lecture 10 part 2

Question 1

What are some physical issues associated with soil?

Answer 1

soil erosion (creates loss of nutrients and arable land) and water imbalance

Question 2

What is the extent of nutrient leaching determined by?

Answer 2

leaching is determined by water, soil texture, and nature of plant cover

Question 3

Where is nutrient leaching small?

Answer 3

when soils are fine textures and where plants are actively growing, also in soils with high CEC

Question 4

Why is nutrient leaching small in soils with plants and high CEC?

Answer 4

downward movement of nutrients inhibited geochemically by
CEC of soil and biologically through plant uptak

Question 5

How does application of fertilizers lead to leaching? What does this lead to?

Answer 5

If in excess then plants will not asborb and it’ll be leached, can lead to eutrophication and baby blue syndrome

Question 6

What are the sources of acidity in soils?

Answer 6

the prescence of signif amounts of Al3+ Fe2+
high amount of microorganisms (produce CO2 and organic acids)
anthropogenic sources (rain and acid rain)

Question 7

What are the three sources of buffering in soil?

Answer 7

Carbonate buffering (soil with carbonate minerals neutralizes acid)
cation exchange buffering (low in carbonate, cation exchange neutralizes the soil, and then aluminum buffering

Question 8

What three things impact salinity of soil?

Answer 8

1. rain water composition
2. limited ppt and high rate of evaporation
3. salt water intrusions

Question 9

What does metal contamination do to soils?What soils retain metals and which ones get leaches?

Answer 9

due to ore depositis and human activites, metal ions can accumulate in soils, the rention of these depends on soil cation exchnage capacity in soils of ph 7-8 metals reatines, in soild ph 4 metals can be leached to ground water

Question 10

What do abandoned coal mines release?

Answer 10

substantial quantities of H2SO4 and
Fe(OH)3 due to the oxidation of pyrite

Question 11

In acid min drainage what happens?

Answer 11

pyrite is consumed by bacteria in aerobic condtions which then produces h2So4 and FeOH, this can leach other metals from the mine and pollute streams if ph too low and H2SO4 can make water acidic

Question 12

What is an example of acid mine drainage?

Answer 12

Iron mountain mine