epa composting unit

7/29/2019 EPA Composting Unit

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What Is Composting?C p g is the controlled he m p (130-150F) dec p of organic materials suchas leaves, grass, and food scraps by variousorganisms. Composting can be divided into threetypes: backyard, or home, composting; vermi-composting; and heat-based composting.

Home composting is the natural degradation ofyard trimmings, food scraps, wood ashes, shred-ded paper, coffee grounds, and other householdorganic waste by naturally occurring microscopic

organisms. e c p ng is the naturaldegradation of similar household organic wasteusing naturally occurring microscopic organismsand the digestive process of earthworms. Heat-based composting is performed by municipal orcommercial facilities that increase the rate ofdegradation using high temperatures.

Varying amounts of heat, water, air, and foodproduce different qualities of compost as a finalproduct. Heat-based compost differs from com-post produced at ambient temperatures (e.g., a

forest floor or home com-posting) because hightemperatures destroy bothweed seeds and pathogens.Composts produced by allthree systems are crumbly,earthy-smelling, soil-likematerials with a variety ofbeneficial organisms.

Composting

Key Poin s

Composting is the controlled decompo-sition of organic materials.

There are three methods of composting:home or backyard composting, vermi-composting, and heat-basedcomposting.

Invertebrates and microorganisms incompost are key to the breakdown ofthe organic materials into a rich soil-like

product. Quality compost is the result of the prop-

er mixture of carbon and nitrogensources and adequate amounts of mois-ture, oxygen, and time. Certain food itemsshould be avoided when home composting.

More than 67 percent of the wasteproduced in the United States (includingpaper) is compostable material.

Compost is a valuable product that canbe used as a soil amendment, mulch, or

even to decontaminate natural habitats,storm water, and brownfields.

Composting helps divert a large portionof Americas organic trash from landfillsand combustion facilities.

WormsA Composters Best Friend

Vermicomposting is a method of composting using a special kind of earthworm known as a red wig-gler (Elsenia fetida), which eats its weight in organic matter each day. Vermicomposting is typicallydone in a covered container with a bedding of dirt, newspaper, or leaves. Food scraps (withoutadded fats) can then be added as food for the worms. Over time, the food will be replaced withworm droppings, a rich brown matter that is an excellent natural plant food. Vermicompostingrequires less space than normal composting methods, and is therefore ideal for classrooms, apart-ments, and those in high-density urban areas.

EPA: The Quest for Less


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How Does Composting Work?Compost contains both carbon and nitrogensources, which can be simplified as browns(e.g., leaves, straw, woody materials) andgreens (e.g., grass and food scraps), respective-ly. Adequate sources of carbon and nitrogen areimportant for microorganism growth and energy.The ideal ratio is 30 parts brown to 1 partgreen. Odor and other problems can occur ifthe ratio or any of the factors discussed beloware not right.

The browns and greens can be mixed togetherto form compost in a backyard bin or in amunicipal compost facility. Whether the com-posting is done on a small scale or large, thecomposting process is the same. To encouragedecomposition throughout the pile, the compostshould be kept moist and turned periodically.

The decomposition of organic materials in com-posting involves both physical and chemical

processes. During decomposition, organicmaterials are broken down through the activitiesand appetites of bacteria, fungi, and variousinvertebrates that will naturally appear in com-post, such as mites, millipedes, beetles,sowbugs, earwigs, earthworms, slugs, andsnails. These microorganisms and insects foundin decomposing matter need adequate moistureand oxygen to degrade the organic materials inthe most efficient manner.

What Are the Benefits ofComposting?

As a method of handling the large amount oforganic waste created in the United States eachday, composting makes good environmentalsense. Instead of throwing organic materialsaway, they can be turned into a useful resource.

In addition, many organic wastes are not ideallysuited for disposal in combustion facilities orlandfills. Food scraps and yard trimmings tend tomake inferior fuel for combustors because of theirhigh moisture content. Decomposition of organicwastes in landfills can create methane, a green-house gas that is environmentally harmfulbecause it destroys atmospheric ozone.

