Marin Master Gardeners
University of California Cooperative Extension
Farm Day 2015 Teacher Packet
Introduction
This teaching resource is designed for teachers whose students will visit our exhibits
at the 2015 Farm Day. Marin Master Gardeners has a three-part exhibit about plant
growth and what happens above and below ground to help plants grow and then
shows students what part of the plants we eat.
Part 1 Photosynthesis
Part 2 Soil Organisms
Part 3 What Parts of the Plant Do We Eat?
Activities:
Teaching Objective
To have the students understand the basis of photosynthesis. To have student know
the parts of the plant and that we eat different parts of the plant.
Introduction to Photosynthesis
All living things need food.
If you are hungry you can get an apple out of a fruit bowl and munch away.
If you kitten is hungry, she wanders to her dish and laps up some milk.
If a bear is hungry, he dips his head and munches some berries from a bush.
But what if the bush is hungry? Where does it get its food? Can it move? How does it
eat? What does it eat? How does a plant eat/grow?
The answer is Photosynthesis. Through the process of photosynthesis, plants make
their own food along with lots of extra food for us and other animals to eat! Though
photosynthesis is very complicated process that scientists are still trying to
completely understand, we do know a lot about the basics.
Plants need 4 basic things to make their food and grow:
 Chlorophyll-the green plant color of the leaves
 Sunlight
 Water
 Carbon Dioxide
Plants use the chlorophyll in their leaves to absorb and store the energy from
sunlight. That energy then mixes water from the plant roots and carbon dioxide in
the air that the leaves “breath in” to make plant sugars. Plant sugars are the food that
plants use to live, grow and make fruit and seeds in order to make new plants. The
sugars push up into the stems to create new stems, leaves and flowers. And, the
leftovers of this process are lots of oxygen that people and animals need to breath.
Important things to remember about photosynthesis and plants
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Plants must have light to grow
Plants must have water to grow
Plants must have green leaves to grow
Plants must have carbon dioxide to grow
If any of these things are missing or if there is not enough, the plant won’t do very
well and may even die.
Observing the Process
Have you ever seen a plant ‘move” to get closer to the light?
Have you seen plants that you pull in your garden with really long roots?
Why?
Plant is searching for more sunlight.
Plant is searching for water.
Classroom Activity
Does photosynthesis happen in the winter when all the leaves drop from many of the
trees?
What do you think happens to plants that live in the desert where there is not very
much water?
What happens to plants in the mountains that are covered with snow all winter
...how does the plant live without sun for so long?
Diagram—here are a few options -we can blow up the one we choose for the exhibit
The Smallest Performers on Earth!
Soil Organisms
Soil also called dirt or is the the top layer of the Earth (like frosting on a cake) and is
made out of small rocks, broken down leaves, twigs, roots and plants, living and dead
bugs, air and water. Soil is important because it holds our plants up. It allows plants to
grow in it which we eat and animals eat. Soil comes in different shapes and sizes
(like clay, gravely, silt and sand). Horizontal layers of soil called “soil horizons”are
formed over long periods of time resulting from weathering, decomposition,
relocation of materials through water movement, and the growing of new plants. The
top layers of soil are where the majority of soil organisms live and help create rich
fertile soil that allows plants on Earth grow.
Source: http://interwork.sdsu.edu/fire/resources/images/soillayers.GIF
O Horizon - The top, organic layer of soil, made up mostly of leaf litter and humus
(decomposed organic matter).
A Horizon - The layer called topsoil; it is found below the O horizon and above the E
horizon. Seeds germinate and plant roots grow in this dark-colored layer. It is made up
of humus (decomposed organic matter) mixed with mineral particles.
E Horizon - This eluviation (leaching) layer is light in color; this layer is beneath the
A Horizon and above the B Horizon. It is made up mostly of sand and silt, having lost
most of its minerals and clay as water drips through the soil (in the process of
eluviation).
B Horizon - Also called the subsoil - this layer is beneath the E Horizon and above
the C Horizon. It contains clay and mineral deposits (like iron, aluminum oxides, and
calcium carbonate) that it receives from layers above it when mineralized water drips
from the soil above.
C Horizon - Also called regolith: the layer beneath the B Horizon and above the R
Horizon. It consists of slightly broken-up bedrock. Plant roots do not penetrate into
this layer; very little organic material is found in this layer.
R Horizon - The unweathered rock (bedrock) layer that is beneath all the other layers.
One of the most exciting things about soil is how it is made. Nature has it's own amazing
process of making soil through the natural process of decay. Decay is when leaves, twigs,
and things like, feathers, bugs, dead trees and plants break down into smaller bits and
pieces. With help from the sun, wind, water, organisms and microorganisms over time,
these things turn back into soil. A big contributor to the decay process is things we
cannot see very well with our own eyes. These are small bugs and bacteria and fungus
also called organisms and microorganisms. Soil is full of life. It is often said that a
handful of soil has more living organisms than there are people on planet Earth.
Soil organisms play a special roll in making new soil because not only do they help with
the decay process but they add nutrients into the soil making soil healthy for future plants
to grow in. Things we consider rotten or garbage like banana peels, grass clippings, apple
cores, piles of leaves, etc., are the soil organisms food source! They feast on these types
of things, digest it and their epelled waste nourishes or fertilizes the soil. Their movement
also helps air and water flow.
