Ammonium Sulfate (AS or AMS) is used in the form of crystals, powders, and granules. This fertilizer is essential for alkaline soils. The deficiency of this fertilizer will severely limit the growth of the plant in the soil and plants cannot reach the vegetative phase. Its composition includes 21% nitrogen in the form of ammonium (NH4) and 24% sulfur in the form of sulfate (SO4). Ammonium sulfate improves the quality and growth of plants specially pistachios, citrus fruits, alfalfa, corn, canola, cotton, potatoes, rice, and wheat. The nitrogen in ammonium sulfate fertilizer has much less leaching than other nitrogen fertilizers and is a source of sulfur for basic functions in plants, specially the production of proteins.Ammonium sulfate prevents the yellowing of young and old leaves caused by soil nitrogen depletion and sulfur deficiency.

Mixing this fertilizer with herbicides and pesticides may improve the effect of the toxins (when the water contains a significant concentration of calcium, magnesium, or sodium). Among nitrogen fertilizers, ammonium sulfate has the lowest water absorption, which reduces clumping and increases its storage time in the soils. Also, its decomposition in the soil accompany to sulfuric acid, and ammonium, increases the acidity and does not harm the environment. Therefore, this fertilizer has less destructive effects on the environment. On the other hand, adjusting the pH of the soil facilitates the absorption of other micronutrients in the soil, including iron, zinc, copper, and manganese.

Time and amount of consumption

It is better to use any type of agricultural fertilizer based on the results of the soil test and the opinion of experienced experts in the region. Time and the method of spreading should be considered too. If ammonium sulfate fertilizer is left on the soil surface, ammonium can be lost as a gas under alkaline conditions. So it is suggested to mix the fertilizer with the soil or use the fertilizer before irrigation or rainfall. If this fertilizer is used more than required, lime can be used to adjust the pH, therefore it is suggested to mix the fertilizer with the soil or use the fertilizer before irrigation or rainfall.