question

the dimensions of the earth.

answer

Diameter: ~8000mi, Circumference: 25000mi, SA:200million mi^2, Earths crust: 35mi

question

2. Understand that definitions of soil depend strongly on the concerns of those making the definitions. so who?

answer

Agriculture, ecology/life, geology, environment, public health

question

the parameters related to soil composition for an idealized surface soil.

answer

45% mineral, 5% organic, 50% pore space

question

basic functions of soils in the environment.

answer

regulator of water supplies. medium for plant growth. habitat for biota. public health. storage of raw materials

question

4 basic processes involved in soil formation

answer

Transformations, Translocations, Additions, losses

question

Transformations

answer

Chemical or physical modifications of elements in soil. Weathering of Rocks and Minerals - Critical to Soil Formation Change in Size and Arrangement of Mineral Particles Decomposition/Alteration of Primary Minerals Synthesis of Reactive Secondary Minerals - Silicate clays, Fe/Al Oxides Elemental Transformation (e.g. Fe3+ Fe2+) Organic transformations: synthesis of Organic Acids, Humic materials, soluble organic compounds

question

Additions

answer

Input of organic matter from leaves, roots, organisms Input of dust particles on the soil surface, water-deposited solids Manure or fertilizer application

question

Losses

answer

Erosion of soil materials Decomposition of organic matter Movement of salts, clays, O.M.

question

Translocations

answer

loss of: Fe/Al oxides, Organic Matter, Iron and clay from water

question

the basics of weathering.

answer

Critical to Soil Formation, Physical and Chemical Alteration and Reorganization of Rocks and Minerals. Critical in the Creation of the Parent Material and Alteration of Parent Material to Secondary Components

question

What are the 2 types of weathering?

answer

Physical weathering; Chemical weathering

question

The breakdown of materials into smaller parts that allows them to be more chemically reactive is ______ weathering

answer

physical

question

By ______ weathering, we alter/reorganize precursor minerals into secondary minerals.

answer

Chemical *most precursor minerals are aluminum + silicon

question

In the presence of oxygen, Fe2+ converts to Fe3+ which forms relatively insoluble oxides of iron, producing a "rusty" coloring. This is an example of a ____________

answer

transformation

question

Which are more reactive, precursor minerals or secondary minerals?

answer

Secondary minerals are the seat of the chemical reactivity

question

Weathering of primary minerals releases Fe2+ which is soluble in water is also subject to ________ downward.

answer

translocation

question

the 5 soil forming FACTORS and what they mean or imply.

answer

Parent Material - original material Climate - temperature, moisture Organisms/biota - vegetation, macro, micro Relief (Topography) - altitude, slope Time - controls extent of other factors

question

What type of parent material dominates Florida's soils?

answer

Florida's P.M. are derived from: Sandy+ Clayey Marine & Alluvial Sediments deposited over BEDROCK alluvial = from streams & rivers marine = from oceans

question

5 Sources of Parent Materials: (explain each) 1) Residual 2) Alluvial 3) Marine 4) Eolian 5) Glacial

answer

1) Residual = formed in place from ROCKS & MINERALS 2) Alluvial = deposited by RIVERS & STREAMS 3) Marine = deposited by OCEANS 4) Eolian = deposited by WIND 5) Glacial = deposited by ICE

question

origin of the sediments that ultimately formed the parent materials for Florida's soils.

answer

Parent Materials Resulted from Influx of Continental Sediments (Marine ; Alluvial)

question

parent material

answer

Original Material

question

Climate

answer

Temperature, Moisture

question

Organisms/biota

answer

Vegetation, Macro, Micro

question

Relief (Topography)

answer

Altitude, Slope

question

Time

answer

Controls extent of other factors

question

How does temperature and rainfall impact soil formation?

answer

it ACCELERATES soil formation: Heat increases rates of physicochemical processes Water increases weathering rates and translocations

question

Why do soils in Florida tend to be more highly developed than soils in the S.W. United States?

answer

It is due to climate: High temperatures and rainfall accelerate soil formation Heat increases rates of physicochemical processes; Water increases weathering rates and translocations

question

What is pedogensis?

