Independent trial shows lower soil compaction for Michelin Ultraflex tyre

A trial conducted by an independent soil scientist has shown the benefits of Michelin’s Ultraflex technology in its CerexBib combine harvester tyre in terms of reducing soil compaction – a significant factor in plant root growth and yield potential. Philip J Wright of Wright Resolutions used a Claas Lexion APS Hybrid Combine at the manufacturer’s headquarters in Saxham to test the CerexBib against conventional agricultural tyres commonly fitted to combine harvesters, such as Michelin’s MegaXbib and MachXbib with standard fitments from two other tyre manufacturers.

The recorded data found a significant difference in the mean level of soil compaction between the Ultraflex technology and conventional technology tyres. The CerexBib fitments created a significantly lower level of compaction (a mean of 1099kPa) compared to the other tyres. Michelin’s MegaXbib (front) and MachXbib (rear) fitments recorded a mean compaction of 1425kPa, while the other brands averaged 1506kPa and 1603kPa respectively.

Commenting on the results, Philip Wright explains: “Overall, it is clear that for depths to 25cm, the compacting effect of the Ultraflex technology tyres is significantly lower than the conventional tyres which all give broadly similar effects. Plant root growth, and yield potential, will therefore be less adversely affected by using CerexBib tyres than the other conventional technology fitments.”

Testing methodology

For testing the Claas combine made two runs through the field for each tyre configuration, with soil compaction measured using a penetrometer at positions chosen randomly along the path of the tyres. Both front and rear tyres were taken into account and all measurements were compared to the areas of the field between the wheels.

Prior to the trial the ground had been loosened by running a subsoiler in two directions at right-angles across the field.  Surface re-consolidation had taken place via a roller attached to the subsoiler, to leave a reasonably consistent profile to the loosened depth of between 325 – 350mm. The soil type was a sandy loam, at low moisture (approximately 13.5 per cent DB at mid-profile) content.

All readings for soil resistance were taken over a six hour period of fine weather, so eliminating any soil moisture variations.  Soil resistance (pressure, in MPa) was measured by a Spectrum Technologies digital cone penetrometer which enabled all data to be logged relative to the depth of measurement in each case.

Throughout the trial tyre inflation pressures were set according to each manufacturer’s recommendations for the relevant axle loadings, which included road mode without header, plus in the field fully laden with header attached.

Related news:

• Michelin launches row-crop sprayer tyre at Cereals 2011
• Michelin presenting Ultraflex tyres at SIMA 2011
• Michelin CerexBib Designed for Heavy Loads from Modern Harvesters