Practice exam #3 - QUESTION 1

All questions are posted at the "Lecture notes" page here in wiki. Please post here your discussion, answers, and/or requests for clarification re. the QUESTION #1

I'm still working on the other questions, but thought i'd get this started! I tried not to look at my notes or anything, so please feel free to tear my errors apart!

a) Translocations, Transformations, Additions and Losses

b) Translocations: Frost-heaving/ freeze-thaw processes, illuviation/eluviation Additions: deposition (wet), natural and synthetic fertilizer additions, residues, Losses: volatilization, leaching, harvesting, combustion, surface runoff, fixation Transformations: oxidation, hydrolysis, Biological-Nitrogen fixation, decomposition

c) Regosolic- No B horizon (undeveloped soil) Brunisolic- Bm Chernozemic- Ah >10cm thick Solonetzic- Bn/Bnt Luvisolic- Bt Podzolic- Bf/Bhf Organic- Of/Om/Oh (extend to a depth ≥ 40cm) Gleysolic- Bg Cryosolic- Permafrost (B,C) z/y Vertisolic- (B,C) ss/v

For clarification, what is the threshold for something to be considered an addition rather than transformation? I feel like I answered somewhat mechanistically, but in a way isn't decomposition an addition? or it's more like the addition is the actual addition of that material that will be decomposed?

Jacob, try to think about the perspective of the soil profile, i.e. is something added to the soil or lost from the soil versus transformed but remaining in the soil.

a) Additions, Translocations, Transformations, Losses. b) Additions: Addition of organic residues, addition of chemical fertilizer, addition of acids through acid rain, addition of salts from salty groundwater percolating into the soil.

  Translocations: Eluviation, illuviation (of clay, Fe/Al oxides/humic substances), mixing of organic and mineral horizons due to churning, argillipedoturbation, cryoturbation.
 Transformations: Oxidation, reduction, decomposition of organic residues, weathering of parent material and primary minerals, mineralization, immobilization, chelating.
Losses: Harvesting, leaching of water-soluble nutrients, gaseous losses such as denitrification, erosion.

c) Regosolic order: dominant soil forming process is either the recent addition of a layer of sediment, or the recent loss of a large amount of the soil profile.

  Brunisolic order: Translocation (leaching) of soluble salts and carbonates.
  Luvisolic order: Translocation (illuviation) of Bt horizons with clay-fraction primary particles.
  Gleysolic order: Reduction (transformations) of Fe compounds in anaerobic conditions (some oxidation at mottles)
  Chernozemic order: Mixing (translocation) of humic compounds from organic horizon to mineral horizons
 Solonetzic order: Accumulation of salts (especially Na+) from parent material (Addition?).
 Podzolic order: Illuviation (translocation) of B horizon with Fe/Al oxides.
Organic order: Decomposition (transformation) of organic residues into humic substances.
Cryosolic order: Cryoturbation (translocation).
Vertisolic order: Argillipedoturbation (translocation)

Think about the diagnostic horizons Blaise to help you identify the dominant soil forming process

Additions: Additions of organic matter to the soil or additions that come from groundwater into the soil (ex: saline groundwater adding salts into the soil).

Transformations: Chemical or biological transformations (ex: The transformation of primary minerals and decomposition of organic matter, going from an oxidized to reduced state or vice versa).

Translocations: Movement between the soil profile but matter staying within the soil itself. (ex:Al and Fe leaching from the A horizon into the B horizon). Losses: Leaching. (ex: Salts leaching out into groundwater and leaving the soil). Or physical removal.

Regosolic Order: Juvenile soil, very weakly developed. Most likely close to an unstable terrain (like near a river or an area that gets constant landslides) ← any of these factors would limit their development. No B horizon.

Brunisolic Order: The leaching of soluble salts and carbonates, the formation of iron and aluminum secondary minerals, and the structure development in the finer textured materials different from the original structure of the parent material. Bm Horizon.

Luvisolic Order: The translocation of clay-sized mineral particles from the A to the B horizon.

Gleysolic Order: Develop whenever surface water accumulates (fluctuating water tables).

Chernozemic Order: Develops in grasslands usually, subhumid / aerid climates. *Chernozemic A horizon.

Solonetzic Order: Develop mainly under grass or grass-forest cover within subhumid/subarid climates, on saline parent materials that are high in sodium.

Podzolic Order: Soluble organic matter and mobile compounds of Al and Fe are readily leached from the A horizon into the B horizon where they accumulate or form into a podzolic B horizon.

Organic Order: Developed largely from additions of organic matter.

Cryolsolic Order: Found in northern Canada where permafront exists close to the surface. Under these conditions, soil water in the lower part of the profile remains frozen all year year round, but the upper part or thaws during summer. Susceptible to cryoturbation.

