Ammonium nitrate

Ammonium Nitrate and Its Starring Role in Fertilizer Accidents, One of the main components in manufactured fertilizer is ammonium nitrate. Like we said, nitrogen is one of those macro nutrients that plants love, so a lot of fertilizers are nitrogen-based.
Of course, we can't just bottle up some nitrogen and pour it on the ole carrot patch. Atmospheric nitrogen has a really strong chemical bond that plants can't easily break, so fertilizer companies create a nitrogen-based substance that's much easier for plants to take apart. Ammonium nitrate is one such compound. And it's used for good reason: The ammonium part sticks around longer without evaporating, so it's great for hot summer fields, and the nitrate is easily used by plants. Even more compelling in the agricultural industry, it's inexpensive to manufacture. You combine ammonia and nitric acid, and you're done.
Composition: nitrogen (N) - 34.4 % (ammonia N (N-NH3) - 17.2 %; nitrate N (N-NO3) - 17.2 %).
Fertilizing effect: ammonium nitrate provides plants with required amount of nitrogen, which is especially important during the period of intensive growth. Fertilization not only ensures effective growth and ripening, faster root development, rapid nutrient absorption, but also prevents leave yellowing. Nitrogen stimulates and regulates many vital plant growth processes. Plants fertilized with ammonium nitrate consume less water, contain more proteins and sugar, have longer vegetation period.
Ammonium nitrate is an important fertilizer with the NPK rating 34-0-0 (34% nitrogen).It is less concentrated than urea (46-0-0), giving ammonium nitrate a slight transportation disadvantage. Ammonium nitrate's advantage over urea is that it is more stable and does not rapidly lose nitrogen to the atmosphere. During warm weather it is best to apply urea soon before rain is expected or to cover it with soil to minimize nitrogen loss