Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Soils
| Question | Answer |
|---|---|
| On average, how many years does it take to form an inch of topsoil? | 500-1000 |
| Do we consider soil to be renewable or non-renewable? Why? | Non-renewable, because it is not replaceable on a human time scale |
| What is land degradation? | The reduction in the capacity of the land to provide ecosystem goods and preform functions and services |
| What are the three main categories of land degradation? | Physical, biological, and chemical |
| What are some examples of physical degradation of land? Which one is the biggest problem in East Texas | Erosion by water, erosion by wind, erosion by tillage, surface sealing, soil compaction. Water erosion is probably the biggest problem of these in East Texas. |
| What are some examples of biological degradation of land? | Loss of biological diversity, depletion of SOM, loss of biomass |
| What are some examples of chemical degradation of land? | Salinization, dispersion/alkalization, acidification, toxic contamination |
| What are the two main categories of erosion? | Geological erosion and human-accelerated erosion |
| What is geological erosion? | Erosion without the influence of human activities |
| What is human-accelerated erosion? | Erosion resulting from humans disturbing the soil and/or natural vegetation |
| What is denudation? | The wearing away of landforms |
| What financial costs result from erosion? | Cost of replacing nutrients. irrigating, and crop yeild reductions |
| What are the annual on-site costs of erosion in the US estimated to be? | Between 10 and 50 billion dollars |
| What are offsite costs of erosion? | The costs of activities that have to be preformed elsewhere due to the erosion like dredging |
| What are the estimated annual off-site costs of erosion in the US? | Between 12 and 40 billion dollars |
| What role do raindrops play in water erosion? | Raindrops transfer kinetic energy to the soil on impact. This can either break up weak aggregates which causes the detachment and dispersion of smaller particles, or it can disperse smaller particles, making them easier to be moved by runoff |
| Describe the steps of water erosion | Rainfall->Detachment of particles->transportation of particles->translocation of particles->Deposition of particles |
| What are some actions that can e taken to prevent water erosion? | Keep soil covered. On a steep slope can put "hard armor," riprap, or gabions. Bioengineering. |
| What are the morphological features of water erosion? | Sheet erosion, rills, and gullies |
| What is sheet erosion? | The uniform decrease in a surface across a parcel of land |
| What is rill erosion? | The removing of thin layers of soil as little rivulets of running water gather and cut small channels in the soil. Can be removed with cultivation. |
| What is gully erosion? | Gully erosion is caused by water concentrating in a natural water course and cutting deeper and deeper into the soil. Gullies cannot be removed by cultivation. |
| What did the Clean Water Act of 1992 do with respect to erosion? | Required that contractors develop detailed erosion or sediment control plans before initiating construction |
| What are some examples of "hard armor" for erosion control on steep slopes? | Riprap - large angular rocks and Gabions- wire mesh containers filled with hand sized stones |
| What are the three types of soil movement due to wind? | Soil creep, altation, and suspension |
| What is soil creep? | The gradual movement of larger particles of soil being pushed by wind along the surface of the ground |
| What is saltation? | The movement of medium sized soil particles due to bouncing |
| What is suspension? | The movement of soil particles via being picked up by the wind and moved parallel to the ground surface |
| What methods/factors affect wind erosion? | Wind breaks, moisture in the soil, texture class, and vegetation surface cover |
| What is the USLE and what is it used to predict? | Universal Soil Loss Equation. Used to predict the long-term average annual rate of erosion on a field slope |
| USLE predicts the long-term average annual rate of erosion on a field slope. What units does it have? | tons/acre/year |
| What type of erosion does the USLE account for? What types of erosion does it not account for? | Only predicts the amount of soil loss that results from sheet or rill erosion on a single slope. It does not account for the additional soil loss that might occur from gully, wind, or tillage erosion |
| After calculating the potential long-term average annual soil loss, this value can be compared to the tolerable soil loss (T) value. What is the tolerable soil loss value? | The tolerable soil loss value is the maximum annual amount of soil that can be removed before the long-term natural soil productivity is adversely affected. |
| What are the factors in the USLE? Where do you get them? | R-rainfall erosivity (from a map). K= soil erodibility (from a K-factor texture class table). LS = slope length and gradient (use LS equation). C= cover management (from tables) P= Erosion control practices (P-factor table) |
