Soil Science

These are able to grow into the litter layer?

Fungi

Which are organisms that are responsible for breaking down waste from all levels?

Decomposers

This letter signifies strong mottling within the master horizon. Which is? __________

G

An area that receives very small amount of precipitation where rooting depth of plants is limited by the presence of permafrost and growing season is extremely short will likely feature this soil order. Which is?

Gelisol

Soil classified as the Turbel suborder are part of this soil order. Which is?

Gelisol

The soil structure peds that resemble bread crumbs are called _____.

Granular

This/these force(s) is/are at play in soil that is fully saturated after a major rain event. Which is/are?

Gravitation, Adhesion, Cohesion

This soil water potential is defined only by the position of an object about some reference point. Which is?

Gravitational

Soil classified as the Torrox suborder are part of this soil order. Which is?

Oxisol

Soil classified as the Rendoll suborder are part of this soil order. Which is?

Mollisol

The fixation of nitrogen is a unique role of?

Mutualists

Two organisms living in beneficial association, such as lichen and mycorrhizae are?

Mutualists

Cation Exchange Capacity of soil can be measured by several different techniques. One of them involves quantification of only one cations in a supernatant. Treated soil sample is first equilibrated with high concentration solution of this monovalent cation, effectively desorbing any other cation from the CEC sites, and treated sample is subsequently extracted with a solution of a divalent cation which is high on the adsorption series. What is the measured cation?

NH4+

From the list of cations that commonly occupy cation exchange sites in soil select all bases.

Na+

Desert grass displacing shrubs can lead to a decrease in SOM.

True

Which of the following is considered the active fraction of organic components in soil?

Decomposing Organic Matter

What are different ways of measuring microbial activity using activity levels?

Decomposition Rates

Rill erosion is erosion that occurs in __________ formed by __________ flow.

Small Channels, Concentrated

Wilt Point defines water held in the soil that is _____.

all at a potential that is too small for plants to absorb

Soils modify ________

(atmosphere, the atmosphere)

The largest pool of this essential, non-mineral plant macronutrient: __________, in nature are diatomic molecules of __________.

(nitrogen, N, oxygen, O) - (nitrogen gas, N2, N2(g), N2 gas, oxygen gas, O2, O2 gas, O2(g))

Soils recycle and store plant __________ and __________.

(nutrient, nutrients) - (carbon, C, SOM, soil organic matter)

Soils provide support for man-made ________

(structure, structures)

Potential energy is equal to -10,000 cm. What is approximately its equivalent in bars?Hint: 1 bar = 1020 cm water (4°C), 1 kPa = 10 cm water, 1 bar = 100 kPa

-10

Positive feedback from heavy continuous grazing followed by drought includes:

-An increase in size of bare spaces

Organize categories used in soil taxonomy in the descending order, i.e. start with the largest, least specific category and end with the most detail category.

1. Order

What are ways to measure the level of microbial activity?

-Counting

Biospheric cycling includes the cycling of:

-Energey

5. 35 cmolc/kg soil

1. Sand

List the items in order of largest C:N ratio to smallest C:N ratio.

1. Sawdust

Select all that apply to soils with high buffering capacity.

-are clay-rich

Common electron acceptors in soil environment have different affinity for electrons, i.e. as the redox potential (Eh) of soil solution decreases different acceptors become important. Order the electron acceptors from the highest to the lowest Eh.

1. O2(g) oxygen gas

Select common sources of microbial food in soil environment.

-organic residue

3. Intermediate

1. Toeslope

6. soil organic matter

1. White

The silt-size soil particle will have diameter between _____ and _____ mm.

0.002, 0.050

Tropospheric CO2(g) content has increased since the onset of the Industrial Revolution. Before the 19th century, global average was about 280 ppm. What is it now?

0.040% by volume

The sand-size soil particle will have diameter between _____ and _____ mm.

0.050, 2.0

Approximately how deep is going to settle particles of very fine aka 'sugar' sand (d=0.1 mm) in soil suspension over eleven seconds? k=8.99×105/(ms)

0.1 m

Calculate the height of capillary rise in macropore of medium size, d=3000 µm.

0.10000 mm

What is the approximate effective diameter of particles that settle one meter in soil suspension over one minute? k=8.99×105/(ms)

0.14 mm

In 2011 how many hectares of arable land was there per capita?

0.20

The height of capillary rise is __________ correlated with the radius of soil pore.

0.20000 mm

Thickness of clay mineral sheets depends on the ration of tetrahedral to octahedral sheets, but has a definite boundaries. Which are?

0.72-1.25 nm

What number best represents "low brightness" of the soil?

1

Potential energy is equal to 10,000 cm. What is its equivalent in Pascals (Pa)?Hint: 1 bar = 1020 cm water (4°C), 1 kPa = 10 cm water, 1 bar = 100 kPa

1,000,000

Agricultural topsoil will usually have SOM ranges between?

1-6%

8. Platy

1. B

You were asked to calculate the infiltration depth (h) for a rain event. Arrange following steps in the correct order.

1. Calculate the volumetric water content at field capacity (θvFC) and the volumetric water content at the time of the rain event (θvrain)

You were asked to calculate the Available Water Content (AWC) for a soil. Arrange following steps in the correct order.

1. Calculate the volumetric water content at field capacity (θvFC) and the volumetric water content at wilt point (θvWP)

Order the following stages of erosion from beginning to end.

1. Detach

5. little deposition / mostly erosion

1. Footslope

Order the possible number of existing species of different groups from largest to smallest.

1. Fungi

4. roughly cube-like peds with either rounded or sharp edges, 5-50 mm

1. Granular

Products of reduction of the common electron acceptors in soil environment can be ranked by the redox potential (Eh) of soil solution. Order these reduced species starting with that formed at the highest Eh.

1. H2O water, either as vapor or liquid

Order the following places in highest percentage of planted crops in total arable, rain-irrigated land to lowest.

1. India

3. 150 cmolc/kg (the same unit as meq/100 g)

1. Kaolinite

Order clay minerals on the list in the order of increasing CEC, i.e. from the lowest to the highest CEC.

1. Kaolinite

12. Silt

1. Micro

12. Sandy Clay Loam

1. Moderate

Calculate the amount of CaCO3 which must be added to an acre furrow slice of highly weathered soil to raise the soil's base saturation to 65%. Soil: CEC = 11 meq/100 g soil & BS = 45%

1.1 tons

From the following options for bulk density select one that could most likely represent loamy soil.

