Review – Exam 2

This is just an outline; make sure you go over everything.

Materials: Exam 2 will cover chapters 13, 14, 15, 18 & 19: everything we have covered in the class. Exam 2 will start Sharp at 6:00 pm. The allotted time for exam 2 will be 6:00 to 6:50 pm

Format: There will be 40 multiple choice questions, scantrons will be provided.

Main Concepts

Chapter 13: * Soil forming factors * Soil formation begins with fragmentation of parent material. * Parent material consists of ancient layers of rock, or more recent deposits from lava flows or glacial activity. * The first organisms to gain a foothold in modified parent material also contribute to soil formation. * Lichens form pioneer communities. * Decomposition of dead lichens further alters underlying rock.
Humus is the organic material resulting from the decay of plant and animal remains. * It mixes with top layers of mineral particles, and supplies needed nutrients to plants. * It creates a crumbly soil that allows adequate water absorption and drainage. * Burrowing animals such as earthworms bring nutrients up from deeper soil layers, improving soil fertility. *

* The organic material resulting from the decay of plant and animals remains is called………….?
HUMUS
* Soil properties: Soil texture
Soil texture is determined by the size of mineral particles within the soil. * Too many large particles (sand, gravel) lead to extreme leaching. * Too many small particles (clay) lead to poor drainage.

* What are the major soil classification types in North America
Over 15,000 separate soil types have been classified in North America. * Most cultivated land can be classified as either grassland or forest soil. * Grassland soils usually have a deep topsoil layer. A lack of leaching results in a thin layer of subsoil. * In forest soils, which are typically high rainfall areas, the topsoil layer is relatively thin, but topsoil leachate forms a subsoil that supports substantial root growth.

* Soil profile
O horizon is made of litter, undecomposed or partially decomposed organic material.
A horizon is the topsoil, or the uppermost layer. It contains most of the soil nutrients and living organisms.
E horizon is formed from leaching darker materials. * Usually very nutrient poor.
B horizon is the subsoil. It contains less organic matter and fewer organisms, but accumulates nutrients leached from topsoil. It is poorly developed in dry areas.
C horizon is weathered parent material.
R horizon is bedrock.

* The wearing away and transportation of soil by water, wind, or ice is called…………?
EROSION
* Soil quality management components * Enhance organic matter * Avoid excessive tillage * Manage pests and nutrients efficiently * Prevent soil compaction * Keep the ground covered * Diversify cropping systems

* Soil conservation practices: Contour farming, Strip farming, Terracing, Waterways and Windbreaks

* Contour Farming Tilling at right angles to the slope creates a series of ridges that slows the flow of the water and prevents soil erosion. This soil conservation practices is useful on gentle slopes.

* Strip Farming On rolling land, a combination of contour strip farming prevents excessive soil erosion. The strips are planted at right angles to the slope, with bands of closely sown crops, such as wheat or hay, alternating with bands of row crops, such as corn or soybeans.

* Terraces Since the construction of terraces requires the movement of soil and the protection of the steep slope between levels, terraces are expensive to build. * Waterways are depressions in sloping land where water collects and flows off the land. * Channels movement of water. * Windbreaks are plantings of trees or other plants that protect bare soil from full force of the wind. * Windbreaks reduce wind velocity, decreasing the amount of soil that can be carried.

Chapter 14: * Shifting agriculture, Polyculture and Monoculture * Shifting agriculture involves cutting down and burning the trees and other vegetation in a small area of the forest. Shifting agriculture often employs polyculture, or the planting of a mixture of plants. * Monocultures promote more efficient planting, cultivating, and harvesting.

* Pesticide and types of pesticide * A pesticide is any chemical used to kill or control populations of unwanted fungi, plants, or animals (pests). * Pesticides can be subdivided into several categories based on the organisms they control. * Insecticides control insect populations. * Fungicides control fungal pests. * Rodenticides control mice and rats. * Herbicides control plant pests. * Biocides kill a large variety of organisms.

* Persistent and Nonpersistent pesticide: Pesticides that breakdown quickly in the environment are called……………….? Nonpersistent * Bioaccumulation and Biomagnification * Bioaccumulation is the process of accumulating higher and higher amounts of material within an organism’s body. * Many persistent pesticides are fat soluble and build up in fat tissues. * Biomagnification is the process of acquiring increasing levels of a substance in bodies of higher trophic-level organisms. * DDT, mercury, and PCBs are all known to accumulate in ecosystems. * DDT was banned in the U.S. in the early 1970s.

