Target Higher Yields

05:57AM Dec 09, 2011
Target Higher Yields 1
( )

The details matter in the high-stakes yield game

Home, sweet home—it’s where you feel most comfortable and can do your best work. Same way with seed, whose home is a warm, cozy furrow in the soil where it’s protected from harsh
elements and supplied with food to help it thrive.

Farm Journal Field Agronomist Ken Ferrie likes to think of that warm, cozy, comfy furrow as a target—the center of your corn production bull’s-eye.

Everything you do, every choice you make, affects the creation of that environment, which results in uniform emergence, picket-fence stands and higher corn yields.

"As you focus tighter and tighter, each step becomes more important than the last," he says. "The closer you get to the bull’s-eye, the greater the consequences if you fail to do something right."

Temperature and moisture. "Sometimes environmental conditions are beyond your control," Ferrie acknowledges. "Nothing you do will be successful if you are forced to plant in mud, dust or frozen ground."

With normal weather, though, you can help create uniform temperature and moisture conditions across your field. "If soil stays wet, you can improve the drainage," Ferrie says. "You also can do vertical tillage to remove dense layers and enable water to percolate downward."

If you can’t improve drainage, modify your tillage system. "Don’t no-till a field with poor drainage," Ferrie says. "Instead, use tillage or strip-till in the fall to improve the seedbed environment next spring."

If you have the opposite problem, a sandy field that runs out of water, forget about tillage and leave cover on the surface to reduce evaporation. "Usually, the cover will be old crop residue," Ferrie says. "But it could be a cover crop, if you can kill it early the following spring."

Think about what you can do to have warmer soil next spring. You can’t actually change the temperature that Mother Nature brings, but you can speed soil warm-up by doing fall tillage, especially in northern states.

Be patient, Ferrie advises. "The soil needs to be warm and dry enough to make a good seedbed before you plant. At the same time, though, you want to strike while the iron is hot." Calculate how many days you have to plant your acres, and how many acres will be ready at the same time.
"If some of your fields are sandy and well-drained, they might be ready for planting considerably sooner than your fields with heavier soils. Then you can allow a longer planting period. If you don’t have diversity, you may need a bigger planter," Ferrie adds.

Target Higher Yields   2
A top-notch stand at harvest requires planting equipment that is calibrated and set to deliver seeds into a uniform seedbed.

Uniform seedbed. A uniform stand requires a uniform seedbed. Getting one starts long before you do tillage, if you till at all.

"A no-till farmer must spread crop residue uniformly across the combine swath and be very careful with wheel tracks," Ferrie says. "During every pass, you need to think about how the tracks you are leaving will affect next year’s seedbed."

Strip-tillers must build strips when the soil is right for fracturing. "In the central U.S., you may have to forgo your fall nitrogen application, rather than wait for soil temperature to fall," Ferrie says. "You may have to have someone build your strips while you are still harvesting."

If you use vertical tillage, you need complete shattering, across every shank, when you do your primary tillage in the fall.

"If the soil isn’t level after that pass, you need to make a leveling pass in the fall," Ferrie says. "Your goal is to have less than 3" peaks and valleys in the spring, after the field overwinters. Then make another leveling pass in the spring."

If you do horizontal tillage in the spring, wait until it is dry enough that your soil finisher or field cultivator will not put in a compacted layer. "Even worse than compaction is creating a lot of clods," Ferrie says. "Wait until the soil is dry enough to flow through the shanks of your tool. Make sure your tillage tool runs at a uniform depth, from wing to wing."

Seed quality. "Buy from a company that uses good quality-control procedures," Ferrie recommends. "Insist on good cold germination and saturated cold germination ratings for the seed lot you are planting. Most seed companies test every lot, so they should be able to provide that information."

Also insist on minimal pericarp damage, which is especially important if you place fertilizer in the furrow, Ferrie says.

If you have any doubts about seed quality, send your own sample off for testing. Most state crop improvement associations can do the tests, or you can ask your seedsman what lab his company uses.

"You can avoid most seed quality problems by buying from reliable sources," Ferrie says. "If someone is offering a fantastic price for seed corn, he might be selling poor-quality seed that a company unloaded on the broker market."

