SB Chapter 16

What type of erosion reducing techniques include reducing velocity of runoff and capturing sediment and nutrients downslope?

Control techniques

Rank the pH of the following soils from the lowest pH (acidic) at the top to the highest pH (basic) at the bottom. Instructions

Humid Agriculturally Productive Arid Environmental soils

Select the four organic material components in soils.

Humus (stabilized organic matter) Fresh residue Decomposing organic matter Living organisms

Match the type of soil water to its description.

Hygroscopic A thin coating of water that adheres to soil particles Capillary Water that occupies the pores between grains Gravitational Abundant water that drains out of the soil

Primary preventative techniques used to reduce erosion focus on ______.

minimizing effects of rainsplash and runoff

Soil is derived from material, such as rocks.

parent

Laterization, salinization, calcification, gleization, and podzolization are the five regimes of soil formation in different environmental settings.

pedogenic

The smallest unit used to measure soils is called a(n) , which measures 2 meters deep and 1 to 10 meters square.

pedon

Salts, such as calcium carbonate, form in arid soils as a product of ______.

periodic rains causing partial chemical weathering

The weathering of bedrock and deposition of sediment by wind or water are ______ processes involved in soil formation.

physical

Which soil component holds soil together and reduces dissolution in water?

Organic matter

What ingredient in soil is the single most important for the soil to be productive and support vegetation?

Water

What is regolith?

Weathered parent material

How does organic matter accumulate in soil?

With the help of living organisms

The three primary soils taxonomies include site-dominated soils, soils with strong climate influence, and ______.

developing soils

Control techniques used to minimize effects of soil erosion in agriculture are ______.

directional planting of wind breaks plants acting as sediment filters

Slopes that are steep ______ develop soils as the necessary materials ______.

do not readily; are easily removed to lower areas

Topography impacts soil properties by influencing ______.

erosion rates

CEC, or cation , is the ability for a cation to exchange with the surface of organic matter or clay.

exchange capacity

In order for a cation in water to become available for plant growth, the cation must ______.

exchange with a cation on a soil particle

True or false: A sandy soil will always have a higher porosity than a clayey soil.

false

Soil profiles are composed of vertical sections of soil called ______ that extend from the surface to the parent material.

horizons

Mollisols are the most agriculturally productive soils. They are found ______.

in mid-latitude grasslands

This is the name for weathered parent material.

regolith

The three primary taxonomies of soil are -dominated soils, developing soils, and soils with strong influence.

site climate

Compare the smaller and larger particles in soil by matching them to their most common characteristics. Instructions

smaller: Clays; secondary minerals Larger: Silts and sands; primary minerals

Organic matter in accumulates through contributions by living organisms.

soil

Precipitation that falls on Earth's surface can runoff, infiltrate the to reach bedrock below, or evaporate upward.

soil

Temperate environments have some of the best soils in the world, even compared to tropical soils. The reason is ______.

temperate soils have less rainfall to leach nutrients

The surface of small particles can overcome the force of gravity and may cause water to pond on surfaces underlain by such materials.

tension

Soil is a physical property of soil that describes the average distribution of particle sizes.

texture

Soil air content is dependent on the porosity of the soil and inversely proportional to ______.

water content

A permeable material is one that is able to transmit readily.

water or fluid

Select the reasons why soils in arid environments have limited development.

- Lack of rainfall - Lack of vegetation

Mollisols are ______.

- very productive soils - are used extensively for agriculture in Asia, Europe, and the Americas

Select the processes that improve the organic content of soil.

-Decomposition of organisms -Litter accumulation, such as dead leaves -Organisms aerating, mixing, and fertilizing soils -Fracturing of soils from roots

Order the soil horizons from the surface layer at the top to the deepest layer at the bottom. Instructions

1. O 2. A 3. E 4. B 5. C 6. R

Imagine a water molecule has evaporated from a lake. Order the steps the water molecule might take to return to the lake through the hydrologic process. (Order the first step at the top and the last at the bottom.) Instructions

1. Precipitation 2. Infiltration 3. Groundwater flow 4. surface water recharge 5. The molecule returns to the lake

Which of the following soils is likely to be the most fertile?

A dark brown soil

Some areas with poor agricultural soil have problems with the nutrients nitrogen (N), phosphorus (P), and potassium (K) leaching into groundwater. What is a reason this could happen?

A low CEC leads to these nutrients leaching through soils, making them unavailable to plants.

Material that eventually becomes soil is transported to a site by water, wind, ice, and/or gravity. Identify the different types of transported parent material.

Aeolian deposits Colluvium Glacial deposits Alluvial deposits

What happens to the air content of soil as the soil becomes more wet?

Air content decreases.

