Soil Science Exam #3

1 / 120
The present level of oxygen (O2) in the atmosphere, as a result of photosynthesis, is:
Click the card to flip 👆
Terms in this set (120)
Aerobic photosynthesis developed on Earth over time, which results what gaseous byproduct? This gas has accumulated in Earth's atmosphere to make Earth habitable by humans and other aerobic organisms.Oxygen (O2)Algae differs from more complex, higher plants because algae lacks what compnents?True Stems, leaves, or rootsIn Science (and in life), what do we do with current, and new, information to understand it?Formally (and/or informally) organize the informationHave a variety of food sources, aeration, acidity, temperatures, and moisture conditions in the soil creates __________________ among soil organisms.BiodiversityPlant-like species, such as plants, bacteria, fungi, and algae, are referred to as:FloraActinomycetes is responsible for the "_____________________" smell of fresh, healthy soil.EarthyThe "Food Web" is based around what is referred to as ____________________levels, in that nutrients and energy pass from one group of organisms to another.TrophicProtozoa are classified within 3 groups (Ciliates, Amoebae, and Flagellates) based on what 2 characteristics?Shape and MovementAnimal-like species, such as gorillas, tardigrades, protozoa, and nematodes, are referred to as:FaunaYeast, Mold, and Mushrooms are the three types of what type of organism?FungiSometimes ants are confused with termites, but ants have narrow "________________" and termites do not.WaistsSoil vertebrates (have a backbone) may be referred to in what generic name?Soil AnimalsSoil Macrofauna are:>2 mm and visible to the naked eye (no microscope needed)Invertebrates represent approximately what percentage of animals on Earth?97%Fire ants are not native species to the United States and were first introduced during what time period in history?1930sEpigeic earthworms have darker pigmentation, are important for composting, and live in the organic-rich, litter-layer at the soil surface. These earthworms are often called:Surface DwellersMacrochannels made in soil and wood act like a sponge to maintain high humidity in areas where termites live and feed. This is because the macrochannels hold:Water and HeatAnecic earthworms make permanent burrows that are _____________________to the soil surface.VerticalTermites are found mostly in grasslands and forests in tropical and subtropical areas, but can be found on what fraction of land on Earth?2/3Ants communicate to each other, and alert each other of danger or a promising food source, by using:ChemicalsAll of the terrestrial earthworms in Minnesota soil are:Non-native SpeciesThe primary food eaten by termites that is digested their gut by special bacteria is:CelluloseWithout humans moving earthworms around, in root balls or as fishing bait, earthworms moves slowly. An estimation of this movement is one half-mile over how many years?100Invertebrates that have an exoskeleton, segmented bodies, and jointed limbs/legs are called:AnthropodsBeetles are important to soil because they provide ecological functions in the soil of:Aeration, Inversion, and Nutrient CyclingTermite colonies are divided up in different castes, which types of termites make up to Reproductive Caste?Adult males and females with wingsTermites use soil and feces cemented with saliva to form:Termite MoundsWhat is NOT a positive effect of earthworms? The others earthworm effects listed can help improve the availability of nutrients to plants.Increases in soil erosion from exposed soilInvertebrates with segmented bodies, such as an earthworm, are called:AnnelidsThe leader of an ant colony is referred to as the:QueenSapric materials have a fiber content that represents what fraction of the total volume?<1/3Which of the following terms essentially have the same definition, in relation to the ability of a soil to function and sustain life, but the popular use of terms have changed over time?Soil Health, Soil Quality, Soil Tilthmajority of soil organisms metabolize carbon-containing materials to acquire carbon for building essential organic compounds and obtain _____________________________ for life processes.EnergyWhen SOM is held within soil pores too small to allow access for most soil organisms, which discourages rapid decomposition, the SOM is said to be:Physically ProtectedOf the 3 Types of soil organic matter (SOM) classifications, which is the least decomposed, lighter yellowish- or reddish- brown in color, and can hold 850% to > 3000% of its weight in water.FibricWhat is the most abundant, naturally occurring organic compound that provides the structural component for plant cell walls, is not digestible by humans, but can be digested by termites and ruminant animal (due to microbes present in the digest tract)?CellulosePick two key factors that control the time needed for decomposition and mineralization:Environmental conditions & Chemical composition of the added residuesThe capacity of a specific kind of soil to function and support life is referred to as:Soil HealthThe general term for thread-like structures in plant tissue, which is also used to classify types of SOM on a physical basis:FiberDecomposition rates are _____________________ when the residue is incorporated into the soil, such as with the land practice of tillage.FasterHemic materials have a fiber content that represents what fraction of the total volume?1/3 to 2/3Soil organisms metabolize (eat) carbon-containing material for food. Yet, in order to grow and multiply, organisms must also obtain what nutrient to help produce cellular compounds, such as amino acids, enzymes, and DNA?NitrogenWhat material has the slowest rate of decomposition? Hint: This is the same material that causes some plants to become "woody" as the plant matures.LigininIf the soil temperature is too _____________________________ decomposition rates can become slower than plant growth, which results in large SOM accumulations in soil.Cold (Low)When SOM is a part of a complex, chemical structure, (such as soil humus), which discourages easy decomposition, the SOM is said to be:Chemically ProtectedFibric materials have a fiber content that represents what fraction of the total volume?> 2/3The conversion of an element from organic form into an inorganic state, which results from microbial decomposition processes.MineralizationOf the 3 Types of soil organic matter (SOM) classifications, which is about halfway decomposed, darker brown in color, and can hold 450% to 850% of its weight in water.HemicOf the 3 Types of soil organic matter (SOM) classifications, which is the most decomposed, very dark to black in color, and can hold up to 450% of its weight in water.SapricIf the Carbon-to-Nitrogen ratio (C:N) of plant residues added to the soil is greater than 30:1, then what will likely happen:Soil microbes will initially deplete the soil of soluble nitrogen.Which of the following describes the "Slow Pool" of soil organic matter (SOM) in the soil?Decomposes slowly, in the soil anywhere from 2-50 yearsWhich of the following describes the "Passive Pool" of soil organic matter (SOM) in the soil?Decomposes extremely slowly, 60-90% SOM, in the soil from about 50 years to 1000s or millions of years (50 - 1000+ years), and is considered chemically and/or physically protected.Which of the following definitions describes "Gross Primary Production (GPP)"?The total amount of CO2 that is fixed by the plant during photosynthesisWhat is the #1 greenhouse gas in the atmosphere?Water VaporWhich of the following definitions describes "Net Primary Production (NPP)"?The amount of CO2 fixed by a plant, minus the amount of CO2 released as plant respiration.Which common greenhouse gas is 25 times more effective in trapping solar radiation than carbon dioxide (CO2) gas?Methane (CH4)In the Spring, carbon-containing plants grow exponentially, which causes the CO2 in the atmosphere to do what?DecreaseIn the Winter, few carbon-containing plants grow and many are decaying, which causes the CO2 in the atmosphere to do what?IncreaseWhat is the #2 greenhouse gas in the atmosphere (carbon-based) ?CO2Soil organic matter (SOM) is generally composed of what percentage of carbon (C)?50%What percentage of the Earth's soil carbon is contained in the 3 soil orders of Gelisols, Histisols, and Inceptisols, due to either large SOM contents or large land areas on Earth.45%Which of the following definitions describes "Net Ecosystem Production (NEP)"?The total amount of primary production biomass, minus the loss of CO2 through respiration by plant-like (flora) and animal-like (fauna) organisms.Soil organic matter (SOM) divided into 3 general pools, which controls carbon cycling, based on what biological feature?How easily the material is decomposed by soil organismsWhat is the generic term used to describe what happens to carbon (from the atmosphere) during photosynthesis in a plant?FixedWhat is the generic term used to describe what happens to carbon during respiration or decomposition of a plant?ReleasedWhat is the process called when the Earth's incoming solar radiation is reflected back into space from snow and ice?Albedo EffectOn a global scale, what resource holds 2-3 times more carbon (C) than is held in Earth's vegetation?SoilsCarbon is the ______________________ most abundant element in the universe.4thWhich of the following describes the "Active Pool" of soil organic matter (SOM) in the soil?Decomposes rapidly, is composed of 10-20% SOM, lasts in the soil for days to 2 years (0-2 years), has a low C:N ratio (good quantity of available N).Air particles in the atmosphere can prevent radiation from being released back into space, which traps heat in the atmosphere. Which of the following is an example of a "unnatural, people-influenced" particulate material that gets released into the atmosphere?Industrial emissionsThe sequence of chemical and biological changes undergone by nitrogen as it moves from the atmosphere into the water, soil, and living organisms, and upon death of these organisms (plants and animals) is recycled through a part or all of the entire process is called the:Nitrogen CycleNitrogen fixation, either directly through symbiotic or indirectly through non-symbiotic associations with plants, is considered the 2nd most important chemical reaction for life on Earth (1st is photosynthesis). Nitrogen fixation also accounts for approximately how much of the nitrogen inputs (as fertilizing