Innovative research looks to control nitrate leaching, protect Nebraska groundwater

Around the world and across Nebraska, nitrogen fertilizer is regularly used to grow crops.  

Some of this nitrogen is converted to nitrate that can be easily lost from the root zone, eventually contaminating ground and surface water. In addition to being harmful to human health, excess nitrate in drinking water is costly for small communities to treat. Sandy, irrigated soils in Nebraska are highly vulnerable to nitrate leaching. Few options exist for controlling nitrogen losses from these fields. These concerns motivated researchers to try something new on this old problem.

In 2018, the Nebraska Environmental Trust awarded the Nebraska Water Center with funding to research how injecting carbon into the subsoil – by way of mulch and sawdust – could absorb and remove extra nitrate from the soil. The project is led by Dr. Dan Snow, research professor and director of the University of Nebraska’s Water Sciences Laboratory.

The project’s goal is to offer a cost-effective method for producers and Nebraska’s Natural Resources Districts to reduce nitrate leaching beneath cropland in areas that are most vulnerable to groundwater contamination. This spring, the research team injected wood mulch to demonstration sites in northeast Nebraska where groundwater nitrate concentrations are especially high. They will monitor differences in nitrate leaching between treated and untreated fields for several growing seasons to measure the method’s effectiveness.

Whether by boots on the ground or an eye in the sky, the Nebraska Water Center is focused on helping the University of Nebraska become an international leader in water research, teaching, extension and education.