Arborist Course Chapter 3 Soil Science

Front 1

The majority of the fine, absorbing roots, of a tree are in the ___ and ___ horizons.

Back 1

O and A

Front 2

Driving vehicles across wet soil will __________ the soil and destroy soil ___________

Back 2

Compact

Pore space

Front 3

__________ ____________ is the soil property that resists changes to the ph

Back 3

Buffering capacity

Front 4

True/False - Negatively charged clay particles hold cations near their surface.

Back 4

True

Front 5

In 1 foot (0.3m) of clay soil with 4 inches (10cm) of water in the soil, approximately how many inches of water would be available to the tree?

Back 5

One

Front 6

_________ ____________ modified the effects of soil texture as the soil particles form clumps or aggregates.

Back 6

Soil structure

Front 7

True/False - Soil can hold water so tightly in micropores that the ability of tree roots to absorb the water is restricted.

Back 7

True

Front 8

Soil texture refers to the relative coarseness or fineness of a soil. Rank the following from the finest texture (1) to the coarser (3).

________ silt ________clay ________sand

Back 8

2 (silt), 1 (clay), 3 (sand)

Front 9

On the pH scale, less than 7 is __________, 7 is ____________ and more than 7 is ______________

Back 9

Acidic, neutral, alkaline

Front 10

True/ False - Over time, mulching can improve soil structure, reduce compaction and add organic matter to soil.

Back 10

True

Front 11

A pH of 5 is ________ times more acidic than a pH of 7.

Back 11

100

Front 12

The process in which ions of essential elements wash down through the soil profile and are lost is called.

Back 12

Leaching

Front 13

Many essential elements are dissolved in soil water in the form of positively charged particles called

Back 13

Cations

Front 14

If the soil is too ____________, iron and manganese may be in a chemical form that is unavailable to trees

Back 14

Alkaline

Front 15

The buffering capacity is the resistance of a soil to changes in pH. Clay soils and soils high in organic matter usually have a __________ buffering capacity.

Back 15

High

Front 16

The _________________ is the zone of intense biological activity near the actively elongating roots.

Back 16

Rhizosphere

Front 17

The diversity of organisms living, moving, and interacting in the soil is often referred to as the ____________ _____________ ___________

Back 17

Soil food web

Front 18

Water that drains from the macropores is called _________________ water. Following drainage, the soil is said to be at _____________ _______________

Back 18

Gravitational, field capacity

Front 19

True/ False - Most soil organisms cause disease or decay in tree roots.

Back 19

False

Front 20

True/ False - Many tree roots exist in symbiotic relationship with fungi that assist the tree in water and mineral absorption.

Back 20

True