SCIENCE DOCENT GUIDE
HELPING HANDS SCIENCE
MATTOS ELEMENTARY
SCIENCE MAGNET SCHOOL
Fourth Grade
How is heat generated during composting?
Math Science Nucleus
2015-16
1 4
CLASS PROJECT
FOURTH GRADE
4 QUESTION: How is energy released during composting?
BACKGROUND: Making compost needs to be monitored to prevent
microorganism from harming people. Compost needs to go through 160
degrees Fahrenheit, 60 degrees Celsius
RESEARCH FOR CLASS: What is soil? How does compost enhance soil? What is
the carbon to nitrogen ratio in compost? What do plants need to survive? How can
you improve heat flow? What if the heat gets too high?
EXPERIMENTAL DESIGN: Compost needs to go through a high temperature to get rid
of bad microbes. Moisture is needed to keep the temperature high over 3 days.
Measure the temperature and graph time vs temperature. Explore how energy is
created as a byproduct of organisms feeding on components of food waste.
DOCENT GUIDELINES
DURATION: 50-60 minutes
GENERAL INFORMATION: Do not spend more than 10-15 minutes for an
introduction and instructions. Allow as much time for the hands on component. If you
are doing an art project, make sure you have all the materials readily available.
If you are teaching a new concept to fourth graders make sure they understand some of
the vocabulary. You may need to repeat large words and have students repeat the
word. Leave about 5 minutes to discuss what they did in the lab and urge them to
develop a summary or conclusion of what they learned.
Note: Background information is added information for the docent only.
2 TEACHE
ER LESSO
ON
FOURTH
H GRADE
ENERGY AND DECOMPOSITION
OBJECT
TIVES:


Obse
erving how biological
b
organisms
o
ccan change
e the
enviro
onment
Meas
suring heat energy from
m decompo
osition.
4
VOCAB
BULARY:
Decompose
D
rs
compost
biogeology
MATER
RIALS:
Dial
D thermom
meter
Worksheet
W
ru
uler
video of the Jora system
Food
F
Chain by Cassy Fries
F
http://imold.utoledo
o.edu/index.html
BACKG
GROUND
ganisms ha
ave chemica
al
Microorg
requirem
ments prima
arily carbon
n for
energy, nitrogen to build prote
eins,
and oxygen for respiration.
Interacting with the
ese are physical requirrements inccluding aera
ation to maintain optim
mal
e not depletting the mo
oisture nece
essary for m
microbial grrowth.
oxygen levels while
Decomp
posers, such as some bacteria an
nd fungi, ge
et their enerrgy by eatin
ng dead
organism
ms. Individ
dual decom
mposers are
e rarely visib
ble without a microsco
ope, but
colonies
s of them (s
such as bread mold) ca
an be obse
erved. Deco
omposers h
have the ab
bility
to break
k down dead
d organism
ms into smalller particless and new compounds, resulting in
fertile so
oil that prov
vides importtant building materialss for plants.
This deccomposition
n process
releases heat. The generation of
ps to make ssure that th
he
heat help
“bad” miccrobes do n
not take ove
er
and causse harm to h
humans.
Compost piles have to be large
e
o go throug
gh this
enough to
3 thermop
philic proces
ss. Measu
uring the tem
mperature is very important to make sure it
goes thrrough all the
ese phases
s.
Compos
sting occurs
s because of
o the
efforts of
o microorga
anisms. Alth
hough
worms and
a
insects also
a
help, microorgani
m
isms
are the key
k workho
orses of
compostting. There are
three ma
ajor organis
sms that arre
importan
nt in compo
osting includ
ding:
 Actinomycet
A
tes—form
filaments an
nd are basic
cally
classified as
s bacteria. They
T
do most of work;
w
largerr than
d form netw
works of
bacteria and
hey tolerate
e lowfilaments. Th
moisture
m
& low pH cond
ditions.
 Fungi
F
are be
est at decom
mposing wo
oody substa
ay-resistant
ances and other deca
materials.
m
 Bacteria
B
are
e small and simple and
d flourish in the early sstages of co
omposting
PROCEDURE
hould go ou
utside and ssee the Jora
ra decompo
oster. Open
n up
Prior to this lesson docents sh
the latch
h and take the
t tempera
ature. You
u should alsso look at th
he following
g u-tube, so
o you
have some understtanding of how
h
to use the Jora. T
The heat ca
an get veryy hot, so be
careful at
a all times with studen
nts.
www.youtu
ube.com/w
watch?v=SiiaqiQPRfV
Vc
https://w
P table ha
ave students
s look at dia
al thermom
meter. Point out that outside is
1. Per
Fahrenheit
F
and
a inside is Celsius. Ask them w
what the long shaft is for? Make
sure they un
nderstand th
hat it is a se
ensor and sshould be ttaken care o
of. We sug
ggest
th
hat is stay in the box while
w
not in use.
