Drainage tile robot could help farmers find nitrate hot spots

Researchers from Iowa State University have partnered with Michigan State University to develop a robot that would detect nitrates and monitor tile health to help farmers keep their land productive.

Nearly half of Iowa’s harvested cropland has tile drainage, according to ag census data from the U.S. Department of Agriculture. The underground drainage systems help to boost crop productivity, but environmental and water groups have pointed out the tiles can also deliver excessive amounts of nitrate and other nutrients downstream.

Mike Castellano, a professor of soil science at ISU, said the robots and nitrate sensors could help farmers detect where, how and how much nitrate they are losing. Castellano spoke Dec. 19 at a virtual field day with Iowa Learning Farms.

“That allows farmers to better manage their field at a precision scale, to improve both productivity and environmental performance of our crop production systems,” Castellano said.

Castellano said current technologies limit nitrate testing to the end of the tile pipe, but the robot would be able to pinpoint “exactly when and where those nutrients are being lost.”

Liang Dong, the director of the microelectronics research center at ISU, has worked with Castellano to develop the nitrate sensor portion of this technology. Dong said the sensor is completed and is being commercialized to be an affordable technology for farmers.

“When the sensor is small enough and the price is low enough, farmers can put the sensors into their drainage tile, and then they will know what is the waterflow and what is the nitrate loss from their field,” Dong said.

The end goal is to put the nitrate sensor, along with a camera and a waterflow sensor, onto a robot that can crawl through an entire tile drainage system and store the information for farmers.

The robot, which is being developed by team led by Xiaobo Tan, a professor of electrical engineering at Michigan State University, still is a prototype.

Christian Luedtke, a graduate researcher working with Tan on the project, spoke at the virtual field day and demonstrated the current prototype.

The nearly 2-foot long robot currently is designed to use several finlike barbs on the front and back to move through corrugated pipes.

Luedtke said he has learned through this project that not all tile is corrugated and it often will change diameters across a field, which present additional challenges to creating the robot. Many farmers have clay or concrete tiles that were installed many generations before.

Luedtke said the robot also needs to be quicker at moving through the pipes, have a battery life of at least a couple of hours and be waterproofed before the research team can begin practical tests in actual tile.

“The water quality issues here in Iowa, if we can help provide a cheap and easy solution for farmers to make decisions to help that, I think that’d be a great effect for our work to have,” Luedtke said.

This article first appeared in the Iowa Capital Dispatch.