Drainage tile robots could help farmers find nitrate hotspots

Researchers at Iowa State University say affordable technology could improve water quality

Researchers at Iowa State University, in collaboration with Michigan State University, have developed a robot that detects nitrates and monitors tile health to help farmers keep their land productive.

According to U.S. Department of Agriculture agricultural census data, nearly half of Iowa’s harvested farmland has tiled drainage. The underground drainage systems help increase crop productivity, but environmental and water conservation groups have pointed out that the tiles can also release excessive amounts of nitrates and other nutrients downstream.

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

“This will allow farmers to manage their fields more precisely and precisely, improving both the 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 is able to “determine exactly when and where these nutrients are being lost.”

Liang Dong, the director of the Microelectronics Research Center at ISU, worked with Castellano to develop the nitrate sensing portion of this technology. Dong said the sensor has been completed and will be commercialized as an affordable technology for farmers.

“If the sensor is small enough and the price is low enough, farmers can install the sensors in their drainage tile and then know what the water flow and nitrate loss are in their field,” Dong said.

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

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

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

The almost 60 cm long robot is currently designed to move through corrugated tubes with several fin-like barbs on the front and back.

Luedtke said he learned through this project that not all tiles are corrugated and that the diameter changes frequently across a field, posing additional challenges to the robot’s development. Many farmers have clay or concrete tiles that were laid many generations ago.

Lüdtke said the robot would also need to move faster through the pipes, have a battery life of at least a few hours and be waterproof before the research team could begin practical testing in actual tiles.

“If we can provide farmers with a cost-effective and simple solution to the water quality issues here in Iowa so they can make appropriate decisions, I think that would be a big impact of our work,” Luedtke said.

This article first appeared in the Iowa Capital Shipping.