Soil Erosion on 'Flower Ground? Not a Problem!
Wednesday, March 1, 2000
filed under: Rotation
For many soil conservation specialists, sunflower would rank fairly
low on the list of suggested crops to plant on erosion-prone soils —
particularly if one is following the ’flowers with summer fallow. A
lack of post-harvest plant residue and resulting low soil cover is the
chief concern commonly expressed.
It’s a concern Duaine Dodsworth does not share, however. In fact,
the northeastern Colorado grower says the only problematic experience
he’s had with planting a crop on ground coming out of sunflower was once
having too much residue for his drill to properly handle.
Like many other High Plains producers who have successfully
incorporated sunflower into their dryland cropping rotations, Dodsworth
takes a “system-wide” approach to managing crop residue and minimizing
erosion. In his case, that system includes plenty of help from the
preceding dryland corn crop.
Sunflower almost always succeeds corn on Dodworth’s sandy loam Yuma
County soils. Along with its significant residue contribution, “I have
lower input costs following corn because there’s not that fallow period
[as is the case] after wheat,” he explains. “So I can plant straight
into the corn stalks.”
Combined with his lack of preplant tillage expense is a minimal
investment in herbicides for the ’flowers. Dodsworth tries to keep the
corn ground as clean as possible in anticipation of the sunflower crop.
Should weed populations warrant it, he’ll apply one or two pre-emergence
burndowns in the ’flowers. In some years, he says, even that treatment
hasn’t been necessary. In-season weed control may consist of one
cultivation and perhaps an application of Poast for volunteer corn
and/or sandbur. Neither operation is needed every year, however.
Dodsworth alters his sunflower planting pattern to take optimum
advantage of the corn residue. Sometimes he will split the corn rows;
at other times he’ll plant diagonally; and in some years he opts to seed
the ’flowers crossways to the old corn rows. He prefers going
perpendicularly because it distributes the residue — some of which has
been moved into the harvested corn rows by winter and early spring winds
— more evenly throughout the field.
A longtime member of the Colorado Conservation Tillage Association,
Dodsworth is serving his second term as the group’s president. His goal
is to be 100-percent no-till, possibly using a chem-fallow period
following the sunflower harvest and prior to drilling winter wheat.
Central to his ability to do so, he reiterates, is the significant
amount of corn residue remaining following the sunflower harvest. His
sunflower stalks are always left standing as well to help blunt winds
and trap winter snows. “The abundance of residue at wheat drilling time
also is partly due to the fact that I usually spray one time in the
spring of the fallow year, and then can get by working the ground two or
three times — using sweeps with treaders — prior to drilling wheat,” he
Unlike a standard High Plains rotation of three or four crops,
Dodsworth is working toward a six- to seven-year rotation. Along with
sunflower and corn, the rotation would encompass proso millet, Roundup
Ready soybeans (of which he had a 38-variety test plot on his farm last
year), two years of wheat and the fallow period.
“That gives me two years of cool-season grasses, two years of
warm-season grasses and two years of broadleaves,” Dodsworth points
out. Such a combination also represents differing levels of crop water
use, helps break up weed cycles, aids with disease prevention and
spreads out his workload. — Don Lilleboe