answer

The process of soil formation as the result of the combination of soil forming FACTORS and PROCESSES

question

What are soil horizons?

answer

Roughly parallel layers in the soil with varying composition and properties

question

6 master horizons discussed and be able to identify/recognize features of each.

answer

O A E B C R the Octopus Ate Emily Because the Crabs Ran (free)

question

O horizon

answer

ORGANIC Organic horizon formed above the mineral soil. Derived from decomposition of plant and animal residues At least 20% organic Range in thickness from absent to meters thick.

question

A Horizon

answer

ABOVE Topmost mineral horizon (topsoil) Subject to significant weathering Accumulates organic material Often darker than soil below. High in plant roots, biotic activity Zone of gas and water exchange

question

E Horizon

answer

EXIT Zone of Eluviation, E = Elluviation = exit, Maximum Losses by Translocation: (Organic matter, Clays, Carbonates, Fe, Al oxides) Generally LIGHT colored (contains resistant primary minerals)

question

B Horizon

answer

BUILD UP ZONE (accumulation zone) Accumulates material lost from above, or forms in place. (translocation, transformation) Usually a Zone of Illuviation (additions, translocation). Clay, O.M., Fe/Al, salts Soil structure Potential color development Potentially HIGH reactivity (concentration of secondary minerals/O.M.)

question

C Horizon

answer

COPY CAT zone - (copies parent material) Closely resembles parent material Unconsolidated Little or no evidence of Alteration or development

question

R Horizon

answer

RESTING in bed zone bedrock

question

Subordinate Distinctions of the O horizon: Explain Oa, Oe, Oi:

answer

Oa-HIGHLY decomposed organic material (sapric) Oe-Moderately decomposed organic material (hemic) Oi-Slightly decomposed organic material (fibric)

question

A horizon subordinate distinctions:

answer

p = disturbed, plowed

question

Subordinate Distinctions of the B Master Horizon: Explain: Bt, Bh, Bw, Bg

answer

Bt=accumulation of silicate clays Bh=illuvial accumulation of organic matter Bw="Weak" development of color or structure Bg=Gleying - wet, low oxygen

question

Accumulation of silicate clays is what B subordinate horizon?

answer

Bt

question

Illuvial accumulation of organic matter is what B subordinate horizon?

answer

Bh (dark colored bc lots of O.M. and many Bh horizons are called spodic horizons)

question

What is the basic relationship between time and the extent or degree of soil development?

answer

Longer time =; greater development

question

What is Vertical horizon subdivisions vs Transitional horizons?

answer

Vertical: Characterized by similar master and/or subordinate properties separated by "degree". (ex. Bt1, Bt2, Bt3 increasing clay content --->) Transitional Horizons: layers BETWEEN master horizons-in between subordinate and dominant (ex: A---> AE---> and then E) (the first letter listed is the dominant character)

question

What color would we expect soil to be with: a) Organic matter b) Iron oxides c) Removal of materials

answer

a) Grey to Black- Organic Matter b) Orange to Red- Iron oxides c) Light Colors- Removal of materials

question

What are the 3 components to soil color?

answer

HVC: Hue, value, chroma

question

What soil color component is the dominant spectral color; related to the wavelength of light?

answer

Hue (Related to the proportions of red to yellow. so 10YR has both yellow and red)

question

What soil color component is related to total amount of light reflected? (aka how light/dark the color is)

answer

Value

question

What is the measure of the strength of spectral color?

answer

Chroma

question

10YR 6/3

answer

Hue: 10 YR Value: 6 Chroma: 3

question

When it comes to value ( going up/down the chart), what value would you expect a LIGHT soil color to have?

answer

High value = light color Low value = dark color

question

What are the 3 particle size separates?

answer

Sand Silt Clay

question

Which particles size separate has a size range of: (2.0 - 0.05) (0.05 - 0.002) (;0.002)

answer

Sand (2.0 - 0.05) Silt (0.05 - 0.002) Clay (;0.002)

question

What are the dominant minerals in: (a) Sand (b) Silt (c) Clay

answer

(a) Sand = Quartz (b) Silt = Quartz/Feldspar (c) Clay = Secondary minerals

question

(T/F) Sand and silt fractions are dominated by secondary minerals The clay fraction is dominated by reactive primary minerals

answer

FALSE: Sand and silt fractions are dominated by primary minerals The clay fraction is dominated by reactive secondary minerals

question

____ _______ refers to the relative amounts of three distinct particle size separates comprising the mineral component of soils.

