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How Sunflower Can Fit on CRP

Saturday, December 1, 2012
filed under: Rotation

Farmers can be likened to chess players, in that they always have to be thinking a move or two ahead to win the game. With more than a million acres of CRP land coming back into production this coming year, growers have even more strategic moves to contemplate.

In North Dakota alone, almost 650,000 acres were taken out of CRP after the 2012 contracts expired in October. Some growers were able to work that land this fall, or are making plans to do so next spring, to put it into production for the 2013 crop season. Approximately 360,000 acres came out of the CRP program in Minnesota and South Dakota combined in this same time period — plus more than 400,000 acres total in several other sunflower producing states, such as Kansas, Colorado, Nebraska, Oklahoma and Texas.

With the right approach, CRP acres can produce a profit right off the bat. But to do that, farmers should focus more closely on what’s going on below ground. First and foremost, producers have to consider why the land was originally placed in CRP. Most was placed in the program because it was highly sensitive to environmental issues such as erosion and poor soil quality. Some of those issues will likely still be present.

Since soil quality will be unknown and variable, a soil test is necessary according to Dave Franzen, North Dakota State University extension soils specialist. “A soil test is really is a must for CRP land,” Franzen says. “You have no idea what the fertility levels are. On land coming out of CRP, we assume that perhaps the nitrogen is low and maybe the phosphate is low as well. But it may not be. A zone-directed soil test would especially give a grower a pretty good idea of what they are dealing with.”


With many acres now returning to production, can a conversion occur without breaking up the ground in a manner that voids all the conservation benefits established by the years the land sat idle? There’s no question the land benefited from the CRP program, so producers are keenly aware of the conservation-minded tillage options.

To till or not to till, that is the question. Tillage is appealing to many farmers in order to smooth out the land. “I would say to growers not to go any deeper than you absolutely have to when it comes to tillage, because even though there is reduced water during drier times like this past year, there is water down in the deeper levels,” Franzen says.

“If a person would till it deep and cover the residue, number one, you would negate any kind of progress of organic matter that had accumulated over the last 20 years or so while the land was in the CRP program. And, number two, if there is any moisture — perhaps from the recent fall rain events that have occurred in the Plains states — that would be gone with deep tillage. If you want to preserve any moisture at all, utilize tillage as shallow as possible to level it out and get it ready for spring. That would be the goal.”

As for tillage options, it’s difficult to make recommendations across a broad area, because each piece of land is different and has variable moisture conditions and residue levels. A no-till approach is certainly an option. In fact, sunflower can be used as a bio-till method. Why waste the fuel and time tilling a field? Let the sunflower root system do it for you.

South central North Dakota farmer Anthony Mock has broken up quite a few acres of CRP and looks at sunflower and corn as his two “go-to” crops in most situations. “Some people think that when they convert over CRP they can’t grow anything worth much on that land for the first two years,” Mock says. “But that just isn’t true. You can get above-average crops off CRP right off the bat with the right management.”

He likes sunflower on CRP land because of the benefits of the deep root system. “When I run out of time in the fall and can’t get into till that land — and then, when spring rolls around and I’m busy again — sunflower is, hands down, the best choice for that CRP ground,” Mock observes.

The key is the aggressive burndown of grasses and broadleaf weeds. He usually makes three passes to make sure he’s gotten rid of anything that might compete with the sunflower — fall, early spring and then right before planting. After killing all the weeds, he goes in with his row-crop planter with Clearfield or ExpressSun hybrids, with no prior tillage.

“I would easily say that our no-till planter is the most valuable piece of equipment on our farm,” says Mock, who farms with his brother Daniel in Emmons and Kidder counties. Taking the time to adjust the planter and paying attention to detail when planting sunflower, Mock says he gains 200-500 lbs/ac versus using an air seeder. “That doesn’t just apply to CRP ground. Making sure you have a good row planter with the right settings makes a world of difference in sunflower.”

Mock raises his plant population to about 28,000 to assure he gets the right stand in sometimes heavy residue situations. He realizes some growers might be skeptical about going straight into CRP without tilling because of the rough ground and heavy residue; but instead of wasting time and money on tillage, he lets the sunflower roots break up that residue for him.

CRP Field Plot Trial

A team from central North Dakota’s Morton County Soil Conservation District witnessed the benefits of sunflower’s root systems in breaking up soil compaction while conducting a three-year field trial looking at CRP land coming back into production. The trial was located in Morton County on roughly three acres over the course of three years (2008-10). The objective was to have a demonstration of bringing CRP back into production under a no-till system.

