Answers to questions will be posted here. Please email questions to Gordon Rees at [email protected] or submit through the form on the Contact page.
1. Q: Are you posting questions and answers on the web site or communicating with all the coaches via email? We would like to see all the relevant questions and answers. A: All questions and answers relevant to the group will be posted here. Emails will be sent out to all coaches only for key announcements and updates (eg the release of an updated handbook), but not for answers to individual questions. I encourage you to check in on this page regularly.
2. Q: Can students use their manual? Based on what I see in the manual, this is a yes. But a line or two later it says "NO NOTES". A: The handbook will not be allowed during the competition. The "official contest handbook" was accidentally left in the list of student-provided materials on p 6, but has been removed in v 2 of the Handbook. The only written materials allowed during competition will be the reference packet, which we will provide to each contestant/team.
3. Q: Will you make the regional practice and contest materials available to those that did not participate in the regional contest too? A: Yes. Cal Poly hosted the Region 6 contest last November, with four contest pits (we have not had practice pits for our region contests). These pits will be used as practice pits for the national contest, so the descriptions will not be posted publicly, but have been made available to coaches.
4. Q: Will you be able to provide HCl for students that are flying? A: Yes. We will provide plenty of bulk HCl, but will ask that you provide your own smaller empty bottles to distribute it to the students.
5. Q: Do you have an idea of what time we will be wrapping up on 4/19? A: I've been trying to work out the logistics for having 26 teams participating, and I think the only option for group judging is to add another 2 hr rotation of teams. That would put us wrapping up team judging around 3:30, and the awards ceremony wrapping up by 5. I'm hoping to figure out how to condense things to cut a couple hours off, so let me know if you have any ideas, but right now that's my best guess. I can put teams that need to fly out earlier in an early team-judging rotation.
6. Q: Do you anticipate registration fees? A: Yes. Registration fees will be $50 per person. Finalized details are included on the Registration page.
7. Q: The handbook states under part D: "the complete definitions will be used in determining official answers." Does this mean the classification to the great group key that you've provide is not official, i.e. we need to use the full Keys to Soil Taxonomy for classification to great groups? A: Yes and no: - Keys to Soil Taxonomy will be used to determine the official answers (using assumptions as outlined in the handbook when necessary). - We will then ensure that our simplified key gets to the same answer. - If when describing the pits our key and Soil Tax disagree, we will revise our key so that it agrees, and notify all coaches of the updates. (I don't anticipate needing updates.) - Therefore: The simplified key can be used in the contest without the students needing to memorize Keys to Soil Taxonomy. (I know it would be less complicated to just state that the provided key is the official one for the contest, which is in effect true, but I'm being a little obstinate on this for philosophical reasons.)
8. Q: On page 11, 1st paragraph, shouldn't the correct abbreviation for "very gravelly" be VGR? A: GRV is the NASIS code, but either GRV or VGR would not be ambiguous and would be considered correct in the contest.
9. Q: Table 20 (pg 24): The erosion hazards described for the runoff classes don't match with the erosion potential table. AND Negligible runoff is listed in table 20, but isn't a choice in table 19. AND Is table 20 needed or used by students, or just for their information? A: Table 20 is intended as purely informational, and is not used directly in the contest. It has now been updated to remove the erosion hazard/negligible runoff wording to avoid any confusion.
10. Q: The effective rooting depth for Factor A in the Storie index includes abrupt textural changes as limiting rooting, but there is not mention of this in evaluation of effective soil depth in part B. Could one or the other be changed so that rooting depth is consistent between the two? A: Great point. Effective Soil Depth (Part B) has now been edited to include abrupt textural changes.
11. Q: If the soil has a depleted matrix color chroma 4 or more and value 2 or less, then "Y" should be checked under depletions, correct? A: Correct. (See Handbook p 15)
12. Q: If students encounter a dissected terrace alluvium deposit no longer step-like in form, what should the mark for position? A: The landform for this type of feature (dissected old terraces/fans where the original terrace/fan morphology is no longer evident) will be marked as upland (see Handbook p 20, Table 16 Upland description). The position of site will then be one of the standard upland positions - Summit through Toeslope. Interpretation of dissected old alluvial deposits (terraces and fans) is often a challenge locally. Terrace deposits should be associated with a water source confined to a stream channel. Alluvial fans should be considered when the material is clearly transported by water, but does not seem to be associated with a stream channel. It is not uncommon in the area for alluvial fans to overlap with stream terrace deposits, making distinguishing between the two very challenging. You'll have an opportunity to see how we handle this at some of our practice pits.