answer

soil texture

question

What indicates the maximum volume of water and gases a soil can hold?

answer

Total porosity

question

How does texture generally affect overall porosity?

answer

All else being equal, finer-textured soils have GREATER overall porosity than coarse-textured soils. (this is due to greater surface area in fine soils!!)

question

How does texture generally affects pore size distribution?

answer

Large Particles Yield Large Pores Fine particles yield small pores

question

How does texture affect water and gas movement in Coarse- textured soils?

answer

Large Pore Spaces Rapid Water Movement Poor Water Retention Gas Exchange Facilitated

question

How does texture affect water and gas movement in fine- textured soils?

answer

Pores are small and convoluted Clay-Air and Water Movement is Very Slow Water Retention is High (holds H20 well!!)

question

Be able to use the soil textural triangle: (a) 70% Sand, 20% Silt, 10% clay would be what kind of soil? (b) 25% sand, 45% silt, 30% clay

answer

(a) Sandy Loam (b) Clay Loam

question

How many textural classes are there?

answer

Depending on the relative proportions of these three particle size fractions, soils are assigned 12 different soil textural classes.

question

What is relationship between soil texture and specific surface area; why is it important?

answer

Water Movement and Potential Reactivity

question

What does Stokes' Law indicate and how can it is used in the hydrometer method to assess soil texture?

answer

Stokes' Law allows determination of the time required for different particle size separates to settle from a suspension. Determination of the amount of materials settled --> yields texture 1 minute = Sand settles out 6 hours = Silt settles out

question

What is the equation for Stoke's Law:

answer

V = K D^2 K (constant)= 11,241 cm-1,sec-1 D= Diameter of particle size

question

Sand with a diameter (D) =1 mm will settle how fast ?

answer

D= 1 mm -> convert to cm D= 0.1 cm V= (11,241)* (.1)^2 = 112.4 cm/sec

question

Explain the hydrometer method and how to calculate % sand, silt, and clay given appropriate measurements.

answer

As particles settle out, the suspension becomes less dense. The hydrometer measures the density of the suspension. The units are g/L. In dense suspensions, the hydrometer floats higher in less dense suspensions it sinks. is calibrated to read zero in pure water at 20 degrees.

question

hydrometer method

answer

Add __ g soil to 1 liter of water 1 min, difference in g is sand settled. 6hrs is clay. put each __g over full __g amount *100%= measurements

question

If you add 40g of soil to 1 L of water and at t= 1 min density = 10g/L. What is the percent of sand?

answer

Sand settled= 40g- 10g = 30 g Sand % = 30g sand/ 40 g soil x 100= 75%

question

Using the initial 40g of soil added to 1 L of water: At t= 6 hours density = 4 g/L; what percent is silt? clay?

answer

Clay content = 4 g/L % Clay: 4g/ 40 g X100 = 10% %Silt: 100 - (75+10)= 15%

question

What numerical value for soil particle density.

answer

2.65 g/cm3

question

T/F: For finer-textured soils there is a lower specific surface area thus decreasing reactivity

answer

False: Fine-textured soils = greater Specific surface area therefore are exposed to more and are reactive!

question

How is soil bulk density computed? and what it is.

answer

BD = (mass O.D. soil)/ (volume solids + pores) Density of soil INCLUDING the particles and the pore spaces. Based on the Number of Particles Packed into a Given Volume B.D. ranges between 1.0 and 1.6 g/cm3 (for mineral soil with 1 - 5% organic matter)

question

How texture, organic matter, aggregation, compaction, and depth in profile affect porosity and bulk density.

answer

Organic matter increases porosity, decreases BD Aggregation increases porosity, decreases BD Depth in profile decreases porosity, increases BD Compaction decreases porosity, increases BD

question

Factors which increase porosity, ______ density

answer

decrease

question

Know the range in bulk densities for a typical mineral soil containing approximately 1-5% organic matter.

