True or False

Question 1

Mineralization increases the inorganic nutrients in the soil

Answer 1

True

Question 2

Actinomycetes dominate acidic cold dry soils

Answer 2

F

Question 3

Sodic Soils have good structure

Answer 3

f

Question 4

Fe and Mn are commonly deficient in very acidic soil

Answer 4

False (very available in acidic soils)

Question 5

Soil Acidifications increased by fertilizers

Answer 5

true

Question 6

Saline soils have high ECE measurements > 4dS/m

Answer 6

true

Question 7

Sodic soils form white crusts

Answer 7

False (saline soils do)

Question 8

CEC increases in humus with higher pH

Answer 8

True

Question 9

Sulfur can be used to increase soil acidity

Answer 9

True

Question 10

Ammonium can be fixed on clays

Answer 10

True

diffuses slowly in soil with a high cation exchange capacity (high clay or organic matter content) because the ammonium is attracted to the negatively charged sites

Question 11

Water moves from a low to high energy state

Answer 11

False (high to low)

Question 12

As decomposition of added organic material proceeds, the C/N ratio in the remaining undecomposed material increases

Answer 12

F

Question 13

Water moves from one site in a soil (water potential of -5 kPa) to soil with a water potential of -40 kPa

Answer 13

True

Question 14

Iron and aluminum hydrous oxides are characteristics of soils that are highly weathered chemically

Answer 14

true

Question 15

Most nitrogen leaching to groundwater is in the form of ammonium

Answer 15

false - nitrates

Question 16

Saline soils are characteristic of arid and semiarid areas with poor internal drainage

Answer 16

true

Question 17

Sodic soils generally have better physical conditions than either saline or saline-sodic soils

Answer 17

false

Question 18

In the early stages of plant N deficiency, the most obvious symptoms are yellowish colours in the youngest leaves

Answer 18

false

Question 19

Most anaerobic microbes in the soil are bacteria

Answer 19

true

Question 20

Cruciferae family do form mycorrhizal relationships

Answer 20

false

Question 21

Define field capacity

Answer 21

when soils stop draining due to gravitational forces

water films are thin enough to hold against gravity

Question 22

Why is plant growth rapid at field capacity?

Answer 22

there is enough air, yet water is held loosely at high potential

Question 23

the higher the CEC of a soil, the higher its buffering capacity

Answer 23

true

Question 24

although kaolinite particles are larger than other silicate clays, their SA is much smaller than other clays

Answer 24

true

Question 25

ammonium fixation would be expected to be greatest in soils containing high amounts of ____________

Answer 25

clay

Question 26

Phosphorous availability in soils is constrained by the presence of significant quantities of ___________

Answer 26

iron and aluminum oxides

Question 27

in order for nitrate to form from soil OM, __________ must be present in the soil

Answer 27

Nitrosomonas

Nitrobacter

Question 28

one would expect well drained soils to have the higher OM contents where the climate is _____________

Answer 28

cool and humid