Canola direct heading: risk management and economics

Photo of Maurie Street
Maurie Street

Photo of crops
A windrow and direct harvest trial in 2010
achieved higher yields with direct-headed

Direct heading canola is becoming a more widely adopted and accepted practice. However, the decision about whether to windrow or direct head canola typically comes down to a complex combination of risk management and economic and seasonal factors.

Research by Grain Orana Alliance (GOA) in central-west New South Wales has shown that optimising the timing and method of canola harvest can result in an economic benefit of more than $200 a hectare.

While this is a heartening result, the choice between windrowing and direct heading canola is not always straightforward. GOA CEO Maurie Street says the decision needs to be made on a case-by-case basis because each paddock and season will be different, as will a grower’s attitude to risk.

There are many pros and cons when comparing the two canola harvesting methods. However, the emphasis varies for individual farm businesses and even for different properties or paddocks within the same business.

In addition to the agronomics and mechanics of windrowing or direct heading canola, there are several points to consider that may also affect the overall cost of production, including:

  • capacity to complete the task in the ideal timeframe to maximise yield and reduce the risk of grain loss;
  • spreading the time and workload of the farm’s total harvest to optimise the use of machinery and labour; and
  • prevailing seasonal conditions and the susceptibility of the crop to weather damage.


The potential economic benefits gained by getting the timing of harvest right generally relate to grain yield and quality. According to NSW agronomist Kathi Hertel, the timing of direct heading and windrowing can have a substantial effect on the value of the crop being harvested.

This means growers should consider which harvest method, or combination of methods, gives them the capacity to complete the task in the ideal timeframe.

Machinery availability and logistics management can affect the capacity to complete windrowing or direct heading on time and may vary each year depending on:
  • the area of crop to be harvested;
  • whether harvesting is by the owner/operator or reliant on contractors;
  • availability, reliability and cost of contractors in a region;
  • labour availability to operate machinery or complete other coinciding operations; and
  • other operations taking place around the time of windrowing or direct heading, such as barley harvest, haymaking or shearing.

Windrowing can give confidence in predicting when harvest is likely to start, usually seven to 14 days later. In contrast, the ripening of a crop left for direct heading can vary depending on the season. A soft finish can delay ripening and a dry finish may mean harvest is not delayed much past that of a windrowed crop.

Mr Street says to remember that if a crop is green and delaying harvest, it is still growing more grain.

Seasonal risk

The decision about whether to windrow or direct head canola can also be influenced by an individual crop’s susceptibility to weather damage. Variations in susceptibility may be related to variety, crop density, yield and maturity, seasonal conditions, temperature and humidity, and the timing of the operation.

In dry, hot years, the focus may be on reducing the potential risk of shattering, managing thin, low-yielding crops to reduce the risk of wind damage, or considering whether low biomass windrows would be too difficult to pick up if they were low to the ground.

In contrast, cool, moist years may present challenges around uneven crop maturity and rain events at harvest. While windrowing can be used to even-out crop maturity, standing crops tend to dry out faster than windrows after a rain event and so harvest will often resume faster.

Pre-harvest sprouting in wet conditions and the subsequent loss of test weight in canola is also more likely in windrowed crops due to the density, humidity and slower drying rate of the windrow.

The risks associated with different seasonal conditions, and the significance of the impact, will also vary for different climatic regions. Whichever operation is undertaken, it should be remembered that the later the crop is harvested, the longer it is exposed to potential damage from wind, rain or hail.

Table 1 Economic comparison of windrowing and direct heading 500 hectares of canola
 Windrowing  Crop area
500 ha
 Hours/hectare  0.11
 Hectares/hour  8.8
 Cost ($/hour)
 Cost ($/hectare)
 Average hours of operation/day
 Time taken to complete windrowing
(days) (based on a 12-hour day)
 Total cost of windrowing ($)
 Value of crop ($/hectare)
 Cost of windrowing/gross crop value (%)


Harvesting windrows
 Crop area
500 ha
 Hours/Hectare  0.11
 Hectares/hour  8.8
 Cost ($/hour)
 Cost ($/hectare)
 Average hours of operation/day
 Area harvested/day (hectares)
 Time taken to complete harvest
of windrows (days) (based on a
12-hour day)
 Total cost of harvesting windrows ($)
 Value of crop ($/hectare)
Cost of harvesting windrows/gross
crop value (%)
 Direct heading
 Crop area
500 ha
 Hours/hectare  0.1
 Cost ($/hour)
 Cost ($/hectare)
 Average hours of
 Area harvested/day
 Time taken to direct
head crop (days)
(based on a 12-hour day)
 Total cost of direct
heading ($)
Value of crop ($/hectare)
 Cost of harvesting windrows/
gross crop value (%)
Note: This comparison does not include desiccation or crop
sealant applications as the necessity will vary depending on individual

crop and seasonal conditions.


Economic considerations

Increasing pressure on crop margins means growers are constantly looking for ways to reduce input and operational costs. An economic comparison undertaken by Ms Hertel is outlined in Table 1.

The analysis compares the costs associated with windrowing, harvesting windrows and direct heading canola, using the following assumptions:
  • crop: 2.5 tonnes/ha, assuming no shattering losses;
  • crop valued at $500/t, 42 per cent oil;
  • windrower: 11-metre width operating at eight kilometres per hour at a contract rate of $30/ha;
  • harvesting windrows, harvester: 11m width operating at 8km/h at a contract rate of $575/hour;
  • direct heading, harvester: 11m width operating at 9km/h at a contract rate of $575/hour; and
  • no stoppages/breakdowns, even well laid windrows, even standing crop without lodging.

The comparison shows that harvesting windrows and direct heading have a similar cost (as a percentage of gross crop value) at 5.2 and 4.6 per cent respectively. However, the additional cost of the windrowing operation adds a further 2.4 per cent of the gross crop value. Excluding this cost may be particularly attractive for growers in lower-yielding regions, where windrowing accounts for a significant portion of the end profit.

In this example, direct heading canola costs $37.26 per hectare less than windrowing, and represents three to six per cent of the crop’s gross value for a 2.5 or 1.5t crop valued at $500/t respectively. Therefore, if yield is compromised by more than three to six per cent by factors such as timing, shattering or wind damage, then the difference in cost is negated.

In the end, the decision about whether to windrow or direct head is likely to vary each year and should focus on reducing risks and optimising yield and quality. It does not necessarily need to be one or the other. For larger growers, windrowing part of the crop and direct heading the remainder of the crop may see the strengths of both systems realised.

More information:

Maurie Street,;

Kathi Hertel,


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GRDC Project Code GOA00001, ORM00004

Region South, North