AE-110
Fuel-efficient field operations depend on a host of factors, including proper engine tuning and adjustment, proper tractor weighting, and well-planned and executed handling of materials in the field. On some farms there also may be opportunity to reduce total fuel demand by changing tillage systems.
In Indiana, fuel requirements for field operations are usually greatest in May and again in October. Precisely when peak fuel demand occurs, how high it is, and how long it lasts depend on such things as weather, crops grown, acreage farmed, and tillage system used -- all of which vary from farm to farm. Both the quantity of fuel needed and the timing of its use, therefore, are important in planning and evaluating the various avenues for fuel purchase and storage.
A review of fuel receipts for the year should give some indication of your particular fuel demand and use pattern. But that could be somewhat misleading for either or both of these reasons: (1) fuel may have been delivered and billed at one tie but used some time later; and/or (2) it may have been used from a common storage tank for both field and farmstead work or for farm and nonfarm activities.
If your fuel-use records take the above into account and you feel that they reflect your soil conditions and management practices, then use these records to determine field operation fuel requirements. If, on the other hand, your records are not that detailed, the information presented here should help you arrive at a reasonable estimate.
Following is a brief discussion of how fuel usage is expressed, a set of tables showing fuel requirements for most field operations, suggestions on modifying the table values for differing conditions, and four examples of how fuel consumption estimates are made. A blank worksheet is provided at the back for your calculations.
Fuel use for field operations can be expressed in two ways - as gallons per hour (gal./hr.) and as gallons per acre (gal../a.). The first way (gal./hr.) is important for determining fuel tank size on new equipment or need for auxiliary tanks, and for scheduling refueling activities during field work. The second way (gal./a.) is more important for evaluating field practices, fuel storage, and purchasing methods.
The fuel consumption of a small tractor and implement in gal./hr. is less than that of a larger tractor and implement. But the fuel use on a per-acre basis will be approximately the same, because the smaller unit has to run more hours to cover a given acreage.
Of course, there will always be differences in the fuel efficiency of two different-sized tractor engines and in the portion of the fuel needed simply to move the tractor. These are usually ignored for estimation purposes.
The approximate fuel requirements (gal./a.) for 32 standard field operations are given in Table 1. Crop harvesting, hauling, and storage estimates are shown in Tables 2 and 3 on a per-acre and per-mile basis. The values in Table 2 do not include fuel required for grain drying.
The estimates in Table 1 are based on the following assumed conditions -- (1) equipment in reasonably good repair and adjustment, (2) a field speed of 5 mph for planting and spraying, and 4-5 mph for other field operations, (3) an average Indiana soil type for tillage and other soil-contacting implements, and (4) row-crop implement settings for 30-inch rows. Tables 2 and 3 assume -- (1) typical grain and forage yield levels, (2) a field speed of 2 1/2-3 mph for grain harvesting and 4-5 mph for forage harvesting, and (30 hauling done by farm trucks.
None of the table values include the fuel required to move the field equipment to, from and between fields, or (in Table 1) to haul production supplies like fertilizer, water, chemicals, etc., to the field.
Because fuel consumption can vary among tractors, soils, yields, and with other factors, the actual fuel requirement for a particular operation on a given farm may be as much as 50 percent higher or lower than the values listed in the tables. The following section discusses some ways to adjust the table values to represent your situation more realistically.
Soils. Soil type can affect fuel use and power requirements for tillage operations. The values in Table 1 are for so-called `moderate-draft' soils (loams and silt loams). For `low-draft' soils (sands and sandy loams), reduce the figures by 35-40 percent for primary tillage, 20 percent for planting, and 10-15 percent for secondary tillage and cultivation. For `high-draft' soils (clay loams and clays), increase the values by the same percentages for the different field operations.
Row width. For planting in 40-inch rows instead of 30-inch, reduce the fuel requirement by 15 percent from the table values. For 15-inch rows, increase planter fuel by 50 percent. Sweep cultivation in rows other than 30 inches should not affect the fuel estimate as the number of shovels per foot of width is normally the same.
Material applied. Nitrogen, bulk phosphorous and potassium, starter fertilizer, water for spraying, chemicals, and seed must all be hauled to the field to be applied. If you haul these materials with your truck, tractor, etc., estimate the fuel requirement at about 10 percent (total for all materials) of that required to haul the harvested crop away from the field.