| Which of the factors in the USLE can be uman altered? | Slope length (L), Slope gradient (S), Cover management (C), Erosion control practices (P) |
| What is rainfall erosivity (R)? | The rainfall erosion index unit, plus a factor for runoff from snowmelt. The numerical value used for R quantifies the raindrop impact effect and provides relative information on the amount and rate of runoff likely to be associated with the rain. |
| What factors can increase runoff? | De-vegetated site. Lots of impermeable surfaces surrounding the site. |
| What is soil erodibility (K)? | The Soil erodibility factor is the soil loss rate per erosion index unit for a specified soil as measured on a unit plot. |
| What are the principal factors affecting soil erodibility (K)? | Texture, structure, organic matter content and permeability |
| What is the slope length (L) factor? | The slope-length factor is the ratio of soil loss from the field slope length |
| True or False: Slope length is easy to influence | True, adding terraces affects slope length |
| How does adding a terrace in the middle of a slope affect its length? | The slope is now split in half, and should be treated as two separate slopes with two separate lengths |
| What is slope gradient (S)? | The slope-steepness factor. It is the ratio of soil loss from the field gradient to that from a 9% slope under otherwise identical conditions. |
| When calculating the LS of a slope with two or more slope gradients, which gradient do you use? | The steepest |
| What is the cover and management (C) factor for the USLE? | The ratio of soil loss from an area with specified cover and management to that from an identical area in tilled, continuous fallow |
| What are the eight subfactors of the cover and management (C) factor? | Amount of bare soil, canopy cover, soil reconsolidation, fine roots, high organic content, onsite storage, steps, residual binding effect |
| What effect does the amount of bare soil have? | Cover such as litter, slash, logs, and surface rocks protect the soil from erosive forces of raindrop impact and runoff. |
| What effect does canopy cover have? | Canopy cover intercepts rainfall and collects water on its foliage |
| What effect does soil reconsolidation have? | Soil reconsolidates and becomes less erodible over time after land is retired from tillage. |
| What are fine roots and how are they estimated? | Fine roots are a dense mat of fine roots present in the top 2 inches of soil. |
| High OM content is a subfactor of the cover and management factor. What does this mean in forested ecosystems? The USLE can account for OM up to what percent? | Under permanent forest, topsoil accumulates a high OM content that is not considered in the USLE soil erodibility nomograph, which only goes as high as 4% |
| What are some examples of onsite storage? | Tractor treads, stump holes, dropped blade, debris dams, slash, logs, litter, chopping, ripping |
| What are steps and how do they form? | Runoff that can build up behind an object that can cause ponding. |
| What is the residual binding effect? | Soil undergoing cultivation after having not undergone cultivation for some time. The magnitude of the effect depends on the amount of roots, organic matter, and structure of the soil. |
| What is the control practices factor? | The ratio of soil loss with a support practice like contour disking. |
| Why is nitrogen a necessary nutrient for organisms? | Needed for chlorophyll, DNA, Amino acids, and cell walls |
| How much nitrogen is harmful to plants? | Too much or too little |
| What are visible symptoms of nitrogen deficiency? | The yellowing of older leaves |
| What is a symptom of excessive nitrogen in crops? | Lodging or falling over |
| What is the difference between reactive and non-reactive nitrogen? | Non-reactive nitrogen is an inert gas that saturates the atmosphere and is unusable by organisms. Reactive nitrogen is. |
| How is reactive nitrogen formed? | By ammonification or by nitrogen fixation |
| What is ammonification? | Bacteria break down organic nitrogen into ammonia |
| What is immobilization? | The conversion of inorganic nitrogen to organic forms. The end products are not available to plants. |
| What is mineralization? | Organic nitrogen is broken down into inorganic forms. The end products are available for plants. |
| What is Ammonia volatilization? | The loss of nitrogen to the atmosphere as ammonia gas, occurs more at higher pH's |
| What are some ways to keep ammonium in the soil? | Irrigating after adding nitrogen |
| What is nitrification? | Ammonia is broken down into nitrite or nitrate |
| How many steps are involved in nitrification? | Two. Ammonia to nitrite, then nitrate. |
| What is the major end product of nitrification? | Nitrate |
| Does nitrification increase or decrease the pH? | Decreases |
| Is nitrification sensitive to soil water content? | Yes, available oxygen is needed for the reaction to occur. Soil water can form nitrous oxide. |
| What is denitrification? | The formation of nitrous oxide due to a lack of oxygen. |
