Staggering corn prices last fall are driving a boom in corn planting this year. As predictions continue climbing, the U.S. Department of Agriculture predicts that growers will plant more than 90 million acres of corn this spring. That’s a 15 percent leap over last season, and the highest acreage of corn the U.S. has seen since World War II. And both USDA and the Food and Agriculture Policy Research Institute predict corn prices over $3.00 per bushel for the next 10 years.
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No-tilling in the heavy residue of continuous corn systems requires good management – but offers tremendous soil-building and cost-saving opportunities.
Photo courtesy of NRCS |
A shift to more corn—especially the likelihood of seeing millions more acres of continuous corn—has some no-till proponents worried. After all, the percentage of corn acres no-tilled in the U.S. is about one-third the percentage of no-tilled soybean acres. But even with high corn prices, high fuel prices threaten farm margins, so the benefits of saving soil, toil and oil through conservation tillage are as relevant as ever.
“I think it’s going to be difficult this year to hang on to 15 percent of our corn acres being in no-till or strip-till with 15 percent more corn going in,” says Bob Frazee, University of Illinois Extension educator in Peoria, Ill. “But I’m optimistic that people are not going back to the moldboard plow, that we’re going to see much of that corn go in with reduced-tillage or mulch-tillage systems.
“When you see that much residue—20 or 30 or 50 percent cover—coming in with cornstalks as compared to corn behind beans, I think we’ll actually come out better as far as maintaining T (Tolerable Soil Loss),” Frazee adds.
Southern comfort
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No-till planting into heavy corn residue requires careful attention to sweeps, openers and closing wheels.
Photo courtesy of NRCS |
“I think there’s going to be a tremendous shift from cotton, at least for the short term,” predicts Hiram Boone, director of the Delta Conservation Demonstration Center’s Ag Training Center near Metcalfe, Miss. “It’s probably going to start a crop rotation that’s really needed.”
In fact, Boone expects the growing interest in corn to help growers in the Delta build up higher levels of organic matter due to the increased crop residue that corn leaves behind compared to cotton. In fact, because no-till improves soil tilth, he’s also not worried about growers engaging in extra tillage to minimize springtime delays.
“When the ground is porous with the residue opening it up, the water drains off of it pretty quickly,” Boone points out. “We haven’t seen that much of a planting delay—not as much as you’d think.
“With double-cropped corn and soybeans, we’ve seen significant improvement in yields,” he adds. “And the residual nitrogen that’s left after corn will benefit next year’s crop.” Boone illustrates that prediction with data from a field of full-season Group 4 soybeans that followed corn last year, yielding 84 bushels per acre on a farm where the average yield is 50 bushels. He credits nitrogen that had been left over from the corn crop, as well as additional N released as the corn residue decomposed last season.
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High corn prices will make corn a huge part of the agricultural landscape for years to come. No-till or reduced tillage will allow growers to plant more acres of corn in a narrower window – and even with high corn prices, growers can benefit from reducing fuel and equipment costs.
Photo courtesy of NRCS |
Think it through
Growers have traditionally been more inclined to break out tillage equipment for corn, especially continuous corn. Concerns about heavy residues and cool, wet soils tend to arise with alarming frequency when the conversation turns to managing continuous corn under conservation tillage. Those are certainly challenges, acknowledges Jim Hudson, technical resource manager for Monsanto, but they’re challenges that can be overcome with a little research, good equipment maintenance, and maybe a bit of coaching from a local, experienced no-tiller.
Think through choosing a hybrid with the vigor for dealing with cooler soils, he advises. Make sure your planter can handle the residue – and that it’s adjusted properly. And map out your pest control strategy in advance to stay a step ahead of weeds, insects and diseases.
“You need to set yourself up for success,” says Hudson. “Identify the obstacles and overcome those obstacles. But don’t leave one of those obstacles in place and expect it to be one of your higher-yielding fields.”
No-till: A Harder Sell In Corn
Corn plantings are expected to spike sharply in 2007 in response to high corn prices, pushing the U.S. corn crop over 90 million acres. That can pose a challenge to proponents of no-till.more corn
Millions of acres of that new corn will be planted instead of soybeans, which are traditionally much more likely to have been managed in a no-till or conservation tillage system. In fact, Illinois’ reports for CTIC’s 2006 Crop Residue Management Survey proudly noted that for the first time, more than 50 percent of the state’s soybean acreage was no-tilled, though just 16.7 percent of its corn was no-tilled.
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Growers have an array of choices that can help overcome typical no-till challenges. Vigorous hybrids. Broad-spectrum seed treatments for disease and soil insect control. Built-in Bts for protection against corn rootworm. And an arsenal of herbicides to keep weeds at bay, which Hudson emphasizes is a vital step toward success.
“Weed scientists strongly recommend the use of a residual herbicide,” he says.
