Minimize driving over the soil as a compacted soil remedy to support healthy soil structure by allowing the soil to breathe, drink, and move nutrients around.
Healthy soils are much more than dirt! In fact, some might argue they’re some of the largest living organisms that serve to help make this planet habitable. The structural, chemical, and biological diversity in healthy soil is mind-blowing, in spite of the affronts we’ve thrown at soil over the years. Rather than thinking of soil as some inanimate growth medium, consider it a complex ecosystem instead.
Not Just Dirt!
Soil structure is key to maintaining its productivity but also key to the ways water, gases, organic nutrients, and minerals move through the greater ecosystem of Earth. Essentially, soils consist of variously sized particles made with silt, sand, clay, and organic matter, bound together to form aggregates in a somewhat consistent way. The aggregates are stabilized by a glue of sorts that’s created by the living organisms residing in that soil. The aggregates are porous and collectively form channels and pockets that allow fluids and gases, as well as invertebrates and microbes, to grow and move around. The spaces in the soil structure allow the soil to breathe, drink, and move nutrients around, and truly support terrestrial life in significant ways.
In a soil with a healthy structure, rainwater is readily absorbed, the oxygen needs of the plants, microbes, and animals living in that soil can be met, and the carbon dioxide they produce can make it back into the atmosphere. Further, when a healthy soil is relatively dry, its structure is usually more stable and weight-bearing. When it’s wet, it becomes more plastic. When plastic soil encounters mechanical force, it moves. If that mechanical force is on the surface, the soil can be squashed to the extent that the aggregate structure is more or less destroyed in a process known as “compaction.” Compaction reduces the pore size, water-holding capacity, gas movement, nutrient-movement capacity, and it reduces the soil’s ability to support life.
Control Compaction
Whether considering your crop ground, perennial pastures and meadows, or even woodlands, traversing land when wet can lead to significant degradation of the soil’s physical structure. Structural degradation of the soil then leads to a cascade of negative effects, including loss of water-absorbing capacity, destruction of microbiota, lost gas-exchange capacity, and, in the case of perennial matrices, damage to the plant roots themselves. While walking that wet ground won’t cause significant damage, driving any type of machinery on it will most definitely cause damage – some of it long-term.
On the farm or ranch, two of the most significant forms of compaction are from animals and machinery. If you pick up a handful of soil and create a ball with it and throw it, if that ball stays intact until it hits the ground, your soil is far too wet to drive on. If you can squeeze it and create a ribbon more than an inch long, it’s too wet! If you absolutely must traverse that land, plan ahead and build a road or create a grassy strip with a sod-forming and forgiving grass species, such as tall fescue. But even then, your best bet will be to wait for the field to dry.
In your perennial pastures and hay meadows, you might identify routes to get from one place to another and accept that you’ll damage the matrix beneath the tire tracks. Ideally, plan these paths away from low, damp areas or other fragile areas, such as a thinly vegetated, sandy hill prone to erosion. If you were to take a different route through these areas every time, you’d do more damage over a wider area, even if you avoided creating muddy ruts on a more well-used pathway. It’s much easier to maintain ruts than to mitigate widespread moderate compaction on pastures and hay meadows. If you drive on perennial matrices and leave any indentation or raise muddy water, it’s too wet to be out there unless absolutely necessary.
When running livestock on pastures, it’s not always possible to avoid compaction, but there are some things you can do to minimize the damage from hooves. Reduce your stocking rate by giving the animals more space. Or, move the herds to more stable, higher, drier ground if a significant rain event is in the forecast. Many folks have designated sacrifice paddocks where they bring animals when soil conditions are too wet. You’ll damage the matrix in those areas, but if you feed hay in them and move the feeder around, you can later plant some compaction-fighting cover crops and work toward partial restoration of that damaged soil.
Compacted Soil Remedy
Entire books have been written on how to mitigate and restore compaction-damaged soils. You can use your tractor and blade to smooth out ruts formed in your permanent two-track lanes so they’ll continue to be usable, and so you’ll avoid the temptation to make new lanes adjacent to the old ones. You can also rip-till for short-term relief, but, in the end, a more complex and integrated approach is needed.
On significantly compacted land, a carefully designed progression of crops is the best long-term solution. Those rotations will likely include brassicas, such as deep-rooted, so-called “tillage” radishes and turnips. Inclusion of cereal crops will create plenty of biomass to feed organisms living both above and belowground and deliver a healthy dose of root exudates that’ll stimulate the microbial world beneath the surface, aid in the cycling and movement of nutrients, and promote aggregation.
It’ll take years to reduce compaction to pre-human levels, but in relatively short order, you can repair that sacrifice paddock or that low area where the tractor and combine got stuck. In time, those damaged soils will heal sufficiently to become truly productive once again.
Hank Will raises hair sheep, heritage cattle, and many varieties of open-pollinated corn on his rural farm in Osage County, Kansas. His home and ranch life perfectly complement his role as a longtime local expert for Grit and Mother Earth News.
