Soil Compaction: Facts and Figures

It is partic­u­larly hard to assess the damage caused by compaction in deeper soil layers. But research data and statis­tics indi­cate a consid­er­able impact on agri­cul­tural produc­tivity.

LONG-TERM LOSS OF YIELD OF COMPACTED AREAS COMPARED WITH NON-COMPACTED REFERENCE AREAS

In Reck­en­holz, Switzer­land, a study by the Swiss Agro­scope Insti­tute and ETH Zurich is inves­ti­gating the long-term effect of soil compaction on produc­tivity. In 2014, trial areas were compacted under wet soil condi­tions with a machine weight of 32 t and high tyre pres­sure in order to be able to measure yield changes in the course of crop rota­tion. In addi­tion, the oxygen and CO2 content, water and gas exchanges and biolog­ical activity in the soil were inves­ti­gated in subse­quent years. The results show that the soil has not recov­ered several years after compaction. Losses in yield remain consis­tent. This is due on the one hand to subsoil compaction, which can hardly be influ­enced by machines, and on the other hand to the topsoil, which has not regen­er­ated in four years despite repeated ploughing.

 

 

FACTORS INFLUENCING COMPACTION


 
Axle load


 
Number of
passes on the field


 
Soil mois­ture


 
Soil pres­sure in
contact area


 
Number and
type of tyres


 
Soil type
and struc­ture

 

 

COMPACTION IN DEEPER SOIL LAYERS IS HARD TO MANAGE

Using wider tyres, total load can be almost doubled without increasing soil pres­sure on the surface. However, the pres­sure reaches much further down.

 

Total weight of machinery

300 t

Total weight of machinery used in a biogas crop rota­tion over three years.

 

 

SOIL DEGRADATION FROM COMPACTION (MILLION HA)

33Europe10Asia4Australia18Africa3Amer­icas

 

 

Compaction risk of Euro­pean soils

36 %

Percentage of Euro­pean soils with
high or very high compaction risk.

Sources: FAO, Inra, Europäische Umwelt­a­gentur, Thomas Keller / Agro­scope, Terranimo, Northern Illi­nois Univer­sity, Biogas Forum Bayern