2. Measureme
M
nts will be in
i Celsius.
3. Go
G through the worksheet with ha
ave them plo
ot the numbers and ha
ave them g
graph
it on the worrksheet. With a ruler make
m
an x a
and y axis. Then number the verrtical
(y
y)as temperature and the horizon
ntal (x) as d
days.
4. Iff students are
a working on the worrksheet, ha ve a small group go o
out to the Jo
ora
compost and
d show how
w to read th
he temperatture. If you
u have 2 do
ocents this is
deal…or the
e teacher can stay with the stude
ents.
id
4 Recording
R
Temperatu
ure Data frrom Compo
ost Bins
Day Te
emperature
e
(C
Celsius)
1
10
0
5
20
0
10
40
0
15
60
0
20
65
5
25
62
2
30
61
1
35
60
0
PLOT
TTING DAT
TA ON A G RAPH (X/Y
Y)
5 BACKGROUND INFORMATION ON CARBON TO NITROGEN RATIO
All living organisms have a Carbon to Nitrogen (C:N) ratio for their tissues. For
microorganisms, carbon is the basic building block of life and is a source of energy, but
nitrogen is also necessary for such things as proteins, genetic material, and cell
structure.
Decomposition of organic materials in your compost pile is greatly increased when you
create the proper balance between the carbonaceous materials (called BROWN
because they are dry) and the nitrogen-rich materials (called GREEN because they are
more fresh and moist). This balance is referred to as the Carbon-Nitrogen ratio, and
shown as C:N.
Microorganisms that digest compost need about 30 parts of carbon for every part of
nitrogen they consume. That's a balanced diet for them. If there's too much nitrogen, the
microorganisms can't use it all and the excess is lost in the form of smelly ammonia gas.
Nitrogen loss due to excess nitrogen in the pile (a low C:N ratio) can be over 60%. At a
C:N ratio of 30 or 35 to 1, only one half of one percent of the nitrogen will be lost. That's
why you don't want too much nitrogen (fresh manure, for example) in your compost: the
nitrogen will be lost in the air in the form of ammonia gas, and nitrogen is too valuable
for plants to allow it to escape into the atmosphere.
1. A maximum of 35% of the carbon in fresh organic material will be converted into
soil humus IF there is sufficient nitrogen present.
2. A minimum of 65% of the carbon in fresh organic material will be given off to the
atmosphere as carbon dioxide due to microbial respiration.
3. The humus formed from the decomposition of fresh organic material will contain
approximately 50% carbon and 5% nitrogen. In other words, the C:N ratio of the
humus is 10:1.
4. Most fresh plant material contains 40% carbon. The C:N ratio varies because of
differences in nitrogen content, not carbon content. (Note: Dry materials are
generally in the range of 40 to 50 percent carbon, and sloppy, wet materials are
generally 10 to 20 percent carbon. Therefore, the most important factor in
estimating the carbon-to-nitrogen ratio of plant or food waste is how much water
is present).
5. Generally speaking, you can get C:N ratios of 30:1 to 50:1 by adding two parts of
a GREEN material to one part of a BROWN material to your bin. A "part" can be
defined as a certain quantity of the material, such as two 5-gallon buckets
of GREEN and 1 packed bucket of BROWN.
6. Play with the chart below. For example, food scraps, grass clippings and
leaves come close to an average of 30:1. How? Add-up the Carbon side of the
6 ratio for all three materials, i.e. 15, 17, 60, and divide by the number of materials,
i.e. three. 92/3 = about 31:1.
GREEN (Nitrogen)
Aged Chicken Manure
BROWN (Carbon)
7:1
Leaves 60-80:1
Fresh manures are way to hot and can burn your
plants and roots!
One of the most important ingredients for composting,
especially shredded or broken down (leaf mulch).
Food Scraps 17:1
Vegetable Scraps 25:1
Straw, Hay 90:1
The best way to use is to shred for faster breakdown.
Coffee Grounds 25:1
Sawdust 500:1
Commercially produced compost is high in
sawdust or shredded bark chips. Use very
sparingly!
Grass Clippings - Fresh 17:1
Woody chips & twigs 700:1
Dry clippings would be higher in Carbon. Therefore,
use as carbon source if necessary.
Be sparing. Best use is small material at bottom of bin
or pile.
Fresh Weeds 20:1
Shredded Newspaper 175:1
Make sure you don't compost weeds with seeds,
unless you insure that your pile gets hot - over
140°F/60°C.
Has no nutrient content. Best used in vermicomposting.