1.40 g/cm3

Calculate the height of capillary rise in micropore, d=0.030 mm.

10 mm

What is the ballpark value for the efficiency of energy conversion between trophic levels?

10%

Calculate the amount of CaCO3 which must be added to an acre furrow slice of highly weathered soil to raise the soil's base saturation to 60%. Soil: CEC = 9 meq/100 g soil & BS = 48%

1080 lb

If a soil is allowed to get very dry so that the %water by volume is 4% , when the %water by volume at FC is 16%, what would be the depth of wetting, how deep will the rain penetrate into the soil, if it rains rains 1.55 inches? [Hint: Assume the rain fills the soil to field capacity before moving deeper into the soil AND water volume (rain fall) = inches of soil × %water by volume change between FC and current condition]

13 Inches

If a soil is allowed to get very dry so that the %water by volume is 4% , when the %water by volume at FC is 16%, what would be the depth of wetting, how deep will the rain penetrate into the soil, if it rains rains 1.55 inches? [Hint: Assume the rain fills the soil to field capacity before moving deeper into the soil AND water volume (rain fall) = inches of soil × %water by volume change between FC and current condition]

13 inches

A 405 g soil sample was collected from the field in a 400 mL container and after it was oven dried the sample weighed 352 grams. The percent water by volume at collection time would be? [Hint: %water by volume = volume of water (or weight) ÷ volume of soil]

13.3%

In order for the cohesive forces to play important role in soil's bearing strength its clay content needs to be at least __________ percent.

15

Estimate negative charge of bulk soil that contains 1% SOM (300 meq/100 g), 5% smectite (150 cmolc/kg) and 15% illite (30 meq/100 g).

15 cmolc/1 kg soil

Estimate negative charge of bulk soil that contains 10% SOM (150 meq/100 g) and 20% illite (20 meq/100 g).

19 meq/100 g soil

Phyllosilicate group minerals have this Si to O ratio. Which is?

1: 2.5

Fresh water represents _____% of water found on the Earth.

2.75

Estimate negative charge of bulk soil that contains 5% SOM (200 meq/100 g) and 10% smectite (100 cmolc/kg).

20 cmolc/kg soil

Groundwater represents _____% of fresh water found on the Earth.

25.5

Soils may have a range of Cation Exchange Capacity (CEC) values. Select a high, but realistic, CEC value for bulk soil.

29 cmolc kg-1

Non-cultivated soils will have SOM ranges between?

3%-10%

In What percentage of global soil resources are forest and woodlands?

30%

Soil moisture represents _____% of water that is accessible for rapid exchange with atmosphere.

33

Munsell color system is a _____ arrangement of possible combinations.

3D

What number best represents "medium darkness" of the soil?

4

Soils may have a range of Cation Exchange Capacity (CEC) values. Select a low, but realistic, CEC value for a bulk soil.

4 cmolc kg-1

This word describes a set of related soils in the landscape that differ, one from another, primarily as a result of differences in the age of parent material. Which is? __________

Chronosequence

The weight of a graduated cylinder is 54 grams, the cylinder is filled with 85 mL of oven dry field soil. The weight of soil and cylinder is 186 grams. Subsequently the soil sample is filled with water. The water is poured carefully and very slowly into the cylinder until all the soil pores are filled with water. The amount of water that this would take is about ______ mL. [Note: Use the formula PS=100-(100xBD/PD) and Assume PD=2.65 g/cm^3]

41

From the following options for soil porosity select one that could most likely represent loamy soil.

47%

A soil has 13.5% total available water holding capacity (AWC). Assume the soil is at field capacity and plant roots are in the upper 30 inches of this soil. If the plants use 0.8 inches of water per week, how many weeks until the wilt point is reached? [Hint: Volume of water = %water by volume × thickness of soil AND Length of time = volume of water ÷ water use per week]

5

SOM contains an estimate of what amount of organic Carbon?

50%

Among following values select one that could represent saturated hydraulic conductivity of soil suitable for most agricultural uses.

5×10-6 m/s

Approximately how deep is going to settle particles of medium silt (d=0.01 mm) in soil suspension over eleven minutes? k=8.99×105/(ms)

6 cm

You have a very light Styrofoam box that you fill with soil. You place the box in the garage and forget about it for a few months during the summer. The garage is pretty hot and the soil eventually becomes very dry. You later pick up the box and determine the box and soil weighs about 138 lbs. Approximately, what is the bulk density of the soil in lbs/ft^3? (Box: l=24 in. w=18 in. h=8 in.)

69

Calculate the amount of CaCO3 which must be added to an acre furrow slice of soil to raise the soil's base saturation to 85%. Soil: CEC = 25 cmolc/kg soil & BS = 28%

7 t

If a soil has 32% water by volume at field capacity and 10% water by volume at wilt point. What is the total potential Available Waterholding Capacity for the upper 3 feet of this soil? [Hint: AWC = FC - WP AND Inches of water = %water by volume × thickness of soil]

7.9 inches

The clay-size soil particle will have diameter between _____ and _____ mm.

<0.002

This upper case letter describes a master horizon and signifies enrichment of mineral soil with organic matter. Which is? __________

A

A soil with very thick, very dark, surface horizons due to prairie vegetation will have horizon designations of __-__-__-__-__.

A1-A2-A3-Bw-C

This process signifies changes in the composition of soil due to materials such as decomposing organic matter, atmospheric gases, or inorganic material deposited by wind or water. Which is?

Additions

Polarity of water not only helps to dissolve other compounds, it is also responsible for behavior of water in liquid state and determines behavior of water at mineral surfaces. This force is responsible for arrangement of water molecules at mineral surface. Which is?

Adhesion

This/these force(s) is/are responsible for retention of water in soil that was able to freely drain after a major rain event. Which is/are?

Adhesion, Cohesion

These parent materials were transported and sorted by wind. Which is?

Aeolian

From the list of cations that commonly occupy cation exchange sites in soil select those with acidic behavior.

Al3+

Isomorphous substitution in tetrahedral layer that results in charge imbalance means that this ion substitutes for the more common atom. Which is?

Al3+

The US system of soil taxonomy classifies soils on the basis of diagnostic horizons, surface and/or subsurface. This subsurface diagnostic horizon is defined by eluvial processes. It is an __________ horizon, and its master horizon and subordinate distinction is __________.

Albic, E

From the list select soil order(s) that have developed under the influence of temperate grassland vegetation.

