Fertilizer blamed for high ammonia in water

Des Moines, Iowa-Agriculture isn’t ready to take the rap all by itself for record levels of ammonia getting into water supplies in parts of the state. The Des Moines Register proclaimed in a front-page article that the cause is the practice of spreading fertilizer on frozen ground, which resulted in ammonia being trapped under heavy ice cover rather than dispersing harmlessly into the atmosphere. The newspaper said the situation at the Des Moines Water Works was so bad in early March that the plant had to draw on an alternative source. “The big issue no doubt is the ammonia levels,” conceded Roger Wolf, environmental manager for the Iowa Soybean Association and major participant in Agriculture’s Clean Water Alliance (ACWA), which has been researching agronomic and environmental issues tied to nitrogen application for the past seven years. “Agriculture isn’t certain of the sources,” Wolf told Green Markets. “But we recognize that agriculture products are part of the issue and we’re investigating to gain a better understanding of what’s happening in the watershed.” Wolf indicated there could be multiple sources, including decaying plant material, sewage wastes, and manure. Whatever the cause, he noted, it took a “perfect storm” with freezing rain, snow, cold weather, and snow pack trapping the ammonia, which volatized in the river. He said there are questions about DAP and MAP, and indicated that ACWA would look at how much has been applied. Wolf added that ACWA may take immediate action. “We’ll be looking at the science involving fertilizer on snow covered ground and adjusting our Code of Practice as necessary.” ACWA, which was formed in 2000, introduced its Fall Nitrogen Code of Practice as a formal agreement among the retailers restricting distribution of anhydrous ammonia for fall application. Anhydrous wasn’t involved in the current ammonia situation, but Wolf disclosed that ACWA is holding a conference call right away with retailers about DAP and MAP and the implications with frozen ground. “I don’t know what will be decided but I expect that additional elements could be added to the code,” he reported.