13. Q: What do students mark if a summit (or ridge)/toeslope is > 2% slope? A: They should mark summit/toeslope for any summit/toeslope. Table 18 (p 22) has been edited to clarify this.
14. Q: Page 19 - Would you consider allowing students to get a copy of this chart (carbonate stages) for use during the contest? A: We've considered it, but we've decided not to provide the chart in the contest. The practice pits should provide adequate practice for the students to be comfortable with this at the level it's used locally.
15. Q: Page 27 - Albic materials - only marked if albic horizon is not marked? But for depleted matrix, it said to also mark depletions. Does this seem inconsistent? A: There are arguments to be made for disparate treatment of the two components, but careful consideration of this language led me to see a potential can of worms to be opened down the road, so the language has been removed and, if an albic horizon is present, both albic horizon and albic materials should be marked.
16. Q: How do students know if a soil has an Aridic/Xeric SMR? AND Will the students get ESP or SAR data to know if it meets natric? A: In the handbook, it states that a Xeric SMR should be assumed unless Aridic is specified on the pit card, and that ESP will be provided if needed for classification purposes and should otherwise be assumed to be low. We've decided to provide SMR and ESP on every pit card, even if it's Xeric and 0%.
17. Q: On your key to soil orders, Vertisols, it says "evidence of shrinking and swelling (slickensides or wedge-shaped peds) in a layer 25 cm or more thick above a depth of 100 cm, and ..." Is that entirely above a depth of 100 cm? or starting above a depth of 100 cm ? A: From Keys to Soil Taxonomy p 38: "If diagnostic horizons or characteristics are criteria that must be “within” a specified depth measured from the soil surface, then the upper boundary of the first subhorizon meeting the requirements for the diagnostic horizon or characteristic must be within the specified depth." In the simplification process, the word "within" was replaced with "above," but we didn't intend to change the requirement. So, starting above a depth of 100 cm.
18. Q: For Calcixerolls, students need to know if free carbonates are present. Is this the same as secondary carbonates? A: "A solution of cold, 1-normal hydrochloric acid (1N HCl) is used to test for the presence of free carbonates in the field." (Soil Survey Manual p 199) Use presence/absence of effervescence to indicate presence/absence of free carbonates.
19. Q: Do you have a simple suggestion as to how the students can tell if a soil with lamellae has "none", "cambic", or "argillic"? A: There was an error in the handbook description of lamellae on this (stated cambic if <15 cm combined thickness). This has been corrected in the updated handbook. Basically: Argillic - Lamellae .5 cm or more thick must total 15 cm or more; Must meet "clay bulge" compared to eluvial horizon above within 30 cm Cambic - Combined thickness must still be 15 cm or more; Texture class of very fine sand, loamy very fine sand, or finer None - Not argillic/cambic
20. Q: Could you comment a bit about the mollic epipedon and aridisols. Soil Taxonomy defines mollic epipedons out of areas with aridic moisture regimes (moisture regime is part of the definition). So even if something meets all the other criteria of a mollic, if found in an aridic moisture regime, it is not a mollic. It appears that the guidebook takes the opposite tact. It says aridisols must have an aridic SMR, AND have an ochric epipedon (suggesting that if they have a mollic epipedon, then they can't be aridisols. Personally, I prefer this latter approach - that the mollic is defined based on the properties and not on the SMR. Am I understanding your intent correctly? Perhaps you could clarify this. Thanks. A: I wish I could claim any intent on this, but it was simply one decision to leave off SMR for our simplified Mollic outline and a second independent decision to include the ochric epipedon requirement for our simplified Aridisol definition. The presence of an otherwise mollic epipedon in aridic parts of the area is not common enough to be something I've had to give much thought. I do agree that I'd personally not exclude mollic epipedons from aridic SMRs. When that does occur, it seems like that's something we'd want to call attention to rather than ignore. Maybe even add a Humids suborder? For the contest, we will leave the definitions as they stand in the handbook.
