When we approach new properties, we assess the whole property, buildings, people use, animals, drainage, existing plants, soils, water requirements, etc. in an effort to create a lasting and flourishing environment for you and all those that interact with this property.
The local environment usually is only successful, when starting from the ground up literally. When modern building techniques are employed big machinery is used. Things like bull dozers, cranes, loaders, trucks, etc. roll over and are parked on the soil. On top of that recycled concrete is laid down for temporary or permanent parking and ends up getting pushed all over the property. Excess building materials are piled up, and old walks and driveway materials are piled up until they can be hauled away. As these materials are loaded on big trucks they are being mixed into the soil profile, which cannot be helped, because of the size of this equipment. The equipment and trucks put tremendous pressure on often very wet soils and further compact them.
Now the standard solution to this is one of two processes. Often a new layer of screened topsoil is applied, and even if this layer is significant (4 inches or more) the construction debris in the soil profile, and the compaction underneath remain. There is also another problem with this method.the new topsoil has different chemical and structural characteristics than the soil underneath. Roots (plants) develop a relationship with the soil (microbes and nutrient) and develop a way to deal with this specific makeup. What happens when the roots meet the different compacted soil profile underneath?
The second process employed by landscape companies is to add compost or other amendment and rotor till the topsoil. Of course a rotor tiller skips across compacted soil and even if many passes are made, and optimum depth is achieved it is rarely deeper that 8 inches.
There are many far reaching impacts of compacted soils. First is that soil is meant to be a living environment, made up of many living organisms and air space so they may breathe. We always talk about planting trees to eliminate carbon dioxide, and I applaud this effort. What if these trees don't produce and live as they are meant to, do they still reduce carbon efficiently. Most of transpiration process (when Co2 is taken in and Oxygen is released) can only happen efficiently when the roots supply adequate water to the leaves. The stomata close up if they don't receive the water, and the Oxygen cannot be removed from a none existent water molecule without. This effect compounds the problem because the leaf opens stomata and releases water vapor to cool it down, the water vapor makes more clouds and rain, so then there is more drought. So this is the other part of the soil problem, available water, which is directly proportional to the air space in the soil. Air space is where water is temporarily stored or transported. The transport or movement of water downward does two things. The plant root is drawn downward in an effort to attain more water, and the other is the restoration of the water table.
Unfortunately there are many more problems caused by compaction and construction debris in the soil. First of all is the runoff of surface affluent. This includes soil particles, fertilizers, herbicides, oil, gas, and other pollutants. Even our modern farming techniques, using huge machines and trucks to grow and harvest food cause major compaction, what may be referred to as hardpan (about 12inches down in the soil profile). The aftermath of long term runoff issues is seen throughout the world. Recently researchers found a direct connection between Crown of thorns Starfish and the runoff created by mass farming in Australia. This Starfish is eating the whole Barrier Reef and we may not have it long if we don't change our ways. Many problems in the Chesapeake Bay can be directly related to runoff.
Having worked in Washington DC and the Annapolis area for 30 years we have observed the decline of plant and animal fauna over this time. Trees in DC are constantly planted on top of concrete and compaction and expected to survive. Most recently we watched them landscape the national mall (I believe a 30 million dollar) project, and most of the trees and plant are already languishing and slowly dying. This is because of compaction. I saw something about more money to sod the mall, but we can sod it all we want and it will die.
We have solutions to all this, we use big machines to destroy, we can use big machines to restore . As you can see on our website we dig up the whole soil profile and remove the concrete bricks, plastic, and other debris. Then we add a long term soil amendment to hold air space and raw leaf compost to start the microbe community up. We have done this to hundreds of properties and there is little if any runoff. This past summer of 2008 we had several 5 inch rains and checked these properties for runoff, still little to no runoff. So we hope to bring a simple but significant message to the world. Soil is important and how we manage it affects many other systems. I won't go into everything here and now, but we can help deal with floods and drought, carbon emissions, air quality and the beauty of our Earth. Life is beautiful. We here at Star Nurseries and Star Environments are willing to help, please call or write. We also want to give to the city of Washington DC and provide our service to create unique environments in public spaces for all to enjoy. Peace to you Brian Post Managing Partner