Soil Aeration

INTRODUCTION TO SOIL AERATION

Trees grown in Toronto and GTA are often subjected to different environmental stresses. They can get stressed from water deficit, extremely high and low temperatures, mineral deficiency in soil (click for more info on deep root feeding), air pollution, or poor root aeration. Trees under mild stress may have early fall color and leaf drop, and trees exposed to more extreme levels of stress can show progressive canopy thinning and limb die back. Basically, trees under stress is a serious issue and, if it is not dealt with promptly, can result in major damages up to the death of the tree.

WHAT IS SOIL COMPACTION AND WHY IS IT IMPORTANT?

Soil compaction, which is the reason for poor root aeration, is the form of stress that is particularly important for the health and well-being of city trees. Roots require a continual supply of oxygen which feeds the roots of the tree and myriads of tiny organisms that play a major role in the tree’s ability to absorb soil borne nutrients. In nature, the roots of the trees would be covered with a layer of topsoil that is composed of fallen leaves. This layer through constant decay will provide a light mulch over the root zones. In urban landscapes, this leaf layer is usually removed every fall and after many seasons of watering, the soil layer becomes highly compacted. When soil is compacted, soil aeration and permeability are decreased, and it becomes more difficult for roots to penetrate the soil.

NEGATIVE EFFECTS OF SOIL COMPACTION:

• Pore space destruction
• Less air in the soil
• Less water in the soil
• Increased Soil Strength