Gorans Discovery Farm in sixth year of research
By Carol Stender
Date Modified: 04/19/2013 3:13 PM
WILLMAR, Minn. — Interest in the Gorans Discovery Farm hasn't waned over its six years in the Minnesota Discovery Farm program.
The meeting room on the MinnWest Technology campus in Willmar was full as farmers, stakeholders and others gathered to learn the latest research results.
Of all the farms in the Discovery Farm program, Gorans is unique. Besides monitoring drainage from the Gorans' fields, researchers also are taking samples of stormwater runoff from the city of Willmar. The water quality of Lake Wakanda, located between the two, also is tested.
A woodchip bioreactor generated special interest as University of Minnesota researcher Andry Ranaivoson explained how a bioreactor and a wetland removed effectively removed nitrates from field run-off.
The ongoing research at Gorans helps the city and Gorans learn more about drainage and water quality in the area.
Kim Gorans initiated the project in 2006, asking U of M researcher John Moncrief to measure field drainage and city of Willmar stormwater run off.
"I said, 'This might go against you, Kim,'" Moncrief said. "He told me, 'Whatever is, is.'"
The project was set up to compare soil fertility sources from a commercial fertilizer field, manure-plus fertilizer field and a control field with isolated drainage on six acres. Isolated drainage involving surface and internal drainage would be compared and Willmar's storm water monitored.
Both water drainage quality and quantity would be monitored including nitrogen, phosphorus and sediment. The water would also be tested for fecal coliform, E coli and other pathogens.
Cameras were added to the test sites in 2009 to monitor the dynamics of crop development and drainage events.
Of the eight contaminants measured only nitrate was higher from fields, Moncrief said.
Open tile inlets were replaced with patterned tile. It's hard to compare the use of open inlets in 2010 yield results with the intensive tiling system that replaced it in 2011 because soybeans were grown one year and corn the next.
Over a four-year period, there was two times more drainage from Willmar storm water compared to farm fields. Willmar has more impervious areas in the city and fields are able to store more than 10 inches of water and has more transpiration at more than 20 inches, he reported.
The sediment loss in storm water was more than 10 times greater from stormwater than from fields.
Cumulative total phosphorus losses over the four and a half year span were two times greater from storm water runoff compared to fields, he said.
Overall, there was seven times more nitrate in drainage of farm fields with good soil fertility compared to storm water.
Nitrate losses were twice as high for fields with good soil fertility compared to the control field. Storm water had 11 times more ammonia/ammonium loss than farm fields.