Ammonium Sulfate: Nutrient Source Specifics
I've helped write a series of fact sheets about the properties of some of the most common commercial fertilizers entitled "Nutrient Source Specifics". They are all available at ipni.net/specifics
I'll post them here too because people searching the web always seem to be looking for this type of information.
|Ammonium sulfate varies in color|
150 years. Initially, it was made from ammonia released during manufacturing coal gas
(used to illuminate cities) or from coal coke used to produce steel. It is made from a reaction of sulfuric acid and heated ammonia. The size of the resulting crystals is determined by controlling the reaction conditions. When the desired size is achieved, the crystals are dried and screened to specific particle sizes. Some materials are coated with a conditioner to reduce dust and caking.
Most of the current demand for ammonium sulfate is met by production from by-products of various industries. For example, ammonium sulfate is a co-product in the manufacturing process of nylon. Certain by-products that contain ammonia or spent
sulfuric acid are commonly converted to ammonium sulfate for use in agriculture. Although the color can range from white to beige, it is consistently sold as a highly soluble crystal that has excellent storage properties. The particle size can vary depending on its intended purpose.
|Ammonium sulfate can be brown|
N and S to meet the nutritional requirement of growing plants. Since it contains only 21% N, there are other fertilizer sources that are more concentrated and economical to handle and transport. However, it provides an excellent source of S which has numerous essential functions in plants, including protein synthesis.
Because the N fraction is present in the ammonium form, ammonium sulfate is frequently used in flooded soils for rice production, where nitrate-based fertilizers are a poor choice due to denitrification losses.
A solution containing dissolved ammonium sulfate is often added to post-emergence herbicide sprays to improve their effectiveness at weed control. This practice of increasing herbicide efficacy with ammonium sulfate is particularly effective when the water supply contains significant concentrations of calcium, magnesium, or sodium. A high-purity grade of ammonium sulfate is often used for this purpose to avoid plugging spray nozzles.