* Why are pesticides so widely used? * Food Production * Worldwide, pests destroy 35% of crops. * Economic Concerns * Pesticides increase yields and profits. * Health Reasons * Insecticides curtail many diseases.

* Alternatives to conventional Agriculture
Prior to the invention of synthetic fertilizers and other agrochemicals, * Animal manure and crop rotation provided soil nutrients. * A mixture of crops prevented regular pest problems. * Manual labor killed insects and weeds.

* Integrated Pest Management * Integrated Pest Management (IPM) uses a variety of methods to control pests rather than relying solely on pesticides. * It requires information about: * Crop plant metabolism * Biological interactions between pests and their predators and/or parasites * Climatic conditions favoring pests * Techniques to encourage beneficial insects * Several methods are employed in IPM: * Disrupting reproduction * Female pheromones * Male sterilization * Natural predators * Aphids can be controlled with ladybugs * Bacterial strains

Chapter 15: * Freshwater resources and areas of the world experiencing water stress * Freshwater Resources Although was covers about 70% of Earth’s surface, over 97% is saltwater. Of the less than 3% that is freshwater, only tiny fraction is available for human use. * The World Health Organization estimates 25% of the world’s population does not have access to safe drinking water. * According to the U.N. Environment Program, between 5-10 million deaths occur each year from water-related diseases, including cholera, malaria, dengue fever, and dysentery. * These illnesses have been increasing over the past decade and without economic investments in safe drinking water supplies, the rate of increase will continue.

* Hydrologic cycle * All water is locked into a constant recycling process called the hydrologic cycle. * Solar energy evaporates water. * Evapotranspiration is the process of plants giving off water. * Warm, moist air rises, cools, condenses, and falls as precipitation. * Some precipitation remains on the surface and evaporates, while most sinks into the soil or returns to the oceans. * * Runoff is surface water that moves across the surface of the land and enters streams and rivers. * Groundwater is water that fills spaces in the substrate. * Water entering the soil is either taken up by plant roots or moves downward until it reaches an impervious layer of rock, and accumulates in porous strata called an aquifer.

* Water lost through the leaves of plants is called…………………? EVOTRANSPIRATION * Aquifer: Unconfined and confined aquifer * An aquifer is an underground layer of gravel, sand, or permeable rock that holds groundwater that can be extracted by wells. * An unconfined aquifer is usually near land’s surface. * The top layer saturated with water is the water table. * The lower boundary is impermeable layer of clay or rock. * Vadose zone (zone of aeration) is the area above the water table unsaturated with water. * The water in these aquifers is at atmospheric pressure and is recharged by rainfall and percolation. * A confined aquifer is bounded on top and bottom by layers impermeable to water. * Water in these aquifers is stored under high pressure and recharged by rain and surface water from a geologic recharge zone. * An impervious confining layer is called an aquiclude. * A permeable confining layer is called an aquitard. * Porosity is a measure of the size and number of spaces in the substrate. *

* What are some human influences on the hydrologic cycle * Runoff and the infiltration rate are greatly influenced by human activity. * A major concern in many urban areas is transportation of storm water. * Water withdrawals are measurements of the amount of water taken from a source. * Water incorporated into a product, or lost to the atmosphere through evaporation or evapotranspiration, cannot be reused in the same geographic area and is said to be consumed.

* Kinds of water use: Urban domestic water use in North America * Urban Domestic Water Uses Over 150 billion liters (40 billion gallon) of water used each day for urban domestic purposes in North America. (Nonconsumptive uses are shown in blue and red, and consumptive uses are shown in green and brown)

* Kinds of sources of water pollution: the amount of oxygen required to decay a certain amount of organic matter is called………………?

* Biochemical oxygen demand (BOD) is the amount of oxygen required to decay a certain amount of organic matter. * If too much organic matter is added, all available oxygen will be used up. * Anaerobic (not requiring oxygen) bacteria begins to break down waste, producing a foul odor.

* Eutrophication * Eutrophication is excessive growth of algae and aquatic plants due to added nutrients.

* Point source and nonpoint source of pollution * A point source is a source of pollution readily located and identified. * Municipal and industrial waste discharge pipes, oil tanker…. * Nonpoint sources are more difficult to identify and control. * Diffuse pollutants from agricultural land and urban paved surfaces come from nonpoint sources. * Acid rain

* Ground water pollution * Major sources of groundwater pollution include: * Agricultural products * Pesticides * Underground storage tanks * Leakage * Landfills * Approximately 90% of North American landfills have no liners to stop leakage. * 96% do not have systems to collect leachate that seeps from the landfill. * Septic tanks * There are over 20 million septic tanks in U.S.; about one-third are operating improperly. * Surface impoundments * About 71% are unlined * 1% use a plastic or other synthetic, non-soil liner * 99% have no leak-detection system * 73% have no restriction on the waste placed in the impoundment.

