The Rural Voice, 1989-07, Page 38;BOPPING CROPPING CROPPING
ellow streaks in growing
crops and plugged tillage
equipment have become an
unlikely couple which has gathered a
good deal of attention from farmers
and researchers. The cause for their
concern is crop residues.
There is no doubt that concentrated
trails of trash, especially chaff, hurt
crop yields, particularly in reduced -
tillage fields. That same trash plugs
tillage equipment and planters.
A combine's uneven straw and
chaff distribution creates a multitude
of headaches ranging from poor weed
control, compacted soils, and poor
stands to nutrient tie-up and poor
performance by planters and drills.
And while no -tillers and double -
croppers probably face the biggest
problem with the straw and chaff,
even farmers in a corn/soys/wheat
rotation could benefit from evenly
spreading residue. If you could
blanket the soil surface more evenly
with residue in a min -till or no -till
situation, you could do a better job of
controlling erosion.
Crop residues act like raindrop
shock absorbers. If spread entirely
over the soil surface rather than left in
windrows, the residue could absorb
impact from raindrops. Otherwise,
when drops hit the soil surface the rain
loosens soil and starts the soil moving.
But only after you've tried pulling
a drill or planter through a thick mat
of poorly distributed straw and chaff
can you begin to appreciate the
shortfalls in your combine or your
custom operator's combine. Residue
problems worsen as grain and soybean
yields go up and as header width
widens.
Most combines off the dealer's lot
have only medium to poor ability to
spread straw and chaff. With a 20 or
24 -foot header, most combines will
spread the straw half that distance at
best.
Those concentrated residues will
plug tillage implements or no -till and
reduced -till drills and planters. It's
SCATTER
YOUR
TRASH
TROUBLES
Mervyn Erb is an independent
crop consultant and agronomist.
also difficult to get drills or planters to
penetrate the residue so they can place
seed accurately. In addition, soils
under the thick mat are cooler and
wetter, again leading to poor germi-
nation or soil compaction.
It's also more difficult to control
weeds in heavy residues. The heavy
residues may shield emerged weeds
from contact herbicides or prevent
pre -emergence herbicides from getting
to the soil surface.
No combine equipped with
standard straw spreaders does very
well spreading straw, though conven-
tional combines are probably better
than rotary models.
One solution is to add chaff
spreaders or combination chaff -straw
spreaders to your combine.
Choppers will reduce straw into
pieces small enough so they don't
hang up on equipment. However, if
it is damp, even chopped straw will
bunch up. Even with a straw chopper,
it's important to distribute the residue
evenly the full width of the header.
Adding more sheet metal and in-
creasing the length and size of the
vanes on the chopper will usually
direct enough straw to the sides to
get a good spread.
But I've noticed cases in which
no -till drills performed worse when
soybean residue had gone through a
straw chopper. Without the chopper,
disc openers were better able to
penetrate the long, brittle stalks.
When they had been chopped, pieces
were too short for openers and often
hairpinned.
Possibly the best advice I could
give you is to use a straw chopper in
conjunction with a straw and chaff
spreader. Your ultimate goal is to
spread your residue the width of your
combine head.
The better the residue is spread, the
easier your job will be, whether it's
preparing bean ground for fall wheat,
no -tilling fall wheat and spring grains,
or even plowing or chisel -plowing
corn ground.0
36 THE RURAL VOICE