Water available in soil is critical to plants, but capillary soil water is perhaps the most important for agriculture. Why?

Capillary water is available for a longer duration than precipitation.

What process allows high pH soils to have a strong ability to exchange cations in soil solution with the organic material surfaces or clay particles?

Cation exchange capacity

What is the active fraction of organic material in soil?

Decomposing organic matter

What are the three types of soil water?

Gravitational water Capillary water Hygroscopic water

Compare the difference between eluviation and illuviation of soils. Instructions

Eluviation - Leaching of clays from surface horizons due to high rainfall Illuviation - Deposition of clays into lower levels of soil

Which type of young soil are you more likely to find in a sandy desert?

Entisols

______ are recently created soils with little to no profile development.

Entisols

Entisols and Inceptisols are both newly formed soils with limited horizon development. How do Entisols and Inceptisols differ?

Entisols are soils with extremely little horizon development, and Inceptisols are soils with the beginning of a B horizon.

Select ways water enters soil.

Infiltration Precipitation

Match the pedogenic regime to its environment. Instructions

Laterization - Red soils are formed from very fast chemical weathering in hot, humid environments. Salinization - Salts are deposited on soil surfaces due to arid conditions drawing moisture to the surface. Calcification - Soil moisture moves upward in semiarid regions depositing calcium carbonate. Gleization - Soil is waterlogged, rates of decay are slowed; the A horizon is rich. Podzolization - Soils are subject to many months of below-freezing temperatures and chemical weathering is slow.

Select materials commonly found above the topsoil.

Leaves Branches

______ determines soil type and formation due to topographic features, geologic setting, rock types, and climate.

Location

Nitrogen, phosphorus, and potassium are critical for healthy plant growth. Match the nutrient to the biological function it provides. Instructions

Nitrogen- Plant growth and dark green leaves Phosphorus- Root development Potassium- Water uptake and conservation

Match the soil horizon letter (O, A, E...) with the description of what type of soil is in the layer. Instructions

O -Surface litter: Organic litter A - Topsoil: Humus, organisms, inorganic E -Zone of leaching: Chemically weathered B - Subsoil: Accumulated material from above C - Regolith: Weathered bedrock or unconsolidated sediment R - Bedrock

From the list of elements below, select the three that are usually the primary ingredients of fertilizers for increasing soil productivity.

Phosphorus (P) Nitrogen (N) Potassium (K)

______ erosion techniques minimize the impact of rainsplash erosion and runoff.

Preventative

Order the soil particle types from largest to smallest, with the largest grains at the top and the smallest grains at the bottom. Instructions

Sand Silt Clay

Match the parent material to the type of soil it will produce. Instructions

Sandstone - Sandy loams and loamy sands Shale - Clay-rich soil Limestone - Highly productive soils

Why is the pH of a soil important to its productivity?

The correct pH allows soil to carry the right amount and types of nutrients and makes them available to plants.

Soils that accumulate on slopes differ from those located at the bottom of slopes or on flat land due to the erosion of soil and organic matter. Compare these images of soil from the same slope, and choose the appropriate description.

The soil on the left is from the side of the slope and the soil on the right is from the bottom of the slope.

True or false: Clay-rich soils have greater porosities than sandy soils.

True

True or false: Similar soil types have similar uses across the globe.

True

Soil erosion is naturally caused by freeze-thaw cycles and rainsplash. Humans tend to ______ soil erosion.

accelerate

The zone of illuviation is also called the zone of because it forms from the deposition of materials that have leached down from the overlying zone of eluviation (leaching).

accumulation

Using the pH scale, a soil with a pH of 5 is ______ and a soil with a pH of 8 is ______.

acidic basic

Using the pH scale, a soil with a pH of 5 is ______ and a soil with a pH of 8 is ______.

acidic; basic

Preventative techniques used to minimize the effects of soil erosion by agriculture include ______.

animal number management strip cropping "no till" agriculture

A fully developed soil will likely contain ______ within its surface horizon.

clay

Soil horizons are ______.

layers in the soil from distinct periods of development

Chemical processes within soil horizons are found in the zone of eluviation, where nutrients and fine particles are ______ soils, or in the zone of accumulation, where chemical ions settle in deeper soil layers or in the water table.

leached through

Soils described as have a texture that is good for agriculture compared to sands that drain water and nutrients or clays that drain poorly or become compacted.

loams, loam, or loamy

A soil with a wide range of grain sizes (poor sorted) will have ______ porosity compared to one where the particles are all nearly the same size.

low

Good soils have a small amount of matter, which binds soil, bonds nutrients, cycles nutrients, and provides energy for organisms.

organic

The soil on the right, developed at the bottom of a steep slope, has a lot more matter than the soil developed on the slope itself (to the left).

organic

This graph represents the components of soil.

organic

The cycle of organic matter in soils is one carried out primarily by ______ in their life and death.

organisms

The ______ of a soil is important as it affects the amount and type of nutrients available to plants.

pH

Grain sizes in soils affect the porosity of the soil because ______.

the grains may not fit together tightly, leaving space between them

Which acronym is used to describe the factors of how climate, organic matter/vegetation, relief/topography, parent material, and time affect soil development?