Because yard trimmings and food scraps makeup about 24 percent of the waste U.S. house-holds generate (EPA, 2003), backyard or homecomposting can greatly reduce the amount of

Composting in Action

An easy way to understand all the factors thatgo into composting is with a hands-on demon-stration. A school can provide the perfect

medium for these demonstrations. Classescould start a composting bin using food scrapsfrom the cafeteria and yard trimmings fromground maintenance. Depending on the scopeof the project, the compost could then be soldto the community in addition to being used onthe school campus. Tour a local compostingfacility, if composting cannot be done atschool. For more information on how tostart a school composting project, go to theCornell University composting Web site at or use thesesuggested activities to get you started:

Start a compost pile or bin in the school oras a class experiment.

Try using compost in place of chemical fer-tilizers, pesticides, and fungicides. Usecompost made by the school or buy it frommunicipalities or private companies.



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waste that ends up in landfills or combustors. Inaddition, compost is a valuable product that canbe used as a soil additive for backyard gardensand farm lands or in highway beautification andother landscape projects.

The benefits dont end therecomposting alsomakes good economic sense. Composting canreduce a communitys solid waste transporta-tion, disposal, and processing costs. In manycommunities, residents pay for each bag or canof trash they put out for pickup. If a householdis composting, it will most likely put less in trashcans and will pay a smaller trash bill.

In backyards and on the community level, inter-est in composting has increased rapidly over thepast several years. Yard trimmings programs

constitute the large majority of compostingoperations in the United States. In these pro-grams, community members place their yardtrimmings in a separate bag or container at thecurb, which is collected and taken to a munici-pal composting facility. These facilities createlarge amounts of compost, which, in manycases, is sold back to community members.People can also purchase compost created byprivate composting companies.

What Are theChallenges AssociatedWith Composting?

Creating quality compostrequires the right mix of mate-rials and attention to moisture,particle size, and temperature.Too little moisture will slow thedecomposition, but too muchcan create odor problems. Toavoid attracting pests and

rodents, composters shouldmonitor the food scraps put inthe compost pile. Meat scraps,fats, and oils are difficult itemsto compost, attract pests, andshould be kept away from thecompost pile, and thrown awayinstead.

While composting increases the rate of naturalorganic decomposition, it still takes months forcompost to mature. If compost is used while it isstill cooking, the high temperatures could killthe plant life on which it is spread. In addition,using compost before it is ready can encourage

weed growth because the high temperatures ofthe pile have not had a chance to kill anypotential weed seeds.

What Are Some Emerging Trendsin Composting?

A large amount of organic waste is created byinstitutions, restaurants, and grocery storesperfect for compost. Across the country, many of

What Can Go Into a Composting Bin?This list is not meant to be all inclusive. Some food products

should not be included because they can attract pests orcompromise the quality of the compost.

M e a c ude Ma a xc de

Fruit and vegetable scraps MeatsTea bags Dairy foodsWool and cotton rags BonesCoffee grounds with filters Fats

Grass/Yard clippings Pet excrementLeaves Diseased plantsEgg shells GreaseSawdust Oils (including peanutFireplace ash butter and mayonnaise)Nonrecyclable paperVacuum cleaner lintFish scraps



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Additional Information Resources:

Visit the following Web sites for more information on composting and solid waste:

U.S. Environmental Protection Agency (EPA):

U.S. EPA, Office of Solid Waste site on composting: Cornell University composting site:

U.S. Composting Council Web site:

To order the following additional documents on municipal solid waste and composting, call EPA

toll free at (800) 490 9198 or look on the EPA Web site

.

Innovative Uses of Compost Erosion Control, Turf Remediation, and Landscaping

(EPA530 F 97 043)

A Collection of Solid Waste Resources on CD ROM

these businesses are participating in pilot proj-ects to compost their food scraps and soiledpaper products. These businesses can not onlyprovide a valuable component of compostorganic materialbut also can reduce theirwaste disposal costs significantly.

