Exam I Study Session Flashcards
(18 cards)
Bulk Density Equation
mass of soil (solids only)
___________________
volume (solids + pores)
Bulk Density:
Typical Range and level that inhibits plant growth
typical range: 1.0-1.9 g/cm^3 #>1.60g/cm^3 inhibit root growth
Particle Density Equation
mass of solids
___________
volume of solids
Percentage Pore Space Equation
100% - (BD/PD x 100)
Percentage Pore Space Typical Range
35%-55%
Percentage Water by Weight
mass water in soil / mass of dry soil x 100
Percentage Water Volume
% water by weight x BD/ water density (1 g/cm^3 unless otherwise stated)
Percentage water volume for sand
> 5%
Percentage water volume for silt loam
> 11%
Percentage water volume for loam
> 14%
Percentage water volume for clay
> 30%
Percentage Air Space
Percentage Pore Space - Percentage water volume
How do you tell the darkness of a Matrix or Mottle?
5 YR 5/8
By looking at it’s value. In this case the 5 on the right side of the YR is the value. The lower the number, the darker it is. This is a mid-dark soil.
How do you determine the brightness of a Matrix or Mottle?
5 YR 5/8
By looking at it’s chroma. In this case, 8 is the chroma. The higher the number is, the brighter it is. This is a bright soil
What does a soil with a high chroma indicate other than it’s brightness?
The soil is well-drained. The higher the number, the better is drains because of the well-oxidized iron compounds.
What does a hue lower than 5 mean?
It is closer to the color of red
What does a hue higher than 5 mean?
It is closer to the color of yellow
What does a hue of 5 mean?
It is 50/50 Yellow and Red