Alfisol, Mollisol

Current examples of soil degradation include?

All of the above

Hydraulic conductivity _____.

All of the above

Which of the following are agents of erosion?

All of the above

Which of the following are historic perspectives of soil degradation?

All of the above

Which of the following are signs of streambank erosion?

All of the above

_____ is part of vadose zone.

All of the above

This parent material shows signs of stratification and was deposited alongside flowing stream that periodically spilled onto the surrounding flood plane. Which is?

Alluvium

At fixed soil texture, as the soil moisture content decreases, the depth of soil compaction _____.

Also decreases

The conversion of organic nitrogen into inorganic ammonia in soil is known as?

Ammonification

Which of these are a lost in the nitrogen cycle due to volatilization?

Ammonium

Which of these are lost due to runoff and erosion?

Ammonium

Which of these are lost during fixation by clays?

Ammonium

Land suitable for food and fiber production is known as?

Arable Land

Soil classified as the Orthent suborder are part of this soil order. Which is?

Argillic

Composition of soil air can be different from the tropospheric air, air in the lowest level of atmosphere. In tropospheric air, with 1% third most abundant gas is __________ gas.

Argon

This upper case letter describes a master horizon and signifies zone of change that was sufficient to alter the parent material in terms of color or structure. This change can be result of accumulation of material translocated or otherwise transported from the horizons above. Which is?

B

Cation Exchange Capacity of soil can be measured by several different techniques. One of them involves quantification of full range of cations in supernatant. These cations were displaced (desorbed) from the CEC sites into the supernatant with the help of this/these cation(s). Which is/are?

Ba2+

These are dominant in disturbed soils?

Bacteria

Streambank erosion is caused by the collapse of __________ along streams, creeks, and rivers.

Banks

Which of these is an input of organic nitrogen to the soil?

Biological fixation by legume plants

Order soil texture classes from highest clay content to lowest clay content.

Clay

With the hydrometer method, only one of the three textural separates is measured directly. Which is? __________

Clay

Plants growing in this soil will frequently experience problems with root growth due to excessive wetness. Which is?

Clayey

This soil has relatively low water erosiveness due to high cohesivity of soil particles. Which is?

Clayey

To measure how well the soil "holds together" the __________ is used.

Clod Test

Breaking down residue, immobilization of nutrients in their biomass, creating new organic compounds, and binding soil aggregates are roles of?

Decomposers

A soil from California is much older than any soil in Missouri. The soil morphology clues that indicate it is old would be _____.

Btq and Bqm horizon

This upper case letter describes a master horizon and signifies lack of influence of any soil forming factor on unconsolidated material underlying the solum. Which is?

C

In addition to the major gases, tropospheric air contains number of trace compounds. List at least four trace gases. Please use chemical formulas and (g) to specify gas phase, no space between the formula and the (g).

CO2(g)

Some trace gases emitted from soils are closely tied to global climate change. List at least three greenhouse gases. Please use chemical formulas and (g) to specify gas phase, no space between the formula and the (g).

CO2(g)

Percent base saturation can be calculated as a ratio between the CEC and sum of charge contributions from these cations. Which are?

Ca2+

The US system of soil taxonomy classifies soils on the basis of diagnostic horizons, surface and/or subsurface. This subsurface diagnostic horizon is defined by accumulation of carbonate minerals. It is a __________ horizon, and its master horizon and subordinate distinction is __________.

Calcic, Bk

The US system of soil taxonomy classifies soils on the basis of diagnostic horizons, surface and/or subsurface. This subsurface diagnostic horizon is defined by absence of weatherable primary minerals and absence of 2:1 secondary alumosilicates, and by very low base saturation. It is an __________ horizon, and its master horizon and subordinate distinction is __________.

Cambic, BW

Spontaneous movement of water into and through pore spaces in soil without the aid of gravity s called this. Which is?

Capillarity

Amount of water held in soil due to adhesion of water molecules to mineral surfaces and cohesive interactions between water molecules is called this. Which is?

Capillary

The way CO2 from the atmosphere enters the short-term cycle is by?

Carbon fixation by photosynthesis

The most important bioavailable pool of this essential, non-mineral plant macronutrient: __________ , in nature are molecules of this polyatomic gas: __________.

Carbon, Carbon Dioxide

In the landscape, this word describes a sequence of related soils that differ, one from another, generally as a result of differences in the topography because topography influences water movements and drainage patterns. Which is?

Catena

Negatively charged sites on soil organomineral colloids attract positively charged particles. Which are?

Cations

Polarity of water not only helps to dissolve other compounds, it is also responsible for behavior of water in liquid state and determines behavior of water at mineral surfaces. This force is responsible for clinging of water molecules to one another. Which is?

Cohesion

__________ is a particle so finely divided that it will not settle under the action of gravity in water suspension, but will diffuse, even in quiet water, under the random impulses of Brownian motion.

Colloid

The soil structural peds that are clearly elongated with mostly rectangular cross section and rounded tops are called _____.

Columnar

The final flux of the long-term carbon cycle is?

Combustion of Fossil Fuels

A biological process that breaks down organic material into more stable molecules is called what?

Composting

The challenge of carrying capacity is to __________ the global resource while increasing utilized acres and increasing input levels.

Conserve

The resistance of soil clods to crushing is an important indicator of agronomic soil quality because it signifies easiness of seedbed preparation. This physical property of soil is called _____.

Consistence

Factors that affect dry matter production include?

Cover Crops

Which of these are the biggest loss in the nitrogen cycle?

Crop Harvest

Bacteria, fungi, and protozoa are examples of?

Decomposers

Losses from the water budget of rooting zone of plants are _____.

Deep percolation, transpiration, evaporation

Factors leading to global land and soil degradation include:

Deforestation

__________ can cause damage to drainage ditches, reservoirs, and down slope crops.

Deposition

Black Sunday was a __________ which carried soil from the high plains to Washington DC.

Dust Storm

This upper case letter describes a master horizon and signifies extreme loss of dissolved or suspended material. Which is?

E

Stokes law uses number of parameters to calculate settling velocity of a particle in suspension. Which of the following parameters is NOT a true or assumed constant?

Effective Diameter

Climate is considered to be _____ factor of soil formation.

Environmental

Topographic relief is considered to be _____ factor of soil formation.

Environmental

The US system of soil taxonomy classifies soils on the basis of diagnostic horizons, surface and/or subsurface. This diagnostic horizon is defined by following parameters: high degree of disruption due to human activity. It is an __________ and its name is __________.

