Soils with seasonal highs can benefit greatly from being tiled.
Water availability on the farm is often a tale of extremes: either too much or too little and not enough balance in-between. Which of the two extremes you typically encounter is probably influencing your decision whether to install tile. Isaac Ferrie, Crop-Tech Consulting field agronomist, addressed the topic of tiling during the 2014 Corn College, hosted by Farm Journal Media.
Ferrie says that soils with seasonal highs or above-ground levels can benefit greatly from being tiled. Likewise, soils with lower water tables will most likely not benefit and can even "go backward" when implementing tile.
"If these areas are small hills and the field is pattern tiled, the problem can become exponentially worse as the tile will be deeper through the hill to hold grade," Ferrie explains. "This drains a low water table even further when it may not have needed drainage to begin with."
One solution, according to Ferrie, is go around these areas or switch to non-perforated tile while going through them.
Ferrie also says that farmers who decide to install tile can benefit from evaluating tile spacing.
"The biggest thing is your tile spacing, tile depth really has to meet your soil characteristics," he says.
"Going into a field you need to know your soil characteristics, depth of soil profile and the hydraulic conductivity, the ease with which a liquid, in this case water, can move through soil," Ferrie adds. "The higher the hydraulic conductivity, the farther we can draw water. You want to know how much of each soil type you have so when you’re setting your spacing, you’re setting it up for the betterment of the majority of the field."
In the evaluation of whether or how to install and use irrigation, Ferrie says a big consideration is that irrigation amounts have to match soil-type infiltration rates.
"We have to make sure we put on only the amount that can get into the soil, so we’re best utilizing the water we’re applying," he notes.
First, Ferrie advises farmers to talk with their tile contractor to determine what they’re willing to do. Find out whether they tile contour or pattern tile only. Next, find some soil series maps of the fields if you don’t already have some.
"Figure out the soil types that are out there and the acres of them," Ferrie advises. "Then through the NRCS or the USGS you can look up the soil series information with a quick search on the Web and actually look at the profile and the depth of the profile. There will be a spot in there where they tell you the hydraulic conductivity, the drainability of that soil, and the ability of that soil to pull water from throughout the profile."
Ferrie says that the higher the hydraulic conductivity, the easier it is for soil to pull water over longer distances or pull water up from a lower soil depth.
"A lot of times when we have better hydraulic conductivity, we can space the tile out further apart because the soil will pull the water to the tile," he notes. "Even if we drain the water down further, it can still pull the water up into the profile, a usable zone."
Also, one of the benefits of tile gates is that they allow farmers to hold water back in the early season to use later. "You can hold water back in the winter, releasing enough water to dry out for spring planting and then replace the gates," he says. "As corn grows, pull the gates during the season. You do not want roots growing into saturated conditions. Drop the water table in the gates to coincide with corn rooting depth, keeping it within reach all season."
Thank you to the 2014 Corn College sponsors:
AgriGold, BASF, Chevrolet, Cover Crop Solutions, FMC, Great Plains Mfg., Precision Planting, SFP, Top Third, Yetter Mfg.