Iowa's bountiful harvests wouldn't be a reality without underground drainage. After years of installing tile in farm fields to increase drainage to improve yields and profits, questions are being asked about environmental impacts. New technologies that may minimize negative environmental impacts will be installed July 12 at the Iowa State University (ISU) Southeast Iowa Research and Demonstration Farm near Crawfordsville.

ISU Extension and the Natural Resources Conservation Service, along with tile manufacturers and local tiling contractors, will install controlled drainage systems and construct a wetland. The demonstrations will run from 9 a.m. to 4 p.m. One project will investigate controlled drainage to determine if this system has an advantage in southeast Iowa over conventional drainage. Controlled drainage allows excess soil moisture lower in the subsoil to be held early in the season in case it is needed later during dry weather.

A wetland will be constructed to see if it results in lower nitrates in tile water exiting the property. Tile will also be placed to compare shallow, close spacing of drainage tile to deeper, wider spacing. Both plowing and trenching machines will be demonstrated. Matt Helmers, Iowa State University Extension agricultural engineer, and Greg Brenneman, Iowa State University Extension field engineer in southeast Iowa, will supervise the research conducted at the farm and collect data for several years. Both will be at the field day to speak with attendees, along with Jim Baker, Iowa State University professor emeritus.

Certified crop advisers can obtain 3 hours of soil and water continuing education credit by attending a special session from 11 a.m. to 2:30 p.m. There is a $40 fee for credit. The rain date is July 13. Food will be available for purchase.

For more information, contact Jim Jensen, Iowa State University Extension farm management specialist, 319-385-8126, jensenjh@iastate.edu or Kevin Van Dee, farm superintendent, Southeast Iowa Research and Demonstration Farm, 319-658-2353, kvandee@lisco.net. The farm is located 13/4 miles south of Crawfordsville on Highway 218, then 2 miles east on County Road G-62, then 3/4 mile north. Watch for Iowa State University field day signs on Highway 218.