What does Compaction mean?
Compaction of the soil happens naturally, but also through foot and vehicle traffic. It slowly squeezes air pockets out of the soil, compacting it and making it tighter and harder. Over time, this results in lithification, or the creation of new stone.
Soil is dynamic. It moves in response to both environmental factors and gravity. When something heavy travels over soil, it presses down, and air is squeezed out from between soil particles. This creates heavy, thick soil with little air, and poor drainage. If compaction continues over time, it can transform previously healthy soil into unhealthy soil, and eventually into rock through a process called lithification.
Compaction affects both gardens and lawns, making it difficult or even impossible for plants to grow properly. The more compacted your soil, the harder it is for plants to send roots through the soil and take in the nutrients needed for growth. The more compacted soil becomes, the worse it drains, as well, often leading to ponding after rain.
Many factors affect compaction. For instance, over working the soil, particularly through tilling, can cause soil to become too fine and then compact quickly. Riding vehicles over the soil, such as golf carts and even riding mowers, can also add to compaction. However, compaction is also a natural process.
There are few ways to successfully deal with compacted soil. For gardens, growing a cover crop and then turning it over the next season can work, as the roots penetrate the compacted area and help to naturally break it up. Another option is to double dig the garden area and manually break up compacted soil. Note that uncompacting soil is not a fast or easy process. Prevention is always better.