Wagons vs. trucks. Tractor-and-wagon hauling usually takes more fuel per acre than a truck of comparable size. Estimate the fuel requirement for trucks (from Table 2 or 3); then double the value for hauling with tractors and wagons.
Gallons Per Acre Field operation Gasoline Diesel ---------------------------------------------------------------------------- Tilling Subsoiling (14 in.) 2.94 2.10 Moldboard plowing (8 in.) 2.59 1.85 Chisel plowing (8 in.) 1.75 1.25 Offset disking 1.33 0.95 Field cultivating, plowed ground 0.84 0.60 Tandem disking, plowed ground 0.77 0.55 Tandem disking, second trip 0.70 0.50 Harrowing, spring-tooth 0.56 0.40 Harrowing, spike-tooth 0.42 0.30 Fertilizing Applying NH3, no-till ground 1.47 1.05 Applying NH3, plowed ground 0.98 0.70 Spraying fertilizer, trail type 0.28 0.20 Spreading fertilizer, dry bulk 0.28 0.20 Planting Strip rotary tilling and planting 1.33 0.95 Field cultivating and planting 1.26 0.90 Wheel-track planting 0.91 0.65 Conventional planting 0.70 0.50 Till planting, Nebraska type with sweeps 0.70 0.50 No-till planing, fluted coulter type 0.70 0.50 Grain drilling 0.49 0.35 Controlling Weeds Cultivating, disk hillers 0.56 0.40 Cultivating, sweeps 0.49 0.35 Cultivating, rolling tines 0.49 0.35 Rotary hoeing 0.35 0.25 Spraying, trail type 0.21 0.15 Haymaking Mowing, cutterbar 0.60 0.43 Mowing/conditioning, PTO 0.90 0.65 Windrowing, self-propelled type 0.75 0.54 Hay raking 0.30 0.22 Other Shredding cornstalks 1.05 0.75 Tandem disking cornstalks 0.63 0.45 Fall ridge forming 0.63 0.45 ------------------------------------------------------------------------ *See text for discussion of how to modify these estimates under differing farm situations.
Gasoline (gallons per acre) Diesel (gallons per acre)
------------------------- ---------------------------
Harvest- Hauling Hauling Harvest- Hauling Hauling
Type of grain ing 1st mile addl mile ing 1st mile addl mile
-------------------------------------------------------------------------------
Ear corn 1.61 0.40 0.24 1.16 0.29 0.17
Shelled corn 2.25 0.25 0.15 1.62 0.18 0.11
Soybeans 1.65 0.10 0.06 1.19 0.07 0.04
Small grain 1.50 0.12 0.07 1.08 0.09 0.05
-------------------------------------------------------------------------------
*Hauling estimates are for trucks; double the figures for tractors pulling wagons.
Gasoline (gallons per acre) Diesel (gallons per acre)
--------------------------------- ---------------------------------
Type of Harvest- Hauling Hauling Blow- Harvest- Hauling Hauling Blow-
forage ing 1st mile addl mile ing ing 1st mile addl mile ing
---------------------------------------------------------------------------------------------
Hay, conv. bales 0.75 0.20 0.15 --- 0.54 0.14 0.11 ---
Hay, round bales 0.65 0.40 0.30 --- 0.45 0.29 0.22 ---
Hay, 1-ton stack 0.70 0.20 0.15 --- 0.50 0.15 0.11 ---
Hay 3-ton stack 0.70 0.10 0.07 --- 0.50 0.07 0.05 ---
Green chop 1.35 0.55 0.20 0.50 0.95 0.35 0.14 0.35
Haylage 1.80 0.30 0.30 0.35 1.25 0.20 0.20 0.25
Corn silage 5.20 2.00 1.30 2.00 3.60 1.40 0.90 1.40
---------------------------------------------------------------------------------------------
* Hauling estimates are for trucks; double the figures for tractors pulling wagons.
Situation. A total of 600 acres of continuous corn, half being within a mile of the farmstead, the rest 5 miles away. A conventional tillage system (moldboard plow) is used. NH3 is applied preplant, 20 percent of the corn is rotary-hoed, half is cultivated, and half receives a late spraying. The soils and yields are `average,' and all field work is done with diesel-powered equipment, including hauling.
Discussion. The percentage figures following `Rotary hoe,' `Cultivate,' `Spray,' `Haul 1 mile,' and `Haul 5 miles' are the percentages of the total acres that normally receive that operation. The 0.62 figure listed under the column `Fuel in gal./a.' for `Haul 5 miles' is the sum (from Table 2) of 0.18 for the first mile and 0.44 for the other four miles (4 x 0.11).
