How tillage systems affect compaction and ability of soil to handle traffic
Soil management has an effect on soil compaction and the ability of soil to handle traffic. Recent research from western Kansas/eastern Colorado/western Nebraska shows us that no-till soils are less susceptible to compaction than conventional- or reduced-till soils.
This is partially because increases in soil organic matter (SOM) increase soil aggregation and improve soil structure. Increases in SOM also lead to improvements in compactability because SOM is elastic and absorbs water.
This is shown in the figure below, which is taken from an article by Humberto Blanco, former K-State Agriculture Research Center-Hays soils agronomist, and others, in a Soil Science Society of America Journal (SSSAJ) article from 2009. At each of the site locations, the no-till treatment had the lowest bulk density, as shown by the lowest line on each of the graphs. Also, at all locations, the line for the no-till treatment is shifted to the right. This means that at equal compactive forces, the plowed soils became compacted at lower water contents, and that it took higher water contents to compact the no-till soil.
Practically speaking, this means that tilled soils are more easily compacted, and that plowed soils become compacted at lower water contents than no-till soils. No-till soils can be trafficked at relatively higher water contents and are less susceptible to compaction than tilled soils at the same water content.
DeAnn Presley, Soil Management Specialist