Always shred and soak in water for fast breakdown.
Fruit Wastes 25-40:1
Nut shells 35:1
Rotted Manure 20:1
Pine Needles 80:1
maycontain undigested seeds that can sprout
Use sparingly. Very acidic, waxy; breaks down slowly.
Humus (soil) 10:1
This is nature's natural ratio. Use sparingly in pile.
Corn Stalks 60:1
Best used to "seal" the pile by putting a 1-2 inch
layer on top.
Shred or cut up in small pieces for fast break down.
Seaweed 19:1
General Garden Waste 30:1
Peat Moss 58:1
Has no nutrient value, mostly filler.
7 FOURTH
H GRADE - DOCENT
T LESSON #1
DECOM
MPOSERS
OBJECT
TIVES:


Learn
ning about the food ch
hain and de
ecomposerss role
Sortin
ng different
decom
mposing orrganisms
4
VOCAB
BULARY:
Decompose
D
rs
producers
Scavengers
S
Carnivore
C
Omnivore
O
MATER
RIALS:
Food
F
Chain by Cassy Fries
F
worksheets
w
BACKG
GROUND:
vironment is
s full of diffe
erent anima
als with diffe
erent needss. Studentss should lea
arn
The env
early how these org
ganisms arre grouped. Every orrganism nee
eds to find food, which
h is
od chain (single chain)) and food w
web (many chains). In food web
bs
the basis of the foo
e many layers. There
e are decom
mposers wh
ho make are
eas ready ffor producers to
there are
grow. Decompose
D
rs can use their eating
g habits to p
produce he
eat (bacteria
a,
actinomy
ycetes) tha
at further bre
eak down organic
o
deb
bris that hellps other orrganisms likke
fungi to adsorb nutrients.
d chains in a specific a
area. Otherr organismss are just likke
There arre many diffferent food
humans in that mos
st vary their diets. If an
a organism
m relies sole
ely on one organism fo
or
e first organ
nism will be
e in trouble if the secon
nd dies outt. Individua
al organism
ms,
food, the
howeverr, prefer sp
pecific food, but they usually
u
varyy their diets depending
g on what iss
available
e. The food
d chain refe
ers to "who
o eats whom
m" relationsship. For in
nstance,
humans eat hambu
urger which
h comes from the meatt of a cow, which eatss only grasss
(herbivo
ore). But hu
umans don''t only eat meat,
m
they e
eat many o
other items tthat come ffrom
both animals and plants
p
(omnivore). If yo
ou plotted tthe entire fo
ood habits of an organ
nism
this wou
uld be called
d a food we
eb.
PROCEDURE:
R
the po
oem “Working on a Fo
ood Chain.””
1. Read
8 2. Make
M
sure students
s
understand the concep
pts of
consumer, producer,
p
and
decomposerr. You can go
th
hrough the poem again and
in
nclude some of the concepts
on the right.
There
T
are many
m
ways to
t refer
to
o the compo
onents of a food
web.
w
If you wish to dettermine
th
he place tha
at an organ
nism
has in a food
d chain you
u would
ms decompo
oser,
use the term
producer and consume
er. A
decomposerr would be
organisms like fungi,
nts and bactteria.
annelids, an
A producer would
w
be
organisms th
hat photosy
ynthesize and
a a consu
umer is pred
dator. There are be
different leve
els when yo
ou develop a food web
b.
2. Hand outt the picture
e on Decom
mposers in Compost. Go over the different
organisms. Note that these are sp
pecific grou
ups. Not all arthropods are found
d in
compost, bu
ut then some like ants are a vital p
part.
9 Through the 4th grade lessons, students will be learning about the different roles
of the organisms found in compost. They will learn about thermophilic (heat
loving), mesophilic (warm loving) and mature (cool) composting and the different
organisms that you find in the compost you are creating.
3. Hand out the plastic models and see if students can identify them on the Lab
Worksheet (Compost Organisms). Some they may be familiar with like beetles
and worms, and others like Fungi and Actinomycetes, might be foreign to them.
4. Discuss the different organisms.
5. Hand out one tub of “Life Cycle of Worms,” and “Life Cycle of Ants.” Ants
(Insect) and Worms (annelids) are very important in cool composting. These
animals are some of the most important organisms that gets soil ready for plants
to grow. Ants are one of the few animals that can digest wood (as students will
learn later) and worms help to churn up the ground and add nutrient as they go
their life cycle.
LIFE CYCLE OF ANTS
Eggs: After mating, a princess ant is considered a queen ant. She finds a good
nesting site to start a colony, where she lays thousands of tiny eggs. She won’t
leave the nest until the first generation of worker ants are ready to search for
food. Once her colony is established, a queen ant may lay thousands of eggs
each day.