21. Q: In the handbook, we noticed _____ error/typo... A: There are several minor errors/typos/clarifications to the handbook that have been pointed out. Rather than list each of those individually on this page, see the Handbook v 2 and the accompanying list of changes from v 1. Feel free to follow up on why we made any specific change, but most are pretty straightforward.
22. Q: I noticed the simplified key for diagnostic horizons does not included part 6c(2) of the mollic definition from KTST (can be <25 cm if >1/3 thickness to lower depth of argillic). I’ve noticed this particular part of the definition is used in some soil judging contests and not in others. I just did a practice scorecard based on a description I found of a Los Osos soil and it keyed out as an Alfisol if we ignore 6c(2) (but should be a Mollisol). Should we stick to ignoring 6c(2)? Any chance you will add that into a later version of the contest handbook? A: I definitely intended to include the 18 to <25 cm thickness if >1/3 of thickness to lower depth of argillic/cambic/natric option, it was just an oversight that I missed it. It has been added to the handbook in v 2.
23. Q: On page 31, it says: "(2) Soils with an argillic horizon (a) Strongly contrasting particle sizes within or below the argillic and within 100 cm of the surface: Deepest of: - Upper 50 cm of the argillic; - Top of the argillic to 100 cm, - Top of the argillic to RLL" The Keys to ST says - The upper 50 cm of the argillic, kandic, or natric horizon or to a depth of 100 cm, whichever is deeper, but not below the upper boundary of a root-limiting layer; If I am guessing right, that means the key above is not correct. For example, if you had a thin argillic, and a strongly contrasting at < 100 cm but also bedrock at < 100 cm; the key above would have you use top of argillic to 100 cm, but I think the correct answer would be top of argillic to RLL. If I am right, then the second choice should be "Top of the argillic to 100 cm if no RLL at < 100 cm" A: Yes, the suggested edit is correct. Please have your students pencil in this correction to their handbooks for the time being. This edit has been incorporated in version 3 of the handbook.
24. Q: In the manual where you mention "reduced matrix" (pages 18 and 28), do you really mean depleted matrix? A: Yes, depleted matrix is intended in those cases.
25. Q: Would a Cd horizon be "low" limiting hydraulic conductivity? Or should we even worry about that? A: If we had given it much thought, we probably would have included Cd horizons with our low hydraulic conductivity materials. We didn't give it much thought. For the sake of limiting the number of edits to the handbook at this point, we'll leave it out of the low hydraulic conductivity definition. If you see a Cd horizon in practice (or maybe even if you don't), it would certainly be worth discussing this oversight on our part with your students.
26. Q: Page 16: added “and abrupt textural changes (as defined in Section D below)” to list of root limiting layers Question 1: Does this affect the available water capacity calculation? Do you stop at the abrupt texture change instead of going to 150 cm? Question 2: Does this affect the particle size control section? Do you treat the abrupt change as a root limiting layer here? A: 1. Yes, for available water, all layers listed as root limiting under Effective Soil Depth will be considered, including abrupt textural changes. 2. No. Keys to Soil Taxonomy is explicit in its list of layers that are considered Root-Limiting for the purposes of particle-size control section determination. It includes, "a duripan; a fragipan; petrocalcic, petrogypsic, and placic horizons; continuous ortstein...; and densic, lithic, manufactured layer, paralithic, and petroferric contacts." We will play by KTST rules in this case, and "RLL" for our simplified key to PSCS should be understood to refer to this list, which does not include abrupt textural changes. These may instead show up as strongly-contrasting particle-size classes.
27. Q: When researching soils in the area I noticed that the only soils with natric horizons in the area around SLO appear to be formed in lacustrine sediments and located in closed basins (old lake basins). Since these basins seem to be at lower elevations, they do not appear to fit the definition of "depression". Since lake plain or basin is not a landform choice and lacustrine is not a choice for PM, what would be the correct landform and parent material choice in this situration? FYI, I was looking specifically at the OSD for the Chicote series found near Soda Lake. If there are other series with natric horizons that I'm missing or if you can provide some guidance on landforms associated with natric soils, it would be much appreciated. A: The correct landform/PM for the soils you describe would be lake plain/lacustrine deposits. We chose not to include these on the scorecard or in the contest in an attempt to limit the scope a little. It's true that Chicote is the only series mapped in the county with a natric horizon, and is primarily on these landscapes. However, if you look at the Monterrey County soil survey immediately to our north, you'll find Placentia soils (Typic Natrixeralfs) mapped right to the county line, but the Na seems to refuse to cross into our county (maybe not a fan of our tax code?). In reality, these soils do show up occasionally in the north part of the county. They're found in alluvium (often fans) and on footslopes, sourced from Na-rich marine rocks.
