Soil in the urban environment is subject to many factors that limit its ability to provide the proper nutrients, moisture and structure necessary for healthy trees to survive in the landscape. Compaction, lack of organic material, insufficient pore space and other critical problems conspire to make a harsh environment for root systems. During construction, top soil is scraped away, natural grades are changed, and the soil environment is radically altered. Additionally, grass, which is in fierce competition for available water, tends to absorb most of the moisture before it has a chance to reach the trees’ root system.
Adding chemical fertilizers is often a “shot in the arm” and does little to nothing towards the effort of rebuilding depleted soil structure. Chemical fertilizers can also cause nutrient imbalances within the tree, causing more problems than they solve. Another issue with fertilizers is that they often increase the salt content within the soil and that can actually draw moisture away from absorbing roots.
Yet, a healthy tree requires a properly functioning root system, which, in turn, must be located within a healthy soil ecosystem. This living ecosystem requires many key elements coming together, often in symbiotic relationships. A primary ingredient is organic matter, which breaks down over time to provide many nutrients that are needed by the tree. Organic matter provides a habitat for the required microorganisms, worms, and other living organisms. It is also necessary for there to be plenty of open pore space within soil for the storage of oxygen and water.
How do you enhance the soil surrounding your tree’s root system? Fortunately, there are new tools and procedures that allow arborists to do just that. The AIR-SPADE®, as shown in the picture, actually removes soil from the root systems without damaging the roots. Originally developed to safely uncover land minds, the AIR-SPADE® has been proven in numerous university studies to safely blow soil from roots with a supersonic blast of air, without damaging the roots.