A Technical Report from The Bartlett Tree Research Laboratories 220
It is now widely appreciated that trees require certain essential nutrients to function and grow. A nutrient is an element that is involved in the metabolism of a tree, or necessary for a tree to complete its life cycle. For trees growing on a forest site, these nutrients are normally present in sufficient quantities in the soil. Landscape trees or urban trees, however, may be growing in soils that do not contain sufficient available nutrients for satisfactory growth and development.