naturally light in texture and in such cases flood-iallowing causes no improvement.
More complete information regarding the practice of flood-fallowing may be
obtained from the literature listed below:
Sngar Bulletins, Nos. 4, 5, 6, and 7, Dept. Agr. British Guiana. Results of field experiments.
Rpts. Chemical Division, 1931-2-3-4-5-6, Dept. Agr. British Guiana. Laboratory investigations.
Tropical Agriculture, 10:91-95. General description.
Agr. Jour. British Guiana, 7:227-230. General description.
Official Gazette, British Guiana, July 26, 1913. Analyses of waters.
Agr. Jour. British Guiana, 7:165. Description of pumps used.
DISCUSSION
Mr. Dickinson noted that the maintenance of water over a field for two years
presumably would involve much water and pumping. There appeared to be some
question as to the relation of iron to the increased fertility and it was suggested
that the brown creek water might contain nutrients.
Mr. Arceneaux stated that he knew of no other place in which a flood-fallow
was used for cane and that in rice fields the practice usually caused puddling
rather than improvement.
PAPER
DEEP TILLAGE WORK IN LOUISIANA USING T H E GYROLETTE
C. L. DENLEY
Godchaux Sugars, Inc., Raceland, La.
One of the Gyrolette plows, developed by Mr. N. C. Storey and manufactured by Fowler Pe Co., Leeds, England, was purchased by Godchaux Sugars, Inc.,
in 1933, and has been used in the preparation of a portion of their land for planting cane and other crops for the past four years.
The Gyrolette is mounted on a Caterpillar Diesel 35 tractor, and has the
following specifications and capacities:
Width of track, 56 inches.
Over-all width of one crawler, 18 inches.
Working width, 6 ft.
Forward speed when plowing, .55 miles per hour.
Rate of plowing, 3 to 3fr acres in 12 hours.
Diesel fuel required, 15 to 18 gallons for 12 hours.
Depth of plowing, 10 to 16 inches.
The Gyrolette breaks up the soil to a depth of 12 to 14 inches, depending
upon the type of soil, as compared to a depth of 6 to 8 inches with the other
available land preparation implements. An important feature of the Gyrolette
work is that the soil is thoroughly pulverized but is left in its original position,
thereby avoiding the ill effects of bringing part of the subsoil to the surface to
be mixed with the top soil, a procedure which has decreased yields of cane in
deep plowing experiments using other implements.
The machine is equipped with a lighting system and is operated twenty-four
hours a day, the plowing done at night being entirely satisfactory.
Land may be broken flat, or a mold-board may be attached behind the machine to form rows in the same operation.
A number of experiments have been conducted to measure the comparative
yields of cane on plots prepared with the Gyrolette and with the usual land
preparation implements used in Louisiana. The yields on these plots were checked
in the plant cane, first year stubble, and second year stubble crops, and the
average of all the yields were as follows:
AVERAGESOF FIVESETSOF PLOTS.
Plant Cane - 1935:
Tons Cane
Per Acre
Normal Juice
Brix
Lbs. Sugar Lbs. Sugar
Per Ton Per Acre
Sucrose
Purity
--Prepared with Gyrolette. . . . . . .
Ordinary Preparation. . . . . . . . .
29.04
25.28
16.53
16.38
13.11
12.75
79.31
77.84
174.30
167.71
5062
4240
26.19
22.12
15.83
15.71
12.17
11.79
76.88
75.05
158.91
163.53
4162
3617
15.00
15.36
11.58
12.07
77.20
78.58
151.59
159.63
3000
2805
First Stubble - 1936
Same Plots As Above
Prepared with Gyrolette... . . . .
Ordinary Preparation. . . . . . . . .
Second Stubble - 1937
Same Plots As Above
Prepared with Gyrolette. . . . . . .
Ordinary Preparation. . . . . . . . .
19.79
17.57
'
It will be noted from the above that the Gyro-tilled plots gave higher yields
of cane and sugar per acre than did the plots prepared in the usual way. There
were no significant differences in juice quality, but the yields of cane per acre were
consistently 3 to 4 tons higher in the Gyro-tilled plots in the plant cane and first
stubble years, and 2 to 2.5 tons higher as second stubble.
A probable explanation of the smaller differences in yields as second year
stubble, which is the third year after plowing, is that the Louisiana cane belt soils
tend to "run together," or pack, during the periods of heavy rainfall which occur
each year.
Lands broken up with the Gyrolette absorb heavy rains more quickly and
with less washing of the soil than do those given the ordinary preparation. This
contrast is very noticeable in fields where the rows have been formed. It has also
been noted that crops growing on Gyro-tilled lands begin to show the effects of
a drought much later, due, no doubt, to a deeper root system, as well as to the
presence of more moisture.
I n one experiment on plant cane the following interesting results were obtained:
On plots prepared in the usual manner, increased yields were secured from
the application of fertilizer with irrigation and also without irrigation. However,
on the plots prepared with the Gyrolette, no increase in yields was secured from
the application of fertilizer or from irrigation. Furthermore, the Gyro-tilled plots
with no-lertilizer and no irrigation gave higher yields than the plots with ordinary
preparation which were irrigated and given fertilizer applications.
A minor objection to the Gyrolette is that it will not satisfactorily dispose
of soybean vines, making it necessary that these vines be buried in advance of the
Gyrolette plowing.
Our records show the following average costs of operation and maintenance
for a period of four years:
Actual Plowing Cost
Maintenance Cost
Depreciation (12+y0 per year)
Interest on Investment (6y0)
Total
$0.87
1.18
1.76
0.85
$4.66
per
per
per
per
per
acre
acre
acre
acre
acre
Satisfactory increases in yields have been secured on all lands prepared with
the Gyrolette. However, due to the high initial cost of the machine, the expensive
maintenance, and the time lost from plowing due to heavy rains, the increased
yields must continue over a period of years to make the use of this piece of
equipment profitable. Further studies are being made to measure the economic
importance of this machine in Louisiana.
DISCUSSION
I n reply to inquiries, Mr. Denley gave the cost of the Gyrotiller outfit as
$1,500, further stating that the cost of deep tillage with the machine was about
the same as that involved in ordinary methods. T h e soil was cultivated only once
before planting. It was further reported that soybeans could not be turned under
wit11 this equipment. Replacement of parts was difficult, as these had to be obtained from England.
The chairinan reported on trials with the Howard Rotary Hoe, an implement consuming about the same power but not plowing as deeply. This machine
would chop up stubble and mix in soybeans, but the blades did not last long
and the cost of replacement was high.
I-
The paper entitled "Drainage of Peat Soils in the Florida Everglades," by
B. S. Clayton, was read by the chairman.