Weather patterns of extreme drought and extreme rainfall are taking their toll in Iowa and all watersheds see the impact. During dry and cool periods like last fall, there is relatively little, if any, conversion of anhydrous ammonia to nitrate and movement of it from the soil or farm fields. Movement of nitrate is expected as the soil warms, especially after the first major rain events following a drought, such as we’ve seen since late April. Of course, last fall was dry, so we did not see movement of nitrates to streams going back to September 2012, which is the usual concern in Iowa.
This spring turned out to be wetter than normal, with some areas seeing several inches of rainfall in a single day, resulting in the recent 14-day nitrate spike we are seeing right now. A new record for Iowa April average precipitation was set this year at 6.52 inches, twice the normal about of rainfall and comfortably beating the old record of 6.25 inches, set back in 1999.
The good news is that the Des Moines Water Works “treated water quality” is safe for people to drink and use, according to current data on the DSM Water Works website. Considering Iowa’s proud first-in-the nation crop production status, it’s also a sign of progress that this is the first time in six years that the nitrate removal plant has even been used. Clearly, if we all do our part, farmers, homeowners, businesses and communities, we will all have a positive impact on Iowa’s watershed, keeping Iowa’s water safe to drink today, and for future generations.
Written by Rick Robinson. Rick is environmental policy advisor for the Iowa Farm Bureau Federation.