Counterintuitive as it may seem, farm fields with the best tile drainage systems generally produced the highest yields during last year’s drought, area farmers and other experts say.
“I saw that right away in the first field I harvested this fall,” said Marion-area farmer Curt Zingula.
Zingula said he became “100 percent convinced” of the benefits of tile in a dry year when he observed a disappointing harvest of soybeans on his traditionally wettest field.
“My conclusion is that you have a better soil structure yielding better root growth in well-drained fields,” he said.
Tracy Franck of Quasqueton said dips in his combine yield monitor data showed him exactly which of his Buchanan County fields were most in need of more tile.
Iowa State University Extension field agronomists reported similar findings at a meeting in October, according to drainage tile expert Matt Helmers, an associate professor of agricultural and biosciences engineering at ISU.
Better yields on better-drained soil “was common this year,” Helmers said.
While it may seem counterproductive to drain subsoil water away from plants in a drought year, “tiling removes only excess water. It does not reduce the amount of plant-available water,” Helmers said.
Tile drains soil only to the depth of the tile — typically between three and four feet — so it does not affect water stored below that depth, said Gene Blazek, whose company, Blazek Corporation of Lawler, installs agricultural drain tile along with its specialty, sewer and water system repairs.
Well-drained soil encourages deep and healthy root systems, which in 2012 enabled corn to tap subsoil moisture to depths well below 5 feet, said Blazek, a past president of the Iowa Land Improvement Contractors Association.
“Tile is always a plus, even in dry years,” said Blazek’s brother, Don Blazek, who farms near Lawler.
“You pay for tile, whether you have it or not,” Don Blazek said.
Thorough tiling of formerly undrained land can increase corn yields as much as 50 bushels per acre, he said.
Increasing tile density on already tiled fields will typically increase yields from 5 percent to 10 percent, he said.
Helmers said more ag drainage tile has been installed in Iowa during the past two years than in any other comparable period.
“Farmers have money to spend, but land prices are so high they are investing in tile,” said Gene Blazek.
Dense tiling can cost as much as $1,000 per acre, but farmers quickly recoup their investment through the increased value and productivity of their land, he said.
Although almost all Iowa cropland has already been tiled, many farmers are installing more of the plastic drainage tubes in a practice known as pattern tiling, he said.
“Back in the 1960s and 1970s, the standard was 80 feet between the lateral lines emptying into tile mains. Now most of the lateral lines are either 40 or 60 feet apart,” Don Blazek said.
Gene Blazek said the demand for ag tile has created a backlog for contractors, encouraging many farmers to buy specialized tile plows that enable them to tile their own fields.
“They have the money. They have slack time after harvest. They already have the big tractors required to pull the tile plows,” he said.Although tiling contractors generally regret the advent of do-it-yourself tile installation, Blazek said farmers can do a good job “if they know what they are doing.”