However, in any case a stable and optimal soil structure for plant growth as well as for water infiltration and erosion control is only achieved by living biological processes in the edaphon like for example the creation of humus. When to Till the Soil Under the above concept the best form of mechanised soil tillage is not to do any. However, the concepts of zero-tillage are not applicable in all cases. Agriculture is always an artificial intervention in natural processes and therefore it has to be accepted that, from case to case, corrective interventions have to be done. Even under zero tillage concepts, some sort of tillage is done through traffic for planting, pest control and harvest.
Traffic causes compaction and is as such one form of tillage.
Each time a problem occurs that might call for a tillage intervention the problem should be carefully analysed to find out a way to control it with a minimum intervention in the soil. The knowledge of these characteristics and the availability of adequate equipment allow to limit the intervention to the minimum necessary. Some of the operations of the second category cannot be avoided. But the majority of the basic operations of the first group are not essential for agriculture. This accounts particularly for the turning operation which represents the most drastic intervention in the soil.