To calculate total fuel requirement for Example A, first list the field operations, along with the appropriate fuel values (as is or modified) from Tables 1, 2, and 3 and the number of acres. Next, multiply `Fuel in gal./a.' by the number of acres to estimate fuel use (in gallons) for each operation. Then sum the last column to get estimated total gallons per year for field operations and crop hauling. Dividing this figure by the acreage involved gives an approximate per-acre fuel usage estimate.
Fuel Fuel in Number Gasoline Diesel
Field operation G or D gal./a. of acres (gallons) (gallons)
----------------------------------------------------------------------
Disk Stalks D 0.45 x 600 = --- 270
Spread P & K D 0.20 x 600 = --- 120
Moldboard Plow D 1.85 x 600 = --- 1110
Disk early D 0.55 x 600 = --- 330
Apply NH3 D 0.70 x 600 = --- 420
Field Cultivate D 0.60 x 600 = --- 360
Plant corn D 0.50 x 600 = --- 300
Rotary hoe (20%) D 0.25 x 120 = --- 30
Cultivate (50%) D 0.35 x 300 = --- 105
Spray (50%) D 0.15 x 300 = --- 45
Harvest corn D 1.62 x 600 = --- 972
Haul 1 mi (50%) D 0.18 x 300 = --- 54
5 mi (50%) D 0.62 x 300 = --- 186
Total Farm Fuel, gal/yr = 4302
(field operations & crop hauling)
4302 gal
Equivalent Diesel gal/a. = ---------- = 7.17 gal/a.
600 a.
----------------------------------------------------------------------
Situation. Same as example A, except gasoline tractors are used for spreading P and K, planting, rotary hoeing, cultivating, and spraying. The farm trucks are also gasoline-powered. However, half of the hauling within 1 mile is done with diesel tractors and wagons.
Discussion. Calculate fuel use as in Example A, this time using `D' and `G' in the second column to indicate the fuel type for each operation. The tractor hauling fuel value of 0.36 gal./a. is simply twice the truck hauling fuel figure from Table 2.
Fuel Fuel in Number Gasoline Diesel
Field operation G or D gal./a. of acres (gallons) (gallons)
--------------------------------------------------------------------------
Disk Stalks D 0.45 x 600 = --- 270
Spread P & K G 0.28 x 600 = 168 ---
Moldboard Plow D 1.85 x 600 = --- 1110
Disk early D 0.55 x 600 = --- 330
Apply NH3 D 0.70 x 600 = --- 420
Field cultivate D 0.60 x 600 = --- 360
Plant corn G 0.70 x 600 = 420 ---
Rotary hoe (20%) G 0.35 x 120 = 42 ---
Cultivate (50%) G 0.49 x 300 = 147 ---
Spray (50%) G 0.21 x 300 = 63 ---
Harvest corn D 1.62 x 600 = --- 972
Haul 1 mi tractors D 0.36 x 150 = --- 54
1 mi trucks G 0.25 x 150 = 38 ---
5 mi trucks G 0.85 x 300 = 255 ---
Total Farm Fuel, gal/yr = 1133 3516
(field operations & crop hauling)
--------------------------------------------------------------------------
Situation. A total of 600 acres is farmed, half being within a mile, the rest 5 miles away. Corn (300 a.) and soybean (300 a.) are grown in rotation, under a conventional tillage system, with the previous corn ground moldboard plowed and the previous soybean ground being chiseled. Post-emergence weed control for corn is the same as Example A. Beans are cultivated once, and half are rotary hoed. The soil and yields are `average,' and all work is done with diesel-powered equipment.
Discussion. This example is worked the same as Example A.
