Go Vertical: Manage the Subsurface Environment for Maximum Yield
FJFD-Ferrie Soil Management
Creating an ideal seed bed and soil conditions can help offset the uncertainty and unpredictability of climate and weather. To do that requires farmers eliminate subsurface density layers resulting in the free flow of water, nutrients and roots through the soil explains Isaac Ferrie, Farm Journal Associate Field Agronomist.
“When we talk about managing or adapting to our environment, different tillage techniques affect the subsurface environment and may increase or decrease our access or amount of water that we can store within the soil,” said Ferrie. “In the years where we go stretches without a rain or we go through a really wet spell, that's where we start to see the vertical system set itself apart.”
Eliminate Layers
A vertical format means creating a subsurface environment with no density layers. That can be either in tilled ground or in no-till. Layers restrict root growth early in the season especially the first three main sets of crown roots in corn. If those roots aren’t moving down through the soil profile, their access to early season water and nutrients is being limited.
“We call them our money maker roots, especially early in the season,” said Ferrie. “If we're trying to avoid stress, we need access to water during the times that are critical for ear development and setting ear limits.”
Eliminating changes in soil density takes tools. Ferrie says the freeze-thaw cycle won’t fix it even for no-till ground.
Tools of the Trade
A lot of tillage tools get labeled as vertical tillage machines even though that may not be the case. Ferrie says vertical tillage should level from the top down.
“A soil finisher has a shovel that gets down underneath and it's busting everything up above that shank and leveling from the bottom up,” explains Ferrie. “When we look at a disc, the concave of the disc acts very much like the sweep of the shovel, getting down underneath, blowing things up and then moving soil side to side.”
Instead, he says when it come coulters, the less concave the better if looking to eliminate layers. The gang angle should be 3° or less, especially on virgin soil.
“The more drastic the soil density change is, the more problematic it can become,” said Ferrie. “Running a soil finisher over chiseled ground can create a sudden soil density change. This change would not be nearly as drastic as running that same soil finisher over a no-tilled field.”
He adds a true vertical machine will not do much, if any weed control, and does not take out wheel tracks.
Water Management Matters
Soil can be divided into three zones: the zone above the density layer, the density layer and the soil below.
“We can still grow very good corn on top of a layer,” said Ferrie. “It's just that you're going to be more subject to timely rains.”
The shallower the layer is the more detrimental it can be. A layer 3” deep can drastically slow water infiltration and percolation rates beyond that depth leaving farmers with just 3" of accessible soil water storage. Deeper soil density layers, or eliminating layers altogether, allows for great water storage.
“A vertical format is not adding yield in every single year,” says Ferrie. “It's just weatherproofing your system for those tougher years.”
