Soil Factors Soil Factors Drainage Natural soil drainage classes Wet or poorly drained soil conditions Natural soil drainage is judged by Color patterns in the soil T he presence or absence of a high water ID: 698445
Download Presentation The PPT/PDF document "Soil Factors Montana NRCS Lesson Plan" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Soil Factors
Montana NRCS Lesson PlanSlide2
Soil FactorsSlide3
Soil Factors - Drainage
Natural soil drainage classes
Wet or poorly drained soil conditions
Natural soil drainage is judged
by:
Color
patterns in the
soil
T
he
presence or absence of a high water
table
Soil texture
The following classes of natural drainage are used on the score card
:
Poorly Drained
Well Drained
Excessively DrainedSlide4
Soil Factors – Root DepthSlide5
Soil Factors - Texture
Definitions
of Terms Used
:
Sand is the gritty material
felt
when moistened soil is rubbed between the
fingers.
Silt
is the floury material
felt
when soil is rubbed between the fingers.Clay usually forms very hard lumps or clods when dry and is plastic and usually sticky when wet. Loam is a combination of sand, silt, and clay.
Size of Individual GrainsSand2.0-0.05 mmSilt0.050-0.002 mmClay0.002 mm or lessSlide6
Soil Factors - TextureSlide7
Soil Factors - Structure
Granular
Platy
Blocky
Prismatic
Columnar
Massive
Single GrainSlide8
Soil Factors - Permeability
Very Slow
Slow
TEXTURE
SOIL STRUCTURE
Massive or Platy
Blocky or Prismatic
Single Grain or Weak Prismatic
c, sic,
sc
very slow
slow
---
sicl
, cl,
scl
,
sil
, l
slow
moderately slow to moderate
---
vfsl
,
fsl
,
sl
---
moderately slow to moderate
moderately rapid, rapid, very rapid
ls,
lcos
, s
---
---
moderately rapid, rapid, very rapid
Moderate
RapidSlide9
Soil Factors – Rock Fragments
Rock fragments are soil particles greater than 2 mm in diameter
Rock fragments can limit the ways we use soil
Available water capacity
Cultivation
Measure rock fragments using a 2 mm screen, then calculate volume of rock and volume of soilSlide10
Soil Factors – Slope
Slope is the steepness of the land
Aspect is the direction the slope faces
Slope and aspect impact plant and animal communities on the landSlide11
Soil Factors – Salinity/Sodium
Soils affected by salts are grouped into 3 classes:
Saline
Sodic
Saline-Sodic
Saline soils have enough water-soluble salts to impair productivity
Sodic soils have poor physical condition and high pH
Saline-Sodic (saline-alkali) are salty with damaging amounts of sodiumSlide12
Calcium carbonate and calcium-magnesium carbonate are important parts of many soils
Hydrochloric acid is used to test for carbonates
Calcium carbonate effervesces when treated with cold, dilute hydrochloric acid
Calcium-magnesium carbonate effervesces if powdered soil is treated with cold, dilute acid
Soil Factors - Calcareous