Larva: Eventually, ant eggs develop into larvae, which resemble tiny pieces of
rice. They have no eyes, only a mouth and they are fed by worker ants that bring
food to the nesting site. It takes between a week and a month for eggs to turn
into larvae, depending on the species.
Pupa: A few weeks to a month after becoming larvae, the growing ants will be
ready to spin cocoons, called pupae. Within a week or so, pale yellow ants will
emerge. They turn their normal color once their exoskeleton hardens. A queen’s
first batch of ants will be smaller because they have not been fed by other worker
ants within the colony.
Ant: Once its exoskeleton hardens, an ant is ready to begin supporting the
colony. Worker ants are by far the most common, but some ants can also
develop into soldier ants, drones, or princesses. The worker ants have distinct
tasks, including caring for eggs, finding food, or expanding and maintaining the
colony.
10 LIFE CYCLE OF WORMS
Eggs:
Earthworms are hermaphroditic, meaning they have both male and female
characteristics, so they can both fertilize and lay eggs. Eggs are contained in a
sheath that slides of the worm after fertilization. The sheath becomes a cocoon
that is deposited in the soil, where it hardened to protect the eggs inside.
Hatchling:
Worm hatchlings emerge from their protective cocoon at different rates
depending on the species, but the range is from three weeks to five months.
Temperature and moisture also impact the amount of time it takes hatchlings to
emerge. Only a few hatchlings survive to exit the cocoon.
Juvenile Worm:
Depending on the species, it takes anywhere from 10 to 55 weeks for worms to
mature. They grow daily and are mature once they have the ability to lay and
fertilize eggs.
Worms:
There are thousands of species that are considered worms, including varieties of
annelids like earthworms and red worms, and parasites like hookworms and
pinworms. In nature, worms are vital to ecosystem because they act as
decomposers, moving decaying material back into the soil where it can feed
plants and continue the cycle of life.
6. Find some worms from outside and put a few at each table. Ideally you would
need a clear container to students can look at the worms.
11 FOURTH GRADE- DOCENT LESSON #2
OBSERVING ROT
4
OBJECTIVES:
 Observing fungi.
 Exploring the ecosystem of rot.
VOCABULARY:



mold
rot
spore
MATERIALS:


microscope
bread from different days
BACKGROUND:
How many times have you looked for an orange to eat and found that the last one left
had grown soft, blue-green fuzz? Have you ever left a wet towel at the bottom of your
clothes hamper and at the time of washing you found that it had green "freckles" all over
it? Or how many times have you found bread that has gone stale and has grown black
"whiskers?" The green fuzz on the orange, the green freckles on the towel and the black
whiskers on the bread are all known as molds. Molds are really tiny fungi belonging to
one of the 5 kingdoms. "Molds" are a term that is not really a natural grouping, but until
scientists figure out exactly where they belong, we will consider them fungi. Molds are
so tiny that we cannot see them unless there are many of them bunched together. To
see just one mold you need a microscope. There are many kinds of molds. One of the
most common molds is the one which turns oranges into green fuzzy balls. It is called
penicillium. This is where the drug penicillin comes from.
Plants use sunlight to make food in their leaves. The green coloring matter acts as a
kind of food factory. Molds have no food factories, so they take the food they need from
their host. All molds are food robbers.
Foods will eventually rot if not kept cool or not eaten within a certain time unless frozen.
The more time food stays around the more of a chance spores from a mold have of
landing on it and growing. A spore is the reproductive part of the fungi.
Wherever there is food, air, and moisture, some mold spores will find their way there to
settle and begin to grow. If a spore doesn't find the food, air or moisture it needs to grow
it does not die. It just waits. It can remain alive for years in its case, waiting for the right
conditions to burst open and grow.
12 Organisms found in the Fungi Kingdom are heterotrophic. Fungi obtain food by
decomposing anything that is organic in nature. Fungi live everywhere. They grow best
in warm, moist places. They are not green and do not possess chlorophyll. Fungi can
grow on vegetables, bread, meat, fur, wood, leather, or anything that is in a warm and
moist area.
Fungi that obtains nutrients from non-living organic matter are called saprobes. Other
fungi obtain nutrients directly from a living host, these are parasites. In either case, the
fungi secretes enzymes that allow digestion to take place outside of the fungal body.
Nutrients are then absorbed across the cell membranes. Together with bacteria, fungi
are the decomposers of the earth. Fungi include yeast, bread mold, and mushrooms.
Fungus itself is made up of a fungal body or what is called mycelium. The mycelium is a
mesh of filaments that branch out in any direction living over or within the organic
matter. Each filament is a hypha. Hypha are transparent thin walled tubes.
