Latest Combine Costings Highlight Cereal Harvest Management Value

July 2006 - UK cereal growers could cut more than £2/ha from their combining bill alone by better harvesting management, according to the latest calculations from leading combine specialists, Claas UK. As well as saving nearly 30% on fuel costs, they have the opportunity to cut combining time substantially, improving the timeliness and security of their harvest while freeing-up labour and machinery for cultivations.

Based on feedback from drivers of the UK's best selling combine - the Lexion 580 - and detailed Claas combining costings, the calculations highlight major savings in both fuel use and harvesting time through better and more consistent drying of stems and grain from pre-harvest Roundup.

"Thankfully, most growers had a relatively trouble-free cereal harvest last year," recalls Claas combine manager, Paul Moss. "Their wheat crops looked fine and ready, with ears comfortably below 16% moisture at combining. But in many cases close inspection showed a surprising amount of greenness in the stems and nodes; something we seem to be seeing increasingly often these days.

"Moisture transfer from the straw during combining meant much of the grain went into the barn at up to 20%, adding both to drying costs and the risk of mycotoxin development.

"At the same time, the greenness of the straw considerably slowed combining speeds," he notes. "Green material feeds into the combine far less smoothly than fully dry straw. Concaves have to be set closer to give the right separation if grain losses are to be minimised. And the straw chopper needs half as much horsepower again to tackle it.

"Feedback from Lexion 580 drivers, indeed, suggests this resulted in typical combining speeds of 4.5 km/hr with a 9m cutterbar in 10t/ha crops, against the 6.5 km/hr possible with completely dry, Roundup-treated crops."

Using his impressive combining costing programme, Paul Moss calculates this represents a difference of more than 1.5 ha/hour and 4.5 litres/ha of diesel. With diesel at 36p/litre and labour at £10/hour, increasing the combining speed by 2 km/hr can be seen to cut combining costs from nearly £8.50/ha to little more than £6/ha. Over a 300 ha wheat crop, he suggests a combining bill saving of just over £700 (Table).

Table: Claas UK Combining Cost Comparisons
Lexion 580; 9m cutter bar; 300 ha wheat at 10t/ha; 65% efficiency*

* Proportion of total harvest time spent combining

"With diesel prices as they are today, quicker combining means a saving of almost £475 in combine fuel costs alone," points out Paul Moss. "Soberingly, that's more than twice the saving in labour.

"What the labour saving really means, though, is more capacity to do others things at the busiest time of the year," he stresses. "Over a 300 ha wheat crop, we're talking about a saving of 23 man hours on the combine. To which we can add an even greater saving in tractor-driving hours. If we assume two tractors hauling per combine, for instance, the total saving is 69 man hours; or an extra seven extended working days for cultivations. It certainly makes you think, doesn't it."

Of course, quicker combining also means more timely harvesting, less weather risk and more chance of preserving critical Hagbergs as well as more flexibility and security in the whole system. Or, alternatively the opportunity to spread the combine overheads over more acres of harvesting.

"But the value of good harvest management doesn't end here," adds Paul Moss. "Moist straw puts far more strain on every part of the combine, increasing wear, maintenance costs and the likelihood of breakdowns. As does the additional burden of green weed growth.

"The straw chopper is a case in point. Blade wear increases markedly with straw moisture content. So you'll either have to replace the blades more frequently or suffer the extra horsepower needed to chop when they're dull. And, I have to say the £440 it costs for an extra set of chopper blades for a Lexion 580 buys a good few hectares of Roundup."

The advanced telemetry systems Claas has developed for the remote monitoring of combine activity and efficiency are offering users an excellent way of assessing and optimising the machine's performance on the move in any particular crop.

By providing a complete breakdown of harvest performance, they are also allowing them to improve the overall efficiency of the combine's use by maximising the proportion of time it actually spends harvesting as opposed to headland turning, standing still waiting for trailers, moving from crop to crop and other non-productive activities.

"The critical speed of combining, though, is something that can't really be improved in this way," Paul Moss accepts. "It fundamentally depends on crop condition. Yes, you could increase cereal combining speeds simply by leaving your crops to ripen for longer. But this would considerably increase your weather and shedding risk while putting even more time-pressure on your whole system.

"Harvest management with Roundup allows you to achieve all the combining benefits of a well-dried, green weed-free crop in a reliable and consistent way," he concludes. "You have to get the job right, of course. Do so, though, and the experience of our users and costings shows you'll reap very considerable rewards indeed."

Roundup Harvest Management Guidelines:

Roundup must only sprayed once the grain is mature - with a moisture content of less than 30%. This is necessary to avoid compromising yield, causing shrivelled grains or increasing the risk of glyphosate residues.

The grain is ready for spraying when ...

1. In wheat and barley , the peduncle (at the top of the stalk immediately below the ear) starts to turn from green to brown;
2. In all cereals, a thumbnail pressed into grains taken from the centre of ears in various parts of the crop (a random sample of 20 should be sufficient) leaves an indentation which does not disappear in any; or
3. In wheat, 75% of the grains taken from the centre of ears in various parts of the crop (a random sample of 20 should be sufficient) have a dark brown pigment strand in the centre when cut in half.

A minimum of seven days must be allowed before combining which should take place only when the grain is ready by normal harvesting standards.