APES 4.1, 4.2, 4.3, 5.3,c5.4, 5.5, 5.6, 5.7, 5.14, 5.15, 5.16 notes and test review flashcards

What is the definition of soil according to the lecture notes?

A living system consisting of a mix of geologic (disintegrated rock), organic matter, water, gases, nutrients, and microbes.

What are the components of soil composition?

1. Geologic matter (sand, silt, clay)

2. Organic matter

3. Water and Gases (O2, CO2)

4. Nutrients and Microbes

What are the three main types of plate boundaries?

Convergent boundaries, divergent boundaries, and transform boundaries.

What results from convergent plate boundaries?

The creation of mountains, island arcs, earthquakes, and volcanoes.

What results from divergent plate boundaries?

Seafloor spreading, rift valleys, volcanoes, and earthquakes.

What is the primary effect of transform plate boundaries?

Earthquakes, typically occurring along fault lines where plates slide past each other.

What is the significance of the Ring of Fire?

It is a path along the Pacific Ocean characterized by active volcanoes and frequent earthquakes due to subduction zones.

What is subduction?

The process where one tectonic plate (usually a denser oceanic plate) slides beneath another plate and melts into the mantle.

How is a hotspot defined in geology?

An area in the mantle from which heat rises as a thermal plume from deep in the Earth, leading to volcanic activity (e.g., Hawaii).

What are the mechanical layers of the Earth?

The Lithosphere, Asthenosphere, Mesosphere, Outer Core, and Inner Core.

What is the Lithosphere?

The rigid outer part of the earth, consisting of the crust and upper mantle.

What is the Asthenosphere?

The upper layer of the earth's mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur.

What are soil horizons?

Horizontal layers in a soil profile that vary in physical and chemical properties.

What is the O-Horizon?

The topmost layer of soil, primarily composed of organic matter such as leaf litter and humus.

What is the A-Horizon?

Commonly known as topsoil; a mixture of organic materials and minerals where most biological activity occurs.

What is the E-Horizon?

The layer of eluviation or leaching; minerals and organic matter are washed out into lower layers.

What is the B-Horizon?

Commonly known as subsoil; a layer where minerals (like iron and aluminum) and clay accumulate.

What is the C-Horizon?

The layer composed of partially weathered parent material.

What is Parent Material?

The underlying geological material (usually bedrock or drift deposits) from which soil horizons form.

Define Physical Weathering.

The mechanical breakdown of rocks into smaller pieces without changing their chemical composition (e.g., frost wedging).

Define Chemical Weathering.

The breakdown of rock through chemical reactions, such as oxidation or acid rain, which change the chemical makeup of the minerals.

What are the three soil texture particles (from largest to smallest)?

Sand, Silt, and Clay.

What is sand's role in soil properties?

It provides high permeability and low water retention due to its large particle size and large pore spaces.

What is clay's role in soil properties?

It provides low permeability and high water retention but can lead to waterlogging because of its tiny particle size.

What is Loam?

A soil type that contains a relatively equal mix of sand, silt, and clay; it is considered ideal for agriculture.

What is Porosity?

A measure of the volume of pore spaces (voids) in a soil sample.

What is Permeability?

The ability of a material (soil) to allow fluids to pass through it.

What is Cation Exchange Capacity (CEC)?

The ability of a soil to deliver important plant nutrients (cations like K^+, Ca^{2+}, and Mg^{2+}) to the root surface.

How does soil pH affect plant growth?

pH influences the solubility and availability of nutrients; most plants prefer a pH between 6.0 and 7.5.

What is soil erosion?

The movement of soil components, especially surface litter and topsoil, from one place to another by wind or water.

What is one effect of using synthetic fertilizers?

Overuse can result in nutrient runoff into water bodies, leading to eutrophication.

What is eutrophication?

A process where excess nutrients lead to algal blooms, depletion of dissolved oxygen, and subsequent fish kills (hypoxia).