| What are some common products of denitrification? | Nitric oxide, nitrous oxide, dinitrogen gas |
| Denitrification is a very common process carried out by microorganisms. | Yes |
| What is anammox? | The anaerobic oxidation of ammonium |
| How can active nitrogen be made from inert nitrogen gas? | Biological nitrogen fixation, Haber-Bosch process |
| What is biological nitrogen fixation? | The conversion of nitrogen gas into ammonia |
| What organisms carry out nitrogen fixation? | Specific bacteria, actinomycetes, and cyanobacteria |
| What is the key enzyme in biological nitrogen fixation? | Nitrogenase |
| What is the Haber-Bosch process? | The industrial process for producing ammonia from nitrogen |
| What are some consequences of nitrogen pollution? | Excess nitrogen causes blue baby syndrome, and causes eutrophication and dead zones |
| What are some ways to reduce the amount of nitrogen pollution? | Calculate application rates, pay attention to timing, avoid monocropping, use cover crops |
| What is a soil pedon? | A three-dimensional unit that represents the primaray characteristitcs of an individual soil |
| What is a polypedon? | A group of pedons |
| What do you get when you combine multiple polypedons? | Landscape |
| Taxonomy | The theory and practice of placing limits on organisms and classifying them |
| We can taxonomically classify soil material that has been influenced and modified by humans. | Yes |
| What is the upper limit of soil? | The boundary between soil and either air, shallow water, live plants, or plant materials that have not begun to decompose |
| Where is the lower limit of soil? | 2 meters |
| When are areas not considered to have soil? | If the surface is permanently covered by water too deep for the growth of rooted plants |
| What are diagnostic horizons? | Key horizons used to classify soils |
| What is a p edogenic horizon? | A horizon that describes processes that are occurring or having occurred |
| A and E | Zones of loss |
| B | Zones of subsurface accumulation |
| C | Zones of minimal to no pedogenesis |
| V | Desert |
| L | Aquatic |
| O | More than 12% organic carbon by weight |
| What is the difference between diagnosic and pedogenic horizons? | The thickness and degree of development |
| Are there diagnostic horizons for the soil surface or subsurface? | Yes |
| What are epipedons? | Diagnostic horizons that form near the soil surface and darkened by organic matter or show evidence of eluviation |
| The hierarchical grouping of natural soil bodies from broadest to most specific. | Order, Suborder, Great Group, Subgroup, Family, Series |
| What is used to define a soil order? | Soil forming processes |
| what is used to define a soil suborder? | Soil moisture conditions, climactic conditions |
| What is used to define a soil Great Group? | The absence or presence of diagnostic horizons and their arrangement |
| What is used to define a soil subgroup? | Gives additional information to the order |
| What is used to define a soil Family? | Particle size, mineralogy, exchange activity, soil temperature, and soil depth |
| What is a soil series? | A unique soil named after a geographic feature of where it was first identified |
| How many soil order are there? | 12 |
| Gelisols | el, glacic, permafrost layer within the top 2 meters, cryoturbation |
| Histosols | ist, histic, folistic, more than 40 cm of organic soil material, found it wet areas |
| Spodosols | od, ochric epipedon, albic, spodic, subsurface accumilation of OM with metals |
| Andisols | and, melanic epipedon, formed from volcanic ash, high content of volcanic glass, high content of amorphous or poorly crystalline material |
| Oxisols | ox, oxic, soils of the tropics, rapid decomposition, lack an organic horizon, low activity clays, uniform profile |
| Vertisols | ert, no diagnostic horizons, slickensides, more than 30% expansive clay, deep cracks, shrink-swell soils |
| Aridisols | id, Ochric epipedon, calcic, gypsic, salic, natric, desert soils |
| Ultisols | ult, ochric epipedon, umbric epipedon, albic, argillic, natric, kandic, subsurface accumulation of clay |
| Mollisols | oll, grassland soils, mollic epipedon, argillic, natric, albic, cambic, accumulation of organic matter but less than 12% of organic carbon |
| Alfisols | alf, orchic epipedon, umbric epipedon, albic, argillic, natric, kandic, subsurface accumulation of clay |
| Inceptisols | ept, cambic, calcic, gypsic, sulfuric, inception of A B horizon, forms under various environmental conditions |
| Entisols | ent, young soils, no diagnositc horizons in the top two meters, no unique soil process |
| Fine, kaolintic, thermic Rhodic Paleudalfs | Alfisols |
| Fine, smectic, thermic Udic Haplusterts | Vertisols |
| Sandy, siliceous, hyperthermic Aeric Alaquods | Spodosols |
| What happened with the famous "subsidence post" in south florida | The top of the post used to be the top of the land surface, when the area was drained to grow cash crops, the soil level decreased |
| What is crustal rebound and what are its impacts? | The rise of earth's crust after the removal of glacial ice |
