Not all land is as easy to farm as large agricultural plains. A lot of sloping land could easily be used for production purposes if you know how to adapt your agricultural machinery for work on a steep incline. To avoid the increased risk of your tractor overturning or excess wear to mechanical parts, it is absolutely necessary to prepare properly and adapt your equipment.
A tractor that is equipped for the plain cannot cope with any type of slope and tilling on sloping land requires major precautions to avoid the campaign turning into a catastrophe.
Loss of adherence is principally linked to the load transfer to the tyres which are lower down. When the tractor is facing down the slope the total weight of the trailer is transferred to the front axle and inversely when the tractor is driving up the hill, the front axle is totally weightless, which can lead to difficulty with steering.
This type of land requires greater precision in your machine’s settings, choice of tyres, calculation of loads, precise adjustment of inflation pressure and above all total respect of the speed corresponding to the load.
The steeper the slope, the greater the load transfer to the downhill part of the machine. Considerable strain will be placed on your tyres if you haven’t factored in the right load, or adapted inflation pressure sufficiently. The tyre may come off the rim when the load transfer is beyond than the tyre’s acceptance capacity and block operations for some time, because repairs in a sloping field may be longer and more complex.
The wider the tyre, the easier it is to work on steep slopes, a tyre with a higher volume of air effectively having a much bigger load capacity. Increasing tyre size allows you to follow the slope more safely and avoid unnecessary manœuvres which, in the end, will save time and money on fuel with this type of land.
The choice of tyre should therefore tend towards wider tyres with solid sidewalls which will provide maximum stability. Series 70 or 65 VX-Tractor tyres have all the advantages of an extremely resistant casing structure associated with solid sidewalls that will resist the frequent deflections linked to the position of the machine on the slope and the lateral load transfer.
Ground-engaging implements make it possible to increase the contact patch with the soil and therefore compensate for the load transfer to the tyres. While this is an advantage while tilling, it can become a disadvantage at the end of the line, when it’s time to change direction. You have to make sure that the trailer is flat when you lift up the tools because when the implement is raised, the centre of gravity moves upwards and this may destabilise your machine which appeared to be stable during tilling.
Wine growing is a typical hillside activity and working on sloping land is more frequent than for other types of crop. Using a straddling frame to work on slopes with an incline of up to 45% is not uncommon and requires adapting your tyres.
The steeper the slope the wiser it is to increase the width of your vineyard tyres. The higher volume of air makes it possible to compensate for load transfers which may be considerable.
If you use duals on the rear axle, the tractor becomes wider and the centre of gravity is lowered, the load transfer takes place towards a surface that is double the size and so all problems of stability during turns, even on a steep slope, disappear.
If you have numerous sloping fields, duals are the ideal solution, because you will handle the steepest slopes without difficulty. The traction capacity of your trailer will win you time and lead to fuel savings by reducing slippage and, the icing on the cake, the load is distributed over a larger surface area so your soil will be better protected against compaction.
The harvest is a tricky moment on sloping land because a combine harvester is a heavy machine with a higher centre of gravity and less stability than a tractor.
An empty combine harvester with no tooling is balanced with around 10,000 kilos per axle. But be careful, when it is equipped with its cutting bar, the load transfer to the front axle is extremely high and the load distribution is no longer the same as you have 23% of the weight on the rear axle and 77% of the weight on the front axle, i.e. around 19,000 kilos when empty.
When the hopper fills up, the load increases by 8,000 to 12,000 kilos depending on the capacity of the container, which means around 28,000 kilos on the front axle.
When you work in a sloping field you have to take into account the grade of the incline in your load calculation and apply an additional percentage of load to the lower tyres, which will be compensated by a higher inflation pressure.
Recent combine harvesters are equipped with a levelling system which enables the two tyres on the same axle to work at different levels. This means that you can work on steep slopes with the machine operating the same as on flat land.
This type of mechanism guarantees a harvest without any problems linked to the load transfer due to the sloping land because it minimises the lateral forces applied to the lower of the tyres.
Harvester tyres are designed for cyclic operations, which is to say with a variable load since the hopper will be filled and emptied regularly throughout the harvesting campaign, adding between 8,000 and 12,000 kilos each time.
The latest generation harvesting tyres allow you to obtain a much better bonus load while working at a faster speed than standard harvesting tyres and with an inflation pressure that can stay at 2.4 bar.
For work in tricky areas, these tyres are particularly adapted, because even if you cannot make use of the maximum bonus load due to the slope, their robust, resistant design guarantees quality work without compacting your soil and without worrying about incidents with the tyres on a slope which could bring your campaign to a standstill if the slightest problem arises.
The Bridgestone-agriculture.eu blog is written and administered by tractor tyre experts who are available to provide you with the advice you need on the subject of your agricultural tyres. They allow you to maximise your productivity with information on all subjects linked to tyres: Cheap tractor tyres — Technical data for agricultural tyres — Air pressure advice — Solutions to avoid soil compaction — Sprayer tyre pressure — Why and how to ballast your tractor tyres — When to use dual wheels — The mechanical causes of abnormal wear — Cheap agricultural tyres – etc…
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