Vertisolic Order: agrilllipedoturbation/mass movement of materials due to shrinkage and swelling of clays during drying/wetting cycles

1.)• Addition, Translocation, Transformation, losses

2.)Translocation-Earth worms moving material Transformation- Decomposition, oxidation and reduction (Al, Fe) Losses- wind, erosion, leeching (in soil solution) Addition- Fluvial deposition, glacier deposition

3.)1.)Regosolic- Addition

2.)Brunisolic- Losses- leaching of soluble salts

3.) Luvisolic- translocation- of clay sized particles from A to B

4.) Gleysolic- transformation- oxidation and reduction reactions

5.) Chemozemic- Addition- accumulation of organic material

6.) Solonetzic- transfer/Addition

7.) Podzolic- transformation- chemical and biological transformations of primary minerals

8.) Organic- transformation- decomposition

9.) Crysolic- translocation- in freezing in thawing cycles.

10.) Vertisolic- translocation- wetting and drying cycles

1. a) Translocation, Transformation, Additions, and Losses

b)Translocation: Movement of material within the soil - organic matter, Transformation: Decomposition of organic matter - nitrification, ammonification (inorganic-organic) etc., Additions - the addition of organic matter to the soil, Losses: loss of nutrients through leaching - nitrate. 

c)*making assumption that enrichment could be considered addition*

Regosolic: addition of material, Brunisolic: addition of Fe and Al, modified horizon (transformation?), Luvisolic: addition of silicate clay, Gleysolic: translocation of water (changing water table0, Organic: addition of Fe and Al, modified (transformation?), the addition/enrichment of organic matter, Chernozemic: addition of organic matter, Solonetzic: high Na (not sure which major category this belongs to) and addition of silicate clay, Podzolic: addition Fe and Al and addition of organic matter, Cysolic: translocation of thawing material, Vertisolic: translocation of mixing soils

here Gretchen you are not asked to identify whether or not it is an addition, transformation, translocation or loss, but simply the dominant soil forming process for each soil order.

By dominant soil-forming process, does this mean the lower case suffixes of the diagnostic horizon? For example if the suffix is p, would we talk about the soil horizon being disturbed by human activities?

Yes, that is correct

a) Additions, Translocation, Transformation, and Losses.

b)additions: fertilize or organic matter (leaves, twigs)

translocation: which done by soil organisms like earthworms move the material in soil

transformation: decomposition (some chemical reaction)

losses: gone with ground water or gases into the atmosphere

c) Regosolic order: (addition) weekly development so there is not much change inside the soil most are on the surface like organic horizons.

Brunisolic order: (losses) slightly development leaching of soluble salts and carbonates

Luvisolic order: (translocation) of clay-sized particles from A to B horizon

Gleysolic order: (transformation) lack of oxygen which means surface water accumulates

Chemozemic order: (transformation) decomposition of leaves and grass roots accumulate at the topsoil

Solonetzic order: (addition) contain high proportion of exchangeable Na relative to Ca ion in B horizon

Podzolic order: (transformation) chemical and biological transformation are intense, resulting in the transformation of the primary mineral and decomposition of organic matter

Organic order: (transformation) developed largely from organic deposits

Crysolic order: (translocation) lower part of the profile frozen for all seasons but upper part ice would change to water "active layer"

Vertisolic order: (translocation) cracking, argilli-pedoturbation and mass movement of materials

NOTE POSTED BY MAJA: This question asks that you specify the most dominant soil forming process for each of the soil orders. The most dominant soil forming processes needs to be very specific. What you have listed above are the general groups of soil forming processes. Pls revise...

Yimin,
Answers for question 1(C) are much better now, but additional clarifications are still needed for these orders:
-Brunisol it's not just soluble salts that are slightly modified, but something else as well)
-Gleysol - it's not about accumulation of water at the soil surface but about water table going up & down within the soil profile, bringing along fluctuations in aerobic & anaerobic conditions (or oxidation & reduction). Question for all students - what is the name of this soil forming process that I just described here?
-Podzol - more specific name of soil forming process that leads to podzolic Bf horizon is needed
-Organic soil - yes, they may be developed on organic deposits, but what is the soil forming process that leads to their development?
-Cryosols - what is the name of soil forming process in this soil that causes mixing of soil mass in it?

Brunisols - soluble salts and carbonates move down through the soil profile (may be redundant with previous answer)

Gleysols - gleying

Podzols - illuviation of Al and FE oxides and/or organic matter in the Bf, Bhf, and Bh horizons due to acidity and subsequent eluviation in the A horizon

Organic soils - accumulation of organic material such as peat and that from other vegetation that grows in saturated or semi-saturated sites

Cryosols - cryoturbation

Question about soil forming processes for Regosols: Does this include the beginning of loss of soluble salts along with poor soil development?

Further question: Will we be examined on great groups, like 'Brown' versus 'Black'

Chernozems or just the orders?

Thanks!

a) Additions, Translocations, Transformations, and Losses b) Additions: Covers anything that involves the addition of matter into the soil body - forest litter falling to the forest floor, fertilization by compost on a farm

  Translocations: Happens when material is moved from one place to another - eluviation, bioturbation
  Transformations: Happens when the chemical composition of a material is turned into something else - mineralization, mobilization, dissolution?
  Losses: When material is removed from the soil body - runoff in soil water, volatilisation

good examples Lukas