- Soil water content
- Treading pressure
- Soil type and initial structure
- Practices to limit treading damage
Factors affecting severity of compaction
A number of factors influence the degree of soil compaction caused by animal treading.
Soil water content
Soil water content is the most important factor affecting the severity of compaction. As noted above, under very wet conditions puddling occurs and this causes serious damage to the soil close to the surface as well as the pasture plants themselves. At or near field capacity, where the soil is plastic, soil compaction often occurs. Whilst this damage is not always visible at the surface, it can occur to considerable depth (greater than 10 cm). Removal of stock from pasture during and shortly after heavy rainfall can, therefore, significantly reduce treading damage.
Treading pressure
Because of their weight, cattle impose a greater treading pressure on the soil surface than sheep. The pressures calculated to be imposed by sheep are around 100 kPa compared to 200-400 kPa for cattle. As a result, the pressures imposed by cattle hooves can be significantly more damaging to soil structure than those associated with sheep. Increasing the grazing density with either animal will increase the degree of compaction and soil disturbance suffered.
Soil type and initial structure
Different soil types can tolerate different intensities of treading before becoming damaged. Some differences are due to differences in drainage characteristics. Those that are well-drained, drain more rapidly after rain and are, therefore, susceptible to severe compaction for much shorter periods. Weakly structured soils with low strength are most susceptible to compaction. Newly cultivated paddocks and those recently resown or aerated generally have low strength and should not be heavily stocked when wet.
On grazed hill country, treading and the resulting disturbance of surface soil can result in increased losses of soil and nutrients through erosion and run-off. Erosion losses generally increase with increasing grazing intensity and are greater under cattle than sheep.
Practices to limit treading damage
Since treading damage occurs when the soil is very wet, avoidance of damage involves removing stock from paddocks at such times and providing adequate drainage to susceptible paddocks.
- Removal of stock from pasture during and shortly after the heaviest rain will reduce damage considerably.
- Farm areas such as large laneways, loafing pads, sacrifice paddocks or paddocks of crop that will later be loosened by cultivation, therefore, need to be readily available for holding cattle while the soil is susceptible to damage.
- In susceptible paddocks, it is important that drainage systems are installed and operated efficiently so that they remain wet for the shortest possible time following heavy rain.
Contact for Enquiries
MAF Information Services
Pastoral House
25 The Terrace
PO Box 2526
Wellington, NEW ZEALAND
Fax: +64 4 894 0721
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