Stephen Lamb, the Sales Manager at Bridgestone, a UK manufacturer of agricultural tyres, discusses tyre usage when looking to reduce soil compaction and increase yields with drilling.
IT’S well worth looking at the use of dual tyres to enable you to drill lightly over the land, where compaction and yield are the key focus and not for any stability or consolidation requirements.
It’s an interesting consideration, and one that would not necessarily have been asked before the advent of IF and VF technologies .
Let’s start with your current dual drilling set-up and look at the following areas:
• Operating Pressure
Once we have these benchmarks, we can potentially look at other solution improvements to the reduction in compaction and an increase in yields from the current dual fitment set-up, compared to that of a single fitment set-up.
As an example of this, consider the following example, where the current set-up has 4qty 650/65 R42 with a 4m trailed drill and an axle load of 6,000kg (single fitment – transport / raised).
If we were to offer, say, 2qty VF650/65 R42 as one alternative, could two tyres be better than four?
Operating Pressures: Total Tyre Width in Inches: Load Applied to the Soil:
So, with both set-ups operating at the lowest pressure setting possible, the singles win here.
However, if there was a greater pressure differential between the two setups and/or the duals had smaller widths of tyres, then duals could well be more beneficial. For example:
Working Width of Implement – 4m Tyre to Field Percentage Contact = Duals = 65%, Singles – 32.5%
So here the duals have a much greater contact with the field, and therefore a greater area of topsoil compaction will be developed than the singles, as both operate at the same pressure.
When it comes to yield loss , independent studies have shown that by having an operating pressure of around 9psi, a yield reduction of around 10% could be encountered within the wheelings. So, if we were to take a field size of 10ha with a yield potential in (un-Trafficked area) of 10t per ha, the following would be the Yield result:
Duals (35% Un-Trafficked – 65% Trafficked )
3.5ha x 10t = 35t + 6.5ha x 9t = 58.5t Total Yield = 93.5t
Singles 67.5% Un-Trafficked – 32.5% Trafficked )
6.75ha x 10t = 67.5t + 3.25ha x 9t = 29.25t Total Yield – 96.75t
As a result of the singles having a lower field contact percentage, the reduction in yields from the wheelings is lower, therefore offering a 3.25t yield improvement.
In this one example, where singles benefit from less load applied to the soil owing to less contact with the soil, there is less reduction of yield loss via the wheelings, along with the additional benefits of not having to fit and remove, nor requiring any road transport width considerations as with duals.
While this is one exercise where singles do benefit, you would need to conduct your own individual exercise to see if an alternative tyre solution specification and/or size could help or hinder your current dual set-up.
Indeed, where you have a significant differential of operating pressures and/or the total tyre width between duals and singles, then one could well outperform the other when compaction and yields are your priority.
It’s about getting the balance right between those elements so it’s a worthy exercise to conduct in order to maximise the performance of your current set-ups.