Seed spacing. A picket-fence stand requires planting equipment to be in top-notch condition and calibrated for your seed.

"Calibrate every year," Ferrie advises. "Even if you only plant a couple hundred acres of corn, and your planter functions well mechanically, it still must be calibrated for the size of seed you are going to plant."

Check your planter’s delivery system to make sure there is no static electricity at the meter that could delay seed release. Make sure the seed tube is undamaged, so seed won’t ricochet on the way down. "Ensure that your row units are running smoothly and not bouncing," Ferrie says.

Starter fertilizer. "A shot of starter fertilizer pushes young seedlings out of the gate and keeps them healthy through tough early spring weather," Ferrie says. "The closer you place starter to the seed roots and the first set of true roots, the faster the response will be."

Make sure that your starter applicator does not interfere with your planter’s depth control or cause the row unit to vibrate. "If you place starter in the furrow, be conscious of the salt content, as well as cracks in the pericarp," Ferrie says.

Manage residue. How you manage residue depends on the soil type you’re planting in. "On heavier soil, you want to move residue out of the way, so the planter functions properly and the soil warms faster," Ferrie says. "Keeping residue out of the seedbed improves seed/soil contact and reduces seedling blight and other problems.

"In heavier soils, set your residue remover so it just moves residue and maybe breaks the soil crust. You don’t want to actually move soil away from the rows because then you may wind up planting into wet soil.

"On light, coarser soils, where blowing sand may cut off corn plants or the soil surface may get hard, you want to leave residue over the furrow to prevent blowing and conserve moisture. Here, you need a sharp coulter to cut residue so you can place the seed below it, while keeping residue out of the furrow."

Down pressure. At this point, you start refining the micro-environment right around the seed.
"Use just enough down pressure to maintain uniform depth and hold the trench open long enough for the seed to fall to the bottom," Ferrie says. "The amount of down pressure required is linked to seedbed conditions. The more uniform the seedbed, the easier it is to set down pressure."

Planting at higher speed requires more down pressure. "If you use high down pressure to offset the effect of high planter speed, you risk smearing the sidewall and not being able to close the slot," Ferrie says. "Excessive down pressure compresses the wheel track on each side of the furrow. That creates a micro-environment in which plants grow more slowly. Excessive down pressure might also cause sidewall scoring, which causes the furrow to open up weeks after planting.

"Down pressure must be adjusted from day to day and field to field, to meet changing conditions," Ferrie says.

Planting depth. Like down pressure, planting depth must change as soil conditions change. "Always plant into moisture," Ferrie says. "Plant shallower if it’s early in the season and soil is cool and moist. As the soil dries and warms, plant deeper, always keeping the seed in moisture."
Even more important than the actual depth, every seed must be placed at the same depth. Each ring of the target circle has been leading to this point.

"Uniform planting depth requires a uniform seedbed, adequate down pressure and a reasonable planting speed," Ferrie says. "It also requires some type of firming device to push the seed into the bottom of the trench."

Target Higher Yields   3
Switching out closing wheels when tillage systems vary will pay off in higher yield.

Closing the trench. "Your closing wheels must provide sufficient firming action above the seed to prevent the soil from drying out and delaying germination," Ferrie says.

That requires keeping the closing wheel centered on the seed trench. "Before planting, check the alignment of your closing wheels, and replace worn bushings," Ferrie advises. "Run your closing wheels staggered, with one in front of the other."

Use the right type of closing wheel for your environment. Make sure the soil above the seed doesn’t dry out too quickly by using a combination of seed firmers, drag chains and firming wheel devices, or spader wheels with firming capabilities. Check with the manufacturer of each wheel for the proper setup.

"If you use different tillage systems, you need different closing wheels for each one," Ferrie says. "Stopping to change them as you move from one system to another may seem like a nuisance, but it will pay off in higher yield."

Using the right closing wheel becomes especially important later in the season. "The difference shows up in ear count. Uniform emergence leads to photocopied plants, which result in more ears," Ferrie says.

Bull’s-eye! Moving inward from the outer ring to the corn-yield bull’s-eye is like laying a foundation and then building upon it. It’s another way of navigating the path to higher yield.