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36 Cards in this Set
- Front
- Back
Floating free in bulk water that is moving laterally and eventually dumped into a surface stream--where in the soil system are they? |
Ground water |
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__________ happens because soil pores are tortuous, irregular, or discontinuous |
Hysteresis |
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If you dig a hole in your back yard and water seeps into the hole, it will fill the hole up to _______ with water. |
The water table / phreatic surface |
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T/F Evapotranspiration includes water vapor losses both from the soil surface and from the leaves of plants. |
True |
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T/F The gravitational potential of water in the soil is usually negative. |
False |
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Soils high in OM commonly hold more available water than comparable soils with lower OM levels most likely due to __________ |
Better soil aggregation |
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At whihh kPa of total soil moisture is the soil water held most tightly? |
-3100 |
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Plant roots obtain better access to soil water when ______ |
Roots grow and extend into moist soil areas |
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T/F The water potential at the field capacity for most soils is in the range of -10 to -30 kPa. |
True |
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T/F Osmotic and matrix potentials are negative. |
True |
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T/F The osmotic potential is created by the presence of salts and other solutes in the soil. |
True |
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T/F The matrix potential is due to the attraction of water molecules to the surfaces of soil particles. |
True |
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When water leaves the saturated ground water zone and enters a surface stream or lake, the best word to describe the process is ________. |
Discharge |
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T/F Acid functional groups on humus may provide negative charges. |
True |
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____________ clays may be negatively charged because of isomorphous substitution. |
Aluminosilicate |
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T/F A 2:1 layer lattice (aluminosilicate) clay has 2 tetrahedral sheets and 1 octahedral sheet. |
True |
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The pool of acidity called "_________ acidity" determines the lime requirement of the soil. |
Residual |
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A soil with a ______ percent base saturation will be more likely to have a relatively high pH. |
Higher |
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________ in the soil make the soil more workable by stabilizing the structural units called aggregates. |
Colloids |
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Which aluminosilicate clay experiences the least amount of swelling and shrinking? |
Kaolinite |
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T/F Montmorillonite is the most common of the swelling/shrinking smectites, which are 2:1 aluminosilicate clays. |
True |
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In isomorphous substitution it is common for __ to replace __. |
Mg to replace Al |
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T/F The reason that an aluminosilicate clay is non-swelling/shrinking may be because the layers are held together by hydrogen bonds or by K+ in hexagonal holes in the domains of the layers. |
True |
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If the pH of a solution is 4.5, the pOH of that solution will be ___. |
9.5 |
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_________ is often used as a China clay. |
Kaolinite |
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Because aluminum can act as either an acid or a base, it is called _________. |
Amphoteric |
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____ is an important soil property to know because it helps determine the availablity of several essential elements. |
pH |
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T/F Buffering is a resistance to change. |
True |
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T/F Humus in the soil may be hundreds of years old. |
True |
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T/F An acquired soil characteristic (property) is always inherited from the parent material. |
False |
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T/F As a non-polar molecule, water can easily infiltrate small pores in the soil. |
False |
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T/F The standard, professionally accepted expression of the water content of the soil uses the calculation: %H2Om=100x (mass water in soil/mass of wet soil) |
False |
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T/F There is no mathematical relationship between the mass water content of a soil and the volumetric water content of the same soil at the sand moisture content. |
False |
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Water has a specific heat of ___ calorie per gram per degree Celcius. |
1 |
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The standard soil water content determination by gravimetric analysis _________. |
Heats the sample in an oven |
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T/F Standard measurement of soil water content expresses the value as kilograms of water per kilogram of dry soil. |
True |