Know Your Nitrate

Headlines ranging from Des Moines drinking water to Gulf of Mexico hypoxia are heightening interest in nitrate levels in tile drainage.  It is more important than ever to know the nitrate levels in the tile draining your fields.  To help better understand nitrate levels in tile drainage, the Minnesota Agricultural Water Resource Center is offering a free, confidential nitrate screening.

When tiles are flowing, collect samples of 2 to 4 ounces of water in clean plastic bags or bottles. Multiple samples are preferred to assess nitrate levels throughout the year.  Discovery Farms Minnesota research indicates that greater than 90% of the annual tile flow occurs from March through July and collecting samples on a weekly, bi-weekly, or monthly basis during this time would provide information on nitrate levels during the time of most flow.  It is important to label each sample with the date and source of the water.  Also, if not immediately analyzed, the samples should be frozen until the day of analysis.

Samples can be brought to the Minnesota Agricultural Water Resource Center booth at FarmFest (August 2-4, 2016).  Samples will be analyzed immediately at the booth and results will be ready in about 20 minutes.  If you are not attending FarmFest, please contact radatz@mawrc.org to set up an alternative analysis.  Well water samples can also be screened if interested.

There are no water quality standards for tile water, but significant reductions are planned during the next three decades.  Tiles samples can be compared to Discovery Farms monitoring data to provide an indicator of potential nitrogen losses.