Which of the following is a function of the root substrate?

1.   ?    provide physical support
2.   ?    retain water for uptake by the plant
3.   ?    provide for gas exchange between the atmosphere and the roots
4.   ?    serve as a nutrient reservoir
5.   ?    all of the above

The term "shrinkage" is used to describe the volume of the substrate lost from the container over time. What root substrate property would have the greatest influence on "shrinkage" of the substrate?

1.   ?    rate of decomposition
2.   ?    bulk density
3.   ?    total pore space
4.   ?    air-filled pore space
5.   ?    none of the above

Using organic matter that has a high C:N ratio (higher than 25:1) as a major component of a root substrate has the potential to result in a depletion or "tie-up" of which important mineral element?

1.   ?    carbon
2.   ?    nitrogen
3.   ?    potassium
4.   ?    calcium
5.   ?    iron

What is the root substrate property that is generally defined as the dry weight of a specified volume?

1.   ?    air-filled pore space
2.   ?    water-filled pore space
3.   ?    decomposition rate
4.   ?    bulk density
5.   ?    cation-exchange-capacity

In addition to the pore size distribution of a root substrate, which other factor affects the air-filled and water-filled pore space?

1.   ?    compaction
2.   ?    container size
3.   ?    particle size of components
4.   ?    all of the above
5.   ?    none of the above

What is the property of a root substrate that refers to the ability of the substrate to attract and retain cations?

1.   ?    bulk density
2.   ?    cation-exchange-capacity
3.   ?    water-holding capacity
4.   ?    electrical conductivity
5.   ?    none of the above

What is a root substrate property that is a measure of the total ions present in the substrate solution?

1.   ?    bulk density
2.   ?    cation-exchange-capacity
3.   ?    water-holding capacity
4.   ?    electrical conductivity
5.   ?    none of the above

Electrical conductivity may be reported as either mmho/cm or mS/cm. How many mmho/cm are equivalent to 2 mS/cm?

1.   ?    1
2.   ?    2
3.   ?    3
4.   ?    4
5.   ?    5

Which is a common difference between a Sphagnum and Hypnum peat?

1.   ?    Hypnum has a finer texture
2.   ?    Hypnum is composed primarily of Hypnum moss
3.   ?    Hypnum in darker in color
4.   ?    Hypnum typically has a higher pH
5.   ?    all of the above

Which is a common difference between a Sphagnum peat and reed-sedge peat?

1.   ?    reed-sedge is usually more decomposed than Sphagnum peat
2.   ?    Sphagnum peat has a much finer texture than reed-sedge peat
3.   ?    reed-sedge peat has a higher water-holding capacity than Sphagnum peat
4.   ?    all of the above
5.   ?    none of the above

What beneficial changes occur to soft wood bark when it is properly composted?

1.   ?    particle size is reduce
2.   ?    C:N ratio is reduced
3.   ?    cation-exchange capacity is increased
4.   ?    microbial populations increase
5.   ?    all of the above

From what is coir made?

1.   ?    mica-like mineral
2.   ?    coconut husk
3.   ?    siliceous volcanic rock
4.   ?    basalt, coke and limestone
5.   ?    none of the above

From what is vermiculite made?

1.   ?    mica-like mineral
2.   ?    coconut husk
3.   ?    siliceous volcanic rock
4.   ?    basalt, coke and limestone
5.   ?    none of the above

From what is perlite made?

1.   ?    mica-like mineral
2.   ?    coconut husk
3.   ?    siliceous volcanic rock
4.   ?    basalt, coke and limestone
5.   ?    none of the above

When comparing coir and Sphagnum peat, which is a true statement?

1.   ?    coir generally has a lower cation-exchange capacity than Sphagnum peat
2.   ?    coir generally has a higher pH than Sphagnum peat
3.   ?    coir usually has a higher chloride level than Sphagnum peat
4.   ?    all of the above
5.   ?    none of the above

For what purpose is ground limestone is typically added to a Sphagnum-peat-based root substrate?

1.   ?    to increased pH
2.   ?    to reduce pH
3.   ?    to reduce electrical conductivity
4.   ?    to provide a nutrient charge
5.   ?    none of the above

In addition to providing calcium, dolomitic limestone also provides which important mineral element?

1.   ?    iron
2.   ?    copper
3.   ?    magnesium
4.   ?    silica
5.   ?    none of the above

Superphosphate may be added to a root substrate to provide which important mineral element?

1.   ?    nitrogen
2.   ?    phosphorus
3.   ?    lead
4.   ?    mercury
5.   ?    potassium

Which is an important mineral element provide by superphosphate but not by triple superphosphate?

1.   ?    sulfur
2.   ?    phosphorus
3.   ?    copper
4.   ?    iron
5.   ?    lead

What is the common name of a material that may be added to Sphagnum peat to break the surface tension and improve the wettability of the peat?

1.   ?    microelement
2.   ?    macroelement
3.   ?    aluminum sulfate
4.   ?    surfactant
5.   ?    none of the above