27. Q: Any chance you have pics of the pits from regionals? A: Yes. I've added pit photos to the folder shared previously with coaches. They're from before we did our final cleanup, but give a decent idea of the pits. Please remember that these pits will be used as practice pits during the national contest, so use with discretion.
28. Q: Why would conductivity not be low for a clay with strong structure? A: The thought here is that there would be some flow between peds with strong structure. This has been something included in at least the last couple national contests, and we maintained it without giving much thought. Given the smectitic mineralogy of most of our clays here, it probably deserved a little more thought, and may not be the best estimate. Some of our local NRCS folks have been looking at Ksat in Vertisols, and should have some actual data relevant to this. I will follow up with them and provide additional info with contest materials, but we'll leave the definitions as they stand for the sake of avoiding too much confusion with changes at this point.
29. Q: If a Bk horizon qualifies as a calcic, can it also be a cambic? Would you mark both on the scorecard? A: No, calcic and cambic cannot overlap. See handbook p.27 or KST p.13: "3. Has properties that do not meet the requirements for an anthropic, histic, folistic, melanic, mollic, plaggen, or umbric epipedon, a duripan or fragipan, or an argillic, calcic, gypsic, natric, oxic, petrocalcic, petrogypsic, placic, salic, spodic, or sulfuric horizon;..."
30. Q: If they see a soil with lamellae, do they describe both components or just the one that makes up the highest percentage? A: They should describe the properties of the dominant component on the scorecard. For example, if the elluvial part makes up the highest percentage, they should call it an "E and B," and describe the morphology of just the "E" part. They will still need to consider the properties of the illuvial component in this case when deciding if it is argillic/cambic, but just the dominant component's morphology will be scored.
31. Q: What is the likelihood of needing muck boots? Can we manage with just hiking boots instead? A: I'd guess that there's a 75% chance you'll never need muck boots. In normal years I'd be more confident, but February and early March have been very wet here, so no guarantees.
32. Q: There is currently a working group focused on defining non pedogenic restrictive layers such as Cd. One the layers creating the most discussion and disagreement is the Cr. I associate Cr with paralithic meaning it is root restrictive. Some think Cr only means that the materials were weathered directly from rock. The question is how will you apply Cr in the contest? Cr = paralithic? or Cr is weathered rock? A: For the contest, Cr = paralithic, root restrictive.
33. Q: There is an error in the classification for Palexerolls (pg 246 KST). It should be under c.i.2 "relative" not "absolute". A: Yep. Fixed in Handbook v 3.
34. Q: Page 28 - 9) Should we strike through the words "within 50 cm of the soil surface"? Identifying aquic conditions is not respective of depth. Only Aquic suborder is. A: Identifying aquic conditions is not respective of depth. However, as far as I can tell, redox depletions and aquic conditions are not exactly equivalent terms. In using presence/absence of depletions as a simplified indicator of aquic conditions, we meant to suggest that if aquic conditions are present anywhere in the profile, we would expect evidence of that wetness to make it up near the surface. This is obviously not a perfect indicator. In fact, after giving this much thought, we decided to remove aquic conditions as an option to mark for subsurface horizons and features, as "it is not possible to define a specific set of redoximorphic features that is uniquely characteristic of all of the taxa in one particular category." (KST p 27) No one field indicator is suitable, so we may be doing our students a disservice by suggesting otherwise. Additionally, students are already thinking about these concepts when looking for depletions, when considering the depth to seasonal high water table, and when choosing "Aqu-" suborders. We don't think this will result in any real loss in learning.
Removing the determination of "aquic conditions" from the contest had a bit of a ripple effect in other parts of the handbook. Handbook version 3 was released in large part to make those adjustments. In terms of concepts and requirements for remaining elements, nothing has really changed. The wording has just been edited to generally replace references to "aquic conditions" with "redox depletions." Whenever depletions are referenced in the handbook, the value ≥4, chroma ≤2 requirement is intended to apply.