Epipedon, Anthropic

The US system of soil taxonomy classifies soils on the basis of diagnostic horizons, surface and/or subsurface. This diagnostic horizon is not mineral but organic. It is an __________ and its name is __________.

Epipedon, Histic

The US system of soil taxonomy classifies soils on the basis of diagnostic horizons, surface and/or subsurface. This diagnostic horizon is defined by following parameters: value/chroma ≤3/3 when moist or ≤5/3 when dry, thickness >18-25 cm, high base saturation at pH=7 (>50%), and high SOM content. It is an __________ and its name is __________.

Epipedon, Mollic

The US system of soil taxonomy classifies soils on the basis of diagnostic horizons, surface and/or subsurface. This diagnostic horizon is defined by following parameters: high value and high chroma, thin, and very low SOM content. It is an __________ and its name is __________.

Epipedon, Ochric

__________ is the wearing away of land durface.

Erosion

_____ occurs when molecules of water break free of the water surface and are carried away.

Evaporation

Aridisol tend to have high degree of soil development.

False

As dry matter production increases, SOM decreases.

False

Atmospheric fixation is a type of biological fixation.

False

Average national yields of current frontiers are higher than yields in farm demonstrations.

False

Bulk density and porosity are two soil parameters, which are not directly related.

False

Carbon from shellfish can only be fixed into calcium carbonate shells.

False

Compounds released as waste can not be used as food for other organisms.

False

Desert grass displacing shrubs can lead to an increase in infilitration.

False

Desert grass displacing shrubs can lead to an increase of resistance to erosion.

False

During the First Mesophilic Stage, frequent mixing is essential to maintain Oxygen gas levels and assure even heating of all material.

False

Gravitational potential occurs only in unsaturated soils.

False

Heavy continuous grazing followed by drought procedures positive feedback between vegetation and soil properties processes including an increase in resistance to erosion.

False

Humans can feasibly establish equilibrium with CO2.

False

Humans only modify the carbon cycle in the short-term cycle.

False

Humus is not resistant to further microbial attack.

False

Influx of atmospheric carbon equaled outflow, after the Industrial Revolution.

False

Isomorphous substitution is not the only source of permanent charge on clay minerals.

False

Matric potential occurs only in saturated soils.

False

Only 5-10% of all biota on Earth have been named and classified.

False

Oxisol will have very high native fertility.

False

Permanent gully erosion can by removed by normal tillage.

False

Raindrops don't provide the most of the energy for detachment.

False

Rill erosion is the most common form of water erosion.

False

Soil compaction is always a bad thing.

False

Soil environment is under equilibrium meaning only one type of electron acceptor is active at any given time.

False

Soil with a coarse texture usually have a higher SOM content.

False

The shape of water molecule is linear.

False

The source of pH dependent charge on clay minerals is dissociation of H+ from carboxyl functional group.

False

The source of pH dependent charge on humus is dissociation of H+ from broken edges.

False

Which method of determination of textural class would you use while excavating soil pit?

Feel Method

Organic matter (OM) accumulated in the duff layer on forest soil can be described by the degree of its decomposition. The least decomposed OM can be described by this word. Which is? __________

Fibric

What composing stage does the temperature raise to 40 degrees Celsius and sugars and readily available microbial food sources rapidly metabolize.

First Mesophilic Stage

Which reflects the flow of energy and nutrients through ecosystems via the trophic levels?

Food Web

Which of the following contains a duff layer?

Fresh Residue

Which of the following makes up <10% of organic components in soil?

Fresh Residue

A deference chip with the smallest possible brightness will be positioned on the __________ part of the color spectrum.

Grey

Soils provide __________ for ¼ of Earth's biodiversity.

Habitat

Organic matter (OM) accumulated in the duff layer on forest soil can be described by the degree of its decomposition. The intermediately decomposed OM can be described by this word. Which is?

Hemic

Gelisol developed over very long periods of time under this type of vegetation? Which is?

Herbaceous

Which are organisms that feed on other organisms to obtain energy and compounds?

Heterotrophs

In general, sandy soil will have _____ saturated hydraulic conductivity than clay.

Higher

Name of the state soil of Texas is __________.

Houston Black

Select all that is classified as soil organic matter.

Humus

Which method of determination of textural class is sufficient for agronomic applications?

Hydrometer

Order clay minerals on the list in the order of increasing expandability of the interlayer, i.e. from the lowest to the highest swelling potential.

Illite

Soil quality is a good __________ of the health of an ecosystem.

Indicator

Types of soil erosion by water include:

Interrill Erosion

Which type of erosion when combined with splash erosion is referred to as sheet erosion?

Interrill Erosion

Based on the ratio of tetrahedral to octahedral sheet clay minerals are classified either as 1:1 or 2:1. From the following list select all 1:1 minerals.

Kaolinite

Fine textured soil with very low plasticity index will be dominated by this secondary phyllosilicate. Which is? __________

Kaolinite

In ephemal gully erosion, rill channels will cut through tillage and planting rows due to __________ position.

Landscape

Which of the following is the smallest amount of organic components found in soil?

Living Organisms

What is the textural class name of a soil with 45% sand and 35% silt?

Loam

Intensive tillage may result in?

Losing Carbon

The material that has not yet formed distinct peds and is frequently found in the C horizon of soils developing from glacial till, lacustrine deposits, or other very fine-textured materials is described as _____.

Massive

In a climatograph, climate trend is discernible (graph is not noisy) because data used to construct it are long term __________ monthly precipitation and monthly temperature of a region.

Mean

Isomorphous substitution in octahedral layer that results in charge imbalance means that this ion substitutes for the more common atom. Which is?

Mg2+

Select common sources of electrons in soil environment?

Microbial Respiration

Where in the continental US can you find predominantly black soils?

Midwest

In the long-term carbon cycle how long does it take sedimentation of biomass to convert to fossil fuels?

Millions of Years

The process of organic nitrogen being converted to ammonium is?

Mineralization

The US system of soil taxonomy classifies soils on the basis of diagnostic horizons, surface and/or subsurface. This subsurface diagnostic horizon is defined by illuvial accumulation of phyllosilicate clays and high base saturation with exchangeable sodium, >15%. Usually, this horizon exhibits columnar structure. It is a __________ horizon, and its master horizon and subordinate distinction is __________.