answer

BD of typical mineral soils = 1.0 - 1.6g/cm^3

question

If BD is high then porosity is ? If BD is low then porosity is?

answer

Bulk density high - porosity low Bulk density low - porosity high Factors which increase porosity, decrease density.

question

What indicates the SIZE / diameter of pores?

answer

Pore size distribution- Macro, Meso and Micropores. macropores > 0.08 mm in diameter large, freely draining sands, inter-aggregate pores large enough to accommodate roots Mesopores Moderate Size 0.08 - 0.03 mm Retain water well against drainage Accommodate fungi and root hairs Micropores < 0.03 mm in diameter small, storage of water Accommodate Bacteria clays, intra-aggregate pores

question

What indicates the fraction of a total soil volume that is pore space/ indicates the maximum volume of water and gases a soil can hold?

answer

Total Porosity

question

What is the reactivity for: Fine-Textured Soils Compacted/Uncompacted Soils High / Low Density Soils High Organic Matter Soils

answer

Fine/compacted/high density = Small pores slow water and gas movement, but increase contact between soil solution and soil particles, INCREASING reactivity (think: this is why clay is so reactive.. bc very fine textured!)

question

(T/F): High organic matter content decreases bulk density

answer

True: High organic matter increases porosity, decreases BD

question

What soil structure is and how it affects soil porosity and pore size distribution?

answer

it affects: the movement of water into and through soil; the degree of aeration; the ability of crop roots to grow through the soil profile; and the ability of the soil to resist soil erosion. Large pores drain freely, small pores store water effectively Poor soil structure can inhibit infiltration of water, water movement, growth of roots.

question

what type, class, and grade indicate relative to soil structure. Know the structural types

answer

types( shapes): Granular,Platy,Block-like, Prism-like class(size), grade (strength)

question

How texture, density, and structure impact water and gas movement and potential reactivity: Fine textured: would react with gas/ H20 slower and therefore be more reactive Course textured- would react with gas/H20 quickly; lower reactivity High density: the higher the density the slower the H20/gas movement There is _____ movement between aggregates and ____ movement around aggregates?

answer

Spheriodal soils have a granular structure. The aggregates are 1- 10 mm (1/25- 2/5 in.) in diameter with rounded corners. This structure is usually seen in the A horizon or the upper layer of fine or medium-textured soils. Granular structure in the seed or transplant zone is important for good contact and early establishment. Blocky soil aggregates are often larger in size (5- 50 mm or 1/5- 2 in. in diameter) and form irregular-shaped or cube-like blocks. This structure promotes good drainage, aeration and root penetration. Usually these structures are found in the B horizon or just below the colour change in many soils. Blocky structures greater than 50 mm (2 in.) in diameter are often an indication of compaction or soil management problems. Platy soils form thin layers or horizontal planes. This type of structure can be found in both surface and subsurface soil horizons. It is commonly seen in undisturbed or no-till soils. Platy structures in sandy soils often indicate compaction problems.

question

Fine textured: would react with gas/ H20 _______ and therefore be more reactive Course textured- would react with gas/H20 quickly; ______ reactivity High density: the higher the density the _______ the H20/gas movement There is _____ movement between aggregates and ____ movement around aggregates?

answer

(a) - slower (b) - decrease (c) - slower (d) slow movement between aggregates but fast movement AROUND aggregates Small pores = Intra-aggregate pores ( within ) Large pores= Inter-aggregate pores ( between)

question

T/F: Large pores drain freely, small pores store water effectively

answer

TRUE

question

What is the boiling and freezing point of water?

answer

The freezing point of water, of course, is 0 degrees Celsius and the Boiling point is 100 degrees Celsius, giving us a liquid range of 100 degrees.

question

How hydrogen and oxygen are bonded within a single water molecule? Know the name of the bond.

answer

The bonding of hydrogen and oxygen in a water molecule is covalent. The hydrogen atoms share their single electron with oxygen thereby completing its valence shell, while oxygen, in turn, shares one of its lone electrons with each hydrogen completing their valence shells.