PROCEDURE:
PRIOR TO LAB: Place a piece of bread into the bottom of a shallow dish. Moisten the
bread with a little water using a dropper. Don't soak it! Allow it to stand open to the air
for 45 minutes. Cover it and leave in a warm, dark place. About 1 week prior to lab, start
a few molds, then 2 days after start another group, and then a third group 3 days before
the lab begins. You should have bread that is 1 week old, and 5 and 3 days old for
students to observe. Include a fresh piece of that same brand of bread. Also include any
other food item that might be molding.
1. Review with students the different kingdoms (use small poster) and their
characteristics. You may want to review some of the lower grade material
if your students have not developed a feeling for the diversity of life. In this
unit, students will look at organisms that they see, but rarely think about as
being living.
The reasons for grouping organisms into certain kingdoms are not always
obvious. The development of the kingdom classification dates back to
Aristotle who divided organisms into animals and plants. Today,
specialists working with different phyla change classifications when they
derive more information. You must realize that we do not know all there is
to know about organisms. The 5 kingdom classification system was first
derived in the early 1960's, and there are many biologists today that use a
6 kingdom division.
The Monera group is now broken up into 2 other Kingdoms, the
Archeabacteria and the Eubacteria. Examples include bacteria or bluegreen algae. Monera as a group, have a very simple nucleus and do not
have a nuclear membrane. The Kingdom Protista is made up of protozoa,
13 consisting of one celled organisms, that have a well defined nuclear
membrane. Protozoa will eat their food and reproduce asexually more
commonly than sexually. The Fungi are characterized in that they lack
chlorophyll and absorb food from the surrounding ground. Fungi possess
organs and reproduce by sexual means (spores). The Plant Kingdom is
characterized by its ability to produce by either sexual or asexual means.
The animal kingdom is divided into invertebrates and vertebrates. To be
an animal requires that an organism eat its food and reproduce mainly by
sexual means. Organs are much more developed in the Animal Kingdom
than the other kingdoms.
2. Set your molds out for students to observe. Make sure you label how old
the molds are. Students should observe different stages of mold growth.
Thin, transparent threads growing all over the slice of bread are a mold
garden. The cluster will look like a tangled spider web. If you single out
one of the threads and observe it with a microscope you will see many
branches of threads. At the ends of some of these branches are little
round balls. These balls are hollow round cases and each one is filled with
tiny seeds called spores. The spores are the mold's seeds. In a 2-3 day
old mold you will begin to see the spores on the garden. The spores are
the black substances sitting on top of the threads. Each black ball or spore
contains more than 20,000 smaller spores of their own. The threads and
their cases have no color but the spores within the cases are all colored.
So mold plants have no color, their spores make them appear to have
different colors. The 3-4 day old mold should have produced hundreds of
millions of new spores. Later they may fall on moist food left out
somewhere, sprout threads of their own, and give rise to new spores.
14 15 WHAT KIIND OF RO
OT DO YOU
U HAVE?
Types
s of rot you might fin
nd under th
he microsc
cope
16 PROBLEM: How does food rot?
PREDICTION:
PROCEDURE:
MATERIALS: microscopes, hand lens
Look at the different molds. Draw what you see.
AGE:
AGE:
AGE:
AGE:
CONCLUSIONS:
17 FOURTH GRADE- DOCENT LESSON #3
ORGANISMS IN COMPOSTING (PART I)
OBJECTIVES:


Identifying microbes in compost.
Exploring the biology of composting.
4
VOCABULARY:





thermophilic
actinomyetes
fungi
Bacteria
mesophilic
MATERIALS:





Microscope
Petri dishes
White spoons
Compost from local composter
Dissecting needle
BACKGROUND:
Bacteria and fungi digest organic matter and convert it into different chemical forms that
are used by other microbes, invertebrates and plants. During thermophilic composting
the populations of various types of microorganisms will change as conditions change.
The world of microbes in compost is diverse and mysterious. The energy that they
release during their struggle to stay alive, creates another ecosystem that helps to
further digest and change organic material.
There is always a challenge in compost in that your mixture produces an end product
that has carbon and nitrogen in balance. Making compost at the beginning can produce
“smells” but once it gets an “earthy smell” then the compost is ready.
In this lesson we will have the student explore the different microbes that they can find.
It is not important what their names are, but that students look for organisms that help
this complex chemical process. Below are some of the organisms the students may
see. Drawing pictures can help them look at the organism careful.
18 Nemato
odes
Nematodes, or roundworms, are
a an abun
ndant inverrtebrates in the soil.
Typically
y less than one millime
eter in length, they pre
ey on bacte
eria,
protozoa
a, fungal sp
pores, and each
e
other.. Though th
here are pesst forms
of nema
atodes, mos
st of those found
f
in soil and comp
post are beneficial.