* Wastewater treatment: Primary sewage treatment, Secondary sewage treatment, Tertiary sewage treatment * * Primary sewage treatment removes large particles via filtration and then pumps remaining water into settling ponds and lakes. * After settling, water is drawn off the top, and although devoid of large particulate matter, it still has a heavy load of organic matter, dissolved salts, bacteria, and microorganisms.

* Secondary sewage treatment is a biological process that usually follows primary treatment. * Such facilities are designed to promote bacterial and other microorganism growth, which will degrade the organic matter. * Wastewater is mixed with large quantities of highly-oxygenated water to encourage this growth. * In a trickling filtering system, wastewater is sprayed over a surface of rock or other substrate to increase the amount of dissolved oxygen. * Tertiary sewage treatment is an additional stage used to remove inorganic nutrients such as phosphorous and nitrogen left after primary and secondary treatments. * This process is extremely costly because it requires specific chemical treatment of the water. * Some municipalities use natural or constructed wetlands to serve this stage. * Some areas use effluent to irrigate golf courses, roadside vegetation, or cropland. The vegetation takes up the nutrients and prevents them from being released into streams and lakes. *

* What is salinization? * Salinization is an increase in salinity caused by growing salt concentrations in soil. * As plants extract water from the ground, the salts present in all natural waters become concentrated. * Irrigation of arid farmland can make salinization more acute due to increased evaporation rates. * Primarily a problem in areas under irrigation for several decades.

* Removing of water from an aquifer faster than it can be replenished is called…………..? Groundwater Mining * What are the causes of wetland loss? * The loss of wetlands occurs because people convert wetlands to other uses. Conversion to urban and rural housing and other infrastructure accounts for just over 50 % of the wetlands loss. Draining wetlands for agriculture accounts for an additional 26%. * * What are the values of wetlands? * The Value of Wetlands Wetlands are areas covered with water for most of the year that support aquatic plant and animal life. Wetlands can be fresh-or saltwater and may be isolated potholes or extensive areas along rivers, lakes and oceans. We once though of wetlands as only a breeding site for mosquitos. Today, we are beginning to appreciate their true value.

Chapter 18: * Kinds of solid waste: mining waste, agriculture waste, industrial waste and municipal solid waste * Mining wastes are generated in three ways: * Waste material is left on the surface * Milling tailings are dumped on the land or stored in ponds. * Waste or tailings drainage often contains hazardous materials. * Agricultural waste * Includes waste from raising animals as well as crop and tree harvesting. * 90% is used as fertilizer or other forms of soil enhancement. * Industrial solid waste consists of solid waste other than mining. * Estimated to be between 200-600 million metric tons annually. * Demolition waste * Sludge * Combustion ash * Municipal solid waste consists of all the materials people in a region no longer want. * 210 million metric tons annually.

* Composition of trash in the United States * Composition of Trash in the United States (2012) Paper, food scraps, yard waste, and plastics are the most common materials disposed of, accounting for nearly 70% of the waste stream. * * Five techniques in waste disposal: Landfills, Incineration, Source reduction, Composting and Recycling
SLIDES!

* The most common method of waste disposal is………………? LANDFILL * New landfills have an impermeable liner and complex bottom layers to trap contaminant-laden is called …………..? leachate. * * Reducing the amount of solid waste generated by using less is………………….? * Source reduction is the practice of designing, manufacturing, purchasing, using and reusing materials so that the amount of waste or its toxicity is reduced.

* Recycling challenges

* There are many technical and economic problems associated with recycling. * Plastics are recyclable, but technology differs from plastic to plastic. * Milk containers tend to be high-density polyethylene (HDPE), while egg containers are polystyrene (PS), and soft-drink bottles are polyethylene terephthalate (PET).

Chapter 19:

* Difference between toxic and hazardous * There are many technical and economic problems associated with recycling. * Plastics are recyclable, but technology differs from plastic to plastic. * Milk containers tend to be high-density polyethylene (HDPE), while egg containers are polystyrene (PS), and soft-drink bottles are polyethylene terephthalate (PET).

* The U.S. Department of Transportation has listed several kinds of hazardous materials. What are they?

* EPA’s criteria for hazardous materials * The EPA defines hazardous materials as having one or more of the following characteristics: * Ignitability (Fire hazard) * Corrosiveness (Corrodes material) * Reactivity (Explosiveness) * Toxicity (May release toxins) * Some hazardous materials, such as gasoline, fall into several categories.