question

How is water made polar?

answer

Oxygen is highly electronegative, in a chemical bond, electrons tend to be drawn toward oxygen, and away from other atoms to which it is bonded. The electrons tend to cluster near the oxygen The overall electrical charge on the molecule is zero, There is a slight partial negative charge near the oxygen atom, and a slight partial positive charge near the hydrogen atoms in the molecule

question

Polarity and how it impacts bonding between water molecules in the liquid and solid.

answer

So, in liquid as well as solid water or ice, water molecules are linked together electrostatically which imparts unusual stability and strength. This accounts, for example, for water's unusually HIGH boiling point compared to other liquids. H20 is a polar molecule, the bonds between O and H are shared mutually but NOT equally. So any H2O molecules near by will orient themselves to H-bond with each other. (Tends to keep water in the liquid phase at higher temperatures than compositionally similar liquids like hydrogen sulfide. So, evaporation requires far less energy resulting in a much lower boiling point.)

question

What is the name of the bond that exists between water molecules in the liquid and solid state?

answer

Hydrogen bond. (An electrostatic bond is established between the water molecules; transitory, but extensive, occurring between each water molecule and an average of between 3 and 4 neighboring molecules at any given time.)

question

Which is more dense: solid water or liquid water?

answer

Solid water = less dense (less molecules in ice) Liquid water = more dense (more molecules) As water cools, it becomes more dense until it reaches a temp of about 4 degrees C. Hydrogen bonding gives water great stability!! And results in a number of unusual properties Cohesion - attraction between water molecules

question

What is the definition of heat capacity? And the value for water?? (Note the units)

answer

heat capacity = The amount of heat input required to raise the temperature of 1 g of a substance by 1oC. (cal/g· C) 1.0 for water

question

What is heat of vaporization?

answer

It is the amount of heat input required to VAPORIZE water (turn from liquid to a gas) Water = HIGH heat of vaporization.

question

Why does water have such a HIGH heat capacity relative to other common liquids like alcohol?

answer

Because of extensive H-bonding in water! When heat is added to water, the molecules speed up or vibrate more freely. This disturbs hydrogen bonds, but causes only a small change in temperature, because much of the heat energy is used to break or disrupt the hydrogen bonds heat capacity = 1.0 for water

question

Why is water SLOW to evaporate compared to other common liquids?

answer

Because of H-bonding !! for H20 to evaporate, all the strong H-bonds must broken so it takes awhile. Also has a HIGH heat of vaporization -; meaning that will take a lot of energy input to turn it to a gas.

question

How heat capacity impacts body temperature.

answer

Extensive Hydrogen Bonding Allows Water to exist as a Liquid at Normal Temperatures And across a wide range in temperatures (your body ca

question

How heat capacity impacts soil temperature.

answer

It is very difficult to evaporate water (alot of energy required), which is good because it keeps soils moist. Soil temperature largely is controlled by moisture (soil water content) Heat energy is required to break hydrogen bonds between water molecules, and heat is released when hydrogen bonds are formed.

question

Why is water relatively SLOW to evaporate?

answer

The addition of heat to water causes a relatively small change in the temperature of the water, because much of the heat energy is used to disrupt the hydrogen bonds.

question

How can we calculate water content on a WEIGHT basis?

answer

Weight=( Moist-Dry weight) /(dry soil weight) X 100%

question

You collect a 200 cm3 soil sample. Its moist weight is 150 g. After drying, the dry weight is 100 g. What is the gravimetric water content?

answer

Grav. water content = (150g- 100g) / (100g) x 100% = 50%

question

How can we calculate water content on a VOLUME basis?

answer

Volume= Vwater/Vsoil x 100% (1cm^3=1 g)

question

You collect a 200 cm3 soil sample. Its moist weight is 150 g. After drying, the dry weight is 100 g. What is the volumetric water content?

answer

Vol. water content = volume water/ volume soil x100% = 50 cm3 / 200cm3 = 25%

question

(T/F): The soil water content depends on the amount of pore space filled.

answer

True

question

At saturation the volumetric water content = ?

