Soils Exam 4-Bulk Density
% porosity=
(1- (BD/PD)) x 100 BD=Bulk density PD=Particle density
high organic matter
low bulk density
strong structures (well granulated topsoil)
low bulk density
high pore space
low bulk density (sponge)
bulk density=
mass of dry soil/ volume of soil
particle density=
mass of solids/ volume of solids mass of solids=bulk density
soil bulk density is affected by both ___ and ___.
nature of solids and the volume of the pores
soil strength increases because...
pore space decreases and soils become more compact
sandy soils
range from 1.2-1.8 g/cm3
as bulk density increases
soil strength increases
as bulk density increases...
the amount of pore space decreases
porosity
the percentage of a soil that is pore space or voids
the average soil has a porosity of about ____, and the pores are filled with ______ or ____ depending on the moisture content.
50%, air or water
low pore space
high bulk density (brick)
Soil bulk density
a measure of how compact or dense a soil is -relates weight of solids to total volume of soil including solids and pores
fine textures: silt loams, clay, clay loams
generally lower bulk density (1-1.6 g/cm3)