Roundup Ready soybeans have been a cornerstone in no-till programs on millions of acres of soybeans. Roundup Ready corn could play a similar role in facilitating no-till corn planting, but Hudson reminds growers of the lessons learned about the technology over the past few years.
“The key to a Roundup Ready system working like a grower wants it to work are full labeled herbicide rates, applying the herbicide when the weeds are within the labeled size, and using products that will kill those weeds,” he says. “Early weed control is important. Only five days’ delay allows some weeds to get such a head start that they may be difficult to control.”
Strip-till gains ground
CRP Conversion Worries
Though an aggressive re-enrollment program is keeping millions of acres of land in the USDA’s Conservation Reserve Program (CRP), about three million acres of farmland are due to come out of CRP this year—just in time for a corn-planting craze to threaten years of soil building and erosion control on those fields.
But Jim Hudson, technical resource manager for Monsanto, cautions growers to think hard before planting former CRP ground into corn. “It was put into CRP for a reason to start with,” he notes. “Chances are it will be their less-productive land. And growers need to think hard before planting it to corn: ‘What is the condition of that land right now? What’s on that land now? Can I get it off? What’s the pH of that soil, and its fertility? What will it really cost me to get that field into condition so I can get the corn yield I want?’”
The answers may lend themselves to keeping that ground in a less-erosive crop. And that could be good for everybody.
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In Illinois, Frazee says wet conditions coming into April have many growers antsy—and could lead to less spring tillage than the state has seen in many years. “Wet soils may prevent them from doing a second spring operation, or even if they switch to a disk from a field cultivator or a soil finisher because of the wet conditions, they may not till so deep,” he says. “That may leave more residue on the surface.”
Frazee also notes that hundreds of growers crowded into winter seminars on strip tillage. Inspired by case studies in Prairie Farmer magazine, accurate guidance systems, University of Illinois data showing that strip-till can boost profitability and reduce fieldwork hours, and even a new state carbon credit trading program, many are exploring the opportunity to concentrate their soil disturbance into shallow, narrow bands.
“It’s the big farmers that are going to this,” Frazee notes. “They’re seeing that they can get rid of unnecessary equipment, get more corn in the ground in a shorter timeframe, and see a net income benefit. We’re seeing a lot of interest in strip tillage.”
Planter practices
Contemplating a conservation tillage program in corn stubble requires a close look at seeding equipment. “You need a planter designed to plant in [high-residue] conditions,” says Hudson. “And you have to make sure it’s set up to perform the way it was designed to perform.” Trash sweeps must be aligned to effectively function in a particular field’s residue and soil conditions. Openers need to be in good condition, and closing wheels have to have enough down-pressure to close the furrow.
Even more basic: “Start by leveling the planter,” Hudson reminds. “Be sure everything is uniform. Otherwise, once you get into residue, your trash sweeps might not perform properly.”
Standing tall
Though residue worries multiply in the spring, corn residue management actually starts when the combine is readied for harvest. That means growers—and the conservationists who advise them—need to be thinking about the 2008 crop this summer.
Find A Mentor
Conservation tillage has evolved over the course of decades. Growers starting a conservation tillage program—or expanding their con-till repertoire to include corn—can tap into years of experience by connecting with a local no-tiller who can serve as a mentor, says Jim Hudson, technical resource manager for Monsanto. “Learning to manage through residue—and it is a learning process—a lot of that can come from an experienced mentor,” he says. “And nowadays, no-till is so widespread that you’re not going to live someplace where you’re not going to have a mentor available.”
Another benefit of learning from a local grower, says Hudson—because of the advances in hybrids, equipment, and crop protection products that have emerged in the past few years, many printed resources are behind the times—and many obstacles they warned about a decade ago, or even five years ago, can be more easily surmounted.
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“During combining, it’s important to leave cornstalks standing and spread what comes back out of the combine as evenly as possible,” Hudson advises. When growers leave thick slugs of chopped stalks and residue behind the combine, they’re setting themselves up to fail. “They’ve built a thatch roof on the soil surface,” he notes. “Thick residue will delay soil drying and warm-up in the spring. It’s also an impediment to getting a planter through.”
There may be some value in fueling the soil microbes that help with residue management, too. “Some people believe that fall applications of nitrogen help residue on the soil surface decay faster and be easier to plant through in the spring,” Hudson says.
Not a fad
If the analysts are right, a major increase in corn acreage is going to be part of the American agricultural landscape for years to come. In order to help growers protect that landscape from soil erosion, and to help them capture a larger share of the projected high corn prices, proponents of conservation tillage will need to help them adjust to managing heavier residue. Frazee expects that residue to help protect more fields from soil erosion, and he’s optimistic that growers will become more comfortable farming in it.
The good news, says Hudson, is that conservation practices help growers focus on good farming basics—and those never go out of style.
“Just because corn is 4 dollars a bushel doesn’t mean you ought to relax on any of the agronomic basics, starting with hybrid selection, weed and insect control, and good seed-to-soil contact,” he says.
