Healthy soils are the basis for healthy lawns. If your lawn is out of whack, you can almost guarantee that your turfgrass will be having problems as well.
Healthy soils have millions of beneficial organisms living in that top layer. Many of these beneficial organisms keep harmful organisms in check and that balance remains relatively constant until some well meaning individual decides to treat a sick lawn with a fungicide that may or may not treat a particular disease. However, what most likely happens is that all the beneficial organisms are killed and the soil becomes a sterile wasteland.
Read more about healthy soils
Some soils are more susceptible to compaction that others. Those soils with excess moisture or excess clay are easily compacted and if left untreated, will become increasingly unfavorable to growing grass of any kind.
Compaction happens when the small airspaces that naturally exist in any healthy soil are forced out either from excess moisture and or pressure such as walking on a wet lawn, thus preventing oxygen from reaching the beneficial organisms living in the soil. These microbes will not reproduce and eventually die off leaving the compacted soil almost barren of these micro-organisms.
It is the micro-organisms in the soil that convert organic matter which is rich in carbon, into a soluble solution that can be used by the turfgrass plant. In fact, the micro-organisms are responsible for almost all of the basic elements being transformed into a liquid solution that can be absorbed through the plant's roots.
Compaction makes it very difficult for root growth and top growth of grass.
Correcting compaction is a vital step in developing a healthy soil that crowds out weeds, reduces diseases, and is better able to withstand drought conditions.
Compaction is improved through several important steps:
Adding Organic Matter
Soil Aeration Treatment
Top dressing your lawn is really a big jump start to improving your soil. The thin layer of what professional lawn care providers call a top-dressing, which is actually finely processed compost, adds a lot of natural organic matter into the top layer of soil. In time, and with repeated applications over a several year period, this layer will develop into several inches of good friable loam that will provide ideal growing conditions for your lawn.
Thatch is a layer of living and dead organic matter that occurs between the green matter and the soil surface.
Thatch is a build up of dead roots, lawn debris and dead turfgrass crowns. It accumulates as these plant parts buildup faster than they breakdown.
What doesn't add to thatch is lawn clippings. Lawn clippings are made up of about 90% water.
As thatch levels accumulate to greater than 1/2", lawn problems may begin, and the thatch needs to be controlled.
More about thatch buildup...