* Acute and Chronic toxicity * Effects of massive doses at once (acute toxicity) and small doses over time (chronic toxicity) differ. * Chronic toxicity is much harder to detect as effects may not surface for long periods of time.

* How hazardous wastes enter the environment? * Businesses and industries are highly regulated. * Individual citizens are becoming more important as sources of hazardous waste releases. * Hazardous wastes enter the environment in several ways: * Evaporation * Spills, leaks, or purposeful releases * Dumping or storing on land * Improper labeling and recordkeeping

* Resource Conservation and Recovery Act (RCRA)

* Cause or significantly contribute to an increase in mortality or an increase in serious irreversible, or incapacitating reversible, illness; or pose a substantial present or potential hazard to human health or the environment when improperly treated, stored, transported, disposed of, or otherwise managed.

* Gave the EPA the responsibility for regulating hazardous waste. * Created the “cradle-to-grave” concept of hazardous waste management by regulating generators, transporters, and Treatment Storage and Disposal Facilities (TSDF) as well as underground storage tanks (USTs) and petroleum products. * This act also defined toxic and/or hazardous waste by using the terms listed and characteristic waste. * RCRA Requirements The Resource Conservation and Recovery Act (RCRA) made generators responsible for proper handling of hazardous waste and established a :cradle to grave” paper train that assured that hazardous waste was treated and disposed of properly. * Several kinds of waste are specifically exempt by law from RCRA regulation: * Household hazardous waste * Agricultural waste that is returned to the soil * Mining overburden and processing waste * Wastes associated with oil and gas exploration and production * Ash from burning coal * *

* and Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)

* In the U.S., the federal government has become the principal participant in the cleanup of hazardous-waste sites. * The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) was enacted in 1980. * This program deals with financing the cleanup of large, uncontrolled hazardous-waste sites and has become known as Superfund. * Because of the provisions of CERCLA, many previously abandoned industrial sites were left vacant. * Developers were not willing to accept the liability they would accept if they purchased the land for redevelopment. * These abandoned sites became known as brownfields.

* The program deals with financing the cleanup of large, uncontrolled hazardous-waste site is called……………? CERCLA * What are the sources of toxic releases? * Sources of Toxic Releases (2012) Mining industries are responsible for about 40% of all toxic waste material released to the environment. These are primarily deposited on the surface of the land. Electric and chemical industries each produce about 15%. These are primarily releases to the atmosphere and land. Metal processing industries are also significant sources of toxic releases.

* Wastes can be treated in a way that their amount is reduced or their hazardous nature is modified. What are the different techniques to treat wastes?

* Pollution prevention (P2) encourages changes that prevent hazardous wastes from being produced. * Many of the actions are simple and cost little. * U.S. army phasing out lead bullets. * Waste minimization involves manufacturing changes that can reduce waste. * Replace hazardous solvents. * Recycling wastes involves using wastes for another purpose, thus eliminating them as “waste.” * Burn waste oils and solvents as fuel. * Incorporate ash or other solid wastes into concrete or other building materials.

* Wastes can be treated in a way that their amount is reduced or their hazardous nature is modified. * Neutralization * Biodegradation * Air stripping * Carbon absorption * Precipitation

* Recycling and treatment activities reduce the amount of hazardous waste that needs to be disposed of by about 20 percent. * The remaining wastes are typically incinerated or disposed of on land. * Incineration (thermal treatment) burns wastes at high temperatures. A well-designed, well-run incinerator can destroy 99.9999% of hazardous materials. * High costs and concerns about emissions have kept incineration from becoming a major method in North America. * Land disposal is the primary method used in North America, because abundant land is available and it is less expensive than incineration. * Deep-well injection * Discharge of treated or untreated liquids into water sources * Placement of liquid wastes into surface holding areas * Storage of solid wastes in hazardous waste landfills

* The Basel Convention * Objectives of the Basel Convention (taking effect in 1992) are to minimize generation of hazardous wastes and control and reduce transboundary movements to protect human health and the environment. * Although most countries have approved the convention, there are still individuals or companies that are willing to ignore the rules.

* What are the four general categories of nuclear wastes? * There are four general categories of nuclear wastes: * Transuranic wastes are highly radioactive waste that contain large numbers of atoms that are larger than uranium with half-lives greater than 20 years. * Uranium mining and milling wastes have low levels of radioactivity but are above background levels. * High-level radioactive wastes are spent fuel rods and highly radioactive materials from the reprocessing of fuel rods. * Low-level radioactive wastes have low levels of radioactivity and are not classified into one of the other categories.

Good Luck!!!