Soil
silt texture is
.002-05
sand has texture of
.05-2 mm
6 functions of soil
1. medium for plant growth 2. engineering medium (foundation for building things), 3. supports soil organisms 4. regulator for water flow and cycle (clay filters the water better than sand and soil type determines how fast water can flow) 5. regulates the atmosphere (the soil can hold carbon and take it out of the air) 6. recycles organic waste such as organic matter when things die they decompose and soil organisms feed on them to turn them into make humus and nutrients are available to be used by plants and animals)
sandy soils are
1.2-.8 g/cm3
ideally soils for growing crops have to be less than ? g/cM3
1.8
particle density constant is
2.65
clay particle size
<.002
what is a rock
a solid compound made from minerals
why care about soil texture?
affects water-holding capacity (clay holds better than sand), permeability (ease which water and air pass through), soil workability, nutrient holding capacity, root penetration
fine-textured soil is
between 1.2-1.6 g/cm3
blocky
can be angular with more sharp edges or subamgular with more rounded edges
soil characteristics
color, texture (particle size), and structure
what is the biosphere
ecological system integrating all living things and organic matter in relation to the other spheres
structure forms through
flocculation and cementation
platey
found in lower horizons and horizontal plates
clay-
geosphere
sand characteristics positives
good infiltration, aeration, and workability, and root penetration
+'s clay
good water and nutrient holding capacities and ion exchange
what are the different structures of soil?
granular, prismatic, columnar, plately blocky, (blocky subangular), single grain, or
What are the three categories for naming a color?
hue ( proportions of the primary colors red and yellow), value (is the darkness and lightness tones), and value (purity of the color)
formed from molten lava
igneous rock
decrease compaction what happens to bulk density and volume?
increase volume and lower bulk density
over half of the soil is made of?
inorganic matter or minerals
what is flocculation
is the movement of things closer together such as water to pores
what is water infiltration
it is the ease of which water enters the soil so sand particles are better
quartz color
light grey
what are the 5 spheres
lithosphere (geosphere), atmosphere, biosphere, hydrosphere, and peodosphere
what types of soils structure are not considered structures
mass and single grain
characteristics of silt
medium at everything
loam properites
medium at everything
type of rock made from heat and pressure
metamorphic rock
columnar
more rounded
what is a mineral
naturally occurring solid structure made from elements that are mixed into one fixed structure
nutrient components from the atmosphere
nitrogen, oxygen, and carbon dioxide
what do plants get from the soil?
nutrients, anchorage, temperature regulation, water. and air
3 things that determine soil color?
organic matter content, water content, and mineral coating type
These three minerals can't come from the soil, but are essential to plant growth
oxygen, carbon, and hydrogen
structure refers to
particle size
-'s sand
poor water and nutrient holding capacities and ion exchange
-'s clay
poor water infiltration, workability, aeration, and root penetration
compaction decreases what soils property besides workability, aeration,and water infiltration
porous space
hematite color
red
bulk density over 2=
rock n
type of rock made from the compression and solidification of weathered materials
sedimentary rock
3 types of rocks
sedimentary, igneous, and metamorphic
what is loam soil?
soil that has a mix of sand, silt, and clay
what is the peodosphere
sphere with soil and interphase above the spheres
what is the geosphere
system on earth that contains the inorganic materials such as the rocks and minerals
soil structure?
the arrangement of sand, silt, and clay into agregates or peds
soil structure?
the arrangement of silt, sand, and clay particles into aggregates or particles glued together
cementation?
the connection and gluing of individual soil particles together by organic matter, gums, iron oxides, and fungal activity s that are produced by microorganisms
bulk density only contains what of soil particles
the dry particle solids and pores of (air and water)
What is soil science?
the study of soil as a natural resource on the surface of the Earth including soil formation, classification and mapping; physical, chemical, biological, and fertility properties of soils; and their relations to soil management
particle density not affected by
tillage, soil compaction, amount of air, water, or organic matter- texture, only includes mineral particles
what is soil?
top layer of earth's surface with unconsolidated mineral particles and organic matter
prismatic
vertical dimensions kind of cubic at the ends
percentages of soil components
water and air= 25-30%, inorganic matter= 45%, and organic matter= 5%
Components of soil
water, air, organic, and inorganic matter
most soils are produced from the
weathering of rocks and minerals
what is bulk density
weight of the dry soil over the bulk volume of dry soil
agregate?
when particles are brought together and consist of soil particles bound together by cemetnary agents
calcite is what color
white
dolomite
white
causes of bad structure
working in wet farmland especially with clay soils, high sodium centralism, exposed soil to rainfall when compaction and porous saces fill up and erosion breaks up solid particles into smaller ones
what color is the mineral geothite
yellow