Streator, Ill., strip-tiller Larry Tombaugh has enjoyed his share of rewards that come with the risk of experimenting with fertilizer application.

The sixth-generation farmer began no-tilling 40 years ago and transitioned to strip-till seeking  higher corn and soybean yields through targeted fertilizer placement and a drier seedbed.

“I’m not a purist when it comes to strip-till,” Tombaugh says. “We’ve been strip-tilling now for 20 years and I think a little bit of tillage in our dark soils in northern Illinois is a good thing. I love it because we get that little mound of dry soil, the fertilizer is right there for the plant to get to and using RTK brings it all together.”

Tombaugh runs a 12-row Redball strip-till unit with a shank setup on the row units to build fall berms 6 to 8 inches wide.

Farm yields appear to support Tombaugh’s philosophy and system. Strip-tilled corn has topped 285 bushels per acre in some fields, and strip-tilled soybeans averaged more than 70 bushels per acre in 2013. He credits a combination of healthy soils, with organic matters in the 4% to 5% range, and a refined approach to fertilization — moving towards a liquid application system this year— as key contributors to his success.

“We had a number of times on the yield monitor where it was over 300 bushels per acre for corn,” he says. “Now that we’re getting in that range, people wonder, ‘How are we going to handle all the residue?’

“We find that in the spring, there’s very little left because the earthworms have gotten to be so plentiful. Our plan is to move to an all-liquid fertility system, so they’re going to be even better.”

Feeding The Crops

Tombaugh admits his move away from dry fertilizer and anhydrous ammonia is an evolving process, but he’s tinkering with reduced amounts of fertilizers applied with the strip-till unit in fall, and then with the planter and through foliar application in spring.

For strip-tilled corn, he typically applies 100 pounds per acre of diammonium phosphate (DAP), 50 pounds per acre of potassium oxide (K20), 50 pounds per acre of ammonium sulfate (AMS) and as much as 200 pounds per acre of anhydrous, depending on whether he’s following corn or soybeans.

In the past, he’s also applied a herbicide with 1 gallon per acre of Crop Boost, a carbon-based acid humate soil amendment, and experimented with applying 1 gallon per acre of a starter fertilizer combination (3-18-18) on baby corn.

Tombaugh wants to stockpile small amounts of liquid fertilizer beneath the soil in fall, rather than risk losing nutrients by spreading them on the surface, while also cutting back on fertilizers with higher salt indexes, such as anhydrous.

“We’ve cut back to 135 pounds of nitrogen as anhydrous on my corn,” he says. “We ended up having 6 inches of rain in a short timespan last year, and I know even with using a nitrogen stabilizer I lost a lot and ended up sidedressing 20 gallons of 32%. That saved my bacon on the corn.”

In spring, Tombaugh is even more experimental with his starter fertilizer program. This past year, he applied 5 gallons per acre of 3-18-18 and 1 gallon of SoilBiotics Growth Boost and Liquid Force in the row through Keeton seed firmers on his 12-row John Deere planter.

He then foliar fed 1 quart per acre of SoilBiotics X-Cell micronutrient boost and supplement when spraying glyphosate.

Shop-Built Applicator

“Since I’m going to liquid I was trying to figure out how to get UAN in the system and we did some trials,” Tombaugh says. “I took a Glencoe cultivator and stripped it down, put spike wheels on we and have a 1,600-gallon tank with a 4-wheel steer cart behind it.”

He did a side-by-side foliar-application comparison of straight glyphosate, Midwestern Bio Ag’s TerraFed, a liquid carbon-based product to stimulate soil biology, and SoilBiotics X-Cell, with an additional application of a high-sugar supplement. He found the best response in corn, which had the SoilBiotics application and at least one pound per acre of the high-sugar product.

“The TerraFed was 272 bushels per acre, the glyphosate alone was 277 and the SoilBiotics foliar without sugar was 279, but adding the sugar took it up to 282,” Tombaugh says. “Part way over in the field, I switched hybrids and that one was actually the best one at yield check at 284.7. I know I had better probably had even better corn than that.”

Soybean Success

With the exception of anhydrous, Tombaugh applied the same amounts of fertilizer to his soybean strips last year and ended up with the best crop he’s ever had.

Tombaugh says he’s always struggled to maintain high-yield soybeans with no-till, but strip-till allowed them to break the 70-bushel-per-acre threshold.

“In 2009, we had a big batch of white mold because it was so wet and I had used an AerWay vertical tillage tool. I had a mat and it just didn’t dry out,” he says. “The biggest benefit with strip-tilling soybeans is having that trench a couple inches wide that really warms up. That really increases germination.”

Tombaugh was applying 5 gallons per acre of 3-18-18 in the soybean strip with 1 gallon per acre of humic acid, but last year added 1 gallon per acre of Liquid Force. In 2012, he saw a 38.3-bushel-per-acre improvement in strips with starter fertilizer and humic acid applied vs. a side-by-side comparison strip without the products.

So what is Tombaugh’s next experiment?

“I’m going to try applying a little nitrogen right off the row for soybeans. I’ve seen some farmers doing it where they’re getting 100 bushels per acre,” he says. “I’ll probably do a single application of a few gallons a few inches off the side, 2-by-2-inch with the planter and see what happens.”