Fuel Fuel in Number Gasoline Diesel
Field operation G or D gal./a. of acres (gallons) (gallons)
--------------------------------------------------------------------------
Disk Stalks D 0.45 x 300 = --- 135
Spread P & K D 0.20 x 300 = --- 60
Moldboard Plow D 1.85 x 300 = --- 555
Chisel plow D 1.25 x 300 = --- 375
Disk early D 0.55 x 600 = --- 330
Apply NH3 D 0.70 x 300 = --- 210
Field Cultivate D 0.60 x 600 = --- 360
Plant corn-beans D 0.50 x 600 = --- 300
Rotary hoe D 0.25 x 210 = --- 53
(20% C, 50% B)
Cultivate D 0.35 x 450 = --- 156
(50% C, 100% B)
Spray corn D 0.15 x 150 = --- 23
Harvest beans D 1.19 x 300 = --- 357
Haul 1 mi (50%) D 0.07 x 150 = --- 11
5 mi (50%) D 0.23 x 150 = --- 35
Harvest corn D 1.62 x 300 = --- 486
1 mi (50%) D 0.18 x 150 = --- 27
5 mi (50%) D 0.62 x 150 = --- 93
Total Farm Fuel, gal/yr = 3566
(field operations & crop hauling)
3655 gal
Equivalent Diesel gal/a. = --------- = 5.94 gal/a.
600 a.
--------------------------------------------------------------------------
Situation. Same as Example C and also utilizing diesel-powered equipment, but with field operation activities for corn and soybeans recorded separately to permit enterprise accounting.
Discussion. Use identical procedures as before for the estimations.
Fuel Fuel in Number Gasoline Diesel
Field operation G or D gal./a. of acres (gallons) (gallons)
----------------------------------------------------------------------
CORN Ground Going to BEANS
Disk Stalks D 0.45 x 300 = --- 135
Moldboard Plow D 1.85 x 300 = --- 555
Disk early D 0.55 x 300 = --- 165
Field Cultivate D 0.60 x 300 = --- 180
Plant beans D 0.50 x 300 = --- 150
Rotary hoe (50%) D 0.25 x 150 = --- 38
Cultivate D 0.35 x 300 = --- 105
Harvest beans D 1.19 x 300 = --- 357
Haul 1 mi (50%) D 0.07 x 150 = --- 11
5 mi (50%) D 0.23 x 150 = --- 35
Total Bean Fuel, gal/yr = 1731
(Field operations & crop hauling)
1731 gal
Equivalent Diesel gal/a. = ---------- = 5.77 gal/a.
300 a.
BEAN Ground Going to CORN
Spread P & K D 0.20 x 300 = --- 69
Chisel plow D 1.25 x 300 = --- 375
Disk early D 0.55 x 300 = --- 165
Apply NH3 D 0.70 x 300 = --- 210
Field cultivate D 0.60 x 300 = --- 180
Plant corn D 0.50 x 300 = --- 150
Rotary hoe (20%) D 0.25 x 60 = --- 15
Cultivate (50%) D 0.35 x 150 = --- 53
Spray (50%) D 0.15 x 150 = --- 23
Harvest corn D 1.62 x 300 = --- 486
Haul 1 mi (50%) D 0.18 x 150 = --- 27
5 mi (50%) D 0.62 x 150 = --- 93
Total Corn Fuel, gal/yr = 1837
(Field operations & crop hauling)
1837 gal
Equivalent Diesel gal/a. = ---------- = 6.12 gal/a.
300 a
----------------------------------------------------------------------
Fuel Fuel in Number Gasoline Diesel Field operation G or D gal./a. of acres (gallons) (gallons) ------------------------------------------------------------------------ _________________ ____ ________ x ________ = _________ __________ _________________ ____ ________ x ________ = _________ __________ _________________ ____ ________ x ________ = _________ __________ _________________ ____ ________ x ________ = _________ __________ _________________ ____ ________ x ________ = _________ __________ _________________ ____ ________ x ________ = _________ __________ _________________ ____ ________ x ________ = _________ __________ _________________ ____ ________ x ________ = _________ __________ _________________ ____ ________ x ________ = _________ __________ _________________ ____ ________ x ________ = _________ __________ _________________ ____ ________ x ________ = _________ __________ _________________ ____ ________ x ________ = _________ __________ _________________ ____ ________ x ________ = _________ __________ _________________ ____ ________ x ________ = _________ __________ _________________ ____ ________ x ________ = _________ __________ _________________ ____ ________ x ________ = _________ __________ _________________ ____ ________ x ________ = _________ __________ -------------------------------------------------------------------------
New 8/80
Cooperative Extension work in Agriculture and Home Economics, state of Indiana, Purdue University, and U.S. Department of Agriculture Cooperating; H.A. Wadsworth, Director, West Lafayette, IN. Issued in furtherance of the acts of May 8 and June 30, 1914. The Cooperative Extension Service of Purdue University is an affirmative action/equal opportunity institution.