Over the next 2 years, government contracts on 12.4 million acres of Conservation Reserve Program (CRP) ground are set to expire. While some of this ground may be renewed, many of these acres will find their way back into ag production.
When it comes to bringing CRP ground back into production, there are huge advantages to utilizing no-till. As no-tillers and conservation educators have preached for years, the option of doing extensive tillage is the quickest way to destroy a decade’s worth of effective soil and water improvements that were made on this land.
On-Farm Research Offered Proof
Back in the mid-1990s, millions of acres of CRP land that had been lying idle for 10 years were about to be released back to landowners. This was among the more than 36 million CRP acres that had gone into the government program, which was signed into law by president Ronald Reagan in 1985.
One of the farmers interested in preserving the benefits of no-tilling CRP ground in the mid-1990s was David Dukes, a corn, soybean, alfalfa and grass producer from Bedford, Iowa.
Knowing that words alone would have little influence on how CRP acres were brought back into production, Dukes began an on-farm experiment in 1993 with 40 research plots on 16 acres. His goal was to demonstrate the value of using no-till to bring this government protected ground back into production. Somehow, he talked Agricultural Research Service scientists in Iowa, Nebraska and Minnesota into cooperating in a comparison of different management systems on his southwestern Iowa rolling hills.
"A fall burndown is the most important part of the entire sod conversion program, as everything else is secondary…"
“It had become clear that we needed a complete system in southwest Iowa that would allow CRP land to be reverted to soybean and corn production while avoiding tillage,” says Dukes. “Ten years before, that seemed like an impossible task, but we made it work with a combination of chemical burndown and no-till planting.”
CONSERVATION MINDED. David Dukes used fall and spring burndowns to prepare Conservation Reserve Program land for a return to crop production without tilling the soil.
Four Steps to Success
As the result of these on-farm trials, Dukes came up with a four-point program to bring CRP land back into production. It is a system that will work just as well today as it did 25 years ago.
1 Mid-Summer Mowing. Mow the sod in August to stimulate new growth and control brush, spreading the residue evenly. In unmanaged areas where shrubs or multiflora roses have grown tall, it can be challenging and may sometimes require some hand cutting during the mowing.
2 Fall burndown. Cool-season grasses, such as bromegrass, orchardgrass and fescue, are most easily killed in the fall. (Warm-season grasses require burndown applications in July and August.) Spray as late in the fall as possible with a modest rate of Roundup and 2,4-D when the regrowth is at least 8 inches tall.
“We sprayed as late as December 1 with good results,” says Dukes. “If there is even a hint of green, we would get good control and it is well worth the time it takes. From our experience, a fall burndown is the most important part of the entire sod conversion program, as everything else is secondary.”
3 Spring Burndown. Even though a fall burndown was done, Dukes also applied Roundup and 2,4-D a few days prior to no-till planting to clean up any grass escapes and early flushes of annual weeds.
“After 10 years of not being disturbed, there are plenty of weed seeds,” he says. “A thick mass of roots and surface residue can readily absorb a heavy spring rain with little soil loss. Expect to no-till these acres last, because they tend to dry slowly the first spring.”
4 No-Till Planting. Dukes found no-tilled soybeans worked best as the first crop into the killed sod. In the mid-1990s, he no-tilled beans into CRP ground with a John Deere 750 drill on 8-inch row spacings. While a fall burndown herbicide allowed most no-till planting equipment to work effectively, the 750 drill’s real advantage was good seed placement in sod that didn’t get killed in the fall.
However, there were concerns with some of the early-rotated acres, where the soil tended to be sticky a couple inches down. The 750 tended to push the wetter soil sideways, causing sidewall compaction and leading to difficulty in closing the seed trench. After a couple of years, Dukes switched to a John Deere 515 drill and a cart with wavy coulters, which worked much better in wet conditions.
Roundup Ready Technology Helped
Before the Roundup Ready technology came along, Dukes often had trouble getting season-long weed control during the CRP conversion. The post-emergence herbicides available at that time would burn back perennial grasses, but often did not kill them. Being able to use Roundup in a growing corn or soybean crop greatly reduced the risk during the transition.
By the time Dukes no-tilled corn in the second year out of sod, these fields were nearly clear of residue. Early in the no-tilling transition, he used a 6-row planter with starter fertilizer attachments. By 2001, he had changed to a 12-row system and stopped using starter.
Mid-90s CRP Results Were Dramatic
After only 2 years with his on-farm Conservation Reserve Program (CRP) trials, David Dukes says the results were dramatic. The Bedford, Iowa, no-tiller found some of the most exciting data revealed how tillage rapidly destroys organic matter and how no-till reduced soil erosion.
- His on-farm data showed that in the top 3 inches of soil, organic matter in undisturbed CRP fields measured 4.2%. Following a year of no-till soybeans, the field tested at 4%. Meanwhile, in conventionally-tilled soybeans in the CRP ground, the organic matter dropped to 3.5%. In the second year after corn, the no-till plot was back to the original 4.2%, while conventionally-tilled fields increased to only 3.7%.
- Dukes found a combination of moldboard plowing and heavy rain add up to a disaster. In a rainfall simulation study, 3.7 inches of water was applied during a 1-hour period on 2 consecutive days. On undisturbed CRP land, only 104 pounds of soil per acre were eroded, while a no-till plot lost 560 pounds of soil per acre. But in a plowed CRP plot, the same amount of rainfall washed away more than 20,000 pounds of soil per acre. “That’s 35 times more than the loss in no-till,” says Duke. “The lesson is: Plow the CRP and lose 10 years of progress. Or don’t plow and you’re actually starting your 11th year of no-till. Why destroy the amazing job Mother Nature has been doing for you?”
“We agonized with that decision, because you can find field research data that show starter works very well in no-till, while other studies don’t show much advantage,” he says. “Surface-applying phosphorus and potassium has worked quite well.”
In 2007, Dukes bought a Great Plains YieldPro 1225 planter that seeds 12 rows of 30-inch corn or 23 rows of 15-inch soybeans. “The only attachments we added were Martin row cleaners,” he says. “We learned that once you’ve improved soil structure with several years of no-tilling, a lot of attachments are not necessary. All you need to do is move the residue a bit and cut a slot for the seed.”
Improving the CRP Program
Now semi-retired and renting his land to a no-tiller, Dukes doesn’t talk to politicians much or speak at farm meetings. But if asked for advice on improving the CRP program, he would start by calling it a “renewal” rather than a “reserve” program. He would reduce it from a 10-year to a 5- to 7-year contract depending on what the landowner planned to do with the land after the enrollment period, such as cropping, tree plantings, pasture, etc.
“During that time, no harvest would be allowed, but mowing would be, and the operator would be allowed to implement a ‘renewal’ plan during the term of the contract,” he says. “Forage production, tiling, terrace construction or tree planting would be encouraged.”
At the end of the contract, he says the land would be ready for its new use. Perhaps warm-season grasses would be established for pasture, or trees would have already gained several years of growth. This would be a great way of renewing land and transitioning it into no-till production.
“The conservation benefits for the dollar would be ten times what we’re getting now,” he says. “Basically, what we’re doing now is taking land out of production for 10 years, but we are not encouraged to make any improvements on it. And growers often don’t have a clue as to what to do with it when it comes out.
“That’s extremely poor management.”