Soil science test #1

What soil characteristics are influenced by parent material?

soil texture

Particle size

movement of water

weathering

translocation of soil particles

natural vegetation

Igneous

formed by molten lava. Quartz, granite, feldspars

Sedimentary

formed for deposition and cementation of weather material. Shale and sandstone

Metamorphic

formed by change in other rock

List and discuss 5 forms of inorganic parent materials.

Residual-formed in place

Colluvial debris- from above

Alluvial stream deposits- made by water

Glacial till- transported by glaciers

Eolian- transported by wind

What are the 5 key roles of soils?

Medium for plant growth

Engineering medium

Recycling system

habitat

water supply

List the 16 elements essential for plant growth.

C,H,O2,N,P,K,Ca,Mg,S,Fe,Mn,Zn,Cu,B,Mo, and Cl

Be able to label a soil profile.

O horizon

A horizon

E horizon

B

C

R parent material

know the characteristics of each horizon layer.

O horizon- layers of decaying plant and animal matter. Found in undisturbed ecosystems and partially decomposed

A horizon- rich with organic matter, dark in color, where plant roots are found, important for maintaining soil fertility

E horizon- intensely weathered and leached, grayish brown in color, iron and organic matter and zone of eluviation

B horizon- zone of accumulation, highs in clays, iron, aluminum oxides, gypsum, or calcium carbonate

C horizon- least weathered, unconsolidated rock and outside the zone of biological activity

R horizon- parent material, consolidated rock with little evidence of weathering

List 4 major components of soil.

Air

water

minerals

organic matter

What is an ideal soil? What is the ideal soil texture?

loam. Has a balance of sand, silt, and clay.

List 3 major particles of soil mineral matter.

sand, silt, and clay

How does climate affect the development of Organic Matter?

temperature and precipitation, which affect the activity of decomposing organisms, ultimately determining how much organic matter accumulates in a given environment

How does organic matter influence soil properties?

improving its structure, increasing water holding capacity, enhancing nutrient availability, boosting biological activity, and providing better aeration

How is soil water different from water?

soil water differs from water in a glass by: doesn’t flow and is a solution

Be able to track an essential element from an ion attached to a colloid surface to entering a root cell.

Be able to discuss the relationship of soil air to soil water.

Inversely related- meaning the pores are full of water there is less air into the pores and vice versa

List 5 and discuss factors that influence soil formation and how they are interrelated.

1. parent material

2. climate

3. living organisms

4. topography

   1. time

List and be able to discuss the 2 types of weathering.

physical weathering (also called mechanical weathering), which breaks down rocks physically without altering their chemical composition, and chemical weathering, which involves the breakdown of rocks through chemical reactions, creating new substances. 

What soil characteristics are influenced by parent material?

soil's texture, mineral composition, nutrient content, pH level, color, structure, and drainage

differentiate between floodplains, alluvial fans, delta deposits and marine sediment.

A floodplain is a flat area of land adjacent to a river where sediment is deposited during flooding

alluvial fan is a fan-shaped deposit of sediment formed at the base of a mountain or steep slope where a stream rapidly loses energy

a delta deposit is a landform formed at the mouth of a river where sediment builds up when the river meets a larger body of water,

marine sediment refers to any sediment deposited on the ocean floor, which can include material from land, organisms, and chemical precipitation

How does temperature affect chemical reactions?

as soil temperature rises, most chemical processes within the soil, like decomposition of organic matter and nutrient release, accelerate. 

How do organisms affect the soil?

adding organic matter through decomposition

aerating the soil

breaking down nutrients

shaping soil structure and fertility

Know how the slope affects the profile of a soil.

influencing the amount of water runoff, leading to higher erosion rates on steeper slopes, resulting in thinner soil layers with less developed horizons, while gentler slopes tend to have deeper, more developed soil profiles due to increased water infiltration and less erosion

List and describe the 4 processes of soil formation.

Transformation- destructive and different compound in the soil

Translocation- clays translocate in the soil (movement of particles)

Additions- alluvium, polluvium (O.M., rainfall, acid rain)

Losses- depending upon topography of the land

Discuss the development of a soil from a young soil to an old soil.

undergoes weathering where the parent material breaks down, organic matter accumulates and more soil horizons begin to show resulting in a deeper soil profile with physical and chemical properties

Know how transition layers and subordinate distinctions are written when referring to a soil horizon.

How is soil classified?

based on its texture, which is determined by the relative proportions of sand, silt, and clay particles it contains

Know the classification system of soils.

Know the 12 soil orders and characteristics of each.

1. entisols- weakly developed soils

2. Inceptisols-

3. Andisols- found near volcanoes

4. Gelisols- found in cold temps and frozen conditions

5. Histosols

6. Subsidence

7. Vertisols

8. Mollisols

9. Alfisols

10. Ultisols

11. Spodosols

12. Oxisols

13. Aridisols

4 Soil orders in Missouri

1. Mollisols- dark green

2. Ultisols- orange

3. Alfisols- light green

4. Vertisols- boot heel

How does surface area affect; water holding capacity, nutrient holding capacity, weathering, aggregation, microbial activity.

larger surface area increases water holding capacity

Know what influences soil color and what soil color tells us.

Soil color is influenced by the minerals, organic matter, water, and climate in which the soil is found. Soil color can indicate the soil's mineral content, age, and how well it drains

How do texture and structure influence water holding capacity?

The finer the texture of a soil the greater is the effective surface exposed by its particles

How do you improve soil structure?

1. Minimize tillage

2. till only when soil moisture is optimal

3. keep soils covered with mulch

4. incorporate crop residues and animal manures