By Sjoerd Willem Duiker
Soil compaction continues to be a serious concern in agricultural production, as equipment tends to become bigger and bigger. It is also a concern for farmers who graze. When compaction has been caused, farmers want to do something to alleviate it, and their typical reaction is to think about tillage. However, soils are alive and perhaps living organisms remediate compaction without doing any tillage. We now know that tillage comes with a lot of baggage – it exposes the soil to erosion, reduces its bearing capacity, making it more sensitive to re-compaction, it weakens soil structure and disturbs the natural pore spaces in the soil, and it harms soil organisms such as earthworms and beneficial fungi.
If we can rely on natural mechanisms to alleviate compaction, that would be a lot better than using tillage. But can we rely on nature to really take care of this problem? A study in a semi-arid region in the Texas Panhandle helps us understand what the roots can do to alleviate compaction. In this study, they compacted former cropland that had been seeded 4 years prior with warm-season grasses, after which the land was left fallow. Then compaction was caused by leaving 900-lb steers in the field for 1 day after a 1.7-inch rain. There were 97 steers per acre (87,000 lbs liveweight/A), so they pounded the land pretty good, but only for one day.
Source : psu.edu