Conserving fuel on the farm

Cathy Svejkovsky, Energy Specialist, National Center for Appropriate Technology (NCAT)

In today’s climate of continually escalating fuel prices, farms must find ways to conserve fuel in order to reduce costs. This article provides useful tips to help you start saving fuel on your farm today. Many are free or low-cost measures that can provide immediate savings. Others have an associated cost, but offer a cost-effective payback. This article will focus on energy conservation in three areas: fuel storage, vehicle operation and maintenance field practices.

Fuel storage
Storage tanks can lose a considerable amount of fuel due to evaporation and leaks. A 300-gallon storage tank, for example, can lose about 120 gallons each year from evaporation. You can reduce that loss to about 15 gallons per year by following these steps:

• Keep fuel tanks well-shaded.

• Paint tanks white or aluminum to reflect the sun’s heat. Light colors reduce evaporation losses.

• Use pressure-relief vacuum caps rather than conventional gas caps.

• Lock unattended fuel tanks.

• Regularly inspect your tanks for leaks. During those inspections, tighten connections between the storage tank outlet and the pump, check valve packings and check for seepage at the nozzle.

Be especially vigilant about inspecting underground storage tanks, since leaks can cause groundwater contamination. Note: Underground storage tanks have the least evaporation, but undetected leaks can contaminate groundwater.

Vehicles and equipment

Before you start an engine
Use the recommended grade of fuel. Buying a better grade of diesel than you need can be a waste of money. Most owner’s manuals specify a No. 2-D fuel for warm weather operation and No. 1-D for extreme cold weather work.

In cold climates, install an electric block heater and timer on equipment. It is less expensive to warm engines with electricity for a controlled period of time than it is to use liquid fuel. Three hours is generally sufficient to warm an engine. Many available units attach to the block using magnets.

If a tractor engine is kept heated all winter for use as a standby generator, you can decrease electrical consumption by installing an air-sensing thermostat set at 20ºF, the point at which it will automatically turn on.

Getting the most out of an engine
Make sure your thermostat works properly. A properly working thermostat saves energy. Most engines run most efficiently when water temperature is between 165ºF and 180ºF. Fuel consumption increases by approximately 25 percent when the engine is operating at 100ºF, instead of 180ºF. Check your owner’s manual for more information.

Minimize idling, which can account for 15 to 20 percent of total fuel used. Letting an engine idle for 10 minutes during an average day, or 61 hours a year, will use about 31 gallons of fuel on a 75-horsepower diesel tractor.

Avoid quick starts – they waste fuel and are hard on equipment.

Perform maintenance. Keeping your farm vehicles and equipment in top operating condition will save fuel and money, help reduce repair costs, improve reliability and minimize harmful exhaust emissions. Common maintenance measures include getting regular tune-ups; replacing air, oil and fuel filters routinely; changing oil as recommended by manufacturers; and using the proper grade of oil. Refer to your owner’s manual for specific maintenance measures for your equipment.

Ensure that gas caps fit properly. Caps that are damaged, loose or missing altogether will cause fuel to vaporize.

Reduce excess weight on vehicles. Lighter loads consume less fuel than heavier ones.

Keep your tires properly inflated. Having just one tire under-inflated by six pounds per square inch (psi) can increase fuel consumption by 3 percent, not to mention reducing the tire’s life. Cold temperatures decrease the air pressure in tires, so check tire pressure regularly when tires are cold. Check your owner’s manual for information on correct inflation pressure.

Have wheels aligned and balanced. Proper alignment and balance – like proper air pressure – help minimize resistance from your tires, which can reduce fuel economy.

Upgrade to more fuel-efficient models. When it’s time to replace your equipment, compare fuel requirements of different makes and models. A higher purchase price can be partially offset by lower fuel costs.

Field practices
Depending on how you manage your fields, you could significantly reduce your fuel use by changing your field practices.

