Can farmers till andmaintain soil health?Yes. While the gold standard
of tillage systems is widely
considered to be no-till, strip-till
can be a happy medium. Myriad
benefits and disadvantages
exist for both. Reversing years of
full-width tillage damage doesn’t
happen overnight, says Paul
Jasa, Extension engineer at the
University of Nebraska. “Think
long term,” he says. “If you’re
thinking short term, you’d be
better off going to Vegas.”What are strip-till and no-till?
Strip-till consists of a series of
6- to 8-inch-wide strips tilledacross a field. The soil in these
strips warms up and dries
quickly, creating conditions
that encourage seed germina-
tion and growth. The rest of the
field is left undisturbed and is
covered with crop residue.
No-till eliminates tillage so
residue from the previous crop
remains on the soil’s surface for
protection. The degree of soil
disturbance ties directly to its
overall health.Strip-till:- Provides a seedbed while
covering and protecting most
13
Does the USDA offer funding to help offset the cost of cover crops?
There are a variety of incentive programs through the Environmental Quality
Incentive Program and the Conservation Stewardship Program. A challenge with
using these programs is that every county is allotted funding, and farmers may
or may not be able to enroll in these programs right away. Plus, farmers must
adhere to USDA guidelines. Your local NRCS office will have more details.
14
Do I have to kill cover crops before planting a cash crop into them?
No. Planting a cash crop into living cover crops or planting green works well
in many cases. For instance, planting soybeans into a living crop of cereal rye
is a common practice, as the Toussaints have done for several years. Cereal rye
is a grass crop that helps suppress weeds prior to planting. Farmers can kill it
with herbicide after planting or by using a cover crop crimper/roller to lay the
cereal rye onto the ground. That helps create a mat to suppress weeds.
15
Are there potential hazards to using cover crops?
Certainly. Cereal rye, one of the most common cover crops, has pitfalls. “Cereal
rye can host Pythium,” says Mark Licht, Iowa State University Extension
agronomist. Its high inoculum load can stress corn planted into cereal rye. That
makes seed treatments effective against Pythium a must. Be wary that cereal
rye can hammer corn when grown too closely because of increased seedling
disease, poor seed-to-soil contact, and potential risk of greenbridge pressure
from armyworm and black cutworm, Licht says.
Since oats winter-kill, these problems don’t exist. That’s why oats can make a
better crop in which to plant corn, he adds. Cereal rye also does not resist cereal
rust pathogens. If left unchecked, these pathogens can imperil subsequent cash
crops. So just like any agronomic tool, farmers must properly manage them,
Licht says.
16
Which cover crops suppress weeds?
Many, says Anita Dille, weed scientist at Kansas State University (KSU). First,
identify the weeds you want to manage, because the cover crop physiology
must align with them, she says.
An overwintering and established grass cover crop like cereal rye or annual
ryegrass can thwart spring emergence of Palmer amaranth or waterhemp.
A fall-planted cover crop best suppresses kochia and marestail. KSU research
from 2016 examined June weed emergence following mid-March planting of
cover crops. Zero weeds emerged in a mix of triticale and oats, while fallow
land had 153 weeds – primarily kochia and Palmer amaranth – per square
meter. A mix of spring peas, triticale, and oats had just six weeds per square
meter. The grass cover crops essentially smothered weeds.
“It’s not 100% control, but herbicides don’t have 100% control either,” says
Lancaster, Pennsylvania, farmer Steve Groff.
50 Successful Farming at Agriculture.com |August 2019 Photography: Gil Gullickson