What do NPK fertilizers contain?

NPK fertilizers are specifically formulated to provide essential nutrients for plant growth, which are nitrogen (N), phosphorus (P), and potassium (K). The correct choice highlights that NPK fertilizers typically consist of various salts that supply these three critical macronutrients.

Nitrogen is vital for the production of chlorophyll and is crucial for growth and development. Phosphorus plays a key role in the formation of DNA and is also important for energy transfer in plants. Potassium helps in the overall functioning of the plant, including water regulation and enzyme activation.

Understanding NPK fertilizers involves recognizing that they can be made from both synthetic and natural sources. However, they predominantly consist of various salts that directly supply the necessary nutrients. This is distinct from options that may refer to organic matter, solely synthetic chemicals, or unprocessed mineral ores, which do not accurately define the composition of NPK fertilizers.