Compost is also being used as an innovativetechnology to clean up land contaminated byhazardous wastes, remove contaminants from

storm water, facilitate reforestation, and restorewetlands and other natural habitats. Composthas been used to restore soil that is contaminat-ed with explosives, munitions wastes, petroleum,fuel wastes, and lead and other metals. Inaddition, various biodegradable tableware

and dishes have been developed; in particular,cups and plates made with a cellulose-basedvegetable polymer.

http://www.epa.gov/http://www.epa.gov/http://www.epa.gov/http://www.epa.gov/epawaste/conserve/rrr/composting/index.htmhttp://www.epa.gov/epawaste/conserve/rrr/composting/index.htmhttp://www.epa.gov/epawaste/conserve/rrr/composting/index.htmhttp://compost.css.cornell.edu/composting_homepage.htmlhttp://compost.css.cornell.edu/composting_homepage.htmlhttp://compost.css.cornell.edu/composting_homepage.htmlhttp://compost.css.cornell.edu/composting_homepage.htmlhttp://www.compostingcouncil.org/http://www.compostingcouncil.org/http://www.compostingcouncil.org/http://www.epa.gov/epawaste/inforesources/pubs.htmhttp://www.epa.gov/epawaste/inforesources/pubs.htmhttp://www.epa.gov/epawaste/inforesources/pubs.htmhttp://www.epa.gov/epawaste/inforesources/pubs.htmhttp://www.epa.gov/epawaste/inforesources/pubs.htmhttp://www.compostingcouncil.org/http://compost.css.cornell.edu/composting_homepage.htmlhttp://compost.css.cornell.edu/composting_homepage.htmlhttp://www.epa.gov/epawaste/conserve/rrr/composting/index.htmhttp://www.epa.gov/


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Grades K-

Step 1:Visit your chosen outdoor area priorto the class trip in order to make sure it is suit-able for viewing natures recyclers. Scout outfour specific stations for the students to visit,including a live tree, an old decomposing log,a large rock (or board) in the soil, and a leaf-

covered patch of soil. To draw insects to aspecific spot, you might want to plant a log orboard in the soil several days in advance.

Step 2: Discuss recycling with the studentsand explain the following concepts (refer tothe Teacher Fact Sheet titled Composting onpage 141 for background information):

Why we recycle and why nature also needsto recapture the value of its organic waste.

What kinds of trash get recycled innature.

Who recycles these materials. Discuss theplants and animals, such as snails, slugs,beetles, millipedes, earthworms, fungi, pill-bugs, snowbugs, mushrooms, and lichenthat perform natures recycling work.

Step 3: Divide the class into small groups of

three to four students. Explain that the studentsare now adventurers on a mission to locate andstudy natures recyclers at work. Remind studentsthat its very important to observe, but not touchor disturb the recyclers or their habitat.

Step 4: Lead the students to your predeter-mined outdoor area and stop at each of thefour stations. At each station, first lead a dis-cussion (see below) and then give each group

Compost Critters

To teach students that nature can recycle its ownresources.

Students will search for and observe some of naturesrecyclers at work, learning what role each plant or ani-mal plays in the recycling process.

An outdoor area, such as a yard, park, or garden,that offers access to some of the following: rocks,trees (dead and living), leaf litter, mushrooms

One or two teachers aides or parents to helpfacilitate the outdoor adventure (optional)

Several sheets of drawing paper and pencils orcrayons per student

One clear viewing container with holes

Observation/classificationMotor skills

DecayMushroomMillipedeFungiLichen

Outdoor expedition:1 hourIn-class follow-up:30 minutes

Sc



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of students the chance to get up close and makeindividual observations. A list of suggested topicsand discussion questions for each station fol-lows:

S a o # v ee

Ask students what makes the tree grow.Where are its roots? Where does it get itsfood from?

Will the tree live forever?

Are its leaves falling to the ground?

S a o #2 D ad, D a o

Ask students how this tree is different fromthe live one.

Have them touch and smell its bark. How is

it different than the live bark? Is it dry ordamp?

Do the students see evidence of the woodbeing eaten? By what?

Have the students look in the crevices andcracks for any of natures recyclers at work. Ifthey see ants, spiders, millipedes, mush-rooms, etc., ask them the followingquestions:

Is it a plant or animal?

Whats its name?

How does it move? How many legs doesit have?

