DWIGHT, Ill. — Developing a foursome can put farmers on
course in their quest for improving soil health and sustainability.
Paul Youngstrum, Natural Resources Conservation Service
agronomist, said the four basic soil health principles are: Use plant diversity
to increase soil diversity, manage soils more by disturbing less, feed the soil
by keeping plants growing throughout the year, and keep the soil covered as much
“You may say, ‘How do we have more diversity in what is
grown? We’re in a corn- and soybean-producing area, and there’s not a whole lot
of diversity,’” he said at soil health seminar hosted by the Grundy County Soil
and Water Conservation District at the Dwight Country Club.
“Once and a while we hear an older farmer talk about ‘the
good old days when we had the rotation.’ The older guys had a diverse rotation
of corn, oats, alfalfa and soybeans.
“Cover crops are one way of diversifying that continuous
corn/soybean growing system.”
Cornstalks and soybean stubble get more respect these days
after being referred to as “trash” for years.
“It was finally realized that this shouldn’t be considered
trash and that the residue is a tremendous resource. Crop residue helps protect
our soil and improve it,” Youngstrum said.
“Crop residue on the surface absorbs the impact of raindrops
falling where the erosion process starts. It helps reduce surface crusting. It
encourages run-in of rainfall rather than runoff. You get more infiltration.
“It helps conserve moisture and reduce soil temperature,
provides food for the microbes and night crawlers and helps to create a good
environment for microbial activity.”
“Basically, the more residue cover we have and the less soil
disturbance we have, the lower our soil loss will be,” he said.
A calculating tool now is available that determines how much
soil is lost through various tillage systems.
Youngstrum said going from a moldboard plow to chisel system
would make great strides in reducing soil loss.
With no-till, the soil loss is reduced even greater due to
more residue cover and less soil disturbance. Cover crops reduce soil loss even
more while adding more organic matter to the soil and helping
“These are management practices, things we can control on
our land, so instead of losing soil, we’re saving it and also improving it,” the
Crop residue also can keep the soil from crusting. Crusting
makes it more difficult for crops to emerge and encourages increased run-off.
In addition, crop residue helps reduce evaporation on the
Youngstrum referred to a study at Kansas State University
that found that 100 percent corn residue cover “had quite a bit less evaporation
during hot weather. Also when temperatures got up there, the residue can help
insulate the surface from high temperatures.”
He said residue should be spread evenly over the field’s
“If you don’t have that, then we’ll have areas where the
residue is warmer, drier in other areas and other areas where the soil is cooler
and wetter and you get uneven stands,” he said.
“Having good residue cover and having it evenly distributed
throughout the field can do a lot toward protecting the soil and helping this
Youngstrum said that not all tillage is bad.
“It does have some negative impacts if it’s done a lot. It
can break down that soil structure, oxidize organic matter, release carbon
dioxide into the atmosphere, disrupt that beneficial fungus network and have
greater soil loss,” he said.
“Tillage basically butchers that soil biology in the soil,
cutting and slicing and taking the root channels and the pores that have been
created by the biology and disturbing that enough to where they’re all broken up
again along with our soil structure.
“Once we stop disturbing the soil, earthworms play a big
role in recycling nutrients and organic matter around the soil, creating a lot
of burrows in the soil and allowing a lot more infiltration of air and
Youngstrum said vertical tillage is an example of a
management practice that doesn’t disturb the soil a lot and creates a better
“We need to look at the biology of the soil as friends of
ours — microbes and things that are helping improve our soil and making it more
productive in the long run,” he said.
“As we do conventional tillage, we actually take the organic
matter, residue and everything and mix it up in that whole surface layer.
Whereas with no-till we’re concentrating the organic matter at the surface and
not distributing it through the soil.”