrogen, sometimes with a small amount of ammonia used to replace some of the nitrogen. However, the cost is high.