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79 Cards in this Set
- Front
- Back
Pathogens and a failure to separate industrial waste (e.g. heavy metals) from human waste can complicate the use of sewage in agriculture.
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True
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Pathogens and a failure to separate industrial waste (e.g. heavy metals) from human waste can complicate the use of sewage in agriculture. |
True |
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Southern corn leaf blight (1970-71) ____. |
Is an example of genetic vulnerability and destroyed almost all of the corn crop in Illinois and Indiana |
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Among common domesticated livestock, manure from ____ contains the lowest level of water, which makes it more affordable to transport for use as a fertilizer |
Chicken |
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Plants that use the C3 photosynthetic pathway do well under relatively hot/dry conditions compared to plants using the C4 pathway |
False |
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After land is put into cultivation (i.e. tilled) loss of soil organic matter happens ____. |
Rapidly at first, then losses occur more slowly |
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Phosphorus is an important component of many structures in plant and animal cells, including membranes, nucleic acids, ATP, amino acids, and chlorophyll |
False |
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In a mass-selected plant variety, overall genetic diversity within the variety is greater than that of any individual seed in the variety. |
True |
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While the crop production industry has narrowed its genetic basis over time, the livestock industry, which relies more on cross-breeding, has maintained a high level of diversity. |
False |
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Of the major grains we rely upon in the USA, corn and soybean are native species, which is part of why they are commonly planted as a rotation in the USA. |
False |
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Polyploid plants often produce larger seeds and fruits than their normal diploid ancestors because of inbreeding depression |
False |
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In Teaming with Microbes the authors say that pesticides, salts from fertilizers, and ____ can kill or injure portions of the soil food web.
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rototilling (tillage)
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During lecture we examined a photograph of cotton roots growing within the soil profile. In the photograph, many roots grew where ____
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rtilizer was appliedirrigation had occurredbulk density was lowThe plow pan was broken by a "ripper" or subsoil tillage device
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Few plants, especially agricultural crops, grow well outside the pH range of 5 to 8.
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True
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About 20 years ago (Pimentel et al. 1995) the annual costs of soil erosion in the USA were estimated to be in excess of $44 Billion
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True
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In the assigned reading (Liming Missouri Soils, G9102), the authors indicated that soybean yields might be reduced 18% when soil pH decreases to about 5
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False
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Where a healthy, dynamic soil community (e.g. bacteria, nematodes, etc.) is present, nutrient availability to plants can be maintained even when residues of higher C:N are present.
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True
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“High-traffic” areas around campsites (e.g. around fire pit or tent) become compacted and can have runoff levels ____ than un-compacted areas; erosion and plant moisture stress can result from compaction. Therefore, camping in designated areas is recommended.
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3x Greater
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In the assigned MU extension guide G9107, we learned that the material most commonly used to adjust soil pH to a higher level is ___
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Calcium Carbonate
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An ideal soil will have 25% of its volume as pore spaces, which could be occupied by air and water.
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False
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In Teaming with Microbes the authors say that ___ are in control of the soil food web because of what they release into the soil.
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Plants
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In Dr. Terry Tollefson's videos on soil biology he presented several microscopic organisms that were found in the soil sample. Other than bacteria, identify three other microscopic organisms from the video using one well-written sentence
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Along with bacteria, Dr. Tollefson's soil sample also contained mites, rotifers, and tardigrades
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During lecture, Dr. Burton presented soil test results from two of his farm fields. What contributed to the "excessive" level of phosphorus in one of the fields?
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The property that Dr. Burton purchased had been sprayed with unwarranted amounts of liquid fertilizer, from a local dairy that had closed, on the bottom east quadrant.
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Sheet Erosion
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Removal of thin layers of soil overtimeSevere problem but often escapes notice
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Rill Erosion
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Areas of concentrated flow that usually follow crop rows Less than 2' by 2'
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Ephemeral Gully Erosion
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Concentrated flow breaks across crop rows, smoothed with tillage, usually develop in same place each year.
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Gully Erosion:
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too large to be smoothed/crossed with equipment
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“Stock density” refers to the amount (weight or mass) of animals on a given area of land irrespective of the amount of time spent on that land area.
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True
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A cover crop that is allowed to grow with the crop is called ____.
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Living Mulch
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Cattle do not benefit much from shade in agroforestry systems because their sweat glands are sufficiently effective in cooling them.
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False
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Allelopathy ____
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Is an effect of one species on another through chemicals, Can be used to suppress the germination and growth of weedsEffectiveness has been observed to change with the plant’s stage of growth
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Mixed species grazing in the Serengeti of East Africa (and in agro-ecosystems elsewhere) results in herbivores eating the same plants, plant parts, and growth stages of plants.
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False
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Examples of animal integration with crop systems include ___.
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Agroforestry and livestock,Aquaculture and crop productionCrop rotations with a grazed forage phase
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Animals transform plant biomass into useful forms of energy and matter.
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True
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Rotational grazing using a greater number of smaller paddocks and higher stock density results in ___ than continuous grazing.
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more uniform animal waste distribution
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Dung beetle populations are affected by both the time of insecticide application and the choice of insecticide used on cattle. Some studies suggest that ___ is less damaging to dung beetle populations.
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Dectins aka Moxidectin
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The dis-integration of livestock and crops in farming operations came about with the widespread introduction of specialized machinery, fertilizers, and pesticides following WWII, but specialization in USA agriculture began decades before that.
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True
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In terms of agro-ecosystem diversity, an example of undesirable “simplification” of the system would be the loss of predatory insects through indiscriminate use of a broad-spectrum insecticide.
