Updated: Apr 24, 2020
Better Farming Drainage Directory
Subsurface field drainage has been a game-changer for agriculture, no doubt, and it has reduced soil erosion from surface run-off, but it has also developed a bad rap for contributing to other forms of nutrient pollution in our waterways. Despite the negative press, tiles are still installed in much the same patterns as they were decades ago, and the goal is still to get water away as quickly as possible. But with moisture as the limiting factor to yield most years, perhaps our goal should be water management and controlling drainage. Perhaps we need another game-changer.
Controlled drainage has been demonstrated to work well on flat ground to increase yields, in Essex for example. Control gates are adjusted throughout the season to back up water in the laterals, raising the water table and reducing the volume of water leaving the outlet. In this way, a farmer has the benefit of good drainage when it is needed for field operations but can, essentially, shut it off during the growing or non-growing season to manage water in the field.
Farmers have also had success using their tile system as a subsurface irrigation scheme, in which they pump water into the laterals to raise the water table when the crop needs it the most. However, this has rarely been tried and for subsurface irrigation to work, there must be an impermeable layer (clay) below the level of the tile to retain water at the root zone, laterals would need to be trenched in at 15 feet and the ground be dead flat.
But, what about the rest of the province, with rolling ground? A drainage company from Illinois may have figured it out. AGREM is a father and son team, Robert and Jeremy Meiners, that have been pushing the industry to see tile systems for their potential to manage water, instead of just draining it.
The trick is to stop thinking in straight lines. AGREM designs systems to curve with the contour. Laterals sweep in long lines, falling on the slightest grade (0.1%) towards the mains. Intercepting water perpendicular to the slope can increase the drainage co-efficient to ¾” and these systems have been installed in fields with up to a 9% slope. On top of that, contoured laterals allow for controlled drainage on a slope. Game changed.
“Traditionally, only gently sloped fields benefited from controlled drainage and sub-irrigation,” says Jeremy Meiners. “But our designs reduce erosion while improving yield on sloping ground, and that should work well in Huron County.”
No one has yet tried a contoured, controlled drainage system in Ontario. So that’s exactly what the Huron Soil & Crop Improvement Association (HSCIA) is aiming to do in a unique partnership with Huron County and the Ausable Bayfield Conservation Authority (ABCA).
The rolling 47-acre field is just south of Clinton, alongside the Bayfield River and has been owned by Huron County since 1895 when it was a working farm for hundreds of the county’s poor, disabled and elderly, adjacent to the House of Refuge. The original home is long gone, replaced with the Huronview retirement community and nursing home complex, as well as the County Health Unit.
For decades, the Huronview field was rented out to the highest bidder. No tile drainage has been installed, years of conventional tillage has meant the knolls lost their topsoil and gullies have begun carving into the field. In 2010, some farmland was retired for the ABCA and local partners to plant trees, install grassed waterways and add two controlled wetlands.
In 2015, Huron County Council voted to rent the Huronview field to the board of the Huron Soil & Crop (HSCIA) for a ten-year lease, and for only a dollar a year. Their goal was for the volunteer board to invest in and improve the field by building soil health and demonstrating the best possible field management.
“The Huronview field builds on Huron County’s efforts to support our vital agricultural industry while protecting water quality, wetlands and woodlands,” says Jim Ginn, mayor Central Huron and Huron County Warden. “County Council is proud to partner with HSCIA, ABCA, the drainage industry and others to host this innovative project.”
The HSCIA board is made up of a dozen area farmer volunteers who have been actively promoting soil health in the County since they resurrected the organization seven years ago. After they took over the Huronview farm, the board got straight to work by planting a cover crop that fall and planting soybeans into a living stand of cereal rye the following spring. They’ve planted three low draws into grassed waterways, went no-till and have inter-seeded cover crops into standing corn. And while they are improving the soil’s infiltration and water holding capacity, they are still struggling with soil erosion and getting equipment through wet spots in the field. They hoped to tile and weren’t afraid to change it up, using the site as a practical field-scale research opportunity to benefit both the environment and the agricultural industry.
When HSCIA got wind of the work that AGREM was doing in the US, they invited Bob and Jeremy Meiners to Clinton for a field walk in March 2018. With drainage contractors and local stakeholders, the AGREM team described the innovative projects they’d been designing. HSCIA hired them to design two innovative systems for the Huronview field, with the hope of running a side-by-side comparison in the various sub-catchment areas and partnering with the ABCA to run water quality and soil monitoring.
They are working with four local drainage contractors, Williams Drainage, Parker & Parker, KMM and Roth Drainage, and aiming to install the system in June 2019, in conjunction with an open house drainage expo and workshops. They are currently seeking cost-share funding from the Canadian Agricultural Partnership (CAP) and partnerships across the industry.
On the south portion of the field, they plan to install two separate contoured systems, the west to be controlled with gates on the headers and the east with no controls. They are working with the adjacent landowner, Bill Gibson, to continue the contoured system across the entire sub-watershed. This area would be monitored for both flow and water quality at both the controlled and uncontrolled header tile, as well as with a flume to capture and monitor surface water.
On the north portion of the field, they plan to install a conventional pattern tile system at 30 feet with enhanced surface water drainage using a contoured terrace. These broad-based berms intercept and redirect water to a ponding area and surface riser inlet, which increases the surface drainage co-efficient on this field to 4½” while allowing these terraces to be fully cropped. Again, they are working with a neighbouring farmer, Rick Kootstra, to extend the system to the top of the watershed for monitoring purposes. This section would be monitored for flow and water quality from two tiles, one from the underground pattern system and the other from the surface water inlets.
Lastly, HSCIA and ABCA plan to leave a portion of the field un-tiled so that it can be monitored as a control, both for surface water quality and for yield.
The system could be later retrofitted in the contoured section to split the tile to 15 feet and run a sub-surface irrigation trial. Control gates could also be retrofitted on the east section of the contoured system if monitoring demonstrates it to be effective. And a small section of pattern tile in the middle catchment area has been modified to drain on less of a grade to retrofit control gates in the future.
The majority of the 100-acre watershed, including 40 acres of woodlot, will outlet into the two controlled wetlands on the property, before eventually flowing into the Bayfield River. Draining tiles to ponds can help to filter nutrients and sediments that come from the field, but they also help to manage the ‘flashiness’ of river water levels after a rain.
Small watersheds that once took days to drain, can now flush in a matter of hours due to field drainage. But while this might be great for farmers, the volume and velocity of water in surface drains and creeks increases the scouring and erosion of the banks downstream. Vegetated two-stage ditches help to manage in-channel erosion but holding water back in wetlands or within subsurface tiles will also help to manage this issue.
In-field water management means storing water at the right times and in the right places. And this gives it time to infiltrate through the soil and eventually recharge ground water aquifers, improving soil and water quality, not to mention the water cycle.
Of course, most fields in the province already have conventional pattern-tiled drainage, but as public scrutiny of agriculture rises, we will need to understand these systems better and seek opportunities to improve water quality through enhancing our existing drainage systems, perhaps with surface drainage terraces, ponding areas or tile control gates. Or perhaps, as older systems need replacing, contoured systems could become the new gold standard in Ontario. Who knows? In any case, innovative field-scale research sites like this one will be critical to improving our industry and, ultimately, changing the game.