True/False
Indicate whether the sentence or statement is true or
false.
|
|
|
1.
|
Of the three primary soil particles, silt is the smallest.
|
|
|
2.
|
Four feet of rise or fall in 100 feet of horizontal distance would represent a
40% slope.
|
|
|
3.
|
Gully erosion is characterized by shallow channels cut into the surface layer of
the soil.
|
|
|
4.
|
Soil structure is the arrangement of primary soil particles into
aggregates.
|
|
|
5.
|
A soil having 20% subsoil mixed into the plow layer or upper 7 inches of topsoil
is considered moderately eroded.
|
|
|
6.
|
Fragipans usually have a loamy or silty texture.
|
|
|
7.
|
An Abney level is an instrument used to measure
|
|
|
8.
|
Soil depth refers to the relative thickness of all of the contiguous layers of
the soil from the surface downward.
|
|
|
9.
|
Coarse sand and gravel is considered a root restrictive layer since it has a
limited moisture-holding capacity.
|
|
|
10.
|
A loam soil texture forms a long, thin ribbon when pressed between the thumb and
forefinger.
|
|
|
11.
|
Class IV land is suitable for occasional cropping.
|
|
|
12.
|
Strip cropping with contour tillage should be used on slopes in the 18 to
25% range.
|
|
|
13.
|
Class VII land should be planted to adapted trees.
|
|
|
14.
|
A sandy textured soil feels gritty and forms no ribbon when pressed between
the thumb and forefinger.
|
|
|
15.
|
Irregular color patters or mixtures of colors in the subsoil is called
mottling.
|
|
|
16.
|
Fragipans are fragile formations of bedrock that crack and break easily.
|
|
|
17.
|
The darker color of topsoil is usually caused by oxidation of soil
minerals.
|
|
|
18.
|
Surface drainage is usually necessary on very poorly drained soils.
|
|
|
19.
|
Soil tilth refers to the content of organic matter in the soil surface.
|
|
|
20.
|
The color of moist subsoil is the best indicator of air and water movement in
the subsoil
|
|
|
21.
|
The soil profile refers to a vertical section of the soil extending through all
its layers and into the underlying material.
|
|
|
22.
|
Lime and fertilizer should be applied at rates higher than test results on
gently sloping soils since some amount will be lost to erosion.
|
|
|
23.
|
Permeability refers to the ability of a soil to evaporate water.
|
|
|
24.
|
Land is one of our most valuable natural resources and cover about 25% of the
earth’s surface.
|
|
|
25.
|
Soils that are underlain with massive bedrock are referred to heavy
soils.
|