Fermen
ntation Mite
es
Fermenttation mites
s, also calle
ed mold mittes, are tran
nsparent-bo
odied
creature
es that feed primarily on
o yeast in fermenting
f
masses orr organic
debris. Literally
L
tho
ousands of these
t
individuals can d
develop intto a
seething
g mass over a fermentting surface
e. As a resu
ult, they ofte
en
become pest species in ferme
enting indus
stries, such
h as winerie
es and
cheese factories.
f
They
T
are no
ot pests in th
he composst pile.
Springtails
ails, or colle
embola, along with nem
matodes an
nd mites, do
ominate in numbers
Springta
among the
t soil inve
ertebrates. They are a major facto
or in contro
olling
fungi populations. They
T
feed principally
p
on
o fungi, bu
ut also on
nematod
des and sm
mall bits of organic
o
detrritus
Redworrms and Ea
arthworms
s
Redworm
ms and earrthworms play an impo
ortant part iin the breakk-down
of organ
nic materials
s and in forrming finish
hed composst. Red worrms are
usually 2-3
2 inches long and arre importan
nt in warm ccomposting
g debris.
The morre common
n earthworm
ms are impo
ortant in nattural soil. A
As worms
process organic ma
aterials, the
ey coat the material wiith a mucuss film that
mall particle
es together into stable aggregatess and helpss to protectt nutrients from
binds sm
being leached out by
b rain. The
ese stable aggregates
a
s give soil a loose and well-draining
structure
e.
Ground
d Beetles
Ground beetles hav
ve many re
epresentativ
ves lurking through litte
er and soil spaces. Mo
ost
of them feed on oth
her organisms, but som
me feed on
n seeds and
d other vege
etable mattter.
piders
Wolf Sp
Wolf spiders are tru
uly "wolves" of the soill and comp
post commu
unities. The
ey don't build
webs, bu
ut run freely
y, hunting their
t
prey. Depending
D
on the size
e of the spid
der, their prrey
can inclu
ude all size
es of arthrop
pods- inverrtebrate animals with jo
ointed legs and
segmented bodies..
Centipe
edes
Centiped
des are freq
quently found in soil and
a in comp
post commu
unities. The
ey prey on
almost any
a type of soil inverte
ebrate near their size o
or slightly la
arger.
19 PROCEDURE:
1. Provide students with copies of the organisms used in composting. Have
the students cut them out and paste then on index card. Information
should be on the back. Add any other information you may want, or tell
the students that they can add information also. They will be using them
for the next class.
2. When they get the cards together ask them to put them into the different
tropic levels (see page 10). You may want to go over some of the
organisms.
3. If you have time, you can have them look at some compost. Get compost
from the Jora compost and put in petri dishes. However, if you do not
have enough time, next lesson will be devoted totally to looking at
compost critters.
4. Have them look at the material and identify different organisms that they
find. You can have them use the work sheet and circle what they see, or
you can give them a blank piece of paper and have them draw what they
see and have them try to identify it with the hand out on microbes
(preferred).
5. One method of collecting invertebrates is to take grab samples of
compost from various locations in the heap. Some organisms such as
centipedes and sowbugs will be more likely to be found near the surface.
Others will be found deeper in the heap. Spread each compost sample in
a large tray or pan, preferably light in color for maximum contrast.
Students should use wooden tongue depressors, plastic spoons, or other
instruments that will not hurt the organisms, to sort through the compost.
Flashlights and magnifying lenses can be used to enhance the
observation. The larger organisms, such as worms, centipedes,
millipedes, sowbugs, earwigs, spiders, ants, beetles, snails, slugs, some
mites, etc., can be observed with the naked eye. To get a closer look,
place samples of the compost in petri dishes or watch glasses and
observe them under a dissecting microscope.
20 21 22 23 24 FOURTH
H GRADE-- DOCENT LESSON #4
#
ORGAN
NISMS IN COMPOSTI
C
NG (PART
T II)
OBJECT
TIVES:
• Looking at compo
ost samples
s
• Identify
ying compo
ost organism
ms.
VOCAB
BULARY:

4
Comp
post
MATER
RIALS:




maturre
petri dishes
d
Meas
suring spoons
micro
oscope
BACKG
GROUND
In outdo
oor compost piles, a wide range of
o invertebra
ates take part in the decomposition
of organ
nic matter. In the last lab,
l
students started to
o observe tthese critters. Below iis a
diagram
m that tries to put many
y of the orga
anisms into
o their taxon
nomic groups.