35. Q: Classification question- Can you tell me why this (Camarillo Series) is a Fluvent? Seems it has a cambic in the Bkgy1. A: The soil described in the OSD should have a cambic. An older description of the Camarillo had horizons Ap, C1, C2, IIC3, IIC4, IVC5, and fit the Fluvent classification. I reached out to some local NRCS folks for their thoughts, and they confirmed that it should be cambic in the Bkgy1 with gypsum masses and prismatic structure, and "this looks like a candidate for a sampling project to start reviewing the series." One note they suggested to watch for (though doesn't apply in this case) is that fine stratifications common in Fluvents qualify as rock structure, disqualifying those layers from cambic consideration in the absence of soil structure.
36. Q: On page 10 you say to use 200 cm for all relevant evaluations (1st para) and then on p 16 and 17 you say to use 150 cm. Can you clarify? A: The intent of the statement on page 10, to extend the lowest horizon to a depth of up to 200 cm, is that you should mentally imagine this last horizon continues to as deep as needed for whatever evaluation you're making. For one evaluation (Storie Factor A), that means you'll need to extend to 200 cm. For most others, including the properties on p 16 and 17, we only consider to a depth of 150 cm. You can still imagine the profile extends to 200 cm in those cases, but that would not change the effective soil depth marked, and water is still only considered available for AWHC down to 150 cm.
37. Q: On pit 4 in San Diego, there were a 2 and a 3 written in the prefix part of the description but lithologic discontinuity was not checked on the back. Is that because everything was considered alluvium? A: That was a mistake on the key. Lithologic discontinuity should have been checked, even when it's alluvium over alluvium.
38. Q: Regarding Q 16, will students be given SAR data? A: No, only ESP data will be provided. Other Na measures (SAR, Mg+Na vs Ca+acidity in KST) will be assumed to not meet requirements for Natric if ESP doesn't make it.
39. Q: I just want to make sure that seeing effervescence is not the same as identifiable secondary carbonates. On page 15 of the handbook, "....visible carbonate masses are denoted separately by using the subscript k on the horizon." On profile 4 of the San Diego soils several Bk horizons were identified but "identifiable 2nd carbonates" was not checked. AND In your answer to question 18 you state that students should "use presence/absence of effervescence to indicate presence/absence of free carbonates." Just so I am completely clear, could you confirm that observed effervescence is only evidence of free carbonates, but alone is not evidence of identifiable secondary carbonates. In other words, students should not select Identifiable Secondary Carbonates on the scorecard solely on the basis of observed effervescence. Is this correct? A: Effervescence is NOT equal to identifiable secondary carbonates, and is NOT enough to select that feature or add a k to a horizon.
Identifiable secondary carbonates: must be visible as masses, nodules, concretions, filaments, or coatings.
k: indicates accumulation of visible pedogenic carbonates. KST definitions for k and identifiable secondary carbonates are not identical, but for this contest the two definitions overlap enough to be considered equivalent.
Free carbonates: (see Q 18) Equivalent to effervescence, not marked on the scorecard, but may need to be considered in taxonomy
In the San Diego pit 4 mentioned, Identifiable Secondary Carbonates wasn't actually an option on the scorecard at that point, but that's the only reason it would not be selected for those Bk horizons. The overlying horizons in that soil also exhibited strong to violent effervescence, but because no visible carbonates were present, those horizons would not get the k designation or have identifiable secondary carbonates.
40. Q: Do you have any guidance on how to distinguish between Bss and Btss horizons? A: Differentiating pressure faces from clay films is challenging in our smectitic soils. I've talked this over with our official NRCS judges, and basically the conclusion was that you need a thin section, but that clay films are uncommon in high clay soils with slickensides in the area. As you won't have the luxury of using thin sections during the contest, we will use the following guideline: If a horizon has: i) 50% clay or more, AND ii) slickensides OR prismatic structure have developed in the same lithologic unit as that horizon (not crossing a discontinuity, but doesn't have to be in the same horizon), Then: Assume that there are no clay films, and that all features that look like they might be clay films are instead pressure faces. In all other cases, if it looks like a clay film, call it a clay film. The result of this rule will be that 't's and 'ss's will rarely be used in the same profile.
