Environmental Issues of Ammonium Sulfate Fertilizer
Considering the widespread use of ammonium sulfate as a nitrogenous agricultural fertilizer, it is not associated with any specific pollution concerns.
In general, regarding chemical fertilizers and their environmental impact, it is important to note that improper use or overuse of chemical fertilizers—often mistakenly considered beneficial—can, over time, disrupt the ecosystem balance, cause chemical pollution of soil and water, reduce soil fertility, and ultimately decrease crop yield. The alkaline nature of most agricultural soils and the use of some fertilizers, such as urea, which increases soil alkalinity, can negatively affect the environment. Urea in alkaline and calcareous soils can exacerbate soil alkalinity and even cause salinity-related toxicity.
Ammonium sulfate, on the other hand, is more suitable for alkaline soils, such as those in pistachio orchards. Due to the presence of sulfur in its chemical structure, which decomposes in the soil to form sulfuric acid, and nitrogen in the ammonium form, it reduces soil alkalinity and has minimal negative impact on the environment. Therefore, compared to other chemical fertilizers, ammonium sulfate has less destructive effects on the environment.
Soil nitrogen comes from both organic and chemical fertilizers. In animal manures and green manures, nitrate—a highly water-soluble anion—is not strongly adsorbed by soil, can easily move toward plant roots, or be lost through leaching. Urea, although readily absorbed, is also mobile and can be lost through water leaching. In contrast, ammonium carries a positive charge and, like other cations, is adsorbed by soil particles. This limits its mobility, leaching, and subsequent loss, making it more environmentally safe.
