Strip-till offers advantageous placement of fertilizer in the root zone, but there are still many decisions for a farmer to make when he takes to the field. Approaches to placement vary regionally and farmers agree that there are no one-size-fits-all strategies, but there are some considerations worth making.
From depth, timing and rate to season, product and method, strip-tillers always seem to be on the hunt for new strategies to improve their fertilizer and nutrient application programs. Strip-tillage already offers advantageous placement in the root zone, but there are still many decisions for a farmer to make when he takes to the field.
Approaches to fertility placement vary regionally and big differences in soil type and climate must be examined to develop best practices. Farmers agree that there are no one-size-fits-all strategies, but there are some considerations worth making.
Kingman, Ind., strip-tiller Doug Davenport has long subscribed to the philosophy that banding fertilizer in the strip can minimize environmental concerns and give his corn plants the best chance at tapping nutrients when needed most during the growing season on his 4,000 acre farm.
But despite more than 15 years of strip-tilling, Davenport admits that he doesn’t have all the answers when it comes to a perfect fertility program.
“Our goal is to apply fertilizer below the surface where it’s protected and there’s the least amount of risk of it walking off because I’ve already paid for it,” he says. “But even though we’ve been banding for the last 25-30 years, it’s an ongoing goal for us to keep improving that aspect of our strip-till operation.”
Strip-Till Strategies editors caught up with several strip-till manufacturers at the 2016 National Farm Machinery Show in Louisville, Ky., earlier this month to solicit advice for novice and veteran spring strip-tillers best practices for fertilizer placement. Here is what they had to share.
1. Consider the Season
Whether a farmer strip-tills in the spring or in the fall, the season has a substantial effect on how different fertilizers act in the soil. Kevin Kuehn, product support manager of Environmental Tillage Systems, notes that fall strip-tillers should be aware of fertilizers that have a tendency toward movement.
“It’s a little obvious, but it’s probably still one of the more important tips. Farmers should be minimizing their leachable fertilizer applications in the fall,” says Kuehn. “It’s still probably best to get a good portion of your nitrogen (N) on with your pre-plant strip-till pass, but don’t get it too hot that you risk seed burn.”
2. Be Efficient with Fill-Up
Although a strip-tiller might have to spend some extra time with a calculator and a notepad to plan things out, Nick Jensen, president of Thurston Manufacturing Company, points out that there are efficiencies to be had by properly timing hopper fill-ups.
“When you’re applying more than one product it’s a good idea to try to time fill-ups in a way that maximizes efficiency,” says Jensen. “Filling up several products at once rather than stopping multiple times for individual products saves fuel and probably more importantly, time.”
3. Time Applications
Strip-tillers who apply N in the spring know that they have to be wary of seed burn. Derek Allensworth, marketing manager with Yetter Manufacturing Inc., says it’s wise to plan spring N applications to allow for a window between building the strip and planting, depending on soil conditions and soil types.
“Proper placement of fertilizer at the right depth and rate is very important so you don’t get seed burn,” says Allensworth. “Each year strip-tillers are faced with different weather conditions in the fall or spring and have to set their equipment for the soil conditions. If you strip-till in the spring, just make sure you don’t leave an air pocket in the strip.”
There isn’t a hard and fast rule for how long mellowing takes, but Kuehn has seen it take at least a full week on some farms.
“The timing is different all over the country, but in South Dakota, we have one customer applying 100% of their nitrogen with their spring pre-plant strip-till pass and they use as much as 400 pounds of urea plus MicroEssentials (MESZ) and potash,” he says. “They end up waiting, at the very least, 7 days before planting. Of course, in South Dakota they have high cation exchange capacity (CEC) soils. The sandier the soil gets the less nitrogen you can apply.”
4. Be Precise
Using equipment that delivers the precise amount of fertilizer it’s set to is essential for an ideal fertility program. Joe Bassett, president of Dawn Equipment, says this is especially the case if a strip-tiller is looking to cut input costs.
“Equal metering, row-by-row, is incredibly important so farmers should make sure that their equipment is set up correctly,” says Basset. “The more you reduce your rates the more you have to focus on getting consistent application.”
Placing fertilizer where the biggest root cluster exists is probably the most helpful yardstick for depth. “About 80% of corn roots are in the top 3-8 inches of the soil, so getting nutrition in 2-5 inches puts it right in that root zone,” says Kevin Kuehn.
5. Consider the Full Nutrient Profile
When it comes to banding fertilizer, it’s easy to get tunnel vision and focus on the nutrients that crops have the biggest demand for, but Kuehn recommends examining the full range of products available.
“It’s wise to pay attention to the full spectrum of nutrition. We take multi-vitamins every day, so why should we only be feeding the corn nitrogen, phosphorus and potassium?” says Kuehn. “We recently had a farmer add calcium and sulfur to his nutrient package on his ground where he spreads hog manure and he saw a tremendous production improvement almost right away.”
6. Split Applications
Many farmers and manufacturers agree that it’s still best to split fertilizer applications across several stages of the growth cycle. Bassett says that if farmers put some nitrogen down with their strip-till bar and planter already, there is an opportunity to split it up even further.
“If you run a 2x2 application through a frame mounted fertilizer opener it doesn’t mean you shouldn’t also be running an in-furrow product also,” says Bassett. “The farmers seeming to have the most success with our fertilizer opener also have an in-furrow solution. It’s helping get the seed growing immediately and feeding it until it can grow out to that denser band.”
Davenport traditionally applies up to 350 pounds per acre of 9-23-30 (a potash and diammonium phosphate (DAP) blend) or monoammonium phosphate (MAP), but as little as 150 pounds per acre on some fields, depending on need. He’ll then apply 10 gallons per acre of 28% N and 2 gallons of ammonium thiosulfate with the planter in 2-by-2-inch placement.
Davenport sidedresses the balance of N, often starting about V4 stage and the multiple applications, combined with cover crops have allowed him to decrease N applications on some fields.
“We had been using about 1.5 pounds of nitrogen per bushel,” he says. “The we were able to get it down to 1.2 and then 1. Today, on farms where we’ve had continuous cover crops for 5-6 years, tiling and good pH, I’m confident we can grow a good corn crop using 0.7 or 0.8 pounds of N per bushel.”
7. Think about Depth
Again, the regional variations play a role in how deep strip-tillers should be banding their fertilizer, but there is a rough consensus on the range of depth.
“One of my customers was part of an extensive nutrient placement study about 20 years ago, and the best results were showing up at 6-8 inches on band depth,” says Lyn Rosenboom of LandLuvr. “That seems to be the ideal depth for P and K, and I still hear my customers talk about that range, so it’s been consistent. “
Kuehn says that placing fertilizer where the biggest root cluster exists is probably the most helpful yardstick for depth.
“About 80% of corn roots are in the top 3-8 inches of the soil, so getting nutrition in 2-5 inches puts it right in that root zone,” he says.
Working with fertilizer providers or a local agronomist is a good way to determine proper depth for fertilizer too, says Allensworth.
“It seem that most strip-tillers are trying to place their anhydrous, P and K depths of about 6-7 inches depending on soil types,” says Allensworth. “Depending on fertilizer, the depth will change because liquid will typically be placed shallower. The strip freshener type machines can typically place fertilizer in the 2-4-inch range.”