Some odd-looking airplanes are flying low in the skies over Iowa this spring. Once again the state Department of Transportation is hiring aerial applicators to dump seeds and fertilizer at construction sites, planting ground cover on the exposed soil. Ole Skaar , an agronomist who works in roadside development for the DOT, says most of the airplanes used for agriculture spray herbicide chemicals, he explains, but the DOT uses them to seed bare ground, so they can get it done without having to drive on the soil.

Skaar says highway construction sites where bare earth is exposed will benefit the most when clover, native grasses and other plants are seeded this time of year. The ground is freezing and thawing, which allows the seed to work into the soil. Spring rains will then provide compaction, so you get good seed-to-soil contact. Then as soon as the soil warms up the germination can begin and the seeds will start growing. Aerial application accomplished that all without a lot of equipment driving on the dirt, which will minimize the amount of erosion and sediment pollution.

Normally airplanes doing that kind of work fly very close to the ground. Skaar says they put out a public alert to avoid startling motorists who may be driving past the DOT construction sites when the seeding is going on. People do call in, surprised by the planes’ activity.

He says they had to be especially careful after 9-11 so people didn’t think it was some kind of terrorist activity. They notify news media to let drivers know what’ll be going on, so they don’t panic at seeing planes flying near the roads. He says people are welcome to find a safe place to pull over and watch the airplanes at work.

While farmers hire the flying applicators to spread seeds, fertilizer and chemicals in spring and fall, Skaar says this is the only time of year the low-flying planes will be working for the DOT. On Monday, he says they’ll be working at the construction site at Highway 34 just east of Ottumwa.