Natric, Btn

Soil is the unconsolidated mineral or organic material on the immediate surface of the earth that serves as a __________ medium for the growth of __________.

Natural, Land Plants

The process of ammonium being converted to nitrate is?

Nitrification

The process that releases 2 moles of acidity per mole of NH4+ converted is?

Nitrification

Composition of soil air can be different from the tropospheric air, air in the lowest level of atmosphere. In tropospheric air, with 78% the most abundant gas is __________ gas.

Nitrogen

These favor the bacterial community in soils?

Nitrogen Fertilizer

Kaolinite belongs among this type of clay minerals. Which is?

Non-expanding

Potential energy is equal to -10,000 cm. What is its equivalent in kiloPascals (Pa)?Hint: 1 bar = 1020 cm water (4°C), 1 kPa = 10 cm water, 1 bar = 100 kPa

None of the above

This upper case letter describes a master horizon and signifies organic origin of this horizon. Which is? __________

O

Soil air gets replenished with atmospheric air. The composition of these two differs in two very important aspects. In soil air, as the content of __________ gas decreases, the content of __________ gas increases, sometime up to 10× the atmospheric value.

O2 or Oxygen

Isomorphous substitution in smectite, expanding 2:1 clay mineral, is mostly located in this sheet. Which is?

Octahedral

SOM is usually measured in the lab as __________.

Organic Carbon

Sources of nitrogen used by plants in soil include:

Organic Matter

An area that receives excess moisture during the entire growing season in tropical climate will likely feature this soil order. Which is?

Oxisol

From the list select soil order(s) that have developed under the influence of (sub)tropical forest vegetation.

Oxisol, Ultisol

Composition of soil air can be different from the tropospheric air, air in the lowest level of atmosphere. In tropospheric air, with 21% second most abundant gas is __________ gas.

Oxygen

A unit of soil structure is called __________ It is formed by __________ processes. In contrast to __________, which is formed artificially (man made).

Ped, Natural, Clods

This scientific term represents all soils on Earth and reflect the fact that soils are integral part of Earth's Critical Zone. Which is?

Pedosphere

These enjoy soils that are filled with fungi.

Perennials, shrubs, and trees

Different sources of negative charge in soils are capable of supplying different types of charge. Clay minerals can supply this/these type(s) of charge. Which is/are?

Permanent

This type of weathering will result in the increase in the relative surface area of the altered substrate. Which is?

Physical

The soil separate of sand-size particles can be made by _____.

Physical Weathering

Which of these is an input of nitrogen to soil is derived from crops?

Plant residue

The soil structure peds that are flat and thin and stack like sheets of paper are called _____.

Platy

The storage of a nutrient in a cycle would be called a:

Pool

Polarity helps water dissolve other compounds. Dissolution is a process in which ions become solvated or surrounded by solvent (water) molecules. Arrangement of water molecules around cations or anions is different. Water molecules arrange themselves around anion with this side. Which is?

Positive Pole

This upper case letter describes a master horizon and signifies presence of bedrock that may be partially fragmented due to weathering, but not to the extent where it could be excavated by hand. Which is?

R

Primary describable hues of soils can be found in these wavelength.

R, Y, YR

In general, northern 2/5th of Missouri (north of present day location of Missouri River) were covered by continental ice sheet until approximately 300,000 years ago, whereas area south of the river was never glaciated. This means that area south of Missouri River will be home predominantly to __________ soils.

Residual

Ephemeral gully erosion is a __________ that occurs in the same location in the field after each erosion event.

Rill Channel

Which of the following is a conversion to SOM from a given organic Carbon analysis?

SOM = Organic C content x 2.00

Order soil texture classes from highest sand content to lowest sand content.

Sand

This soil has relatively low water erosiveness because individual soil particles are relatively heavy. Which is?

Sandy

This soil is frequently called 'light' despite the fact that fixed volume of this soil weighs more than the same volume of the other soils. Which is?

Sandy

This soil texture will have rapid entry of water into the soil. Which is?

Sandy

This soil will frequently suffer from drought due to excessive percolation. Which is?

Sandy

Organic matter (OM) accumulated in the duff layer on forest soil can be described by the degree of its decomposition. The highly decomposed OM can be described by this word. Which is?

Sapric

__________ is a form of detachment caused by runoff.

Scouring

The third stage of the composing process is what?

Second Mesophilic Stage

What composing stage is the curing stage?

Second Mesophilic Stage

Which type of erosion is the most common type of erosion and makes up about 70% of total erosion?

Sheet Erosion

Order soil texture classes from highest silt content to lowest silt content.

Silt

What is the textural class name of a soil with 25% clay and 55% silt?

Silt Loam

The material that has not yet formed distinct peds and is frequently found in the C horizon of soils developing from glacial outwash, alluvial deposits, or other coarse-textured materials is described as _____.

Single Grained

Measured active acidity (pH) reflects activity of hydrogen ion (H+) in _____. Which is?

Soil Solution

Measuring various key attributes of soil organic matter indicates __________.

Soil quality

Changes in __________ occur over time due to human use and management, or to natural events.

Soil quality, soil health

Improper managment of __________ and __________ resources has caused the downfall of many civilizations.

Soil, Water

__________ is a product that is __________ from parent material.

Soil, different

Where in the continental US can you find predominantly red soils?

Southeast

__________ erosion is the impact of a raindrop, resulting in displacement of soil particles.

Splash

The US system of soil taxonomy classifies soils on the basis of diagnostic horizons, surface and/or subsurface. This subsurface diagnostic horizon is defined by illuvial accumulation of organic colloids, and also (hydr)oxides of aluminum and iron. It is a __________ horizon, and its master horizon and subordinate distinction is __________.

Spodic, Bhs

Humus coats that sand, silt, and clay particle and helps establish and maintain a __________ structure.

Strong

The soil structural peds that are mostly rectangular with rounded edges are called _____.

Subangular Blocky

The US system of soil taxonomy classifies soils on the basis of diagnostic horizons, surface and/or subsurface. This diagnostic horizon is defined by following parameters: value/chroma ≤3/3 when moist or ≤5/3 when dry, thickness >18-25 cm, low base saturation at pH=7 (<50%), and high SOM content. It is an __________ and its name is __________.

Surface Diagnostic Horizon, Umbric

Soils classified as Houston Black, the state soil of Texas, are vertisol that developed under this type of native vegetation. Which is?

