What is a key feature of Ammonium Phosphate as a fertilizer?

Ammonium phosphate is particularly valued as a fertilizer because it is a source of water-soluble nitrogen in conjunction with phosphorus. This characteristic makes it beneficial for promoting plant growth, as both nitrogen and phosphorus are essential macronutrients that plants require for various physiological processes. Nitrogen supports the development of foliage and overall vegetative growth, while phosphorus is crucial for root development, flowering, and fruiting.

This combination, being water-soluble, allows for better availability to plants, especially in the early stages of growth when they require readily accessible nutrients. The other choices do not accurately represent ammonium phosphate; for instance, it does not provide potassium, which is provided by other fertilizers; nor is it exclusively a source of ammoniacal nitrogen, as it also contains other forms of nitrogen. Additionally, it does not contain high levels of urea nitrogen, which is found in different types of fertilizers. Therefore, the key feature of ammonium phosphate as a fertilizer is its role as a source of water-soluble nitrogen combined with phosphorus.