Tillage farmers should take the opportunity now to recalibrate fertiliser spreaders in preparation for the new growing season.
The reality is they may be out spreading fertiliser on the likes of winter barley crops before the end of February.
The all-important starting point of the calibration process is ensuring the proper attachment of the spreader to the tractor, according to Teagasc.
One of the first things we are looking for is the spreader being level across the back of the tractor, in other words, that it is not lying to one side or the other.
This will ensure an even spread of fertiliser across the working width of the machine.
The next task is that of ensuring the spreader is stable and that it will not sway from side to side in the field. It is also important to check that the discs of the spreader are moving freely.
Here, it’s a case of checking that the bearings are in full working order. In addition, the vanes would want to be free so that they can be easily adjusted, again depending on the type of machine.
Other settings to be looked at include the headland control. This must be functioning correctly; it can be controlled form inside the cab.
It is important to ensure that the control comes all the way down into the full flow of the fertiliser.
Inside the machine
Inside the machine, the priority is to ensure that the agitator is working properly. Its role is to ensure that an even flow of fertiliser is delivered to the discs at all times.
The reality is that different fertilisers will flow out of the spreader at different rates. And even the same fertiliser, if stored under different conditions, will flow at differing rates.
In order to take these issues into consideration, a calibration check should include the removal of one disc from the spreader. An adaptor can then be inserted.
This ensures that fertiliser coming from the machine, once the tractor is started, will flow directly into the bucket.
After a prescribed period of time, usually 30 seconds, the amount of fertiliser captured by the bucket can be weighed.
The figures generated can then be correlated with information contained on calibration apps that are available from all fertiliser spreader manufacturers.
If the results are different, then it is a case of adjusting the regulator setting on the machine.
Fertiliser spreaders in the field
Once the fertiliser spreader has been calibrated and the settings modified, it is very important to ensure a number of additional criteria are met, once the machine is in the field.
The first of these is the height of the spreader, relative to the crop; the recommended figure is 75cm.
It is also important for the tractor to be operating at the correct speed and that the appropriate spread widths are being obtained.
This may mean marking the field out with cones or using a GPS system. The set-up and calibration of fertiliser spreaders is very important to ensure even distribution of fertilisers when spreading.
Proper calibration not only maximises the benefits of fertilisation, but also minimises the risks of over- or under-application, which can lead to yield losses, environmental pollution, and increased production costs.
Regular maintenance, including cleaning, lubrication, and inspection of components, is essential to ensure proper functionality. Worn vanes, in particular, can significantly impact the spread pattern and distribution uniformity.
As vanes wear out over time, this will result in uneven spreading, resulting in areas of over- or under-fertilisation. By replacing worn vanes promptly, farmers can maintain consistent application rates and optimise fertiliser efficiency.
To mitigate the risk of over-application and to reduce environmental impact, farmers can utilise headland control mechanisms.
These systems allow operators to adjust the spread pattern when spreading at the field’s edges, preventing excess application in headland areas.
By minimising overlap and reducing wastage, headland control mechanisms not only conserve resources but also help protect nearby hedgerows and watercourses from pollution.
This proactive approach to precision farming is said to promote sustainable agricultural practices while enhancing crop productivity and environmental stewardship.