answer

total porosity So if soils are completely saturated with a volumetric water content of 75%, what is the total porosity? Tp = 75% also!!! Vol. water content = Total porosity @ saturation !!!!

question

What are the 2 forces that are responsible for water movement in soils?

answer

Gravity Capillarity

question

What 2 forces make up Capillarity? (spontaneous movement of water into /thru pore spaces in soil without the aid of gravity)

answer

Adhesion: attraction of water molecules to a surface (they ADHERE to a surface) Cohesion: attraction of water molecules to each other (they all "hold hands")

question

How do adhesion and cohesion work together to create capillarity in soils?

answer

There is Adhesion to the tube or pore wall and there is Cohesion between water molecules

question

T/F: Capillarity (and gravity) move water in saturated soils

answer

FALSE: Capillary and gravity move water in UNSATURATED soils (bc saturated soils can't hold any more water)

question

If a pore radius decreases, how will this impact capillary forces?

answer

pore radius decrease, capillarity increase If pores shrink; capillarity forces become stronger

question

1) Describe the capillary forces in a loose, sandy soil: 2 ) what dominates: capillary forces or gravity? 3) Where will water move?

answer

Loose sand = large pores spaces Capillary forces will be weak, gravity dominates Water will move mostly downward

question

1) Describe the capillarity forces in a compacted clayey soil: 2) what dominates: capillarity forces or gravity? 3) Where will water move?

answer

1) compacted clay = small pore radius = strong capillary forces 2) capillarity forces dominate 3) Water will move multi-directionally

question

What are the capillarity strength's for: Particle/pore size = Large, medium, small

answer

Large particle/pore = weak capillarity Medium = moderate capillarity Small = strong capillarity

question

Macropores would have ______ capillarity forces

answer

weak (not much water being sucked through large area)

question

T/F: Any factor that shrinks pore diameter, tends to increase the strength of capillary forces which will increase the overall influence of Capillary forces relative to Gravity

answer

TRUE

question

how porosity differences due to structure would exert different capillary forces on water.

answer

Macropores = weak capillarity / Micropores = strong capillarity

question

At saturation, all the water movement will be by ________

answer

At saturation, all the pores are filled and capillary forces are satisfied. All water movement will be by GRAVITY

question

As water content in a soil decreases,_____ pores empty first and the size of the pores still holding water also decreases

answer

large

question

As water content in a soil decreases, what happens to the capillary forces?

answer

Thus, capillary forces become STRONGER and begin to control water movement

question

Gravity dominates flow at ____ water contents Capillarity dominates flow at _____ water contents

answer

high low

question

Energy waiting to be used or exploited

answer

potential energy

question

The greater the height, the _______ the gravitational potential energy.

answer

GREATER Gravitational potential energy is due only to the height of an object (water) above a reference point. The higher the elevation the greater the energy.

question

What are the units of gravitational potential energy?

answer

Units are Cm of height above a chosen reference level.

question

The choice of a reference point for gravitational potential is arbitrary. T/F

answer

True (Know that the choice of a reference point for determining gravitational potential up to you.)

question

Is gravitational potential energy independent or dependent on soil properties?

answer

gravitational potential energy is NOT impacted by soil properties; just by height from the reference level. so it is independent of soil properties

question

Capillary potential energy applies to what types of soils? (sat / unsat

answer

Matric/Suction Potential Energy Applies to unsaturated soils In a saturated soil, this quantity would be zero, since all the pores are filled. Therefore, quantification of matric potential energy will apply to unsaturated soils.

question

What "Relates to the ability or potential of soils to move water into pores without gravity" ?

answer

Capillary Potential Energy

question

The matric/capillary potential energy of an unsaturated soil is always _______

answer

NEGATIVE more negative = stronger capillary forces

question

Which would have the stronger, more negative, capillary forces: Clay or sand?

answer

Clay = small pores = STRONG capillary forces (would have a highly negative potential) Sand = large pores = WEAK capillary forces

question

Is Pressure potential energy positive or negative when strong?

answer

Positive In soils, submergence potential is measured based on the depth below a water table. The soil in this case is saturated and will exert a pressure downward, forcing water through the pore spaces below resulting in flow. In this case the pressure is positive rather than negative as is the case for matric potential which is operating in the capillary fringe, drawing water above the water table.

