Tillage for
Cotton Production
Tillage operations are among the most costly and
time-consuming practices in cotton production. So
farmers are continually seeking ways of avoiding
unnecessary procedures. The fall of the year is an
excellent time to evaluate crop response to the tillage
practices that were employed during the crop season.
Inspection of vegetative growth, including plant
height and root development, can be used to determine
the extent of compacted areas in the field.
Particular attention should be given to such indicators
as small, stunted plants and root systems lacking a
complete, straight , and sizable tap root. When such
symptoms are found , the farmer should dig a hole in
the soil profile to locate hard layers, taking particular
note of the depth and thickness of such layers.
Depth of the compacted zone is important in
determining the selection of the proper tillage implement
to remedy the problem. If the zone of compaction
is within the reach of a moldboard or disk
plow (approx. 12-16" maximum), ordinary plowing
will probably suffice. Where a deeper layer is inhibiting
plant growth , chisel tools will be necessary.
Studies in California have shown that chiseling
directly beneath the seed row is the cheapest and
most effective means of improving root penetration.
Dramatic yield increases were obtained where deep
chiseling was combined with a needed soil pesti cide
or chemical additive. Power required for effective
chiseling results are in the range of 40 hp per chisel. If
chiseling cannot be done simultaneously with bedding,
the field should be bedded first so that the
chiseling can be done directly below the planted strip.
Every effort should be made to chisel when the soil is
dry , as results throughout the cotton belt have shown
that chiseling in moist soi ls, especially fine-tex tured
ones, is ineffective. As a rule of thumb, if the chisel
pulls easily, it is not accomplishing the job.
If no compacted layers were found during the fall
inspection, one could consider a minimum tillage
system. A workable system would include stalk
shredding, discing to level beds, plowing only deep
enough to bury trash, and final seedbed preparation.
Guide 400 A-205
This many operations may not appear to fit the
normal concept of minimum tillage. However, when
only shredding and bedding were used in New Mexico
tillage tests, plant residue on the surface was a significant
problem , and after several years, water and root
penetration severely limited yield on the clay soil at
the test site. Such a system would not be recommended
for more than one year.
The effectiveness of the tillage system can easily be
evaluated in the spring after the first irrigation using
only a small iron rod as a probe. This probe, or
penetrometer, is a 3/8" smooth iron rod with a sharp
point. If the soil is near field capacity, the rod should
penetrate to a depth of two feet with less than 50
pounds of force . This indicates that soil compaction
is not severe enough to inhibit root development.
Although it is too late to remedy a problem, if
compaction should be found at this time, the information
can be used to improve tillage practices the
following year.
No one system of tillage can solve all soil problems
in cotton production. Tillage itself can cause compaction
when the same operations are performed in
the same manner year after year. Mold-board plowing,
for example, can cause a plow pan or a compacted
layer if the plow is set at the same depth each
time the field is plowed . The farmer should be aware
of, and prepared to use, a variety of tillage practices
to prevent compaction by repetition.
By inspection of the previous crop and use of the
soil probe, the farmer can select those practices
needed in each field for the coming season. Some
judgement is involved in practice selection. Several
years of trials, "look and see," may be necessary to
obtain a suitable tillage system for each particular
field condition .
Authors :
C.M. Hohn, Extension Agricultural Engineer
G.H. Abernathv, Agricultural Experiment Station
W.S. Jackson, Extension Associate Agronomist
New Mexico State University is an equal opportunity employer. All programs are available to everyone regardless of race,
color, or national origin. New Mexico State University and the U.S. Department of Agriculture cooperating.
Reprinted 8/75
Publ ished and d istributed in furtherance of the Acts of Congress of May 8 and June 30, 1914, by the Cooperative Extension
Service of New Mexico State Univers ity, Philip J . Leyendecker, director, and the U.S. Department of Agriculture, cooperating.
NMSU Cooperative Extension Service and Agricultural Experiment Station Publications
