As a new soybean crop emerges on Conservation Reserve Program land, Iowa farmer Craig Embretson (left) and David Gibney of the Natural Resources Conservation Service find an exceptional surface-residue level of 80%.
Craig Embretson, an avid outdoorsman and serious no-till farmer, has been working hard to perfect his crop system, which includes corn, soybeans and deer.
Many of his eastern Iowa fields border wooded areas that provide perfect habitat for whitetails. But there’s another reason that deer love his crops: his successful no-till program.
It starts by splitting acres 50/50 between corn and soybeans, which gives Embretson a balanced grain marketing plan and lets him apply costly fertilizer to only half his acres each season. This helps maintain high levels of surface residue that slowly decompose back into the soil.
"When land is in CRP [Conservation Reserve Program], it not only protects the topsoil from erosion but also stores up carbon," explains David Gibney, district conservationist with the Natural Resources Conservation Service.
With nearly 20 years of no-till experience, Embretson says his corn runs from 190 bu. to 205 bu. per acre; bean yields weigh in at 55 bu. per acre.
His biggest no-till challenge came a few years back when 430 acres of a neighbor’s farm came out of the 10-year CRP. The landowner, Wayne Peterson, of Elkader, Iowa, wanted to sell, but he also wanted the land left in capable hands. He chose Embretson, who had established a proven no-till track record on fields right across the fence.
Embretson outlined the steps needed to put the CRP acres back into production. His goals: minimum soil disturbance and maximum weed control.
Timing is key. Embretson timed the mowing and first herbicide application in the summer and fall the year before crops were planted. He suggests growers converting acres from CRP back to crops check with their local Farm Service Agency office for date guidelines.
"Wayne mowed all the acreage between Aug. 5 and Aug. 10. Most of it was bromegrass with some patches of milkweed and Canada thistle," Embretson says. "It was dry, and we wanted to get some regrowth before spraying. That way, we could get good herbicide coverage on new leaves and plants greening up."
Embretson sprayed 1 qt. per acre of generic glyphosate, mixing in ½ pint of 2,4-D. He timed the application for Sept. 25 to 28 with the field turning yellow in about a week. The first killing frost would keep weeds and brome dormant until spring.
The final step that fall was a complete soil test of all fields, including pH samples.
Planting pointers. The next spring, because of different field sizes, Embretson split the land with 228 acres to soybeans and 180 acres to corn, then selected Roundup Ready seed varieties for each crop. For soybeans, he planted some fields in 15" rows, with higher-yielding soil in 30" rows. The soybean planting goal was 165,000 seeds per acre. He planted two different seed varieties and brands.
"Make sure you have a good set of row cleaners on your planter to push heavy residue out of the row," Embretson says. "Don’t get in a hurry to plant, especially on CRP ground going to corn. It’s going to take longer for soil to warm up under all the residue."
Before planting corn, he knifed in anhydrous ammonia, then planted in 30" rows, dividing fields among three different Roundup Ready hybrid numbers. "Don’t bet everything the first year on just one number," he advises.
Kevin Steffey, research entomologist at the University of Illinois, suggests planting treated seed on fields going back to corn from alfalfa or sod. "You may not know exactly which secondary insect is there," he says, "but you can be sure something will be there."
As corn emerged, Embretson spotted insects, so he tank-mixed an insecticide with his glyphosate/atrazine treatment and applied it at the five-leaf stage. One soybean field with nutsedge was treated twice, all other corn and soybean fields once.
In June, Gibney helped Embretson conduct a surface residue analysis that measured more than 80% residue.
"That’s very good, even for no-till," Gibney noted.
- Early Spring 2011