Tips for improving diesel efficiency on your farm

With red diesel prices reaching new highs, what steps can farmers take to protect their businesses against spiralling fuel costs? Paul Spackman gets some practical advice. Keep reading for information on: Sentry benchmarking data; calculating fuel costs; improving fuel efficiency on-farm and practical things you can do.

Fuel use across 18,279ha (45,167 acres) of Sentry-managed farms has declined by an average of 2% a year over the past 15 years or so, and the company now uses about 40% less fuel per hectare than it did in 1990.

Not bad considering the horsepower and fuel tank size of modern kit has increased considerably and the average Sentry unit covers about 700ha (1750 acres), about 200ha (500 acres) more than the mid-90s. But, with red diesel prices heading towards 70p/litre, it is vital all farmers strive to improve fuel efficiency, the firm’s technical director Trevor Atkinson says.

“Until recently, fuel has never really been seen as a significant cost on farms, as prices have been about 20p/litre. Therefore there’s been very little work done recording fuel use. But, the situation has changed dramatically – last year our fuel spend doubled – and we, as farmers, have got to do everything we can to keep that 2% trend coming down.”

Substituting last season’s Sentry benchmarking data with current diesel prices highlights how drastically things can change, he says. “Within two years profitability drops from 2007 levels by 74%. If you’re using 100 litres/ha of fuel, for example, every time diesel price goes up 1p/litre, that’s £1/ha straight off the bottom line.”

This makes it even more essential to accurately record fuel use at the farm and individual field and operation level, and get to grips with how much fuel is used to produce one tonne of wheat, or total fuel cost per ha or per hour (see table). “Bunded, metered tanks make doing this much easier.”

Understanding fuel efficiency
Knowing how much fuel it takes to establish, grow and harvest one tonne of wheat is a simple, yet effective, way of identifying areas for improvement and potential cost saving, Mr Atkinson says. Figures vary considerably, depending on establishment methods used, soil type and a host of other factors, but analysis of 23 Sentry business units (most made up of several separate farms) last year, found a typical wheat crop used about 9-10 litres/t of fuel. Some were as low as 5 litres/t and others up to 15 litres/t.

“The higher fuel use tends to indicate traditional establishment systems where more passes are used to establish the crop, whereas min-till or direct drilling systems are at the other end of the scale,” Mr Atkinson says. “We’re not necessarily saying you should be doing one or the other, it’s simply raising awareness.”

Calculating fuel cost/ha/hour, or litres used/ha can also be useful indicators of efficiency, he adds. “Last year we saw a £16/ha difference in fuel cost per ha between the top and bottom 25% of our farms and there was a 37-38 litre difference in the amount used per hectare. Knowing this means you can then look at the reasons why.”

Large machines with high work rates, for example, may have a lower total fuel cost per hectare than small kit, but a higher cost per hour, he says. “To reduce costs, we’ve got to be more efficient with whatever capital we’re using.”

Improving fuel efficiency on farm
One of the biggest areas for potential fuel savings is in crop establishment, Sentry business manager Robert Kilby says. “A lot of farms still go down the traditional subsoil, plough, power harrow route, which is fine in certain situations, but you really need to get out there and check there’s a need for deep cultivations first.”

In some cases it may be possible to switch to less intensive systems, as Sentry’s 360ha (880 acre) Whelan Farms, Kent, did six years ago. The farm used to subsoil about 30% each year and plough and combination drill everything, but excessive machine wear on the flinty soil prompted a move to direct drilling. “The change was nothing to do with fuel saving at first, but we’ve found it to be an excellent bonus now.”

Last season the farm spent £16.38/ha on fuel for growing wheat; £3.30/ha less than in 2002 (before the switch to direct drilling), despite average fuel prices going from 16p/litre to 39p/litre. For 2008, Mr Kilby had budgeted on fuel prices averaging 60p/litre, taking this to £25/ha, but with diesel prices nearer 70p this will jump to £30/ha, or £3.60/t of wheat produced.
“We’re still better off than with the old system, plus it saves on labour and machinery as well.” The machinery repair bill of £35/ha is £5/ha less than 10 years ago. “That’s still quite high, but not bad considering how much the price of metal has gone up,” he says.

“Direct drilling works for us, but we still look to other methods as and when they’re needed,” farm manager Neil Macleod says. “There are areas where we still subsoil, especially on oilseed rape land.”

Block cropping and careful planning of work schedules can also give valuable fuel savings, not least by cutting out unnecessary travelling, Mr Kilby continues. In-field support using chemical or water bowsers for spraying, or trailers to carry fertiliser or seed out to the field, avoid journeys back to the yard and improves the output of key machines, he says.

Mr Macleod says all fields on one 80ha (200 acre) block at Whelan Farms are linked by 24ha (60 acre) strips, which allows the sprayer to drive between fields without having to fold up the booms. “It saves time, as well as diesel.”

Other simple things, such as using the correct ballast for the machine and operation, adjusting tyre pressures for road and fieldwork and properly servicing equipment all give small, but useful, fuel efficiency improvements. “Farmers need to stop thinking about power and focus more on ballast and grip,” he says. Reducing engine revs in-field is important and Mr Macleod thinks people should take more account of this when choosing tractors to buy. “Variable transmission gearboxes for example, allow you to do the same job at lower revs.”

Mr Kilby says it is also worth looking at whether farms can justify a 4×4 as a farm truck at current diesel prices, or would a van doing 40-50mpg do instead? “Not carrying loads of weight around in the back helps improve fuel use as well.”

Keeping a rein on fuel costs – things you can do:

	Correct machine settings Check cultivations (eg, subsoiling) are necessary and consider reducing depth where possible Use correct ballast for machine and operation. Remove ballast when not needed Use correct tyre pressures – too low can increase drag, too high can increase wheel slip- burning precious fuel
	Regular maintenance and servicing Focus on injectors and fuel filters. Replace worn parts – eg, especially blunt blades on combine straw choppers, burners and jets on grain driers Reduce engine revs where possible. John Deere research suggests reducing rpm by 20% saves 15-40% on fuel
	Plan work carefully Adopt block cropping approach Use in-field bowser or trailer when spraying or applying fertiliser instead of travelling back to yard
	Review fuel purchasing Buying in bulk may give small save saving (1p/litre) Hedging fuel purchase is possible, but can require a minimum order of 1m litres
	Ensure fuel supplies are secure Lock tanks, use fuel meters
	Avoid unnecessary running about Do you really need a 4×4 or will a more economical van do?