The field was two decades or more under CRP cover and was entirely in grass. The series of paired plots compared various crop rotations, and one remained untouched for comparison.

Many interesting aspects were discovered. One was that the grass roots were no more than 8-10 inches deep, which was surprising to the observers. And further down in the soil, the researchers discovered two different layers of soil compaction. The grass had not penetrated those compaction layers over the course of 20-plus years.

One of the goals of the test plot demonstration was to find ways to penetrate those compaction layers and “kick start” the soil back into production. Cover crops were used to do just that. A cover crop cocktail mix of turnips, beets, soybeans, sunflower, peas and different types of clover was used to break up the soil compaction layers. Other than the cover crops, plots were planted into sunflower, corn, soybeans and wheat.

Soil compaction can hamper shallow-rooted crops, but not sunflower. “We found sunflowers are an excellent bio-till plant with their tap root. We used the sunflower roots to help us find the compaction levels,” notes Morton County soil conservationist Michele Doyle. “Those roots find any and every area to penetrate down in the soil, going after moisture and nutrients. We had sunflower roots with a 90-degree angle two and three times trying to get down into the depth of the soil, and they helped break up the compaction layers.”

Doyle says the soil on this piece of land was surprisingly devoid of organic matter, after 20 years of grass cover. To help preserve the delicate soil, a no-till system is a must. “Our goal is zero bare ground,” Doyle claims. “It may sound radical, but it just totally makes sense. The practice is critical for the carbon/nitrogen balance in your soils. You have to keep that carbon up in your organic matter, plus have the residue to provide surface armor to protect your soil. And, sunflower as an excellent bio-till plant fits nicely into the no-till plan.”

Soil Nutrients
Not only does the deep-rooted nature of sunflower help break up soil compaction, the plant is also able to root down farther in the soil profile to seek out available moisture and nutrients. Breaking up the soil compaction can jump start the soil organisms making nutrients available to the sunflower and subsequent crops.

The grasses that have been growing on the CRP land for up to two decades tend to be shallow-rooted and inefficient users of nutrients, so there could possibly be some nitrogen left in the soil deeper down. Even though most soil samples show low levels of key nutrients, this may be due to the fact that few samples go beyond the first two feet of soil.

According to NDSU’s Franzen, most soil samples from CRP come back showing very low levels of nitrogen. However, that quickly changes when the land is brought back into production — particularly the first year. Some of the residue will start to break down once the soil is disturbed while being seeded. The activity of planting will stir up that dormant organic matter and put it into close contact with the soil organisms, so it starts to break down a little more rapidly and the degradation process starts taking place. So nitrogen from that surface matter breaking down will continue to become available later in the season. That’s where sunflower has an advantage. It’s a later-planted, long-season crop that will take up nitrogen and utilize it late in the season, Franzen explains.

Another depleted nutrient in CRP ground is phosphorous, Franzen points out. Some of the soils were pretty depleted going into CRP, so that might be inherently low. So with just a small amount of applied phosphorous, sunflower would do well — better than some small grains with a higher phosphorous requirement.

While the traditional markers that growers often use to gauge an estimate on soil nutrient needs (e.g., cropping history and historic yields) are not available on land that has sat idle for 20 or more years, there is benefit to starting with sunflower on a clean slate on CRP. The disease and pest baggage has all been erased during this time. Starting fresh with sunflower right out of the gate can be very beneficial to the land and profitable for the grower.

Though some growers might think that CRP land would be deprived of nutrients, Anthony Mock approaches CRP land with a plan of action similar to what he uses on all other acreage in his operation, drawing upon the regular recommended rates while shooting for ton ’flowers. He applies urea, phosphorus and ammonium sulfate at planting.

“That fertilizer gets things going in that ground, to get things started and let sunflower scavenge for the rest. Then, when the plants get going, they can get a boost ahead of the weeds. Once they get established, ’flowers can really handle that dense root mass of CRP,” Mock asserts. “That deep taproot grows through even some of the heavy grasses to get the nutrients it needs. Sunflower is also doing the work for the next crop by breaking up the soil mass deep in the profile.”

While it’s logical and financially prudent to focus on yield potential, CRP land must be approached a little differently. Some growers might think that land being brought back into production won’t produce to its potential for the first two years or so, but that’s simply not the case. Sunflower’s deep root system is an excellent option for the first crop on CRP land — not only for the profit potential it offers, but also for the work the plant does down in the soil for the subsequent crops’ benefit as farmers think ahead.

— Sonia Mullally
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