After Iowa strip-tiller Frank Moore knelt down last Saturday and poked his fingers into the black dirt in one of his strip-tilled fields, he had one immediate conclusion.
"This soil is dry enough that I could plant into it," says Moore, who strip-tills corn and no-tills soybeans near Cresco, Iowa. He's also a certified crop adviser and a technical service provider with the USDA's NRCS.
With temperatures in the 40s, a bright blue sky and warm sun, the weather seemed more like April than mid-February. But planting's getting closer and Moore's now focusing on the strip-tilling that didn't get done last fall and needs to be done this spring.
This will be the third growing season that he's strip-tilled corn, after more than 20 years of ridge-tilling and then no-tilling.
For the fall of 2009 and 2010, a custom strip-tiller applied phosphate and potash in strips. But then this custom operator switched to manure application only, so Moore connected with an area farmer who strip-tills. That strip-tiller bought a new strip-till rig — a 16-row John Deere 2510S with 30-inch spacings — and it took some time last fall to get everything set up right.
"He did 450 acres of strip-till last fall and if we had had 3 more days, we would have gotten it all done if the weather hadn't turned cold and the ground hadn't frozen up," Moore says.
So, for the first time, Moore's looking at spring strip-tilling corn. This includes strip-tilling about 200 acres of corn-on-corn, as well as a field of about 120 acres that in 2001 was comprised of 18 acres of CRP, 50 acres of soybeans and 50 acres of corn.
Moore has DAP and potash strip-tilled in the fall on ground that will be planted to corn the following spring. In the fall of 2009, he intended to have a 2-year crop removal rate of phosphorus and potassium custom applied. But, as it turned out, about 25% more potash was applied than was planned. With that extra potash, Moore figures there's some still present in the soil.
In the fall of 2011, with the high price of fertilizer and with the carryover potassium still present in the soil, Moore reduced the phosphate and potash that was applied in strip-till to about 65% of a 2-year crop-removal rate for a corn-soybean rotation for most fields.
Also, on two fields he had 100% vs. 65% of the 2-year phosphate and potash rate applied in alternating strips so he could compare the yield results and see which practice is more profitable.
This spring, he'll have the new custom strip-tiller apply anhydrous ammonia, DAP and potash on a newly rented farm that is in CSP. Moore's in CSP on all of his other acres and he voluntarily agreed to limit pre-plant nitrogen application to no more than 30 pounds per acre on those fields.
"Normally, I would apply 10 gallons per acre of 28% UAN per acre of nitrogen in the spring, prior to planting, which is about 30 pounds of actual nitrogen per acre," Moore says. "Then I sidedress the balance of the corn's nitrogen requirements in mid-to-late June. My goal is to apply a total of 125 pounds of nitrogen from both pre-plant and sidedressing on corn following soybeans."
Using Adapt-N To Improve Profits
Moore not only fine tunes his fertilizer program by splitting applications, he also does onfarm testing of Adapt-N, which is a nitrogen management tool developed by Cornell University. He's been evaluating Adapt-N in Iowa for Cornell with three other Iowa crop consultants — Michael McNeil, Shannon Gomes and Hal Tucker, who comprise MGT Environmental Technology.
Moore says Adapt-N is the only nitrogen-management tool he knows that factors in local weather data and combines it with other farm-specific information such as the timing, rate and form of fertilizer, the soils in the farm fields and the tillage systems a farmer uses.
"Based on all of this information, Adapt-N estimates how much soil organic matter exists to convert nitrogen to nitrate-nitrogen," he says. "By taking all of these factors into account, the mathematical model in Adapt-N provides farmers a fine-tuned recommendation of how much nitrogen is available to the crop and whether additional nitrogen is needed.
"It's essentially like a late-spring test for soil nitrate, You can run the calculations every day during the growing season to get an estimate of how much nitrogen is available to the crop."
Using Adapt-N with strip-till corn makes sense to Moore.
"By switching to strip-till corn from no-till corn, I was able to place fertilizer in a band, which I think will eliminate the nutrient-stratification problem that can develop with broadcasting it in no-till," he says. "Strip-till also provides the benefits of clearing residue from a strip and tilling it, which should warm up the soil more quickly than no-till."
On two fields in 2011, Moore compared two 16-row-wide strips where he used the nitrogen rate recommended by Adapt-N vs. what he normally would have applied.
"I applied 19 gallons per acre of 28% UAN vs. 25 gallons of UAN," he says. "On one field, the yields with the two rates were exactly the same - 200.7 bushels per acre. On the other field, the corn yield with 19 gallons of nitrogen yielded 1.2 bushels per acre less than with 25 gallons of nitrogen."
Moore says the cost of the extra 6 gallons of UAN per acre with the 25 gallon-rate was $8.82, which was all profit where no yield loss was seen.
"At $5 corn and a 1.2-bushel-per-acre yield reduction, there was a loss of $6 per acre of income, but a savings of $8.82 per acre in costs, which showed a profit of $2.82 per acre," he says. "And with the reduced rate, there was more than 17 pounds of nitrogen that wasn't applied to the environment."
Spring Strip-Till Decisions
If there's enough time this spring, Moore plans on having 200 acres of corn ground strip-tilled this year and will then plant it to corn. This will be the first time he's grown any strip-tilled corn-on-corn.
"I may end up no-tilling soybeans into the corn stalks," Moore says. "Although I ridge-tilled and no-tilled corn into soybean stubble for about 25 years, I'm not comfortable with no-tilling corn-on-corn. At the current prices of corn and soybeans, growing corn on these 200 acres makes more sense, financially, than soybeans."
Moore uses a 16-row John Deere 1770NT planter, set to 30-inch spacings and equipped with Martin interlocking row cleaners, for both corn and soybeans. He pulls this with a 240-horsepower John Deere 8310 tractor with front-wheel assist.
Moore has mulled whether to buy his own strip-till rig, but that would mean a number of major changes.
"I would need a tractor with more horsepower, which I would only use for strip-tilling," he says. "A tractor with that much power would be overkill for planting. I would need at least a part-time employee to run the strip-till rig, and I would also need a dry-fertilizer cart. With the larger tractor and another employee, I would need more acres to justify the investment."
Moore is weighing the possibility of buying a strip-till rig with two other strip-tillers, but joint ownership brings another set of decisions, including what brand to buy and when someone will get to use the equipment.
"One of the farmers has a 12-row planter, while I have a 16-row planter," Moore says. "It can be done, but it just adds more things to consider when putting the equipment together."
Strip-Till Works For Corn
While Moore's only been strip-tilling for the 2010 and 2011 growing seasons, he's pleased with the results of strip-tilled corn vs. no-tilled corn.
"My corn yields have been as good or better as the county average and those of the neighbors," he says. "In fact, the strip-tilled corn yields have been my two highest yields, by year, in all of the years I've been farming. In 2011, they averaged 180 to 185 bushels an acre, with several fields exceeding 200 bushels per acre."
Moore says some lighter soils brought the whole-farm average down. Averaging 180 to 185 bushels per acre for corn last year was good, he says. Before it turned dry late in the summer, he estimated the corn would yield 220 bushels per acre or even better.
Moore says the excellent corn yields in the past 2 years are not only due to strip-tilling, but also to sidedressing.
"By splitting our nitrogen application and sidedressing the corn, we're not losing nitrogen to the weather," he says. "Even so, nothing trumps the weather. In early August, the corn looked perfect. But by early September, the combination of dry weather and a severe windstorm took its toll on the crop.
"With all that the crop went through, I was pleased with how the yields ended up."