SCSC 301 Exam 2(100% Accurate)
Soil water Energy - ANSWERdifferences in energy level of water from one site to another determines
direction and rate of water movement in soils and plants. Wetter soil has water held at a higher
energy, etc.
Matric Potential - ANSWERmost limiting potential factor to plants, baseline is pure free water
(assigned a value of 0), water has low energy and is bound with little freedom to move
Saturated - ANSWERall soil pores are filled with water, matric potential is zero. Theoretical
Satiated - ANSWERessentially all pores are filled with water, matric potenial is essentially/almost
zero. 'real-world' saturation conditon
Gravitational Water - ANSWERwater in the largest pores (macropores) that is mainly under the
influence of gravity
Field Capacity - ANSWERpercentage of water remaining in the soil after the saturated (satiated) soil
has drained of gravitational water, 0.1-0.33 bars of tension
Permanent Wilting Point - ANSWERthe moisture content of the soil at which plants wilt and fail to
regain their turgor overnight, about 15-30 bars tension
Plant Available Water - ANSWERamount of water release between field capacity and permanent
wilting point.
Hygroscopic Water - ANSWERwater held so tightly that it is considered 'non-liquid' and will not move
by capillarity
Infiltration - ANSWERthe entry of water into the soil, units are cm/h
Percolation - ANSWERdownward movement of water through the soil
, Permeability - ANSWERease with which gases, liquids or plant roots penetrate or pass through a bulk
mass of soil or a layer of soil
Saturated Flow - ANSWERmovement of water when the soil is saturates/satiated. all/most pores are
filled; movement by gravitational and capillary forces.
Ways to increase infiltration - ANSWERcover crops, conservation tillage, furrow dikes, contour rows,
terraces, strip cropping, adding organic matter to encourage structure
Universal Soil Loss Equation - ANSWERA(water erosion loss)=R(rainfall factor)*K(soil erodability
constant)*(L[length of slope]S[gradient])*C(crop management factor)*P(erosion control practices)
T value - ANSWERamount of soil loss that is tolerable without degrading soil's long-term productivity;
varies with critical soil properties.
Sheet Erosion - ANSWERremoval of a relatively uniform layer of soil by runoff water
Gully Erosion - ANSWERerosion where water accumulates in narrow channels, extending depth by
removal of soil to depths of 1-2ft to several meters
Wind erosion - ANSWERmost susceptible soils are sands, loamy sands, and sandy loam, as well as
soils from volcanic ash
Sesquioxides - ANSWERoxides of iron and aluminum, often present in mature soils and emit
reds/yellows in color
Physical Disintegration of Rock - ANSWERstage 1 in soil development; freezing/thawing,
wetting/drying, heating/cooling, etc
Chemical Alteration - ANSWERstage 2; visible life often appears on the rock in the form of lichens and
mosses
Changes in Mineral Distribution - ANSWERstage 3; more acidic minerals are more resistant, more
basic minerals are more weatherable (often mafic minerals)
Soil water Energy - ANSWERdifferences in energy level of water from one site to another determines
direction and rate of water movement in soils and plants. Wetter soil has water held at a higher
energy, etc.
Matric Potential - ANSWERmost limiting potential factor to plants, baseline is pure free water
(assigned a value of 0), water has low energy and is bound with little freedom to move
Saturated - ANSWERall soil pores are filled with water, matric potential is zero. Theoretical
Satiated - ANSWERessentially all pores are filled with water, matric potenial is essentially/almost
zero. 'real-world' saturation conditon
Gravitational Water - ANSWERwater in the largest pores (macropores) that is mainly under the
influence of gravity
Field Capacity - ANSWERpercentage of water remaining in the soil after the saturated (satiated) soil
has drained of gravitational water, 0.1-0.33 bars of tension
Permanent Wilting Point - ANSWERthe moisture content of the soil at which plants wilt and fail to
regain their turgor overnight, about 15-30 bars tension
Plant Available Water - ANSWERamount of water release between field capacity and permanent
wilting point.
Hygroscopic Water - ANSWERwater held so tightly that it is considered 'non-liquid' and will not move
by capillarity
Infiltration - ANSWERthe entry of water into the soil, units are cm/h
Percolation - ANSWERdownward movement of water through the soil
, Permeability - ANSWERease with which gases, liquids or plant roots penetrate or pass through a bulk
mass of soil or a layer of soil
Saturated Flow - ANSWERmovement of water when the soil is saturates/satiated. all/most pores are
filled; movement by gravitational and capillary forces.
Ways to increase infiltration - ANSWERcover crops, conservation tillage, furrow dikes, contour rows,
terraces, strip cropping, adding organic matter to encourage structure
Universal Soil Loss Equation - ANSWERA(water erosion loss)=R(rainfall factor)*K(soil erodability
constant)*(L[length of slope]S[gradient])*C(crop management factor)*P(erosion control practices)
T value - ANSWERamount of soil loss that is tolerable without degrading soil's long-term productivity;
varies with critical soil properties.
Sheet Erosion - ANSWERremoval of a relatively uniform layer of soil by runoff water
Gully Erosion - ANSWERerosion where water accumulates in narrow channels, extending depth by
removal of soil to depths of 1-2ft to several meters
Wind erosion - ANSWERmost susceptible soils are sands, loamy sands, and sandy loam, as well as
soils from volcanic ash
Sesquioxides - ANSWERoxides of iron and aluminum, often present in mature soils and emit
reds/yellows in color
Physical Disintegration of Rock - ANSWERstage 1 in soil development; freezing/thawing,
wetting/drying, heating/cooling, etc
Chemical Alteration - ANSWERstage 2; visible life often appears on the rock in the form of lichens and
mosses
Changes in Mineral Distribution - ANSWERstage 3; more acidic minerals are more resistant, more
basic minerals are more weatherable (often mafic minerals)
