Certified Arborist Practice Exam

What is a common issue associated with deep root fertilization?

1. Dissolved in water

2. Injected below the absorbing roots

3. Wilting, marginal burning, dieback

4. Fertilizer salts causing symptoms

The correct answer is: Wilting, marginal burning, dieback

Deep root fertilization is a technique used to provide nutrients to trees by injecting fertilizers into the soil at depths below the surface. One common issue associated with this method is the potential for wilting, marginal burning, and dieback of the tree's leaves. These symptoms arise when excess nitrogen or other fertilizer salts accumulate in the tree's root zone. Over-fertilization may lead to a sudden influx of nutrients, particularly nitrogen, which can overwhelm the tree and result in damage to the roots or foliage. When fertilizer salts are too concentrated, they can draw moisture out of the surrounding soil and plant tissues, leading to wilting. Marginal burning is a sign of leaf scorch, where leaf edges turn brown and dry due to stress from either excess salts or water loss. This can compromise the tree's health if left unaddressed. Understanding these potential symptoms is crucial for arborists and those involved in tree care. Being aware of the risks associated with deep root fertilization helps in implementing best practices to avoid nutrient overload and to successfully support the tree's growth without causing harm.