Temperate Grassland

Hydrophilicity of soil mineral surfaces, or high affinity for water, is responsible for the ability to transfer some water from a pool of free water to soil against the gravitational force. We say that the soil has suction, negative pressure or __________

Tension

Isomorphous substitution in illite, non-expanding 2:1 clay mineral, is mostly located in this sheet. Which is?

Tetrachedral

The part of the Carbon cycle that includes the creation of limestone is called?

The Geological Cycle

The part of the Carbon cycle that is also known as the aquatic cycle is?

The Long-term Cycle

_____ is the driving force of the hydrologic cycle.

The Sun

These enjoy soils with a C:N ratio closer to 1:1.

Tomatoes and corn

This process signifies usually downward movement of soil colloids of mineral and/or organic origin with percolating water. Which is?

Translocation, Translocations

Adsorbed potassium and ammonium ions are held with just about the same amount of strength.

True

The second stage of the composing process is what?

Thermophilic Stage

What composing stage are easily decomposed compounds used and form "humus-like" compounds?

Thermophilic Stage

Arable land's productivity is influenced by management/inputs.

True

Assuming carbonates were present in parent material, the current depth to carbonates in soil profile increases with increasing precipitation.

True

Bedrock is not a part of the regolith.

True

Calcium ions tend to displace adsorbed potassium ions from the surface of negatively charged clay mineral or SOM.

True

Clay particles are more difficult to detach, because they generally form more stable aggregates.

True

Concentration of cations (and anions) is higher closer to the surface of soil mineral/organic colloid than it is in the bulk soil pore water.

True

Depositon can create highly productive soils

True

This parent materials was transported by ice/glacier and remained unsorted. Which is?

Till

Fungal hyphae is destroyed in large amounts by?

Tillage

One of the functions of humus is that is creates good soil __________.

Tilth

During the Second Mesophilic Stage, temperatures fall back to ambient and material is recolonized by mesophilic organisms.

True

Fine-textured soils have lower matric potential than coarse-textured soil.

True

Fire is a way CO2 is released into the atmosphere during the short-term cycle.

True

Heavy continuous grazing followed by drought procedures positive feedback between vegetation and soil properties processes.

True

Hugh Hammond Bennett was the chief of the soil erosion service in 1933.

True

Humus is Nitrogen and Phosphorus protected, because it is not readily soluble.

True

If the thermophilic stage on composing gets too hot, organisms in the pile may be killed.

True

In 2000, India had the highest percentage of planted crops on total arable, rain-irrigated land.

True

In a healthy soil, you want compaction to be minimal.

True

In soil, matric and submergence potential can coexist only at the surface of free water.

True

In soil, some capillary water is bound to hygroscopic water (water of adhesion) so tightly that it is unavailable to plants.

True

In temperate parts of Northern hemisphere, southern aspect on a slope above 10% speeds up soil development.

True

In the 2000 World Soil Resources Report, China had crops on 71% of it's total arable, rain-irrigated land.

True

Interlayer cations balance the charge deficiency created by isomorphous substitution in tetrahedral or octahedral sheets and bridge (hold together) adjacent layers of clay mineral.

True

Interrill, rill, and gully erosion are forms of transport.

True

It is estimated that around 950 square miles of land in the Gobi desert become desertified on a yearly basis.

True

Just like the long-term cycle, the geological carbon cycle starts by CO2 dissolving in water.

True

Matric potential of the soil is defined by the difference between a depth of free water in a pipe open to atmosphere and a depth at which is buried porous cup, which is connected to the aforementioned pipe.

True

Newly formed humus is a combination of resistant materials from the original plant tissue and humin.

True

Only dry matter that remains after harvest will influence long-term SOM content.

True

Permanent gully erosion can result in the removal of the whole soil profile in a localized area.

True

Plant material is transformed from one organic compound to another mainly by organisms in the soil.

True

Residue increases the roughness of the surface, which decreases wind / water velocity.

True

Residue is an essential for funal growth

True

Rill erosion occurs at a fast rate in channels.

True

Sawdust is more likely to create a period of nitrogen starvation than legume hay.

True

Soil quality is the capacity of soils within landscapes to sustain biological productivity, maintain environmental quality, and promote plant and animal health.

True

Soil with a fine texture usually have a higher SOM content.

True

Soils in an area with excessive rainfall usually contain lower amounts of SOM due to leaching.

True

Splash erosion provides most of the detachment energy for water erosion.

True

Streambank erosion is accelerated by intensive cultivation, grazing, and traffic along streams and the lack of riparian zones.

True

Submergence potential occurs only in saturated soils.

True

Substantial increase in the concentration of dissolved ammonium ion can cause decrease in soil pH.

True

Sugar, starches, and proteins have fast decomposition rates compared to structural compounds.

True

Symbiotic relationships are mutually beneficial for host organism and bacteria.

True

The American Dust Bowl was caused by poor cultivation practices.

True

The Soil Conservation Service (SCS) was created in 1933.

True

The amount of nitrogen in the atmosphere is approximately 78%.

True

Wetting can increase strength of otherwise non-cohesive sandy soil.

True

When organisms break down plant material they create by-products, wastes, and cell tissue.

True

A molecule of water has eight valence electrons. And the shape of water molecule is determined by the arrangement of these electrons in bonding pairs and lone pairs. A molecule of water has this many bonding pairs of electrons. Which is?

Two

A molecule of water has eight valence electrons. And the shape of water molecule is determined by the arrangement of these electrons in bonding pairs and lone pairs. A molecule of water has this many lone pairs of electrons. Which is?

Two

Soil classified as the Ustult suborder are part of this soil order. Which is?

Ultisol

Soil is the __________ mineral or organic material on the immediate surface of the earth that serves as a natural medium for the growth of land plants.

Unconsolidated

Most pages in the Munsell soil color book bear reference chips that go from low _____ chips at the bottom of the page to high _____ chips at the top of the page.

Value

Based on the ratio of tetrahedral to octahedral sheet clay minerals are classified either as 1:1 or 2:1. From the following list select all 2:1 minerals.

Vermiculite

Soil classified as the Udert suborder are part of this soil order. Which is?

Vertisol

The state soil of Texas is classified as this soil order. Which is?

Vertisol

This letter signifies distinctive change in color or structure without accumulation of silicate clays in the master horizon. Which is? __________

W

Repeated freeze thaw cycles lead to fracturing of rock due to ice __________ formation.