| Why might we want to know if we have a spodosol? | Because they contain high concentrations of aluminum |
| We have one spodosol in east Texas. Where is it? | Big Thicket |
| Andisols have a high retention of phosphorus. Do you need to manage for phosphorus in andisols? | Yes, its not in an actively exchangeable form |
| Fine, smectic, thermic, vertic alorthods, list the taxonomic names | Order: Spodosols, Suborder: Orth, Great group: al, Subgroup: vertic, Family Fine, smectitic, thermic |
| This soil does not have a permafrost or gelic material within 200 cm of the soil surface. Has less than 40 cm of OM, lacks a spodic horizon, lacks andic soil properties, does not contain an oxic horizon, and exists in an arid region. | Aridisols, its in an arid region. |
| CRIFF | Cooperative Research in Forest Fertilization: a forest soil classification system |
| H CRIFF Classification | Depressions, very poorly drained |
| A and B CRIFF Classification | Savannas, very poorly to somewhat poorly drained |
| C and D CRIFF Classification | Flatwoods, very poorly to somewhat poorly drained |
| E CRIFF Classification | Uplands, moderately to well drained |
| F CRIFF Classification | Uplands, moderately well to well drained |
| G CRIFF Classification | Sandills, excessively well drained |
| Which of the CRIFF soils can you manage for loblolly or cash crops? | A, B, C, D, E, and F |
| What are some characteristics of A and B soils? | Poorly drained, leading to accumulated OM and extrime acidity, dominated by AL and H, high CEC leading to locking down of phosphorus |
| How should you manage A and B soils? | Bedding, fertilization with phosphorus and nitrogen at or near the time of planting |
| What are some characteristics of C and D soils? | Poor drainage, have a spodic hrizon, OM is translocated deeper into the profile, nitrogen and phosphorus limited |
| What is the difference between C and D soils? | D is slightly better drained |
| How should you manage C and D soils? | Bedding, manage for nitrogen and phosphorus |
| What are some characteristics of E and F horizons? | high clay content and good capacity to retain nutrients and moisture, excellent loblolly pine sites, better drained than A through D |
| How would you manage E and F soils? | Good for loblolly, may receive combinations of mechanical tillage and chemical site prep, may have to manage for phosphorus |
| What are some characteristics of G soils? | Dry, leached, acidic, low on macronutrients and micronutrients, not suitable for crops |
| What are some characteristics of H soils? | Excessive wetness and frequent flooding |
| What are the three spatial scales of soil variability? | Small scale, medium scale, large scale |
| What are some small examples of small scale soil variability? | Microtopography, thickness of parent material, organisms, and past management practices |
| What are two ways to reduce/account for small scale variability when sampling? | Increasing the size of individual samples and composite sampling |
| How does decreasing the diameter of your sample core influence the mass volume relationship of the sample? | Anything that's in contact with the wall of the core gets compacted, the larger the diameter, the less proportion of your sample can be touching the core. In large samples compaction is not a big issue. |
| What is medium-scale soil variability primarily due to? | Topography and parent material |
| What do landscape models do? | use an understanding of soil formation to predict what kinds of soils are likely to occur at different points in the landscape |
| What is a set of soils? | A sequence of soils that occur together on the landscape |
| What is a lithosequence? | A sequence in which the only thing that changes is the parent material |
| What is a chronosequence? | A sequence of soils in which the only thing that changes is age |
| What is a toposequence? | A sequence of soils where the changing characteristic is related to, or caused by, a change in relief |
| What is a catena? | A set of soils that has a change in two factors, drainage and relief |
| What are generally the four members of a catena? | Summit, shoulder, backslope, footslope |
| What is a soil association? | A grouping of individual soils that occur together in a predictable pattern on the landscape |
| What is large-scale soil variability likely due to? | Climate and vegetation, secondarily related to parent material differences |
| A map unit boundary provides an exact location where soil A yields to soil B | No, the boundary is just an estimate |
| What are the two approaches to delineating soil boundaries? | Grid pattern across the landscape and transects based on soil landscape relationships |
| What is a consociation? | A map unit with one obviously dominant soil type and only minor dissimilar components |
| What are complexes and associations? | Map units that contain two or more dissimilar components that occur in a regularly repeating pattern |
| What are undifferentiated groups? | Map units that consist of two or more components that are not consistently associated geographically |
Created by:
FireBat