What color is it?

Why is it living under this dead log? Whatdoes it eat?

How many of these creatures are livingtogether?

If its possible (and safe), capture a few of

these recyclers in your clear container and letthe students view them up close. You maywant to impose an item limit to prevent toomuch disruption for the critters. Studentscould draw the recyclers they see in natureor wait until they return to the classroom anddraw from memory. Make a point of return-ing the creatures safely to their homes afterthe viewing is over.

S a o #3 a e Ro k or Boa d

Have the students watch as you carefully liftthe rock from its position. Ask students tolook at whats underneath it.

Whats it like under the rock? Is it dark and

moist?

Can the students see any of natures recy-clers at work here? If they do see life, askthem the same questions as above:

Is it a plant or animal?

Whats its name?

How does it move? How many legs doesit have?

What color is it?

Why is it living under this rock or board?What does it eat?

How many of these creatures are livingtogether?

S a o #4 ea a d S

Have the students use their hands to digthrough the leaves and into the soil.

Ask them to compare these leaves to theleaves still on the live tree. How are they dif-

ferent? Are these leaves older? Are they wetor dry?

Have the students look for evidence ofnatures recyclers; again, identify and discussany animals or plants that they find.

Ask the students to feel and smell the soil.How does it compare to the dead log theyvisited earlier?

Step 5: Before returning to the classroom,visit the live tree station again. Ask students tothink again about where this tree gets its food.Discuss how the decaying log, busy creatures,and moist, rich soil all play a role in keeping thetree alive.



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1. Back in the classroom, pass out paper andcolored pencils or crayons to the students.

Have each student draw one of the recyclershe or she saw outside. Ask each student toverbally describe to the class how this crea-ture moves, what its called, and whatrecycling role it plays in nature.

2. Ask the students how they are like naturesrecyclers. Do they recycle anything at home?How does it get reused?

3. Have the students draw a tree in differentstages of its life, showing the tree 1) bud-ding, 2) in full growth, 3) with leaves falling,

4) as a dead tree, having fallen as a log anddecaying back into the earth, and 5) as anew tree growing from the soil.

1. Engage students in a role-playing activity.Have students pretend that they are different

recyclers (ants, millipedes, worms, mush-rooms, spiders). Ask the students how theseanimals or plants moved or behaved. Havethe students imitate this behavior.

2. Study natures recyclers in the winter by col-lecting some leaf litter, bringing it inside, andwarming it with a lamp. Dormant recyclers,such as millipedes, ants, spiders, and wormswill come to life under the heat.

3. Conduct another nature walk, this time giv-ing each student a recyclable paper bag.

Have them collect dead leaves, sticks, nuts,or other teacher-approved items on theirwalk. When students return to the classroom,discuss what role these items have in natureand in the natural cycle of life. Is the itemdead or alive, what is it called, is there anyevidence of natures recyclers at work? Helpthem glue or tape these items on a piece ofconstruction paper and display them. Havethe students perform leaf rubbings by placinga leaf under a piece of paper and coloringover it to reveal its shape and texture. Ask

the students to explore how each leaf is simi-lar or different from others.



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Grades 3-

Step 1: Photocopy and distribute one copyof the Compost Chefworksheet to each stu-dent. Introduce the following concepts (referto Teacher Fact Sheet titled Composting onpage 141 for background information):

Explain to the class what compost is andhow it is made.

Discuss why composting is important inmanaging and reducing trash that is sentto landfills.

Explain how composting works, and hownitrogen, oxygen, and water all play a partin the creation of compost.

Compost Chefs

To teach students how composting can prevent foodscraps and yard trimmings from being thrown away andhow different components, such as air, moisture, andnitrogen, affect composting.

Students will create four compost bins that differ in their

amounts of air, moisture, and nitrogen. Students willobserve and record the differences these conditionscause in the composting process.

