Farm Ireland

Friday 17 November 2017

Cutting fuel use will lead to bigger savings

Dermot Forristal

With high prices the new norm, fuel is now a significant cost on tillage farms. It typically takes 85 litres of fuel per hectare (19l/ac) to cultivate, sow, fertilise, spray and harvest a cereal crop.

This does not include transport to or from fields, grain or input haulage, grain drying or straw baling.

In practice, fuel use varies hugely between farms and, while we can do little about some of the factors affecting fuel use, we can change others.

In this article, we take a look at some of the key factors that influence fuel use. Not all of them are easy to implement and some have disadvantages which would outweigh their benefits, but to remain competitive, they must be considered.

Change your cultivation system

The depth/intensity of cultivation can have a huge impact on fuel use. The adoption of shallow minimum-tillage can more than halve consumption, reducing fuel requirements from 37l/ha to 17l/ha, a saving of €1,800 per year on a 100ha (250 acre) tillage area.

That fuel saving can give a total machinery cost saving of perhaps three times that, however, as less power input is required reducing machine wear, depreciation and labour.

The adoption of direct drilling would save even more fuel and associated machinery costs.

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While these tillage systems can deliver big savings, suitability for our climate makes adoption a challenging decision.

Don't plough so deep

While a change to min-till may be out of the question, shallower ploughing can save fuel. If you reduced plough depth from 250mm to 175mm (10" to 7"); you could expect to save at least 30pc in fuel consumption.

At 7l/ha, this would amount to about €650 on fuel alone on the 100ha unit or perhaps three times that saving if the impact on all machinery costs is considered.

Avoid distant land rental

Moving machinery on the road can cost dearly in fuel, labour, depreciation and wear and tear.

A study carried out last year showed that in an extreme situation, the renting of an isolated 9ha land block at a distance of 21km from the farm base could add €150/ha in machinery costs; with more than one-third of that being fuel costs.

While the distance of the land block to your home base is important, block size in relation to machine capacity and the cropping of that block will also determine costs.

Select tractors carefully

Tractor models differ in fuel use. The true measure is 'specific fuel consumption' or the amount of fuel used per unit of power produced.

The best information source is the independent OECD test.

Tractor models can differ by 18pc or more. A 12pc difference in fuel use in an 100kW (136hp) tractor could amount to €1,900 per year in fuel if the tractor is worked for 1,000hrs at power-demanding tasks.

Match the tractor to the task There is a general move to bigger tractor power units on farms but without necessarily having the work to justify them.

While this can add unnecessary depreciation costs, the frequent mismatching of tractors to the task can result in fuel wastage. A 120kW (160hp) tractor will use more fuel operating a smaller sprayer or spreader than a more correctly matched tractor.

Drive efficiently

Diesel engines are at their most efficient when loaded. In addition to matching the tractor and implement; where possible, shift up a gear and reduce the engine speed. Use the economy pto speed (eg 540 at 1,400rpm) for fertiliser spreading, spraying etc.

Tyre choice

A sinking wheel increases rolling resistance and fuel consumption.

Similarly, excess wheel slip wastes energy moving soil. Fit large enough tyres and operate them at the correct pressures to reduce power loss.

Tractor or Truck

Despite the availability of high road-speed gearboxes, tractors are not particularly fuel efficient on the road.

Trucks are generally more fuel efficient to move loads with a lower consumption for every tonne moved per kilometre.

The 4x4 commercial jeep

The 4x4 jeep is extremely popular on farms and while there is no doubting its versatility, they are generally expensive to run. The fuel consumption of a 4x4 is 60 to 100pc more than a small two-wheel-drive commercial vehicle or modern diesel car.

Use a car for long road journeys where the 4x4 is not needed. Choose your model carefully: the standard fuel consumption figures allow comparisons to be made.

Finally: know how much fuel you use

Record all diesel purchases and allow for stocks at the end of the year to get a picture of overall fuel use. This is the starting point for fuel savings.

Irish Independent