TILING ISN'T what it used to be. The development of new technologies and designs has given tiling a whole new image. Now tiling is viewed as a complete water management system designed to boost a field's productivity.
“In previous years, we simply concentrated on getting water off the fields,” says Wayne Skaggs, William Neal Reynolds Professor and Distinguished University Professor at North Carolina State University. Skaggs has been researching water management systems for nearly 40 years. “And what we've been looking at since the 1970s is that not all fields need the same intensity of drainage at all times,” he says. That has led to controlled drainage systems that manage how, and when, water moves out of the field, which is why tiling is now more commonly referred to as a water management system.
“New designs and changes to current systems have really improved,” says Leonard Binstock, executive director of the Agricultural Drainage Management Coalition. “Now instead of simply going up the slope of a field, we can develop systems that go across the slope.”
And it doesn't end there. “Systems can be designed to manage the water table, provide subsurface irrigation, monitor and manage nutrient outflow on a field,” Binstock says. “The industry is taking a different approach on the design of these systems so they are truly a water management tool to use as a profit center.”
Yield monitors drive tiling
A key driver in producer interest in tiling hasn't been a tiling tool at all. It has been a yield monitor. “The introduction of yield monitors allowed producers to see how their yields would vary depending on where the tile was located in a field,” says Truitt Clements, sales manager for Bickett Farm Tiling, Ridgway, IL. “They would see that there was more production over the tile lines.” As a result, interest has increased in installing tile on narrower centers (40-ft. centers instead of 60- to 90-ft. centers).
Clements also says more farmers are becoming interested in subsurface irrigation systems, where the tile actually becomes a way to put water back into a field during dry periods. “Those systems are more expensive, because the tile lines are on 12-ft. to 15-ft. centers. But there's a lot of interest, especially with higher commodity prices,” he says.
The advent of advanced navigation and positioning systems also has made tiling more precise. Simple GPS-based systems help engineers develop sophisticated maps and drainage systems. “We survey a field with an RTK system, develop a topo map of the field, and provide our customers a detailed map with how all the laterals and mains will be installed,” Clements says. “The producer can see exactly how the field will be tiled.”
Newer GPS-driven tiling systems allow for a system that is more effectively designed and installed, according to John Downey, business segment sales manager for water management for Trimble. “Today, producers have tools that can develop optimum depth and tile for the producer, providing constant depth ditching and placing the tile at a uniform distance below the ground,” he says. “That translates into better crop yields.”
Trimble has introduced the latest version of FieldLevel II, which is part of the company's FmX Integrated Display system. “FieldLevel II will design a tiling system based on the constraints you put in, including slope and depth,” says Chris van der Loo, product manager at Trimble. “This system can be used for self-propelled or pull-type plows that install tile.”
These types of systems also can provide tremendous benefit if installing contour drainage. “Producers are no longer limited to installing tile along a contour,” Downey says. “Now they can go across contours to maximize the efficiency of their water management system.”
Tiling also has become a more complex issue as the agricultural community deals with what's coming off the field, and how to better manage that flow. “The management of drainage from tile lines is more of an issue, especially with the export of nitrates into downstream waters,” says Matt Helmers, associate professor, Ag and Biosystems Engineering at Iowa State University.
A major reason to manage nutrient outflow has been the nutrient-enhanced water that is reaching the Gulf of Mexico. “Public perception of agriculture has been that we need to develop a plan to deal with nutrients coming from the soil,” Binstock says. “And that being a driver, we are looking at ways we can better manage the outflow from tile lines.”
“The fact is that when you move from simply draining water off the field to managing how, and when, it moves off the field, it impacts the way you design and install your system,” Skaggs says. The newer GPS-based technologies do a better job of designing controlled drainage systems for a field.
Gated control structures and well-planned patterned tile systems can help manage the water table under farmland. These systems can reduce winter release of nutrient-rich drainage water. They can allow growers to drain the root zone for fieldwork and spring planting, while conserving water in the soil profile for summer crop use.
The new controlled outflow systems can add 8 to 10% to the cost of a tile system. “But that can average out to less than $2 per acre annually for the complete system, amortized over 15 years,” Binstock says. “And in a study at Purdue we saw a 2 to 4% yield increase with this system.”
Current structures for the controlled drainage system are above ground. However, Agri Drain, Adair, IA, will release WaterGate this spring, an automatic subsurface water management valve that is fully automatic and can be completely buried for field operations (800/232-4742, www.agridrain.com).
FOR MORE INFORMATION
North Carolina State University Water Quality Group
Campus Box 7637
Raleigh, NC 27695-7637
919/515-3723; Fax: 919/515-7448
Agricultural Drainage Management Coalition
Owatonna, MN 55060