Four thin, plastic buckets (5 gallons each) or otherplastic container (e.g., milk jug)

One hand drill or punch-type can opener One copy of the Compost Chefworksheet per student Grass clippings (shredded, if possible)

Vegetable and fruit peels Weeds (shredded, if possible) Hay (shredded, if possible) Sawdust Coffee grinds Thermometer Bloodmeal One marker or pen Tape Four pieces of construction paper (3 by 5 inches each) Garden trowel

Computation

Observation/classificationMotor skills

CompostNitrogenOxygenDecomposeBeddingOrganic

Set-up: 1 hour

Follow-up: 15 minutes to1 hour on an occasionalbasis for up to 4 weeks

sc



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Step 2: Pick an appropriate project space.This activity can either be conducted in anindoor area of the classroom that has beencovered with a protective drop cloth or in adesignated area outside of the school. If youchoose to leave the compost buckets outside,make sure the chosen area will not be disturbed

by recess or after-school activity. Use the handdrill and carefully poke several holes in the sides(near the bottom) of three of the buckets ormilk jugs.

Step 3: Have the students sit in a circle withinview of you and the compost buckets. Divide theclass into four groups and assign a group ofstudents to each bucket. Using the constructionpaper and marker, label the buckets onethrough four.

Step 4: Work with each group of students toset up the buckets. As each mixture is created,discuss its ingredients and ask students to recordthe recipe on theirCompost Chefworksheets.Following are directions for setting up eachbucket:

Bucket #1Compost lacking nitrogen. Place mostly brown carbon-containing

materials in the bucket, such as dead leaves,straw, and coffee grounds. On top, add afew vegetable and fruit peels.

Moisten, but do not soak, the mixture withwater.

Bucket #2Compost lacking moisture. Place a mixture of green grass clippings

(make sure they are dry), bloodmeal, andvegetable and fruit peels in the bucket.

Place a few layers of brown dead leaves,straw, and coffee grounds into the mixture.

Do not add any water.

Bucket #3Compost lacking aircirculation. Use the bucket without the holes.

Place several layers of mostly high-nitrogengrass clippings, bloodmeal, vegetable peels,and fruit peels in the bucket.

Moisten the mixture with water.

Bucket #4Perfect Compost. Layer (in an alternating pattern) leaves, cof-

fee grounds, straw, and vegetable and fruit

peels, and a small amount of grass clippingsin the bucket.

Moisten the mixture with water.

Step 5: Explain that, as compost chefs, thestudents must monitor their creations. Give eachgroup written instructions on how to care for itscompost bucket over the next few weeks. Forexample:

Bucket #1 Use a garden trowel to stir your compost

mixture regularly: once every 3 days for thefirst 2 weeks, then once per week.

Add a dash of moisture to your compost mix-ture with a sprinkle of water every other week.

Ask students to pretend they are

gardeners. Ask them if they would

use compost to help their gardens

grow. Why or why not?



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Bucket #2 Use the garden trowel to stir your compost

mixture regularly: once every 3 days for thefirst 2 weeks, then once per week.

Keep your compost mixture dry.

Bucket #3 Add a sprinkle of water to your compost mix-

ture every week.

Make sure you dont stir your mixture.

Bucket #4 Add a sprinkle of water to your compost mix-

ture every week.

Use the garden trowel to stir your mixtureregularly: once every 3 days for the first 2

weeks, then once per week.Step 6: At each interval of stirring or water-ing, have all of the groups visit each compostbucket and record their findings, including tem-perature, appearance, and smell. Students canuse theirCompost Chefworksheets for this task.

Step 7: After 4 weeks, have the students usethe trowels to dig into each compost pile andexamine it closely. Ask them to compare andcontrast the compost in each bucket. Ask stu-dents which mixture decomposed the most.

Step 8: Use the finished compost from Bucket#4 as soil for classroom plants or a garden.Have students explore how compost aids newvegetative growth.

1. Ask students to list the most important ingre-dients for a good compost pile (nitrogen,water, and air circulation). Have themexplain what role each ingredient plays indecomposition. Ask each group to name themissing ingredient in its mixture (Group #4wont have a missing ingredient).

