Grant helps farmers use innovative irrigation system to reduce nutrient loss

MCGA.2013-0089Written by Jonathan Eisenthal

When Chad Davison, 34, came home to the farm from a business career at Target Corporation he brought with him a love of logistics and technological innovation — he had most recently managed the shelf inventory of brand name coffee at all the Targets in North America.

His dad made the family farm run on hard-won agronomic know-how.

Where the two overlapped was in a love of land stewardship and the rewards precision agriculture can offer — especially in a 4,500 acre row-crop farm in the Red River Valley town of Tintah, Minn.

This year, the Davisons decided they could use a newly installed water system to measure the volume of nutrients like nitrogen fertilizer flowing out of tile drainage lines and off the farm into the environment beyond their fields.

Using a Minnesota Corn Growers Association (MCGA) Conservation Innovation Grant, the Davisons purchased a field-edge monitor that measures nutrients and sediment in the water flowing through their tile lines. The grant also helps pay for the technical assistance needed for collection and processing of samples and tabulating data.

“Losing nitrogen off the farm is something we hate to see because we want the natural environment around us to be as pristine as possible,” Chad Davision said. “But for the farmer, that nutrient loss is also an economic loss, because if that fertilizer we paid for is moving off the field, then it isn’t helping the crop and we’re producing less and losing money.”

What makes this project especially exciting is that the Davisons can use a their state-of-the-art sub-irrigation system in one section of the farm to measure how water levels and nutrient loss interact.

Several years ago, Chad became intrigued with the idea of using sub-irrigation to tackle one of the thorniest problems that has challenged the valley recently. Sub-irrigation is a system that retains water in the soil profile through the use of boards set part way across tile drainage outlets. Such a set-up releases water down to top of the board and then retains the water that won’t pass the board.

Heavy spring rains in the Red River Valley can often carry away topsoil and nutrients like nitrogen fertilizer, and sometimes overrun the banks and cause devastating floods. Ironically, since drought often follows flooding in the same year, by late July, the smallest hint of moisture has all but disappeared.

By using sub-irrigation Chad believes they can increase the water-holding capacity of the land while also assuring that rain water wouldn’t pond up and drown the young crops.

Working with the Minnesota Department of Agriculture, the Davisons hired tile drainage engineers at Ellingson Tiling Company to design and install their sub-irrigation system last year. The family converted an existing well into a water retention device to hold all of the overflow. This extra supply of water could then be pumped back through the tile drains to raise the water table later in the summer, when dry weather and a lack of moisture often stresses and damages the crops.

“Our sub-irrigation system has three separate zones in a field that totals a little over 200 acres,” says Chad Davison. “One is 150 acres, one is 50 acres and one is about 10-20 acres. Because we have the three distinct zones, we can set each one to keep the water table at a different depth. We can then see if this impacts the volume of the nitrates flowing out of each to the wells, to see if there is an optimal water level. As a bonus, we will be tracking how the water level impacts the yield in each of the three zones.”

Be sure to check in the coming weeks for additional feature stories on Conservation Innovation Grant recipients. Click here to read a story on grant recipient Keith Hartmann. Here is a story on grant recipient Wayne Dewall. MCGA expects to announce another round of Conservation Innovation Grant funding this fall or winter.

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