25 1. May want to look at some of these animations to help understand
decomposition.
http://imold.utoledo.edu/index.html
2. Make sure students have their cards of the different organisms.
3. Go through how to use a reflecting microscope.
4. Use small petri dishes and put some compost in them. You may want to
take the students out to the compost pile in the garden to collect.
5. As the students find different organisms, make a list on the board.
26 FOURTH GRADE – DOCENT LESSON #5
SOIL DESCRIPTION
OBJECTIVES:
 Investigating natural soil.
 Comparing compost with natural soil.
4
VOCABULARY:
 soil
 soil horizons
 topsoil
MATERIALS:
 worksheet
 different soil samples
BACKGROUND:
Soil is composed of organic matter and broken down rocks. The organic matter is from
other surrounding life that has started to mix with the small rocks. Many soil dwelling
organisms spend their lives breaking down dead animals and plants, releasing nutrients
for use by growing plants. These decomposers, sometimes called reducers, are
responsible for the fertility of the soil.
The constituents of soil are extremely variable in size, shape and chemical composition.
The size of particles is one of the most significant characteristics. Water absorption, air
movement, rate of solution and ease of tillage are a few things that are affected by
particle size.
The texture of soil refers to particle sizes and is classified on an arbitrary scale. It can
be coarse, sandy, or clayey. Sand would be about the size of sand, coarse would refer
to soil that is larger and clayey would be smaller. You can also describe the structure of
soil by how the soil particles tick together. When particles are rather porous and small,
the soil is considered to have a granular or crumby structure, which is characteristic of
many soils high in organic matter. Soil that is lumpy usually sticks together. Sometimes
soil has magnetite in it, a magnetic mineral that is attracted to a magnet.
Humus, the partially decayed organic matter accumulated in soils, is a dark-colored
structure less material. Making compost would simulate and speed up nature’s way of
making humus.
Soil horizons can be different for high productive areas versus low productive areas.
The ideal soil horizon as shown in the Pre Lab, may not be present in all areas. You
can use the following to help guide you with your students.
27 PRODUCTIVE
A. contains more organic matter in most areas, most weathered and leached at all
levels, loose, easily tilled, fertile
B. Yellow layer containing small quantities of clay and easily penetrated by air, water,
and plant roots
C. slightly weathered, permeable, calcareous
NON PRODUCTIVE
A. light gray layer, low in fertility and difficult to till
B. heavy clay layer impermeable to air, water, and plant roots, massive stable
aggregates of small particles
C. heavy clay parent matter
Nutrients in the soil are important to plants in order to survive. Nutrients can be
complex organic molecules like carbohydrates, fats or protein. They can also be
inorganic like zinc or copper. However all nutrients are composed of elements in a
chemical state that can be used by the organisms.
In a process called photosynthesis, plants use energy from the sun to change carbon
dioxide (CO2 - carbon and oxygen) and water (H2O- hydrogen and oxygen) into
starches and sugars. These starches and sugars are the plant's food. Photosynthesis
means "making things with light". Since plants get carbon, hydrogen, and oxygen from
the air and water, there is little farmers and gardeners can do to control how much of
these nutrients a plant can use.
The 13 mineral nutrients, which come from the soil, are dissolved in water and absorbed
through a plant's roots. There are not always enough of these nutrients in the soil for a
plant to grow healthy. This is why many farmers and gardeners use fertilizers to add the
nutrients to the soil.
The mineral nutrients are divided into two groups: macronutrients and micronutrients.
Macronutrients can be broken into primary and secondary nutrients. The primary
nutrients are nitrogen (N), phosphorus (P), and potassium (K). These major nutrients
usually are lacking from the soil first because plants use large amounts for their growth
and survival. The secondary nutrients are calcium (Ca), magnesium (Mg), and sulfur
(S). There are usually enough of these nutrients in the soil so fertilization is not always
needed. Also, large amounts of Calcium and Magnesium are added when lime is
applied to acidic soils. Sulfur is usually found in sufficient amounts from the slow
decomposition of soil organic matter, an important reason for not throwing out grass
clippings and leaves.
Micronutrients are those elements essential for plant growth which are needed in only
very small (micro) quantities . These elements are sometimes called minor elements or
28 trace elements. The micronutrients are boron (B), copper (Cu), iron (Fe), chloride (Cl),
manganese (Mn), molybdenum (Mo) and zinc (Zn). Recycling organic matter such as
grass clippings and tree leaves is an excellent way of providing micronutrients (as well
as macronutrients) to growing plants.
Notice that all the components are ultimately composed of chemicals. However, there
are inorganic components that are "given" or specific to an area. The ecosystem has to
build itself on soil (organic matter + rock). Organic matter is carbon based, but rocks
can be made of a variety of chemical compounds which add character to a particular
soil. Remember, minerals make-up rocks, and minerals can be composed of elements
or compounds.
