Mechanisation: How to maximise fuel efficiency to cut costs

Mechanisation is the major component of crop production but is also becoming very costly due to the price increase of farm machinery and diesel fuel. It is therefore important to utilise farm mechanisation systems efficiently and thus save fuel costs when conducting farming operations. Some important factors are to be discussed in this article to improve fuel efficiency.

Maintenance practices for tractors and equipment

Proper maintenance of tractors and equipment is very important to optimise fuel consumption. Timely replacement of air and fuel filters can reduce fuel consumption and increase engine power. Changing oil regularly and greasing moving parts according to a maintenance plan will also increase tractor efficiency and prolong its lifespan.

Timely maintenance and repairing of planters and implements will increase field efficiency and reduce total cost inputs. Well-maintained tractors and implements will minimise breakages and save time and money.

Using a large tractor for light loads is inefficient. It is important to utilise the optimum engine capacity of the tractor because tractors are mainly priced by engine capacities (R/kW). Using a too-small tractor for operations that need more engine power is also inefficient because engine overloading and too much wheel slip can lead to higher fuel consumption.

The graphs in Figure 1 reveal the relationship among the major parameters influencing fuel efficiency.

Figure 1: Common relationship of implement work rate, wheel slip, total and specific fuel consumption. Photo: Supplied/ARC

As indicated by the graphs above, the implement will be perfectly matched to the tractor when the specific fuel consumption in l/ha is at its lowest point and the work rate in ha/hour is at its highest point, which will be at the best wheel slip point as well. The graph also shows that wheel slip is necessary for efficient traction although too much wheel slip will increase fuel consumption and decrease the work rate.

Selection of operating speed

The correct operating speed selection is important to optimise fuel consumption. Every operation has an optimum speed to work on. The higher the speed, the higher the engine load. The engine-specific fuel consumption is at its lowest when operating the engine at close to maximum power.

Too fast operation speed may lead to engine overloading and inefficient operation results. Too slow operation speed may lead to underutilisation of engine power or excessive wheel slip. Gearing up and throttling back can lead to fuel savings. Make sure not to overload the engine; excessive black smoke indicates overloading.

Ballasting tractors correctly

Properly ballasted tractors with recommended tyre inflation rates can improve fuel consumption and increase traction efficiency by creating the required amount of wheel slippage for the specific implement and field conditions. A certain amount of wheel slip is necessary to create good traction.

The average necessary wheel slip percentage on soft terrain is between 10 and 15% but may vary according to the field conditions and working speeds.

Field test for matching tractor and implement. Photo: Supplied/ARC

Field efficiency and precision agricultural practices

Field efficiency refers to the time the operation takes versus the turning and other non-productive time. Spending too much time turning around at short fields or overlapping tillage operations within a field can result in higher fuel consumption. Planning road travel trips as optimised can also save fuel.

Energy and thus significant fuel savings can be achieved by using global positioning guidance systems such as auto-steer with a planting operation or any other soil preparation activities.

Site-specific farming using equipment guidance, yield monitoring systems, field mapping, and applications for precision crop inputs can provide many economic and environmental benefits in addition to energy savings. It is therefore very important to make use of precision agriculture technologies to save costs on many aspects of farming practices, including the very expensive fuel cost.

Fuel storage and biodiesel

Proper fuel storage can save fuel before it goes into the tractor. Keeping above-ground fuel storage tanks shaded and painting them a light colour can reduce the loss of fuel via evaporation caused by heat from environmental circumstances.

If you produce crops for biodiesel production like sunflower or soybeans, and you have the knowledge and equipment to produce biofuel, please take the opportunity to save money by using biofuel.

Using solar power by employing solar-powered pumps instead of diesel engine-driven water pumps will also reduce your diesel costs on the farm. Solar power systems can be considered to replace diesel generators for electricity supply to reduce fuel costs and hence the total cost.

Many practices and techniques can assist a farmer in saving fuel costs as long as one keeps their mind and eyes open. Significant savings on fuel can be achieved through the effort of analysing and optimising farming practices, especially mechanisation practices whenever it is possible and economically viable to do so.

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