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True
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Cover crops are often planted in mixtures of at least one grass and one legume
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True
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_______ clay minerals have more surface area for the exchange of nutrient ions when hydrated. |
Highly Expansive |
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In the USA, water erosion is typically a bigger problem in eastern states. |
False |
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Windbreaks (a.k.a shelterbelts or hedgerows) are not meant to stop the wind, but rather to change its course and rate of flow. |
True |
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___ is regarded as the “Father of soil conservation” in the USA. |
Hugh Hammond Bennett |
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Stiff-stemmed grasses could be used to prevent "sandblasting" injury to sensitive crops if the grasses are planted perpendicular to the prevailing direction of erosive winds. |
True |
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Soil organic matter could be called the "signature or evidence of past plant and biological activity |
True |
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Few plants, especially agricultural crops, grow well outside of the pH range of 5 to 8. |
True |
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The least obvious form of soil erosion is called sheet erosion. It can be a severe problem but can escape notice since thin layers of soil are lost over time. |
True |
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Raindrop impact on tiny soil particles was equated to a bomb blast during lecture because of the power of raindrops to disperse soil particles from unprotected soil. |
True |
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Lawn clippings and soil from edging become sources of organic contaminants and nutrients in untreated storm runoff. They should be |
Swept or blown back into the lawn or composted |
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Soil Structures can be promoted by |
earthworm activity microbiological activity Root exudates |
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Some methods of reducing soil erosion include: |
alternating strips of permanent grass and annual row-crops on a slope tilling a clayey soil to form ridges perpendicular to the direction of the prevailing wind. installation of terraces to slow water movement down a slope |
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In Teaming with Microbes the authors say that pesticides, salts from fertilizers, and ____ can kill or injure portions of the soil food web. |
Tillage |
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As the name implies, "no-till" agricultural equipment cause zero disturbance of the soil during planting operations. |
False |
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Excess water in the soil can lead to high levels of oxygen in the soil as a result of root respiration. |
False |
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The figure indicates that at least __% groundcover (e.g. cover crop or residues from the previous crop) is required to reduce erosion by 80% when compared to the level of erosion occurring on bare soil. |
30% |
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The shrink-swell capacity of a soil is an important consideration for an engineer when constructing a building, road, or bridge. |
True |
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Where a healthy dynamic soil community (e.g. bacteria, nematodes, etc.) is present, nutrient availability to plants can be maintained even when crop residues of higher C:N are present. |
True |
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The USDA map used in lecture identified areas subject to wind erosion as the states of the Great Plains and coastal areas in eastern and southern states. Only the southeastern "bootheel" region of Missouri is identified as being at risk of wind erosion. |
True |
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During lecture we examined a photograph of cotton roots growing within the soil profile. In the photograph, many roots grew where ____. |
bulk density was low irrigation had occurred fertilizer was applied |
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The ___ soil horizon normally has the lowest bulk density in undisturbed soil. |
None of the above – Roman numerals are used to identify soil horizons |
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Types of tillage that result in more disturbance (e.g. moldboard plowing vs. chisel plowing) result in greater losses of soil carbon into the atmosphere. |
True |
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“High-traffic” areas around campsites (e.g. around fire pit or tent) become compacted and can have runoff levels ____ than uncompacted areas; erosion and plant moisture stress can result from compaction. Therefore, camping in designated areas is recommended. |
3x greater |
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Mycorrhizal fungi infect the roots of most crop plants in a beneficial (symbiotic) relationship. The mycorrhizae gain carbohydrate from the plant, while the plant gains ____. |
Enhanced water and phosphorus uptake |
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In the assigned reading (Liming Missouri Soils, G9102), the authors indicated that soybean yields might be reduced 18% when soil pH decreases to about 5 |
False |
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In the assigned MU extension guide G9107, we learned that the material most commonly used to adjust soil pH to a higher level is ___. |
Calcium Carbonate |
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In addition to the millions of tons of topsoil in “dust bowl’ storms, thousands of people suffered (and many died) from mysterious illnesses resulting from dust inhalation. |
True |
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In Teaming with Microbes, the authors say that ___ are in control of the soil food web because of what they release into the soil. |
Plants |
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The tendency of a soil or clay mineral to increase or decrease in volume when they are hydrated is called its "shrink-swell capacity". |
True |
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An ideal soil will have 50% of its volume as pore spaces, which could be occupied by air and water |
True |
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Windbreaks (trees planted in a line perpendicular to the prevailing wind direction) can modify windspeed to reduce soil erosion for a distance of 10X the tree height (or more). |
True |
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___ is often used as an alternative to planting permanent windbreaks of trees or shrubs. |
Sunflower, Corn, and Sorghum |
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A strip-tillage system results in ___. |
Only about 50% of the field area being tilled Faster soil warm up in the spring |
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Soils differ in the amount of water they hold at ____ , which is the moisture left in the soil after the downward pull of water has pulled away gravitational water. |
Field Capactity |
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The ability of soil to hold and buffer nutrient ions (i.e. a measure of soil fertility) is measured by ___. |
Cation Exchange Capacity |
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____ results in lower runoff and erosion. |
Increasing vegetative cover Increasing residue cover |
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Unfortunately, no genetic varieties (within a crop species) have been identified that are more resistant to wind and lodging |
False |
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Most crops will generally perform well in a loamy soil, however, paddy rice requires a clayey soil. |
False |
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Human-accelerated erosion is typically many times worse -- perhaps 10 or 1000X worse -- than geological erosion. |
True |
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In the soil biota videos assigned during lecture, Terry Tollefson said that soil scientists had estimated that there might be as many as ____ different species in a gram of soil. |
None of the above |