By Ben Nuelle
Agriculture’s Clean Water Alliance’s (ACWA) gathered water quality samples this year in the Raccoon and Boone River watersheds. The samples reaffirm the need for continuous improvement and greater collaboration.
Funding provided by ACWA resulted in the collection of 2,500 water samples from 75 sites. ACWA Chairman Harry Arenholtz said the results are not surprising, considering weather patterns during the past decade. He said what they have observed historically is extreme wet periods that follow extreme dry periods create transport issues with nitrates.
“When our group formed back in 1999, one of the first things we implemented was as an alliance or as a group was to follow a code of practice primarily around commercially applied fertilizers. What that code initially does and we’ve expanded on it or moved downed the road was to delay fall nitrogen application until the soil temperatures were below 60 degrees and now we are saying 50 degrees so the nitrogen that is applied in the fall when those temperatures reach those lower levels, bacteria action is slow,” Arenholtz said.
More than half of the 45 Raccoon River water monitoring sites reported their highest average nitrate levels in ten years of data collection. The Boone River also experienced high nitrate concentrations across 30 sample sites.
Arenholtz said the original goal of the ACWA was to control commercial applications of nitrogen but since then has expanded.
“Our group has expanded into what I would call demonstration projects and those include bioreactors, buffer strips, and more recently we’ve got a big push on cover crop adoption. Fall seeded cover crop and that cover crop is one of the most effective was we can hold and keep the nitrogen on the farm rather than it leaching down through the soil profile and into the runoff water,” Arenholtz said.
ACWA is a group of 12 crop input suppliers and Ag retailers in the Raccoon and into the Des Moines River watershed.