United States Department of Agriculture
Bureau of Entomology and Plant Quarantine
A STURDY BUT COMPACT SOIL SIFTER FOR FIELD USE
By A. W. Morrill, Jr.,
Division of Truok Crop and Garden Insect Investigations
In order to examine heavy sand-loam soils of tobacco fields
for the determination of the wireworm population, a soil-sifting
apparatus was developed which was similar to those previously de-
scribed by workers in California j/ and Washington _/ but differed
in several important respects. It was desired to have a sifter
which was portable and of a size that would permit it to be rolled
between the tobacco rows at setting time, yet one which would be
sturdy enough to handle heavy loads of samples and to stand con-
stant usage. The present machine, which is capable of sifting
five 1-cubic-foot samples in 30 minutes at a rate which does not
prevent close observation, is believed to meet these requirements.
It may be constructed by any competent iron-worker at an approxi-
mate cost of $60, not including the gasoline engine, which may be
secured for about $30 additional.
The soil sifter is pictured in figures 1 and 2. The body
frame measures 30 by 24 by 6 inches and is constructed of 6-inch
strap iron having a 2-inch strap band riveted to the top edge for
strength and a 1 -inch angle iron riveted to the bottom. This re-
tains in place the several wood-framed screens of hardware cloth of
various meshes, which may be changed to suit the condition and type
of the soil. In these investigations two screens of hardware
cloth with meshes of I inch and inch, and one screen of !-inch
mesh hardware cloth covered with 18-mesh window screening, are used.
I/ Campbell, R. E., and Stone, M. W. Soil Sifters for Sub-
terranean Insects. Circular ET-49, May 1935, illus.
2/ Lane, M. C., and Shirck, F. H. A Soil Sifter for Sub-
terranean Insect Investigations. Jour. Econ. Ent. 21: 934-936,
Lane, M. C., and Shirck, F. H. A Mobile Soil Sifter. Cir-
cular ET-70, January 1936, illus.
The body of the sifter is supported on four uprights of
1 -inch cold-rolled stock, 1 inch thick, which are movably attached
by a !-inch iron rod, and at the other end are similarly attached
to the wooden frame support. These uprights are 181 inches in
height from the center of one rod to +he center of the other. Holes
drilled in the points of attachment allow oiling.
By means of a brazed motorcycle connecting rod, 11 inches
long, the body of the sifter is attached to an 8-inch bicycle
sprocket (fig. 1). This turns on a steel shaft (1-3/16 in.) held
by two pillow blocks (fig, 2) and is connected by roller-block
bicycle chain to another similar sprocket, which is connected by
bicycle chain to the motor (fig. 3). This double attachment relieves
strain or the motor and assembly in starting and prevents bucking
by the rachine The roller-block chain costs more than the usual
block bicycle chain but is stronger and does not wear so quickly.
Power is provided by a second-hand '-horsepower, air-cooled
gasoline motor of the type commonly used on washing machines and
power dusters. This is equipped with a foot-pedal starter and
muffler and is improved by use of a carburetor air cleaner. The
wooden frame to which the sifter is fastened is 231 inches wide by
46 inches, allowing space for attachment of the motor, The appa-
ratus can be wheeled by one man between the tobacco rows by the
use of demountable wheels, or dragged by two or three men. After
the tobacco is well grown, however, it is advisable to leave the
sifter at the ends of the rows, and carry the soil samples to it in
The specifications for the principal parts of the soil
sifter are as follows:
angle iron (6 lbs.)
band iron (4 lbs.)
uprights, U-shaped (1 lb.)
rigid p11low blocks (4)
steel rods, (2 lb. cut)
bicycle sprockets (2)
bicycle sprockets (1)
roller bicycle chain
used motorcycle con rod
24 in.wide,30 in.long, 6 i.n.high
1- x i1 x in.
2 in. wide x in.
Approx. cost: $3.85
20 in. high
C. R. stock, 1 x I x 48 in.
1-3/16 in. dia.
1-3/16 in. dia.
8 in. dia.
3 in. dia.
6 feet long
brazed to 11 in. long
8 x 8 x I in. iron stock
Approx. cost: $14.85
uprights (9 lbs.)
braces and attachments (4 lbs.)
machine bolts (24)
18 in. high (center to center)
12 x 2 x 221 in. machine steel
11 x in. iron stock
z in. dia. and 24 in. long
x 6 in.
Approx. cost: $7.97
4 hp., gasoline, single
cylinder, air cooled
Approx. cost,: $36
The sifter can easily be assembled in about 30 hours, includ-
ing all forge work and drilling. Screens for the sifter can be
constructed from 3-inch pine boards and hardware cloth of the
appropriate mesh. Construction details are shown in the diagram
Figure l.--Close-up i
assembly of soil-sifting
Figure 2.--General vi o
in place. Wind or,
-ir,, and eccentric
t Windsor, Conn.,
, shovi ng screen
-,...... esii> i ii :i
SCREW ADJUSTMENT FOR CHAIN
SCALE 1: 8
Figure 3.-Diagram of essential portions of soil sifter.
UNIVERSITY OF FLORIDA
B II 1 2 I0923 5200I11ii Iil III lii liil1l
3 1262 09239 5200