Examples of Soil Organisms:
Earthworms: These can be seen with the naked eye and may be the most important
contributors to soil health and recycling of organic matter for nutrients. Earthworms
break down organic debris and expel waste material called casts or castings, which
are high in nutrients and beneficial bacteria. Plants use these nutrients to maintain
health and growth, while the bacteria help to stabilize and improve the structure of
the soil.
Nematodes: The nematode is a unique soil creature, They are non-segmented
worms and found in almost all soil types, but most are too small to see without some
sort of magnification. They usually feed on fungi and bacteria, but some are plant
parasites that attack plant roots. As nematodes digest a bacterial population, a lot of
nitrogen is released, increasing the amount of that valuable nutrient available to
plants. However, those nematodes that feed on plants create puncture wounds that
can quickly lead to infection by fungal and bacterial cultures. Nematodes move
mainly by swimming, so they are most often found in wet, sandy soils.
Bacteria: Microscpic one-celled organisms that lack chlorophyll and may be
parasites on plants or animals, causing disease; most are beneficial agents with
fermentation and decay of organic matter.
Fungi: A lower order of a plant organism, excluding bacteria, that have no chlorophyll
or vascular system.
Arthropods: Arthropods range in size from microscopic to several inches in length.
They include insects, such as beetles and ants; crustaceans such as sowbugs;
arachnids such as spiders and mites; myriapods, such as centipedes and millipedes; and
scorpions.
Nearly every soil is home to many different arthropod species. Several thousand
different species may live in a square mile of forest soil.
Arthropods can be grouped as shredders, predators, herbivores, and fungal-feeders,
based on their functions in soil. Most soil-dwelling arthropods eat fungi, worms, or
other arthropods. Root-feeders and dead-plant shredders are less abundant. As they
feed, arthropods aerate and mix the soil, regulate the population size of other soil
organisms, and shred organic material.
Classroom Activities
In the Soil
Bring in different kinds of soil for your students to analyze. If possible, have students
use hand lenses and microscopes to see what is in each kind of soil. You can collect
soils from a garden, beach, park, or nursery. Have your students record what they see.
Which soil has the most rocks? Which soil has the most bits of dead plants and
animals? Which soil is darkest, and which keeps its shape longest when you stick
your thumb in it?
To extend the activity, have students predict which soil holds the most water. Then
have students pour a small amount of water in each soil sample and place it in a
warm place. After an hour, have students check to see which soil stayed damp the
longest.
Worm Farm
Some animals, like insects and worms, live in the soil. Worms are helpful to the soil
because they mix all the parts of the soil. The worm tunnels allow air and water to
reach the soil as well. They also ingest soil as they eat whatever plants, fruit, or
compost you feed them. After they eat, they leave behind casings which add nutrients
to the soil that plants need to grow. Start a worm farm with your students. Use an
aquarium, terrarium, or other clear container. Add soil and worms and have students
observe. You can purchase worms from gardening stores and nurseries. Don't forget
to water the soil and keep it damp. Composting fruit and vegetable scraps will extend
the lesson even further. Plant seeds in the soil of your worm farm and observe how
they grow.
Soil Painting
Different soils vary in color and texture. Invite students to bring in a small amount of
soil from their yards or from places around their communities. Make sure they label
where they got the soil. Divide the students into small groups and have them compare
and contrast the soil. Why might one soil be darker than the other? What might make
one soil reddish in color? Where in the community might you find drier soil or sand?
Have students discuss and write down their ideas. Then have students create soil
paintings. They can use glue and their soil samples to create landscapes, abstract
paintings, or even portraits. Encourage them to be creative! Then have students share
their artwork with the whole class.
Parts of the Plant
We learned that plant grows above and below ground in order to reach water,
sunlight and nutrients. The different parts of the plants are:
Seeds—Allow the plant to reproduce
Stems—Carry water and food through the plant
Roots—Take up water and minerals from the soil and provide stability to the plant as
it grow
Leaves—provide the surface area for plants to collect sunlight and conduct
photosynthesis
Flowers —help plants produce seeds. Its fragrance and color attract insects that
pollinate the plant so it can reproduce.
Fruit – Protects the seeds.
And depending the plant, we eat EVERY part of the plant!
Foods that we eat that are ROOTS: Beets, Onion, Carrots, Potatoes, Turnips, Yams
Foods
that
kale,
chard,
Foods
that
seeds,
black
beans,
seeds
that we eat
are LEAVES:
Brussel
sprouts,
cabbage,
spinach,
lettuce,
parsley
that we eat
are SEEDS:
Pumpkin
peas, corn,
beans, pinto
sunflower
Foods that we eat that are STEMS: asparagus, celery, rhubarb, bok choy
Foods that we eat that are FLOWERS: broccoli cauliflower
Foods that we eat that are FRUIT: apple, avocado, grapes, cucumber, banana, squash,
pear, orange, peaches, strawberries, tomatoes, pineapple, plum, melons
Classroom Activity
Have students bring in a plant they eat. Identify what part of the plant it is.
Share their favorite parts of the plant to eat. What plants did they eat yesterday?
RESOURCES
Books:
Compost Critters, Bianca Lewis
Seed, Soil, Sun, Cris Peterson
Useful Websites:
http://www.brainpop.com/educators/community/lesson-plan/soil-activities-forkids/?bp-jr-topic=soil
http://www.blm.gov/nstc/soil/Kids/index.html
http://www.soils4teachers.org/lessons-and-activities/teachers-guide/soil-biology