Wedge

Soil classified as the Xeralf suborder are part of this soil order. Which is?

alfisol

Soil developing for thousands of years from weathering-resistant, nutrient poor parent material like dune sand under temperate climate may remain in the __________ stage.

Youth

Distinctive layers within a given master horizon are indicated in the following way. Which is?

a numeral following the complete description of the horizon

If two different parent materials are present within the soil profile, the presence of the lower of the two is indicated in the following way. Which is?

a numeral preceding the description of the lower master horizon

Sometime it is impossible to clearly identify where one master horizon ends and the other starts. Such boundaries are referred to as "diffuse" and marked in specific way. Which is?

a symbol composed of two capital letters describing the two adjacent master horizons

From following choices select all plausible causes of soil compaction in agricultural or forest soil.

a) moldboard plowing

From the following list select all cements that are important, to any extent, in aggregation of tropical soils.

a)soil organic matter aka humus

This/these force(s) is/are at play in shaping a droplet of water on glass. Which is/are?

adhesion, cohesion

Which is NOT one of the functions of soil biology in development of soil?

addition of inorganic matter to soil

A soil parent material will develop soil horizons after _____.

additions, losses, translocations, and transformations have acted on the parent material

If the soil below a septic drain field is a loamy texture, the drain field for the septic tank will most likely _____.

allow the water to percolate easily so the system will function normally

Complexity of soil profile will increase with passage of time. Eventually though, after hundreds of thousands of years, soil profile of soil forming under very intense weathering conditions will simplify and become dominated by this group of minerals. Which is?

aluminum (hydr)oxides

From the list select soil order(s) that have developed in volcanic parent material and in the US are associated (among others) with the temperate rainforest vegetation.

andisol

Soil classified as the Geland suborder are part of this soil order. Which is?

andisol

The soil structural peds that are mostly rectangular with sharp edges are called _____.

angular blocky

From the list select soil order(s) that have developed under the influence of desert vegetation.

aridisol

Soil classified as the Cambid suborder are part of this soil order. Which is?

aridisol

From the list select soil orders that can be found in Texas.

aridisol, mollisol, entisol, inceptisol, alfisol, vertisol, ultisol

Plant Available Water Capacity (AWC) is defined _____.

as the amount of water held by soil and potentially available to plants

The water held in a saturated soil will _____.

be the same as the volume of pore space the soil has

Soil profile is composed of three layers with distinct textures: loam topsoil, clay loam, and sandy loam at the bottom. The sandy loam soil layer will _____.

be wetted in the lower part by capillary water rising from the water table, and wetted in the in the upper part after the clay loam is saturated

A molecule of water has eight valence electrons which are arranged in two bonding and two lone pairs. The arrangement of these four pairs is responsible for the molecule geometry, which is tetrahedral, and for the molecular dipole moment. Center of the positive charge is between these two electron pairs. Which is?

bonding pair one and bonding pair two

Period 2 elements are heavily represented among essential plant nutrients. Select all period 2 micronutrients among following choices.

boron (B),

This letter signifies presence of nodules within the master horizon. Which is?

c

These two alkaline earth metals are among the eight most abundant elements in Earth's continental crust AND essential plant macronutrients. Which is _____ and _____?

calcium (Ca), magnesium (Mg)

These two alkaline earth metals are among the eight most abundant elements in Earth's continental crust. Which is _____ and _____?

calcium (Ca), magnesium (Mg)

Clay minerals in the clay-size soil separate are product of _____.

chemical weathering

Period 3 elements are heavily represented among essential plant nutrients. Select all period 3 micronutrients among following choices.

chlorine (Cl)

What is the textural class name of a soil with 35% clay and 35% silt?

clay loam

This type of primary particles is one of the most important cementing agent in soil aggregation. Which is?

clay-size particle

Multiple sources contribute to negative charge of soils. Select all plausible sources from the list.

clay-size particles

A soil map unit is a _____.

collection of areas defined and named the same in terms of their soil components (i.e. soil series)

A soil is considered _____ when the percent composition is 25% water, 45% mineral, 5% organic, and 25% air

ideal

Soil classified as the Ustept suborder are part of this soil order. Which is?

inceptisol

From the list select soil order(s) that have developed under the influence of temperate forest vegetation.

inceptisol, alfisol, entisol

Clay minerals are built from two blocks, tetrahedra and octahedra. Isomorphous substitution, the source of permanent charge on clay minerals, can occur in this block.

either in tetrahedra or in octahedra, or in both simultaneously

Soil classified as the Orthent suborder are part of this soil order. Which is?

entisol

What are all possible pathways for liquid water once precipitation reaches the soil surface?

evaporation, infiltration, surface runoff

Reserve acidity reflects amount of hydrogen ion (H+) and aluminum ion (Al3+) in _____. Which is?

exchange sites on organomineral colloids

Stokes law uses number of parameters to calculate settling velocity of a particle in suspension. Which of the parameters can be replaced with a constant 'k' in the simplified version of the law?

fluid density, particle density, gravitational force, fluid viscosity

Stokes law uses number of parameters to calculate settling velocity of a particle in suspension. Which of the constants is constant only at specific ambient temperature?

fluid viscosity, fluid density

Sedimentary rocks are _____.

formed from sediments that have undergone compression and cementation.

From the list select soil order(s) that have developed under the influence of boreal forest vegetation.

inceptisol, spodosol, entisol

From the following list of binding and/or cementing agents of soil aggregation select all those that can be destabilized by common physical disturbances such as tillage or pulling logs out of the forest.

fungal hyphae, soil organic matter aka humus, fine roots

From the list select soil order(s) that have developed under the influence of tundra vegetation.

gelisol

Parent material is considered to be _____ factor of soil formation.

genetic

Soil Series are usually named after _____.

geographic location that is near where the particular soil profile was first described

This soil water potential is independent of soil properties. Which is?

gravitational

Stokes law uses number of parameters to calculate settling velocity of a particle in suspension. Which of the following parameters is a true constant?

gravitational force

Polarity of water not only helps to dissolve other compounds, it is also responsible for behavior of water in liquid state and determines behavior of water at mineral surfaces. Water that is not under the influence of mineral surfaces and drains from soil as soon as infiltration ceases is called this. Which is?

gravitational water

This letter signifies illuvial accumulation of organic matter in the master horizon. Which is?

h

From the list select soil order(s) that have developed in organic parent material and could be associated with wide variety of climatic and vegetation conditions.

histosol

Soil classified as the Folist suborder are part of this soil order. Which is?