question

Equal to the distance below a free water surface =

answer

Pressure potential

question

Which would have the stronger, more negative, capillary forces: Dry or moist soil?

answer

Dry = Stronger (the urge to suck any available water is high) Moist = weaker

question

T/F: Pressure potential only occurs under saturated conditions.

answer

True

question

Calculate TOTAL potential energy at a given point in a soil given the appropriate parameters.

answer

Total Potential Energy=?g +?m + ?p

question

What is plant available water?

answer

Plant Available Water = Field Capacity - Permanent Wilting Point (Water left in previously saturated soil after its been drained by gravity) - (water that plants can't access)

question

Know how to determine if water will flow between two points in a soil and the direction of flow.

answer

Water will always flow from areas of high total potential to low total potential. to do this: Sum the individual potentials at each point Determine if there is a difference in potential between points

question

How can we calculate gradient? (The driving force for water flow)

answer

Gradient = (TpA- TpB ) / (dist. b/t A & B)

question

Know that the greater the gradient, the _______ the driving force for water movement.

answer

stronger

question

T/F: Water moves in response to capillary potential energy only.

answer

FALSE: Water moves in response to differences in TOTAL potential, not just one potential

question

The ease with which water moves through soils is:

answer

Hydraulic conductivity

question

(a) Texture - small particles = small pores = ______ conductivity (b) Density - high density suggests _____ porosity and small pores (c) Structure - inter-aggregate macropores ______ conductivity (Between Aggregates)

answer

(a) poor (b) low (c) improve

question

How do we combine hydraulic conductivity and the gradient to determine overall Flow of water in soils? Note the units of flow.

answer

Hydraulic conductivity is determined by measuring the volume of flow through a cross sectional area of soil per unit time Darcy's Equation: Q = K * gradient in cm/hr

question

10YR 5/10

answer

hvc, color in middle of hue yellow-red, 5 medium value(lightness), chroma of 10

question

gravitational potential energy

answer

independent of soil properties due only to the height of an object (water) above a reference point. The higher the elevation the greater the energy. Units are centimeters of height above a chosen reference level.

question

Capillary Potential Energy

answer

Applies to unsaturated soils Relates to the ability or potential of soils to move water into pores matric and Suction Potential

question

capillary pot energy in saturated soils

answer

. In a saturated soil, this quantity would be zero, since all the pores are filled

question

Soil Texture and Matric Potential

answer

Fine-textured soils generally exert stronger capillary forces than do coarse-textured soils because pore sizes are smaller.

question

total potential engergy

answer

Total Potential is the Sum of the Gravitational, Matric, and Pressure Potentials Water moves in response to differences in total potential energy between two points

question

units of potnetial

answer

cm of water

question

What are the 7 existing orders in Florida?

answer

Entisols Ultisols Inceptisols Alfisols Mollisols Spodosols

question

T/F Ultisols are "young soils" weakly developed sandy or clayey

answer

FALSE: Entisols = young soils/ weakly developed!!

question

T/F Bt soil means that there is an accumulation of silica clay

answer

TRUE

question

Bt soil is REQUIRED for Alfisols and _____

answer

Ultisols

question

Which is associated with ACIDIC vegetation and is formed under wet conditions? Also it is often very poorly drained and contains Pine Flatwoods?

answer

Spodosols

question

T/F Spodosols are the #1 soil in state of FL

answer

TRUE State soil: Myakka Fine Sand

question

"p" applies to which horizon?

answer

A p - plowed / disturbed

question

(T/F) Stokes' Law determines the density of a soil suspension.

answer

False - hydrometer measures the density of a suspension

question

(T/F) Water has exceptionally high electronegativity.

answer

True

question

(T/F) Water's POLARITY is directly responsible for many of its unusual properties.

answer

True

question

(T/F) The strength of capillary forces is inversely related to the radius of the pore space.

answer

True

question

(T/F) The high heat capacity of water makes it a good coolent to use in condensers to keep from over heating.

answer

True- because water can absorb alot of heat and not increase temperature that much

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