The difference between diammonium phosphate (dap) and nitrogen phosphorus potassium fertilizer (npk fertilizer)

The main difference between DAP and NPK fertilizers is that DAP does not contain potassium, while NPK fertilizers also contain potassium.

The term DAP refers to diammonium phosphate, which is a phosphate fertilizer; the most common phosphate fertilizer in the world. Therefore, we produce this fertilizer using phosphoric acid and ammonia, two important components in the fertilizer industry. And NPK fertilizer is an important source of nitrogen, potassium and phosphorus. These are the three main nutrients required for the growth and development of crops.

What is DAP fertilizer?

Diammonium phosphate fertilizer is a source of nitrogen and phosphorus and has a wide range of uses in agriculture. The main ingredient of this fertilizer is diammonium phosphate with the chemical formula (NH4)2HPO4. Additionally, the IUPAC name for this compound is diammonium hydrogen phosphate. It is water-soluble ammonium phosphate.

During the production of this fertilizer, we react phosphoric acid with ammonia to form a hot slurry, which is then cooled, pelletized and screened to get a fertilizer that we can use on the farm. Also, we should run the reaction under controlled conditions, because the reaction uses sulfuric acid, which is dangerous to handle. Therefore, the standard nutrient rating for this fertilizer is 18-46-0. That means, it has 18:46 nitrogen and phosphorus, but it has no potassium.

Generally speaking, we need about 1.5 to 2 tons of phosphate rock, 0.4 tons of sulfur to dissolve the rock, and 0.2 tons of ammonia for the production of DAP. In addition, this substance has a pH of 7.5 to 8.0. So if we add this fertilizer to the soil, it creates an alkaline pH around the fertilizer particles, dissolves in the soil water, so users should avoid adding this fertilizer in large quantities.

What is NPK fertilizer (npk fertilizer)

NPK fertilizers are three-component fertilizers that are very useful for agricultural purposes. This fertilizer is a source of nitrogen, phosphorus and potassium. Therefore, it is an important source of the three major nutrients that plants need for growth, development and normal function. The name of the substance also expresses the nutrients it provides.

The NPK rating is a combination of numbers that gives the ratio of nitrogen, phosphorus, and potassium that this fertilizer provides. It is a combination of three numbers separated by two dashes. For example, 10-10-10 means the fertilizer provides 10% of each nutrient. Where the first number is the percentage of nitrogen (N%), the second is the percentage of phosphorus (in the form of P2O5), and the third is the percentage of potassium (K2O%).

The difference between diammonium phosphate (dap) and nitrogen phosphorus potassium fertilizer (npk fertilizer)

Diammonium phosphate (DAP) is a nitrogen and phosphorus source widely used in agriculture. These fertilizers contain diammonium phosphate – (NH4)2HPO4. This is the source of nitrogen and phosphorus. However, NPK fertilizers are three-component fertilizers that are very useful for agricultural use. It contains nitrogenous compounds, P2O5 and K2O, and is a major source of nitrogen, phosphorus, and potassium for agricultural use.

The infographic below details the difference between DAP and NPK fertilizers in tabular form.