Pivoting to reduce nitrogen losses

Iowa farmers, working with government agencies, ag retailers, Iowa State University (ISU) and others have over time made significant strides in reducing the amount of phosphorus leaving fields and entering the state’s surface water. Now as farmers’ focus shifts to reducing nitrogen losses, water quality experts participating in a water quality panel discussion at last week’s Iowa Farm Bureau annual meeting expressed confidence that long-term progress to reduce phosphorus losses can be repeated for nitrogen losses.

“We are now pivoting to a focus on nitrogen loss reduction, and with the technologies we are putting in place, we believe we will see similar success,” said Shawn Richmond, director of environmental technology for the Iowa Nutrient Research and Education Council (INREC). 

Richmond was joined on the annual meeting panel by Matt Helmers, an ISU professor and director of the Iowa Nutrient Research Center; Matt Lechtenberg, water quality coordinator for the Iowa Department of Agriculture and Land Stewardship (IDALS); and Adam Schnieders, water quality coordinator for the Iowa Department of Natural Resources (DNR).

The pivot by Iowa farmers to expand their focus on reducing nitrogen losses through planting cover crops, installing wetlands and other practices is being driven by the state’s ground-breaking Iowa Nutrient Reduction Strategy (INRS), the water experts said. 

A key to measuring the progress on the strategy has been establishing a baseline using high-tech LIDAR surveys done in 2010, aerial photography and other tools, Richmond said. That baseline, which is an extended period from 1980 through 1996, allows researchers to measure progress on conservation and work on reducing nitrogen loss, he said.

“It’s important to establish a baseline, so that we can make clear comparisons and not just pick times,” Richmond said.

The work to support Iowa agriculture’s the pivot to nitrogen reduction work has grown into a wide-ranging effort, the water quality leaders said.

Iowa and national conservation agencies are revamping cost share programs to promote practices that reduce nitrogen loss. Researchers at ISU and other institutions are developing new technologies to help farmers reduce nitrogen loss. Ag retailers and others are monitoring and tracking progress and working with farmers to establish more conservation practices. And Iowa towns and cities are collaborating with farmers to encourage conservation practices to reduce nitrogen in their source water supplies.

“We know that we are all in this together and it’s going to take all of us to reach our goals,” Schnieders said.

After decades of concentrating on soil conservation and reducing phosphorus loss, IDALS is adjusting its cost share models and to promote practices proven to reduce nitrogen loss in key watersheds, he said.

“Many of the edge-of-field practices that can address nitrogen loss don’t have as much return to landowners as soil conservation programs,” Lechtenberg. “We are adjusting our cost share program to address that.”

The dedicated water quality funding through Senate File 512, enacted in 2017 with strong Farm Bureau support, is helping IDALS support the construction of wetlands, saturated buffers, bioreactors and other edge-of-field practices, Lechtenburg said. The bill provides $270 million dedicated water quality and conservation funding over 11 years.

A good example is Conservation Reserve Enhancement program (CREP) wetlands. IDALS currently has some 30 of the nitrate-trapping wetlands in development, or a third more than the department has done in the last 15 years. “We don’t have all the dollars today, but because of Senate File 512, we know they are coming. That helps with the planning for them.”

Helmers noted that new technologies are helping farmers take on the challenge of reducing nitrogen losses. Saturated buffers, now a key practice for nitrogen loss reduction, are not in the state’s nutrient reduction strategy because they were still being developed when the strategy was being written, he noted. 

“When we started this in 2013, we really didn’t know about many of the nitrogen reduction practices,” Helmers said. “A lot of these have been developed, in part, because of the emphasis on nitrogen loss reduction.” 

There is more research in other practices, such as oxbows and drainage water retention, that show promise, Helmers added.

Tracking progress on water quality is a big part of the state’s water quality strategy and a key focus for INREC, Richmond said.

Working with retailers, the organization is tracking infield practices, such as cover crops and no-till, Richmond said. In addition, the group is working with Iowa DNR and others to map progress over time on conservation structures, such as terraces, buffers and wetlands,” he said.

“It really provides us with a great story of where we are now and where we need to go,” Richmond said.

The Iowa DNR works on reducing nutrients from point sources, such as factories and municipalities as part of the state’s water quality initiative.

Increasingly, Schnieders said, cities, such as Cedar Rapids, are working with farmers to help incentivize conservation practices that reduce nutrient loss in watersheds.