41. Q:Figure 3 on page 19 of the handbook illustrates the various stages of carbonate accumulation. In that figure, for stages IV and V the laminar cap is designated as Bkkm1 while the remainder of the petrocalcic is designated as Bkkm2. In this contest, if a laminar cap is observed, would it be designated as a separate horizon? Or, because it is likely to be thinner than the 10 cm minimum thickness (handbook, page 8), would it be lumped with the rest of the petrocalcic horizon (assuming the total thickness is >10 cm)? A: For the contest, a laminar cap will only be designated as a separate horizon if it is more than 10 cm thick. Otherwise, lump it with the rest of the petrocalcic.
42. Q: Looking through the county surveys provided I came across the Pismo series: https://soilseries.sc.egov.usda.gov/OSD_Docs/P/PISMO.html I suppose the simplest way I could ask my question: should a soil like this arise, what would be the expectation for the students to mark in the "particle size control section/class" field on the scorecard? I am assuming this is the reason for the "other" category (maybe I missed a clarification on this in the handbook), so the correct answer for the contest would be "other/sandy"? Just want to make sure I am not providing conflicting information to the students.10 cm)? A: In our handbook we didn't get into the nuance of cases when a particle-size class would not be used (such as this psamment), so we would accept either the answer they'd get by following our simplified key for PSCS (25-RLL in this case) or "other." We don't have an "other" option for particle-size class, so "sandy" is probably the best option here.
43. Q: SCL over LCoS, if there is >50% fine sand and coarser in the SCL, is not strongly contrasting according to KST, but that rule is not presented in your key. Could this be strongly contrasting (loamy over sandy)? AND There are approximately 20 contrasting PSCs that are theoretically possible for these soils by my estimation. Since this part is not open book, is there any way to narrow these choices? A: We hope you take some time to discuss strongly contrasting particle-size classes with your students, and show them the full rules in KST (such as the SCL over LCoS case mentioned). However, given the complexity of this concept and the different possibilities, for the contest purposes we will narrow the list of possible contrasting classes to those listed as examples in the simplified key on p 31 (and in the reference packet): Clayey (or clayey-skeletal) over sandy, or Loamy (or loamy-skeletal) over clayey with absolute difference of 25% clay (or more).
44. Q: On page 25, should we delete the sentence "If the soil has aquic conditions....". ? A: Yes, delete that sentence.
45. Q:Could you please clarify your comments regarding Question 26: are you saying that everything defined as an abrupt textural change will be considered to be root limiting, and therefore soil moisture storage will not be calculated below the abrupt textural change? (this is how I read the manual and your answer to Q26.) What I am wondering about is a case such as a loamy sand E horizon with 9% clay overlying (with an abrupt or clear boundary) a sandy loam Bt horizon with 19% clay that would technically have an abrupt textural change. Would you really consider this to be root limiting? Perhaps more importantly, it seems like the underlying sandy loam might possibly be the best rooting environment in the profile because it would hold more plant available water than the overlying droughty material. But it sounds like you would (by the rules) not include this zone (the sandy loam Bt horizon) below the contact with the abrupt textural change when calculating available water. Am I understanding your intent, or am I missing something? (perhaps all your local instances of ATC are much more striking with the underlying layer being so clayey as to really be root restrictive.)? A: For contest purposes, yes, if it meets the criteria for abrupt textural change, consider it root-limiting. Most abrupt textural changes I've encountered in CA meet the 20% absolute increase, and are treated as root-limiting in determining the Storie Index rating, so that's why we've included them as RLLs here. The point made in this question is a very good one, though, and given another shot at it, I would probably want to refine our approach to take this type of situation into account.
46. Q:We are not planning on bringing muck boots. Should we reconsider? A: Having been to all the pits last week, and given the current weather forecast, I'm pretty confident that you won't be wading in water at any of the pits, but there's a good chance of muddy shoes at one or two. We'll do our best to minimize water with pumps and pallets where needed.
47. Q: In the ref. packet there are these somewhat cryptic criteria: Cambic w/ aquic color requirements: i. Value of 3 or less and chroma of 0, or ii. Value of 4 or more and chroma of 1 or less, or iii. Any value with chroma 2 or less and redox concentrations What are these referring to? A: It's meant to just refer to the color requirements for Cambic in (KST p 13) 2.a.(3). These are the colors that qualify a horizon as Cambic when there are depletions within 50 cm of the surface (contest rules substitute for aquic conditions here).