2. Have the students explain how compostingreduces the amount of waste that we send tolandfills.

3. Ask students to think of places in naturewhere composting might occur naturally.

1. Collect and evaluate the data on each stu-dents Compost Chefworksheet. Have thestudents create charts or graphs based onthe temperature data they collected. Whichpile had the highest mean temperature?What does a high temperature mean in

terms of decomposition?2. Explore composting as a natural cycle. Study

the nitrogen cycle and have students makediagrams of its components. (The nitrogencycle is the continuous cyclic progression ofchemical reactions in which atmosphericnitrogen is compounded, dissolved in rain,deposited in soil, assimilated, and metabo-lized.) Use composting as a lead-in todiscuss other natural cycles.

3. Start a schoolwide compost bin using the

appropriate wastes from school lunches.Have students decide which wastes can beadded to the pile and have different classeswatch over and stir the pile each week. Haveeach participating class start a small flowergarden plot, using the compost as a soilamendment.



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Week 1

Smell:

Compost Chef

Name:

___________________________________________________

Temperature:

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Week 1

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Grades 3-

Step 1: Locate and mark the two school-yard garden plots you plan to use, making

sure they receive plenty of direct sunlight.Secure permission for gardening from theproper school authorities.

Step 2: Discuss composting with the stu-dents and explain the following concepts (referto the Teacher Fact Sheet titled Compostingon page 141 for background information):

Recap how the students made the compostand what materials they used.

Discuss how this compost can now be usedin a garden.

Explain why compost can be more effectivethan just natural soil.

Step 3: Take the class outside to the gardenplots and divide the students into two groups.Explain how the composting experiment willwork. Tell one group that they will only addwater to the soil to help their plants grow.Give the other group a bucket of compostand tell them to use the trowels to mix it intotheir soil before watering it.

Compost Crops

To teach students how composting can prevent foodscraps and yard trimmings from being thrown away andto show them the usefulness of compost in gardening.

Students will assess the effectiveness of compost as a

soil amendment by planting and comparing two gardenplotsone that relies just on dirt and one that relies ontheir homemade compost.

*Compost* (See prerequisite above) Two 4- by 4-foot garden plots in the schoolyard Two packets of flower seeds (have your students

vote on the type and color) Two seed packets of a vegetable that grows well

in your locale One watering can Two garden trowels One copy of the Compost Crop worksheet per student One tape measure or ruler

ComputationObservation/classificationMotor skills

DecomposeCompostRootNutrient

Setup: 1 hourFollow-up each week:15 minutes

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m

*Prerequisite:* This activity involves the use of previously made compost. Your students can use the compost they madefrom completing one of the following activities: Compost Chefs or Worms at Work.



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Step 4: Have each group plant flower seedsand vegetable seeds according to packetinstructions in their respective plots.

Step 5:Ask the students to predict which plotwill grow better and faster. Have them recordtheir predictions and reasoning on their

Compost Crop worksheets.

Step 6: Break each of the two groups intopairs of students and assign each pair a weekduring which they are gardeners. During thatweek, those students are responsible for visitingtheir groups plot each day. They should water itand use the tape measure or ruler to record anychanges in plant growth on theirCompost Cropworksheets. Create a gardener calendar for theclassroom to remind students when its their turnto watch over the plots.

Step 7:After 4 or 5 weeks, have the entireclass visit the garden plots again. Discuss whichplots plants grew faster. Ask student volunteers togently dig up one plant from each plot. Have thestudents examine and compare the root structuresof each plant. Have several students dig aroundin the plots soil, discuss the differences in textureor moisture they find, and have them notice howmany earthworms or bugs they find.

Step 8: If the vegetables in the plot are ripe,pick them and have a class snack from thecompost harvest.

1. Have students list the benefits of composting,both from the standpoint of preventing wasteand as a garden soil supplement.

1. Use the two garden plots as a lead-in to amore in-depth science lesson on soil and

compost. Compare the relative amounts ofmaterials in different soil samples. Have stu-dent volunteers collect a handful of soil fromeach plot. For each sample, fill a liter (orquart) jar about one-quarter full of soil, thenadd water to about the three-quarter level.Screw the lid on tightly and shake hard forabout a minute. Let the jars stand for severalminutes. The mixture will separate into lay-ers, with the largest particles (gravel andsand) settling on the bottom, and finer parti-cles (clay and silt) settling above. Organic

matterleaves, twigs, and any animal mat-terwill float on top of the water. Discussthe differences between the soil and com-post/soil plot samples. Explore thecomponents of your local soil and compost.