What is Furrow Irrigation?

A method where trenches are cut between crop rows and filled with water; it is inexpensive but about 35\% of water is lost to evaporation/runoff.

What is Flood Irrigation?

The entire field is flooded with water; it is simple but can lead to waterlogging and high evaporation losses.

What is Spray Irrigation?

Water is pumped from a well and sprayed through nozzles; it is more efficient than furrow/flood but more expensive.

What method of irrigation is considered the most efficient?

Drip irrigation, which delivers water directly to the plant roots via hoses, losing only about 5\% to evaporation.

What is salinization?

The buildup of salts in soil resulting from repeated irrigation, which can eventually reach toxic levels for plants.

What is waterlogging?

A condition where soil remains under water for prolonged periods, saturating the soil and depriving plant roots of oxygen.

What are Aquifers?

Underground layers of water-bearing rock or sediment; a major source of irrigation water (e.g., the Ogallala Aquifer).

What is Integrated Pest Management (IPM)?

A comprehensive approach to controlling pests using a combination of biological, physical, and chemical tools to minimize environmental impact.

Give an example of Biological Control in IPM.

Introducing natural predators, such as ladybugs to eat aphids, or using parasites and pathogens.

Give an example of Physical Control in IPM.

Using barriers, traps, or hand-picking pests to remove them from crops.

How is Chemical Control used in IPM?

It is used as a last resort, employing targeted, narrow-spectrum pesticides rather than broad-spectrum chemicals.

What are the pros of rotational grazing?

Improves soil health, enhances carbon sequestration, promotes livestock health, and reduces erosion.

What is overgrazing?

When too many animals graze for too long on a patch of land, leading to soil compaction and loss of vegetation.

What is desertification?

The process by which fertile land becomes desert, typically as a result of drought, deforestation, or inappropriate agriculture (like overgrazing).

What impact does monocropping have on biodiversity?

It reduces biodiversity to a single crop type, making the system highly vulnerable to pests and disease.

How does tilling impact the environment?

It disrupts soil structure, kills microbes, and releases sequestered carbon into the atmosphere as CO_2.

What is No-Till agriculture?

A farming practice that avoids tilling to leave crop residues on the field, which reduces erosion and keeps carbon in the soil.

What is the purpose of contour plowing?

Plowing along the natural curves of the land to slow water runoff and prevent soil erosion.

What are windbreaks (shelterbelts)?

Rows of trees or shrubs planted to block wind and reduce soil erosion on flat farmland.

What is Terracing?

Cutting 'steps' into steep hillsides to create flat areas for farming, which prevents water from washing away soil.

What is Strip Cropping?

Planting different crops in alternating strips (e.g., corn and clover) to reduce erosion and improve soil nutrients.

What are Cover Crops?

Crops planted between growing seasons (like rye or vetch) to protect the soil from erosion and add nutrients.

What is a consequence of slash-and-burn farming?

Loss of habitat/biodiversity and the release of greenhouse gases (CO_2) contributing to global warming.

What was the Green Revolution?

A period of rapid agricultural technological advancement (1940s-1960s) involving high-yield seeds, synthetic fertilizers, and irrigation.

What are Genetically Modified Organisms (GMOs)?

Organisms whose genetic material has been altered to provide traits like pest resistance or drought tolerance.

What is a CAFO (Concentrated Animal Feeding Operation)?

A large-scale industrial facility where livestock are raised in high densities for meat production.

What is one environmental concern regarding overfishing?

The depletion of fish stocks and the destruction of marine habitats via methods like bottom trawling.

What is Aquaculture?

The farming of aquatic organisms such as fish, shellfish, and seaweed in controlled environments.

What role do native plants play in sustainable agriculture?

They aid in preventing runoff flooding/erosion and improve air quality through carbon sequestration.

How do impervious surfaces affect the water cycle?

Surfaces like concrete prevent water infiltration, leading to increased runoff and potential urban flooding.