A new field drainage technology could help reduce runoff from farm fields and reduce the risk of harmful algae blooms in Lake Erie and other Ohio lakes. The system, called an Inline Water Level Control Structure, is designed to keep water and nutrients, such as nitrates and phosphorus, on the land where crops can use them, Ohio State University's Farm Science Review organizers say.
Working with the Ohio Land Improvement Contractors Association (OLICA), two new water control structures were installed at the Molly Caren Agricultural Center during Farm Science Review last week. The new installations bring the total number of the systems in use there to eight, says Matt Sullivan, Farm Science Review assistant manager.
He says the Molly Caren site serves as a model for drainage technology. The new control structures are part of the site's comprehensive water-management plan.
"We call them nutrients in the fields, but it's called pollution when it's in the stream," Sullivan says. "Farmers want to stay on the nutrient side. Using this system, farmers are able to keep more nutrients in the field, hold more moisture in the soil and get the best yields possible. It's one of the best drainage-management practices there is in agriculture right now."
In this system, several drainage lines are installed throughout the field, leading into one main line that is connected to the water level control structure. Inside the structure is a series of stop logs or boards that, when placed on top of each other, create an underground dam that allows the user to control the height of water that remains in the soil, he says.
"The water builds up into the soil, which acts like a reservoir so the crops can use the water when they are growing," Sullivan says. "If nitrogen is in the water, the plants can use it like a reservoir of nutrients.
"The system helps to provide water and nutrients to the plant and holds back pollutants from the water. The benefit for farmers is almost endless."
The structure can cost $1,000 to $2,000, he says.
Louis McFarland, field day chairman for OLICA, installed the drainage system at the Farm Science Review site. He says the system, one of which is typically installed for every 2 ft. of elevation on a farm, can be especially beneficial to farmers during a drought.
"Store that water that used to go out of the tile, so especially in a year like this when it is an exceptionally dry year, the crops have the ability to use that as a reserve to increase their production," he says. "We're not damming the water completely up. If you have a big rain, the water will go up over the boards and right out of the outlet so you're not flooding your crops. That's the reason why it's called controlled drainage; you're controlling the water at the level that you want for your intended purpose."
But, Sullivan cautions, the system doesn't work in every field. It works only on relatively flat land, not fields that have sloping grounds.
"It's not a solution to stopping all pollution from getting into waterways or for preventing all fields from losing nutrients," he says. "But it can help most farmers."