Conservation or reduced tillage
In conservation tillage, also known as minimum tillage or reduced tillage, crops are grown with minimum cultivation. Fuel savings vary, but could be as much as $10 per acre compared to traditional tillage methods. And, you can cut tractor use in half with no-till methods.

The trade-off is a possible increase in the amount of chemical used for weed control and fertilizer. In conventional tillage, the operator normally will plow, disk and harrow before and after planting. Reduced tillage minimizes these operations by either eliminating seedbed preparation or combining it with other field operations like planting.

Some practices that will reduce tillage are:

• Preparing the seedbed just ahead of planting to reduce the chances of rain between preparation and planting, and the possibility of having to reseed. Prepare a seedbed only in the row area, leaving the middle rough.

• Combining operations. For example, you may be able to combine the final seedbed preparation with planting, the fertilizer operation with a tillage operation, and so on.

• Using herbicides that don’t require incorporation, in areas with minimal weed problems. You may also plant at optimum time to combat weeds by crop competition, reducing the need for herbicides.

Tractor operation
Use the correct size equipment for the job. Choose the smallest, lightest tractor appropriate for the job to get the best fuel mileage. If you use equipment with too much or too little horsepower for the job, your fuel efficiency will decline dramatically.

Avoid unnecessary driving. Technologies such as cell phones and radios can be used to solve problems from the field, rather than driving. Combine errands into a single trip, if possible.

Operate at the recommended speed. Power requirements increase with increased speed, resulting in greater fuel use. Consult your owner’s manual for speed recommendations.

Use effective travel patterns. Lay out your fields to minimize turns and to keep the track on a level path (keeping erosion-control practices in mind). Coordinate livestock grazing location with tractor field work to minimize idling time when opening and closing gates. Installing cattle guards can eliminate stopping and idling time.

Tire slippage
Tractor tire slippage should be from 10 to 15 percent. Insufficient ballast can create excessive tire slippage and increase fuel consumption, not to mention premature engine wear. Remove extra ballast for lighter loads. You’ll get better fuel economy, reduce soil compaction and your equipment will last longer. Ballasting a tractor (adding weight to the rear for increased traction or to the front for stability and good steering) can correct slippage.

The correct weight to match the job is important. Too much weight increases rolling resistance and strains the tires and drive train. Too little weight increases fuel consumption and tire wear.

Check advantages and disadvantages of single tires versus duals. In soft, loose soils, duals will increase the contact area between the tire and soil, which can be more effective for increasing drawbar power than adding ballast.

Drawbar work
Gear up and throttle down. Studies show that, on average, the drawbar load on a farm tractor is only 50 percent of its rated capacity. For partial drawbar loads, gearing up and throttling down to reduce engine speed (rpm) can reduce fuel consumption considerably. According to the Iowa State University Extension, fuel savings can range from 5 to 15 percent at 75 percent power, and 15 to 30 percent at 50 percent power.

Because of the drop-off in fuel efficiency at higher loads, many diesel engines run more efficiently at 50 percent load and a reduced engine speed than at 100 percent load and full engine speed. Therefore, a large diesel tractor used for light drawbar loads can actually use less fuel if geared up and throttled back than a smaller tractor working at its full rated capacity.

For best fuel efficiency, select the gear that provides the desired ground speed at the reduced engine rpm, without overloading. (Overloading is indicated by black smoke or sluggish response to acceleration. Check your owner’s manual for the “working rpm range” of your tractor.)

Matching equipment to task
Ask yourself if certain practices are slowly siphoning your energy dollars. Take a look around and see where better planning or a small investment might save energy and money in the long run.

As this article illustrates, there are a lot of ways to reduce fuel consumption on your farm or ranch. Get started today on a fuel conservation plan and you could increase profits, prolong the life of your equipment, help protect the environment and more. HG

References omitted but are available upon request at editor@progressivedairy.com

—Excerpts from National Sustainable Agriculture Information Service (ATTRA) publication. For more information visit the ATTRA website at www.attra.org or call 800-346-9140