Soil sci chapter 1 Flashcards
Components of the global ecosystems
atmosphere, biosphere, hydro, litho
air surrounding the eart
atmosphere
environment in which living organisms are found and with which they interact
biosphere
total body of water that exists or close to the surface of the earth
Hydrosphere
upper (oceanic and continental) layer of the solid earth
lithosphere
interaction of litho hydro atmo and hydro
Earth system science
envelop of the earth where soil occur and where soil-forming processes are active
pedosphere
living, dynamic system which forms at the interface between atmosphere and lithosphere in response to forces exerted by climate and living organisms acting on parent material as conditioned bytopography/relief over the period of time
soil
as a rule, particles as considered as “soil particles” if they pass the
2mm sieve
upper top soil, lower top soil
A horizon 0-45cm
lower subsoil layer
B horizon 45-90cm
materials leached from above layer, lighter color- less accumulation of leached material
lower subsoil layer
darker color due to organic carbon
upper top soil
lighter color due to leeching and less organic matter
lower top soil
soil scientist focus on the ___ that are within ___ from the surface
porous material, 2m
dimensions involved in the study of soils
classic concept, modern concept
soil is 3- dimensional body
classic concept
what are in the classic concept
(3-dimensional body)
#length
#breadth
#depth
Soil is a space-time structure
modern concept
what is in modern concept
Soil is space time structure
#length
#breadth
Depth
time dimension
3 soil boundaries
upper boundary
lateral boundary
lower limit
generally considered as air-solid surface interface or free water-solid surface interface
upper boundary
deep water or barren areas of rock, salt, ice, or shifting dessert sand dunes
lateral boundary
difficult to define, but generally thought as the common rooting depth (shallow in the desserts, deep in tropical tropics) of the native perennial plant
lower limit
sediments at depth greater than where emergent plants grow is not considered as
soil
Three-dimensional section of the Earth’s surface with specific pattern of topography, rocks, soil, water, flora and fauna
landscape
an interacting system of biologic community and its non-living environment
ecosystem
5 functions of the soil
production function
ecological regulator
habitat and living space
engineering function
cultural heritage function
why we study soil
to understand how soil chemical and physical properties affect various uses of soils
to learn how to conserve and utilize soil properly
to understand how soil properties can be modified to improve their quality for practical use
2 concept in the study of soils
pedology
edaphology
study of soil as a natural entity (origin classification and description)
Pedology
study of soil from the standpoint of plant growth
edaphology
starting 19th century ____ was already considered as a natural science that deals with a natural body of the soil
soil science
3 periods of development of soil science
ancient
pre-soil science period
early soil science period
ancient
_____ years ago chines attempt to classify soil
4,000 years ago
greeks and romans started simple soil studies
2,000 years ago
who gave the soil name ____ and describes soil properties that affects growth
Theophrastus (371-286 BC)
“edaphos”
developed a classifictaion system of arable soils and emphasized the suitability of soils for farming
Cato
5 components of soil formation
climate
d living organisms
parent material
topography/relief
time
- Established
agricultural chemistry snd formulated the mineral theory of plant nutrition
–The
Law of Minimum
J. Von Liebig (1803-1873)
Developed the key
law in Soil Physics (
Henri Darcy (1803-1929)
Law) that describes water flow in soils
Darcy’s
Law
-Established
first systematic long
term field fertilizer experiment in the worldfamous Rothamsted Experimental Station
Joseph Henry Gilbert (1817-1901
In his book “Pedology or General and Special
Soil Science” (1862), he argued for the
recognition of Soil Science as an
independent natural science
-Founder of Soil Science
F. A Fallou (1794 – 1877)
In his book “Russian Chernozem” (1883), he
discussed the factors of soil formation and he
introduced the ABC horizon
nomenclature system
-Father of Modern Soil Science
V.V. Dokuchaev (1846-1903)
One of the first to
apply soil science to solve
problems in agriculture and is considered the
“Father of American Soil Science”
- E.W. Hilgard (1833-1893)
-In 1941 published
“Factors of Soil Formation”
s
- H. Jenny (1899-1992
The global scientific organization of soil
scientists and soil science
practitioners
The International Union of Soil Sciences (IUSS)
Divisions of Soil Science
- Soil genesis
- Soil survey & classification
- Soil physics
- Soil microbiology and biochemistry/ soil
ecology - Soil fertility
- Soil mineralogy and chemistry
- Soil and water conservation
deals with the dynamic and
complex topmost layer of the Earth’s crust
which is the product of Earth’s surface
processes
Soil science-
the science of the
Earth from which soil science branched out in
the
. Geology
- The most widely accepted hypothesis about
the origin of the Earth is the
solar nebular hypothesis
Earth was formed from condensing gas and dust
about
4.6 billion years ago.
caused the gas and dust
particles to come together with heavier
particles gravitating to the center and lighter
ones collecting outside.
Gravitational forces
used to determine the age of rocks and other
natural materials by means of their
radioactive contents
. Radiometric dating
scientists have determined that the Earth
consists of three layers
crust
mantle
core
the thinnest
and rigid outermost layer
a) crust,
the middlelayer which is largely plastic;
; b) mantle,
center which is liquid on the outside but solid
inside
c) core
The liquid portion of the outer core
generates the earth’s
s magnetic field
The abrupt
boundary between the crust and the mantle is
called
Moho discontinuity.
There are two types of crus
: oceanic crust and continental crust
is about 6 km thick and basaltic in composition
. Oceanic crust
is typically about 35 km thick
and granitic in composition
continental crust
. Water surface area comprises of ___
the Earth’s total area which is ____ largely
ocean.
70.8% (97%)
The hydrosphere is closely linked to the other spheres particularly the atmosphere through the
hydrologic cycle (or water cycle),
The two types of liquid water in the
hydrosphere
seawater and river/freshwater
n. Seawater is
mainly a _____ solution
Na+ and Cl
while river water
is a ______ - solution
is a Ca+2 and HCO3 -
- is also called the zone of life
Biosphere-
About 95 percent of the
biosphere is composed of six elements
C, H, O, N, P and S
These are the major constituents of
the living tissue.
C, H, O, N, P and S
e term given for the rigid crust
and the upper portion of the mantle of about
100 km thickness. T
D) Lithosphere
The crust is composed of
various kinds of rocks which are grouped into
three types: i
: igneous, metamorphic and
sedimentary. Th
explains the
mechanism by which the Earth’s continents andoceans are moving and rearranging themselves.
the theory of plate tectonics
a German meteorologist and
geophysicist, who proposed in his book
Die Entstehung der Kontinente und Ozeane (Theorigin of continents and oceans) of
1915 that continents are drifting.
Alfred Wegener
➢ Plate Tectonics states that the lithosphere
is divided into a number of rigid plates that float
and drift on the plastic
ASTHENOSPHERE
the largest and one of the
most active plates. I
Pacific Plate
e occurrence of
thousands of volcanoes around the Pacific
Ocean known as
the Ring of Fire.
is the thin soil cover formed
from the weathering of the rocks in the upper
portion of the crust.
Pedosphere
pedosphere functions as ____ where biological
processes interact with chemical
processes at the interface of the lithosphere, biosphere, atmosphere and hydrosphere
reactor
waves that travel through the earth
seismic wave