PROCEDURE:
1. A soil profile is a slice of earth several feet deep that illustrates the layers
of soil. Most soil profiles have a surface layer of organic material and two
or three layers of soil layers with different characteristics. Students in this
lab will look at 4 samples representing ideal O, A, B, and C horizons.
2. Give students soil samples, magnet, microscope, and beaker of water. It
would be ideal to get local samples for this lab and to record where the
sample came from. They will only use the water for samples collected by
the teacher, the reference collection should only be observed. It is difficult
to dry soil samples.
3. Instruct the students to look at the reference soil samples under the
microscope and describe what they see. They should ask themselves if
the sample has broken up rocks or very fine clay particles. They should
also see if there are other distinguishing characteristics like plant debris or
animal remains
4. If you have time you may want students to go outside and dig a hole to
see the soil horizon around the school. This may be difficult in some
areas. Students could collect some of the samples. If not enough time is
available, the teacher should pre-collect the samples.
5. Instruct students to put a little amount of the soil in some water to see if
anything floats. Plant debris that may not have been obvious under the
microscope may float.
6. Use the magnet to see if there is any magnetite, which is a magnetic
mineral. You can use the magnet with the reference collections. The
presence of magnetite means that the parent rock may have been granitic.
Magnetite erodes out of the rock and is left in the soil
29 PROBLEM: How can
c you disttinguish the
e different ssoil horizonss?
CTION:
PREDIC
Surrface: organ
nic material dead
plan
nts, animal material
O horizon
h
Top
psoil: plant roots,
r
bacte
eria,
fung
gi, small an
nimal
A horizon
bsoil: Fewer organisms
s less
Sub
tops
soil; plants don't grow well
B horizon
Alte
ered Parentt Material:
Wea
athered, les
ss living ma
atter
laye
ers above were
w
formed
d form
it
C horizon
MATER
RIALS: different soils samples,
s
ma
agnet, micrroscope, ha
and lens, cu
up of water
Look at the differen
nt horizons of soil and describe e
each below.
SOIL
DE
ESCRIBE CHARACTE
C
ERISTICS
30 HO
ORIZON
FOURTH GRADE- DOCENT LESSON #6
MAKING SOIL FROM COMPOST
OBJECTIVES:
• Exploring the different between soil and compost
• Using compost to make soil
VOCABULARY:



4
Compost
Soil
proportion
MATERIALS:





wheelbarrow or bins
small shovels
small rake
gloves
Gary the Gardener
BACKGROUND:
Many people think compost is soil. It is not. Compost is a human way of making
nature go faster and creating a product that can add nutrients to the soil to be used by
plants. Compost is great for mixing into the soil when you are planting a new plant. It
helps a sandy soil hold moisture and nutrients better and improves clay soils too.
Soil is organic matter plus rocks. The organic matter is from leaves, bark, dead plants,
animals, waste of small invertebrates as well as vertebrate. Other organisms like ants,
worms, beetles, and fungi (to name a few) eat on the matter and convert it to humus,
which is equivalent to compost. Rocks are made of minerals (which in turn is composed
of elements). Minerals provide the macro and micro nutrients and they erode into a
useable form.
Compost can be created faster and the ingredients can be controlled. It basically
produces carbon and nitrogen. Nitrogen is an important macronutrients that plants
require. Compost also helps to break up the soil so it can retain water easily. Most
compost is not ready for plants to grow because they are missing the important macro
and micro nutrients needed for plants.
Rocks are made of minerals. Minerals are made of elements. As water passes through
rocks, the water starts to break down the minerals to release elements. It is these
elements that are used in the process of supporting larger plants and organisms like
worms that basically eat and dissect soil to get nutrients.
31 Soil can be depleted if too many plants take their nutrients for their growth, compost can
help provide the organics so soil is rich in nutrients.
PROCEDURE:
Please remember that many children do not do gardening and unfamiliar with tools.
You may want to read “Gary the Gardener” to go over the use of tools.
1. Using compost to enhance soil helps to increase the nutrients. However,
you have to be careful of not adding too much, because it can change the
pH of the soil. Student learn about pH in the fifth grade, so you can tell
students that too much of a good thing can be harmful.
2. Tell students that they are going to make a 1:1 proportion of compost to
existing soil. Hopefully you can find an area where you can dig some up
for the students. Maybe use a coffee plastic tub and have students put
one part soil and one part compost in a larger bin or wheelbarrow.
3. Mix the mixture with a small shovel.
4. Find an area either in the garden or around the school yard that you can
help put nutrients by adding the new nutrient rich soil.
5. Rake the area so it looks good and then water the area.
32