materials) to crops in the United States?20%Which soil horizon typically contains the most soil nitrogen?ANitrogen increases the content of what in seeds and foliage?ProteinSoil organic matter (SOM) is roughly composed of how much nitrogen? (Can be used as a quick calculation)5%When too much nitrogen is available, excessive vegetative growth occurs; the cells of the plant stems become enlarged but relatively weak, and the top-heavy plants are prone to falling over with heavy rain or wind. This is called:LodgingHealthy plant foliage contains what percentage on nitrogen, depending on species and age of the leaves?2.5-4%Plants deficient in nitrogen tend to exhibit a stunted appearance, thin stems, and a yellowish or pale green color in leaves called:ChlorosisThe conversion of organic forms of nitrogen to inorganic ammonium ions (NH4+) through a 2-step process is called:MineralizationThe process where ammonium ions (NH4+) in the soil are oxidized by certain soil bacteria and eventually yield nitrate ions (NO3-), which occurs under aerobic conditions, is called:NitrificationPlant roots take up nitrogen from the soil in what 2 primary forms?Nitrate (NO3-) and Ammonium (NH4+)The conversion of inorganic-N ions into organic-N is called:ImmobilizationIn plants, nitrogen is needed (is a part of) what components?Enzymes (Control biological processes) Nucleic Acids (genetic control) Chlorophyll (photosynthesis) Amino Acids (create protiens)Plants commonly respond to nitrogen (N) by turning a deep, rich shade of this color during the growing seasonGreenOrganic soil nitrogen represents what percentage of the total nitrogen in the soil?90-98%In plants, nitrogen stimulates and/or increases:Root growth and development & plant productivity (in terms of plant biomass volume & weight)Nitrogen increases what in cereal grains?PlumpnessThe atmosphere is composed of 78% of this type of non-reactive nitrogen gas:Dinitrogen (N2)The process when nitrate ions (NO3-) are converted to gaseous forms of N (NO, N2O, N2) by a series of biochemical reduction reactions, which occurs under anaerobic conditions, is called:DenitrificationAny form of nitrogen (N) that is readily available to living organisms, which is usually bonded to hydrogen (H), oxygen (O), or carbon (C), is referred to as:Reactive NitrogenHaving a soil nutrient management system that is 'practical' and 'balanced' is important because:We need sol to be productive without destroying the ecosystem, which creates long-term sustainability. & We rely on soil to provide food, fuel, clean water, and a medium for plant growth, so the soil needs to be healthy.Sometimes managed ecosystems can become unbalanced. What activity is an example of removing nutrients from a managed ecosystem?Harvesting CropsThere are 2 major global problems related to soil phosphorus (P). Having too much P in the soil can cause what problem?Accelerated eutrophicationAn example of human-influenced (artificial) subsurface drainage, which is the horizontal (side-to-side) movement of water under the soil surface, that is sometimes installed in agricultural fields is referred to as:Tile drainageWhat are the 4 aims of Nutrient Management?Produce high-quality plants in a cost-effective way & protect the environment beyond the soil & Effectively use and conserve nutrient resources & Maintain or enhance soil health / soil qualityThere are 2 major global problems related to soil phosphorus (P). Not having enough P in the soil can cause what problem?Land degradationPollution that is from runoff and/or from locations not easily identified is termed:Non-point source pollutionNegative nutrient budgets (impoverishment of soils) can lead to what?Nutrient deficienciesWhat is a simple way of defining a 'Balanced Ecosystem'?Inputs = OutputsSoil organic matter (SOM) contains about how much phosphorous (P)?0.58%Investing in the long-term health of the soil - through the use of organic fertilizers to build-up soil nutrients for future use - would be an example of:"Feed the Soil" approach to nutrient managementNutrients that are "tied-up" in (or contained within) soil organic matter (SOM) are referred to as being:ImmobilizedNutrient budgeting is the balance what 2 aspects of an ecosystem?Inputs & OutputsManaged ecosystems can become unbalanced with intensive animal production systems. What nutrient-related issue can be caused with increased animal confinement in a specific area? (Assume these animals are not grazing the local vegetation)Nutrient LoadingOne of the 4 aims or nutrient management is to: Produce high-quality plants in what way?Cost- EffectiveNutrients in the soil that are available for plant uptake are referred to as being:LabilePlant production goals depend on the industry associated with the production. What are 3 types of different industries that are related to plant production?Agriculture & Forestry & OrnamentalOnly investing in what nutrients are needed to grow the plant during one season - would be an example of:A "Feed the Plant" approach to nutrient managementDense vegetation situated along the bank of a stream or other body of water (i.e. riparian zone) are referred to as:Buffer stripsPositive nutrient budgets (excessive nutrients in soils) can lead to what?Nutrient run-off