As an example from the event, a 3 by 3 axle tandem manure tanker arrangement (Figure 1) equipped with 900/65R32 tires with over 6 t/tire of weight, showed very different stresses on the soil when the tires were inflated at 10 psi compared to 40 psi (Figures 2 and 3). Obviously the 40 psi inflation pressure needed for carrying this weight on the road, is problematic in the field. Conversely, travelling on the road at 10 psi would lead to shortened tire life, probable tire failure, and difficult steering.

Figure 1. Tandem manure tanker with 900/65R32 tires with over 6 t/tire of weight, evaluated at 10 and 40 psi.

Figure 2. Soil Stress resulting from manure tanker tires inflated at 40 psi.

Figure 3. Soil Stress resulting from manure tanker tires inflated at 10 psi.
Matthias Stettler from the Bern University of Applied Science in Switzerland has a long and well respected history in soil compaction research and extension. He was the anchor behind the Compaction Action day and employing the stress sensor technology used in the demonstrations. Matthias left us with the following take home messages to consider.
- Strengthen your soil through crop rotation, permanent soil cover and reduced tillage
- Do not drive on wet soil, travel fields only when conditions are suitable
- Minimize field traffic and the proportion of field area tracked
- Know what your equipment weighs
- Distribute the equipment weight over as many tires/axles as possible
- The goal is axle weights of less than 5t/axle
- Target tire pressure to less than 15 psi
- Use high volume tires (the larger the better)
- Consider central tire inflation systems that allow pressure management to optimize road and field travel.
- Explore new tire technologies that are coming to market
While time limitations and conditions make it difficult to avoid soil compaction, the IFAO Compaction Day showed us many things we can consider in our management decisions on how to avoid and/or lesson the severity of soil compaction. We did not address mitigating soil compaction once it has occurred. That is for another day.
Additionally we are working with several partners including IFAO, OSCIA, GFO, equipment companies and OMAFRA to have the sensor technology available here in Ontario so that we can hold small and large demonstration events and research on soil compaction. To have such an event in your area or hosted by your organization please contact Ian McDonald, Crop Innovation Specialist, OMAFRA at ian.mcdonald@ontario.ca or 519.239.3473. We have a number of events already planned for this summer.