ISA Soil and Water Management Questions and Answers

Question 1

An arborist inspects a mature street tree in a heavily used urban plaza.
The soil is hard-packed, and the tree exhibits stunted growth, sparse foliage, and some branch dieback.
These symptoms are most likely the primary result of which soil condition?

Accepted Answer

Reduced pore space limiting oxygen and water availability

Answer

High soil salinity from de-icing salts

Answer

A chronic nutrient deficiency

Answer

Competition from surrounding turfgrass

Question 2

Which of the following statements best distinguishes between soil texture and soil structure?

Accepted Answer

Texture refers to the proportion of sand, silt, and clay, while structure describes how these particles are arranged into aggregates.

Answer

Texture is the percentage of organic matter, while structure is the soil's pH level.

Answer

Texture can be easily modified with amendments, whereas structure is a permanent, unchangeable property.

Answer

Texture governs nutrient availability, while structure primarily affects soil temperature.

Question 3

A homeowner wants to ensure the survival of a newly planted tree during its first dry summer. What is the most effective irrigation practice an arborist should recommend?

Accepted Answer

Apply water deeply and infrequently, thoroughly soaking the root ball and surrounding soil.

Answer

Lightly sprinkle the leaves and soil surface daily to cool the tree.

Answer

Water frequently with small amounts directly at the base of the trunk.

Answer

Mix a water-soluble fertilizer with every irrigation to force rapid growth.

Question 4

The amount of water held in the soil after the excess has drained away due to gravity, which is considered the ideal state for plant water uptake, is known as:

Accepted Answer

Field capacity

Answer

Saturation

Answer

Permanent wilting point

Answer

Hygroscopic water

Question 5

A client's property has a low-lying area with heavy clay soil where a maple tree is failing to thrive, showing yellowed leaves and poor growth. The ground remains saturated for several days after rainfall. Which action would provide the most effective long-term solution?

Accepted Answer

Install a French drain or grade the area to redirect surface water away from the tree.

Answer

Prune the tree's crown to reduce its water needs.

Answer

Apply a thick layer of sand over the soil surface.

Answer

Fertilize heavily to compensate for poor nutrient uptake.

Question 6

An arborist is preparing a tree care plan for a municipal park. To improve water retention in the soil and reduce temperature fluctuations in the root zone, which of the following practices is most recommended?

Accepted Answer

Applying a 2- to 4-inch layer of organic mulch over the root zone.

Answer

Installing a perimeter of landscape fabric around the trees.

Answer

Regularly aerating the soil with a deep-tine aerator.

Answer

Applying a pre-emergent herbicide to control all weeds.

An arborist inspects a mature street tree in a heavily used urban plaza.The soil is hard-packed, and the tree exhibits stunted growth, sparse foliage, and some branch dieback.These symptoms are most likely the primary result of which soil condition?

An arborist inspects a mature street tree in a heavily used urban plaza.
The soil is hard-packed, and the tree exhibits stunted growth, sparse foliage, and some branch dieback.
These symptoms are most likely the primary result of which soil condition?