histosol

When the hydrometer procedure is used for determining the soil texture the _____.

hydrometer is raised above 1.0 by the greater density of the soil-water suspension

Oven dry soil set free on a counter in the lab will increase its weight over time because of the hydrophilicity of soil mineral surfaces. The increase in weight up to the air dry point is due to this type of water. Which is?

hygroscopic

Storage of water in rooting zone of plants is equal to the difference between _____ AND _____.

inputs AND losses

You are working in Iowa where you determine that a soil sample of loam texture has a bulk density of 0.9 g/cm^3. This means that the soil _____.

is from an uncultivated grassland and has a very high content of organic matter

This letter signifies accumulation of carbonates in the master horizon. Which is?

k

Soils on slopes become prone to landslide when one of the soil layers becomes liquefied. Soils will transition from solid to viscous liquids at this water content. Which is know as?

liquidity limit (LL)

A molecule of water has eight valence electrons which are arranged in two bonding and two lone pairs. The arrangement of these four pairs is responsible for the molecule geometry, which is tetrahedral, and for the molecular dipole moment. Center of the negative charge is between these two electron pairs. Which is?

lone pair one and lone pair two

This process signifies changes in physical and/or chemical makeup of the soil due to removal of materials such mineral particles, organic matter, or leaching of dissolved ions. Which is?

losses

This letter signifies cementation or induration of the master horizon. Which is? __________

m

Second smallest unit of soil aggregation, which is formed by tying of the smallest aggregates by fungal hyphae and fine rots, is called this. Which is?

macroaggregate

The smallest unit of soil aggregation, which is produced by cementation of primary particles, is called this. Which is?

microaggregate

Which method of determination of textural class would you use for engineering applications?

micropipette

Weathering of parent material provides _______, while decomposition of dead plant residue such as roots, leaves, stems, and wood is the source of _____.

mineral fraction, soil organic matter

Soil is the unconsolidated __________ or __________ material on the immediate surface of the earth that serves as a natural medium for the growth of land plants.

mineral, organic

Cation Exchange Capacity (CEC) just like any other chemical property has it units. Which is?

moles of charge per kilogram of soil (molc kg-1)

This letter signifies accumulation of sodium in the master horizon. Which is?

n

This letter signifies accumulation of sesquioxides of iron and aluminum in the master horizon. Which is?

o

Ideal location for describing soil color is _____ and _____.

outdoor, in shaded location

Soils are under threat from degradation. Select all forms of soil degradation from the list.

overgrazing, urbanization, deforestation, pollution, poor ag practices

This letter signifies plowing or other disturbance of the A master horizon. Which is?

p

Different sources of negative charge in soils are capable of supplying different types of charge. Humus can supply this/these type(s) of charge. Which is/are?

pH dependent

Different sources of negative charge in soils are capable of supplying different types of charge. Select all plausible types from the list.

pH dependent

At very high pH, >8, negative charge of bulk soil will be dominated by this source. Which is?

pH dependent charge of soil organic matter

At very low pH, 4-5, negative charge of bulk soil will be dominated by this source. Which is?

permanent charge of clay minerals

Two alkali metals are among the eight most abundant elements in Earth's continental crust, but only ONE of them is an essential plant macronutrients. Which is?

potassium (K)

Inputs into the water budget of rooting zone of plants include _____.

precipitation and infiltration

The soil structural peds that are clearly elongated with mostly rectangular cross section are called _____.

prismatic

This letter signifies accumulation of silica in the master horizon. Which is?

q

Most importantly iron (Fe) but also manganese (Mn) and sulfur (S) are chemical elements that can be subject to

reduction/oxidation

This letter signifies illuvial accumulation of organic matter AND sesquioxides in the master horizon. Which is?

s

Humus can absorb __________ its weight, <50% of the water plant available.

six times

These two alkali metals are among the eight most abundant elements in Earth's continental crust. Which is _____ and _____?

sodium (Na), potassium (K)

From the following list select two cements that are most important in aggregation of temperate soils.

soil organic matter aka humus, secondary alumosilicates aka clays

Soil classified as the Cryod suborder are part of this soil order. Which is?

spodosol

If water enters soil from two openings in a pipe, one at the top and the other on at the bottom, that is buried in the middle of very dry loamy soil, the water will _____.

spread at the same rate from the top and bottom in concentric circles of wetting front until some parts of the soil become saturated

This soil water potential is defined by the distance of an object below a free water surface. Which is?

submergence aka hydrostatic

Soil is the unconsolidated mineral or organic material on the immediate __________ of the __________ that serves as a natural medium for the growth of land plants.

surface, earth

This letter signifies accumulation of silicate clays in the master horizon. Which is? __________

t

In the Bouyoucos Hydrometer Method, the hydrometer is placed in the suspension of soil in water after the suspension has been stirred and a reading is taken:

the 40 second reading represents the amount of silt and clay in suspension.

The soil separate of silt-size particles can be made by _____.

the grinding action of ice (glaciers) on the sand and gravel size particles

When water is added to an already moist soil _____.

the molecules move to the pore spaces and eventually drain from (percolate out) the soil

Cation Exchange Capacity (CEC) is the _____.

the sum of the negatively charged sites per unit weight of soil

A very heavy rainfall (5 inches) event takes place in 2 hours Friday morning on a very flat landscape in Dallas area. Texture of the surface soil here is a clay loam and the soil has been conventionally tilled for at least last 50 years. What would you expect to find Friday afternoon?

the surface soil saturated and standing water above the soil because the water could not quickly infiltrate the surface and get into the subsoil

In the landscape, this word describes a sequence of related soils that differ, one from another, entirely as a result of differences in the topography because the soils in the sequence all share the same parent material. Which is?

toposequence

This process signifies change of chemical identity and/or structure of mineral or organic matter in the soil environment. Which is?

transformations

_____ enables mass flow of mineral nutrients to plant.

transpiration

From the list select soil order(s) that have developed in lacustrine deposits or other very fine grained parent material and could be associated with wide variety of climatic and vegetation conditions.

vertisol

Soils purify and store __________

water

You were asked to calculate the depth of infiltration for a rain event that has occurred shortly after collection of soil core. What parameters, smallest number, would you measure? Note: The volume of the soil core is known.

weight of the soil at the field capacity

You were asked to calculate the maximum Available Water Content (AWC) for a soil. What parameters, smallest number, would you measure? Note: The volume of the soil core is known.

weight of the soil at the field capacity