2. Have the students compile their measure-ments and recordings from theirCompostCrop worksheets on the board. Dependingon the age group, ask all of the students tomake graphs charting the growth in eachplot. Ask them why plants in the compost

plot grew more quickly.3. Discuss the root structures of the plants from

the different plots. Ask students if the plantfrom the compost plot was more developedin its root structure? Why?

4. Ask the students to think about the differ-ences in the soil of the two plots. Did theysee more earthworms in the compost plot?Why? Why would these creatures be attract-ed by the compost? How did the presence ofearthworms affect the growth of the plants?

5. Start a schoolwide compost bin using theappropriate wastes from school lunches.Have students decide which wastes can beadded to the compost pile and have differentclasses watch over and stir the pile eachweek. Have each participating class start asmall flower garden plot, using the compostas a soil amendment.

Ask students to pretend they are

world-famous gardeners giving

an interview about the secrets

of their success. How do theymake their plants grow so well?



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Plot #1

(just soil)

Plot #2

(compost and soil)

Plot #1

(just soil)

Plot #2

(compost and soil)

Plot #1

(just soil)

Plot #2

(compost and soil)

Plot #1

(just soil)

Plot #2

(compost and soil)

Plot #1

(just soil)

Plot #2

(compost and soil)

Compost Crop Worksheet

mo a e dded

S S a u ks

a S e

se ce fP a GW c a

M asu e e fG

g oO e v on

ay

a 2

ay 3

ay 4

a 5

Name:

____________________________________



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Grades 4-

Step 1: Explain to the class what compost isand how it is made (refer to the Teacher FactSheet titled Composting on page 141). Discussthe use of worms, the need for and use oforganic waste, and other vocabulary words.During the course of this lesson, informstudents of good and bad foods to use incomposting, as well as the reason why it is bet-ter to compost than to throw food scraps away.

Step 2: Place bin on top of two bricks andput tray under bin.

Step 3: Have the students tear each sheetof newspaper lengthwise into strips that are 1to 3 inches wide and place half of the pile inthe bin.

Step 4: Have the students multiply the num-ber of pounds of newspaper by 3 to determinethe total amount of water needed (a pint ofwater weighs a pound, and a gallon of water

Worms at Work

To teach students that food scraps and yard trimmingscan be made into compost instead of being thrown away.

Students will create a compost bin using worms andfood scraps and monitor changes in the bin over time.

Large plastic bin (about 8 to 16 inches deep) withholes in the bottom for aeration

Tray for underneath the bin Two bricks or other large sturdy objects 9 to 14 pounds of newspaper One bag of potting soil 1 pound of red worms Food scraps (such as bread, vegetables, fruits,

eggshells, grains, coffee grounds, tea bags) Do NOTinclude meat, bones, mayonnaise, fish, peanut butter,candy, or nonfood items

Tarp or drop cloth Bucket or other carrying container Household gloves (optional) Copy of Vermicomposting Data Sheet for each student

ComputationObservation/classification

Motor skills

CompostVermicompostingCastingsDecomposeBeddingOrganic

Setup: 1 hourFollow-up: 15 minutes to1 hour on an occasionalbasis

Sc



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weighs 8 pounds). Then add half of the water tothe bin with newspapers.

Step 5: Sprinkle two handfuls of soil and therest of the newspaper and water. Have the stu-dents mix the contents well and distribute evenly

in the bin.

Step 6: Gently place the worms on top of thebedding, spreading them evenly. Keep the binuncovered so the students will see the wormsmoving down into the bedding to avoid light.

Step 7: Use the attached data sheet to recordall activities surrounding the worm bin, includingthe date the bin was set up, the number ofworms (or pounds of worms) added to the bin,and the number of people contributing food

scraps (number of people in the class). For theremainder of steps for this activity, have studentsrecord the date and day food is added, includ-

ing the type of food and its weight, as well asthe amount of water added. The compost binshould always remain moist.

