1. Soil Loam: a mixture suitable for growing plants Components:
Mineral Particles
Water
Air
Organic Particles
Organisms
1 acre-foot of soil may contain 3 tons of organisms!
Mineral Particles - We will ignore boulders, rocks, stones and pebbles
air capacity
water capacity
nutrient capacity
size
drainage
sand
1-0.1 mm
+++
+++ - -
silt + ++ + +
clay
< 0.001 - -
+++
+++
None of these single particles is ideal for growing plants
Loam: a mixture suitable for growing plants

2. How Do We Know If We Have Loam?
Surface Active Agent
Surfactant
Perfect Loam
Calgon Water
mix, let settle
Not all loams are “perfect”
clay
20%
silt
40%
sand
40%

3. Let’s Try Another Example
( NOT ON VIP! )
Sandy Clay Loam
Supports Plant Growth
clay
30%
silt
20%
sand
50%

4. You cannot draw ON the lines, but you MUST stay parallel to them!
Let’s Try A More-Challenging Example
( NOT ON VIP )
You cannot draw ON the lines, but you MUST stay parallel to them!
Clay Loam
Supports Plant Growth
clay
32%
silt
35%
sand
33%

5. You cannot draw ON the lines, but you MUST stay parallel to them!
Do You Really Understand This?
( NOT ON VIP )
If so, then you should be able to work this process backwards just as easily as forwards!
You cannot draw ON the lines, but you MUST stay parallel to them!
Try to determine the percentages of sand, silt, and clay for the dot of the i in silt loam.
clay
13%
silt
63%
sand
24%
100%
How do you check your work?

6. limited in CT soils due to acid rain…
Macronutrients
C. Hopkins Café: Mighty Good C H O P K N S Ca Fe Mg
CO2
H2O
limited in most soils the three parts of normal fertilizer
limited in CT soils due to acid rain…
dolomitic limestone
Fertilizer Guaranteed Analysis: N-P-K
Balanced Fertilizer:
Good for flower garden
Example Analysis:
10%
15% 5%
%phosphorus =
%potassium =
%nitrogen =
Single Fertilizer:
Nitrogen good for lawn
Another Example: 0% 0%
25%
%phosphorus =
%potassium =
%nitrogen =

7. Pioneer farmers tasted the soil to decide where to homestead
Micronutrients
Come on cousin, see Mo by Al and Cleo Co Mn Cu Zn Si Mo B Al Cl
Micronutrients are just as important but are needed in smaller amount
These metal ions serve as cofactors for many enzymes
Leached out of soils by acid rain
Added to some blended fertilizers
Recommended for Connecticut
Nutrients Available to Plants Via Soil Water
Water dissociates:
H2O H+ + OH-
[H+] = 10-7M pH 7
[H+]:
pH Scale:
Pioneer farmers tasted the soil to decide where to homestead
acid neutral alkaline
sour sweet bitter
vinegar dH2O soap
cranberry bean grass

8. Cation Exchange - how plants “mine” soils
clay particle
opposite charges attract
Root
Ca2+
Ca2+
Mg2+
Cu2+
Mo2+
hydrogen cation replaces metal cation
Mg2+
Zn+
Ca2+
Ca2+
Fe3+
Ca2+ H+
Ca2+ H+
hydrogen cation secreted
Ca2+ H+
Ca2+
Ca2+
Ca2+ H+
released metal cation available for root uptake
Ca2+
root hair
Ca2+
metal cations move up xylem

9. roots have nothing left to mine!
Cation Exchange - how acid rain depletes soil
NY: SO2 + H2O -> H2SO3 -> 2H+ + SO32- H+
CT soil is left without metal cations! Fertilizers with micronutrients are needed. H+ H+ H+ H+ H+
Root
root hair H+
Ca2+
Mg2+
Zn+
Cu2+
Fe3+
Mo2+ H+ H+
Ca2+
Mg2+
Zn+
Cu2+
Fe3+
Mo2+ H+
Ca2+
Mg2+
Zn+
Cu2+
Fe3+
Mo2+
hydrogen cations replace the metal cations
Ca2+
Mg2+
Zn+
Cu2+
Fe3+
Mo2+
Ca2+
Mg2+
Zn+
Cu2+
Fe3+
Mo2+
roots have nothing left to mine!
Ca2+
Mg2+
Zn+
Cu2+
Fe3+
Mo2+
released metal cations wash into streams, rivers, and Long Island Sound
Ca2+
Mg2+
Zn+
Cu2+
Fe3+
Mo2+
Ca2+
Mg2+
Zn+
Cu2+
Fe3+
Mo2+
NY: NO2 + H2O -> H2NO3 -> 2H+ + NO32- -> CT acid rain!
Ca2+
Mg2+
Zn+
Cu2+
Fe3+
Mo2+

10. Soil Horizons A B C D black Leaching zone: roots here (topsoil)
Horizons subject to erosion
black
Leaching zone: roots here (topsoil)
Black color is caused by organic particles B
“red”
Accumulating zone: nutrients (subsoil)
Prevented by:
Mulching
Proper cultivation
Perennial planting C
rocky
Weathered bedrock D
solid
Bedrock
Rotting material makes humus particles
Improve drainage (air capacity)
Increase water holding capacity
Increase nutrient holding capacity
leaves, grass clippings, compost, green manure, horse manure