ClORPT

Select ways water leaves soil.

Vegetation absorption Evaporation

Match the soil horizon with the description of how it forms. Instructions

Zone of leaching (E) - Results from vigorous chemical weathering that leaches iron, clays, and organics Zone of accumulation (B) - Results from the accumulation of leached material from above Regolith (C) - Is weathered bedrock from below and is little affected by overlying processes

The three settings for soil water are hygroscopic water, water, and water.

capillary gravitational

Describe how soil is formed in response to the role of climate and organisms by matching each stage with its description. Instructions

1. Bedrock starts to disintegrate. 2. Organisms break down rock further. 3. Soil horizons begin to develop. 4. Developed soil supports thick vegetation.

Order the quantity of soil water from the most at the top to the least at the bottom. Instructions

1. Saturated 2. Field capacity 3. Wilting Point

______ are soils formed from volcanic ash and ejected materials.

Andisols

Soil development is slower in polar regions than in the tropics, primarily due to which reason?

Availability of water

The acronym ClORPT is used to list factors of soil development. Match the specific letters to the factors they represent. Instructions

Cl- Climate O- Organic matter/vegetation R- Relief/topography P- Parent material T- Time

Match the soil to the level of CEC (cation exchange capacity) it might normally have. Instructions

Clay Rich- High CEC Sandy- Little to no CEC

Soil properties such as texture often define soil uses. Which soil texture type is best for agricultural uses?

Clay loam

Which statement best describes the porosities of sandy versus clayey soils?

Clayey soils have higher porosities.

In the hydrologic cycle, water is constantly in motion. Select the ways in which soil is a medium for moving water.

Evaporation Surface runoff Infiltration

True or false: Control techniques for soil erosion are aimed to minimize the effect of rainsplash.

False

True or false: Soils derived from parent materials are consistent across the globe if derived from similar parent materials.

False

True or false: Soils in warm environments form with an abundance of water for vegetation growth, accumulate lots of organic matter, and experience little nutrient leaching.

False

What are the effects of soil erosion?

Filling in of reservoirs Spreading of bacteria and viruses Loss of agricultural productivity

______ are found in areas with permafrost, which makes them susceptible to deformation if radiant heat from heavy roads or buildings causes them to defrost.

Gelisols

What level of permeability could be expected for a soil with a granular structure and sand-sized particles?

High permeability

An acidic soil contains a high number of H+ ions, and ions such as Mg+, K+, and Ca2+, known as ______, will be repelled.

cation

The term can either mean a very small-sized particle or a silicate mineral with a sheetlike texture.

clay

Decomposed shale makes a -rich soil, decomposed makes sandy loam or loamy sand, and soil created from , a sedimentary rock rich in calcium carbonate, creates highly productive soils.

clay sandstone limestone

In soils, smaller particles are and mostly secondary minerals. The particles are silts and sands, and mostly primary minerals.

clays larger

Oxisols, Ultisols, Vertisols, and Aridisols are soil orders formed in warm , with moisture levels ranging from tropical to arid and relatively warm temperatures.

climates, environments, places, locations, or areas

Directional planting of trees as windbreaks and filter strips capturing runoff sediment are types of ______ techniques for soil erosion management.

control

As land is cultivated and soil is forming, nutrients become available for plants as the active fraction, or organic matter, is consumed by organisms.

decomposing

Newly formed clay soils have high permeabilities. As overlying material or human and animal activity compact the material, the permeability ______.

decreases

As precipitation infiltrates a soil, it begins to get the soil wet. As the soil's water content increases, the air content ______.

decreases because less pore space remains for air

Soils formed in warm, wet climates develop ______ than soils in arid or temperate climates.

faster

As soil forms through weathering and the accumulation of organic matter, layers called are created over time.

horizons

Soil layers parallel to the surface and having unique physical, chemical, and biological properties are called soil .

horizons

Soils with a CEC will leach nitrogen, phosphorus, and potassium into local water systems.

low

Clayey soils have a lower CEC than sandy soils, so it follow that they have a ______ pH.

lower

When analyzing soils, the smallest unit is a pedon. An area of up to 10 pedons is called a(n) , and an area with several different soil types is considered a landscape.

polypedon

Heavy soils that retain too much water and do not disperse nutrients are heavy, or drained soils. Soils that drain and leach nutrients are droughty.

