Soil as Habitat for Microbes - chemical properties
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Transcript of Soil as Habitat for Microbes - chemical properties
b.stev
Soil as Habitat for Microbeschemical properties
CHEMICALS in the soil aid their growth
MICROBES USE SPECIFIC CHEMICALS
many require, carbon, in order to
survive
others survive utilising certain
compounds
WHY ARE MICROBES IN SOIL?
“aerobes” : need O2
“anaerobes”: don’t need
oxygen
NUMBERS OF MICROBES IN SOILa small teaspoon of soil contains approx
Algae 1000 - 1
million
Fungi 100,000 – 1
million
Bacteria 100 million – 1
billion
ONLY:through microbial action do organic fertilizers become useful to plants
(Texas A and M University, 2008)
A microbial process is ESSENTIAL to how a nutrient cycles through the soil
CHEMICAL is absorbed for use
a PRODUCT excreted in another form
FOR A PLANT: it is whether a chemical is absorbed
if a microbe had not processed the
chemical, the plant would be deficient of its product
ALSO regulates the quantities available to
plants
THE same principal applies to these subjects:
ANIMALS - what it is that the animal ingests as
nutrient
DECAYING MATTER - replenishing organic
material
EXCRETIONS – breakdown animal waste
WEATHER FLUCUATIONS - work to maintain
equilibrium
(Texas A and M University, 2008)
years of RESEARCH has been performed
on nutrient cycles & how this occurs
the MAIN CYCLES are: nitrogen/ carbon/ sulphur/ water/
phosphorus
the next picture: shows the cycle of
nitrogen
observe what occurs in the soil
this is all because of microbial action
there is a COMPLEXITY of chemical reactions occuring
this is the habitat that microbes
utilise & maintain as part of the
“,Nitrogen Cycle,” within soil
(Pidwirny. M. Dr, 2008)
EXACTLY what do MICROBES do IN THE SOIL?
“Lets take the - Nitrogen cycle, & look at it closely”
NITROGEN is extracted from the air &
placed into the soil from microbial
action
the plants absorb the product
it is even given back as nitrogen gas to
the air
nitrogen gas in the air is altered to ammonia in the soil
N2 + 3H+ + 3e- = NH3
NH3 + H+ = NH4+
THEN ammonia is altered to ammonium ion
2NH4+ + 3O2 = 4H+ + 2H2O + 2NO2
-
THEN ammonium ion becomes nitrite ion
O.K: lets look closely – first,
2NO3- + 12H+ + 11e- = N2 + 6H2O
ALSO: nitrogen gas is made from nitrate & is then emitted into the air
2NO2- + O2 = 2NO3
-
nitrite ion is THEN altered to nitrate
each EQUATION is performed by a different microbe
PLANTS use the nitratenitrate as a nutrient
(Wikipedia, 2008)
These reactions all occur simultaneously
The HABITAT has an
equilibrium between the different chemicals &
it is the microbesmicrobes that work to maintain this
Bibliography
Wikipedia. (2008). Nitrogen cycle- wikipedia,the free encylopedia. Retrieved September 20, 2008, from http//:www.en.wikipedia.org/ wiki/Nitrogen_cycle - 45k -
Pidwirny. M. Dr. (2008). 9(s). The nitrogen cycle. Retrieved September 20, 2008, from http//:www.physicalgeography.net/fundamentals /9s.html - 15k
Trakhtenberg. I. (2001). Activities. Retrieved September 20, 2008, from http//:www.soil.gsfc.nasa.gov/activ_98/microact.htm - 16k -
Texas A and M University. (2008). Welcome to soil and crop sciences at Texas A and M University. Retrieved September 20, 2008, from http//: www.organiclifestyles.tamu.edu/soil/microbeindex.html - 32k -