Step 8: Use food scraps that you broughtfrom home or that you asked students to bring

from home or save from school lunch, and havestudents add them to the bin. Food can beadded daily, weekly, or monthly. Do not over-load the system; bury food relatively evenlyamongst the different plots. On the datasheet, instruct students to keep track of howmuch food they are providing the worms andwhere it is placed (see diagram on data sheet).

Step 9: Place a sheet of newspaper over thetop of the bin to prevent flies from circulatingnear the area. Store the bin in a cool place out

of direct sunlight, and keep the lid tightly shut.

Step 10: Have students check the bin fre-quently as they add food scraps to see thechanges that occur. After a period of 3 to 6months, depending on the size of the container,most of the food and bedding will be trans-formed into worm castings, the nutrient-richwaste materials that worms excrete.

Step 11: In order to harvest the compost, orhumus, for use (if you choose to), you mustchange the bedding and temporarily remove theworms. Spread out a tarp or drop cloth in anopen area and dump out the entire contents of

Have students write a poem, such

as a limerick, that describes what

compost looks like and how it

feels when touched.

d p a e a se e ac e s aped es

a e b

Sco p ff ea e a f eo e e

u e ca g a e ca y ou

e ga de

Step 11: How To Harvest Compost

1 2 3



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the bin. Have students help you divide thematerials into several cone-shaped piles (largeron the bottom, so the worms will burrow into itand avoid the light). Direct students to scoop offthe material from the tops of the piles, and putthe castings into a container to carry out to the

garden (see illustration on the previous page forhelp). Repeat this procedure until most of thecompost is harvested.

Step 12: Have students put worms back inthe bin, along with any uncomposted food andold bedding. Your class can start a new stock ofbedding and add in any additional worms tobegin the process again.

Step 13: Create a garden in which to use thecompost as a soil amendment, or use the com-

post on the schools beds or lawn.

NOTE: Other critters may make their way intothe compost bin. Many are beneficial, includingmold, bacteria, sow bugs, beetle mites, whiteworms, snails and slugs, flies, round worms,and millipedes. You do NOT want the followingin your bin, however: flat worms, ground bee-tles, centipedes, ants, and pseudo scorpions. Ifyou find any of these organisms, start over.

1. Ask students to define and describedecomposition.

2. Ask students why it is beneficial to compostitems instead of throwing them away.

Ask the students to make observations about theworm bin each week. Do smaller pieces of food

tend to break down faster than larger ones?What does the compost smell like? What organ-isms do they notice? Are the worms multiplying?

1. Have students take the temperature of theworm bin once a week to determine the vari-ations that occur while food is composted.Use a thermometer that can measure up to170F. Have the students create bar graphsshowing the increase or decrease in temper-ature over time.

2. Let students use a pH paper to test the acidi-

ty of the worm bin once a week. Does thepH change based on the foods that areadded? Have the students keep a record ofthe foods that are added and the pH andchart a graph showing the correlation. If thesoil is too acidic, the worms may try to leavethe bin. Try adding a little lime.

3. Give students gloves to gently examine thecritters inside the bin once a week. You mightalso examine a sample of the soil under amicroscope (at the beginning of composting,

bacteria are present that help break downthe food; later larger organisms such as sow-bugs and round worms play a larger role.)Obtain an identification guide to inverte-brates and insects and see how many youcan identify. Have students draw the differentkinds of critters and discuss the differences ineach (number of legs, body parts, function).



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Date Day Weight Type Amount Buried Notesof food of food of water in site #added added added

Vermicomposting Data Sheet

Date bin was set up:___________________________________________________________

Number of worms (or pounds of worms) added to bin: ____________________________

Number of people contributing food scraps on a regular basis: ____________________

On the back of this paper, draw the worm bin,

including its dimensions, and assign plots to cer-tain sections so you can track decomposition offood placed in each numbered area.

Harvest date: _____________________________

Total days:________________________________

Total weight of food buried: _________________

Weight of uneaten food left over:_____________

Average weight buried per day:

Name:

Example:

(If you run out of spaces, get an extra copy of this sheet from your teacher.)

epa composting unit

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