Equipment is also available to allow application of anhydrous ammonia using a disk or cultivator. Ammonia is a clear, colourless gas. When it vaporizes, however, the low temperature causes water vapour in the air to condense to fog. Because a small amount of ammonia can cause the condensation of a relatively large amount of vapour, ammonia losses usually appear worse than they actually are. For example, it has been estimated that 2 ounces of ammonia can produce 13 gallons of mist.
Ammonia is toxic to plants.
To prevent damage to germinating seeds or seedlings, preplant ammonia should be applied at least 10 cm deep, with the seed being planted no more than 4 cm deep. The applicator outlets should be no more than 50 cm apart to minimize the concentration of ammonia within the band. Otherwise, delay planting for several days after ammonia application. Because anhydrous ammonia is very cold and very alkaline, some soil organisms are killed in the zone where the ammonia is applied. However, the effect on the soil is temporary.