poorly quickly, fast, or rapidly

Heavy soils that do not drain well are ______, and soils that drain too quickly are ______.

poorly drained soils; droughty

Given a soil with a volume of 100 cm3 and a pore space of 40 cm3, the is 40%.

porosity

Managing the number of animals grazing, using "no till" agriculture practices, and strip cropping are techniques for soil erosion management. Listen to the complete question

preventative

Leave litter is important to underlying soil development because it ______.

protects it from erosion and runoff

Soils from tropical regions get their color from the oxidation of iron and aluminum, a form of natural rust.

red or reddish

Location is an aspect of soil formation identifiable through factors such as ______.

rock types and topographic setting

When rain hits soils, it tends to promote surface sealing where water does not fully infiltrate the soil. Rainfall then moves over the surface in a thin la

sheet

Sand, , and are the three categories of particles based on size that are used to describe the mineral fraction of soils.

silt clay

Soil is used to describe in what shape peds, soil aggregates, or clumps of soil particles have formed.

structure

The way soil particles are grouped or attached to each other in aggregates is called soil ______.

structure

When analyzing a clay with high porosity but low permeability, ______ will cause the water to pond on the surface of the soil.

surface tension

Compared to the other soils developed in warm conditions (e.g., Ultisols, Oxisols, and Vertisols), Aridisols are significantly different because ______.

they form in very dry environments, resulting in very little vegetation

The O and A horizons together are ______.

topsoil

Soils that are red are often found in ______ environments.

tropical

A parent material ______.

weathers to form new soils

Saturated soil can be too for plants and wilting point is too for plants; both conditions are hostile to growth.

wet dry

Entisols are new soils with no profile development. They are found ______.

widely spread across the world

Soil erosion affects areas of human health, drinking water supply, food production, topography, and ______.

wildlife health

On this map, the High Plains markers, shown in red, are areas of erosion, and the Midwest markers, shown in blue, are areas of erosion.

wind water

Compare eluviation and illuviation by choosing the sentences that correct describe their relationship.

- They both concern clay. - Eluviation is leaching; illuviation is deposition. - They both are about vertical movement.

When a scientist describes a "clay", what do they mean?

A sheetlike, silicate mineral A very small particle

When a soil is alkaline, it has a high pH, few H+ ions, and more negatively charged ions (anions) present. Will cations be attracted or repelled?

Attracted

Which of the following are roles that organic matter plays in soils?

Cycles nutrients Binds soil and nutrients Provides energy for organisms

What type of soil structure is displayed in this soil sample?

Granular

Match the ped shape descriptions with the soil structure types. Instructions

Granular Small spherical grains Blocky Irregular chunks Platy Horizontal plates Columnar Fragments that are taller than they are wide Structureless Loose singular grains Massive No obvious structure

Imagine an agricultural field with wilted plants. What mechanism do you think could explain the problem?

Insufficient capillary water

Which of the following describe peat?

It is composed of partly decayed moss, wood, and other plants. It is formed in marshes and bogs.

The indicators of soil health, such as good infiltration, water retainment, reduced evaporation, nutrient cycling, reduced erosion, and available energy for organisms, are all achieved by which soil component?

Organic content

Match the type of soil particle to the correct size. Instructions

Sand 2.00 - 0.05 mm Silt 0.05 - 0.002 mm Clay < 0.002 mm

A soil sample consists of 30% clay, 60% sand, and 10% silt. Using the image of the soil texture triangle, determine the name of this soil's texture.

Sandy clay loam

Which of the two conditions of soil water are hostile to plant growth and health?

Saturated and wilting point

A soil sample consists of 10% clay, 30% sand, and 60% silt. Using the image of the soil texture triangle, determine the name of this soil's texture.

Silt loam

In the hydrologic cycle, water is constantly in motion. Select the ways in which soil is a medium for moving water.

Surface runoff Evaporation Infiltration

Well aerated soils, with good air content, are generally ______.

brightly colored

Precipitation, infiltration, groundwater flow, and evaporation are steps in the cycle.

hydrologic

A soil that has been compacted so that its permeability is extremely low is called .

impermeable

Porosity is the amount of pore space in a material and is expressed as a ______ of the whole material.

percentage

In the process of soil formation, physically weathered and eroded quartz is an example of a(n) mineral, and chemically weathered clays are examples of minerals.

primary secondary

Humans grow food in a critical resource called . The quality and type of this resource vary across the planet, and erosion presents the greatest threat to it.

soil

cations such as Na+ that are carried in become available for plant growth by exchanging with another cation attached to a particle.

water or groundwater clay or soil

Soil development in tropical (humid) environments tends to be faster than soil development in arid environments (both warm or cold), due to the availability of .

water or moisture