Soil Overview

Soil Overview - A
Good
rich
soil
needs…
 • ...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: A
Good
rich
soil
needs…
 •  Soil
 –  
a
complex,
breathing
en8ty
 –  Soil
 –  Plants
 –  chemistry
 9
macronutrients
 •  Needed
for
plants
to
grow
 •  C,
H,
O,
N
 –  Crucial
–
96%
of
a
plant
 •  K,
Ca,
Mg,
P
(phosphorus)
S
(sulfur)
 7
micoelements
 •  Fe,
Cl,
Mn
(Manganese),
B
(Boron)
,
Cu,
Mo
 (Molybdenum)
,
Zn
 –  Less
than
0.01
%
dry
plant
weight
 •  TOXIC
in
large
amounts
 Elements
need
to
be
in
a
usable
form
 •  E.g.
plants
cannot
use
N2
 –  Bonds
are
too
strong
 •  Uses
NO3‐
 •  Simple
inorganic
forms
 –  Usually
ionic
 Minerals
 •  Basis

 –  complex
silicates
(we
will
discuss)
 –  O,
Si,
Al,
Fe,
Ca,
Mg,
K,
Na
 –  Mainly
sand
and
silt
sizes
 Clay‐sized
par8cles
 •  Very
small

 –  Bond
with
elements
 –  Stop
leaching
of
nutrients
 –  Very
important
 Humus
 •  Decayed
plant
ma]er
and
waste
 •  Decayed
animal
ma]er
and
waste
 –  60%
C;
6%
N
 •  Fars,
oils,
lignin,
protein,
sugars,
acids
(organic
and
 inorganic)

 –  Colloidal
 Air
&
water
 •  CO2,
O2
 •  H2O
+
dissolved
nutrients
 sunlight
 •  Energy
for
the
reac8ons
 roots
 •  Growth
is
NOT
random
 –  Finding
H2O
and
nutrients
 –  Can
even
a]ack
other
roots
 –  receptors
 Bacteria
 •  Billions
of
microflora
and
microfauna
 –  Break
down
materials
to
simple
compounds
 –  Mobile
 –  Interact
with
minerals,
humus,
plants,
roots
 •  Keep
live
plant
from
decaying
 –  1
ton
/
acre!!
 •  1
tsp
=
5
million
bacteria
+
250,000
fungi
+
1
million
 ac8nomycetes
 Earthworms
&
others
 •  Turn
over
soil
 •  Very
important
–
dead
and
alive!
 •  Casts
for
“crumb”
structure
 •  +
algae
 •  Fungi,
ac8nomycetes
 –  Earthy
smell
 •  Mites
‐
insects
 Voids
 •  Filled
with
air
and
water
 –  Good
if
“crumb”
“granular”
 –  Living
space
for
animals
 –  Space
for
hairs
on
roots
 Topsoil
 •  1‐6%
organic
material
 fer8lizers
 •  Balance
NPK
 –  Macronutrients
 –  Most
fer8lizers.


 A
delicate
balance
 ...
View Full Document

Ask a homework question - tutors are online