Purpose

The purpose of my experiment was to determine which decomposer was the most efficient and produced the best quality compost when using yard wastes. There were four variables that I added to my experiment; nematodes, red worms, a commercial composting agent and a control group. After adding these decomposers to a mixture of leaves, grass, and twigs, I wanted to know the efficiency level of each group on decomposing the simulated compost pile.

By completing this project, I could provide a way for the citizens of Washington to have a natural and easy way of disposing their yard wastes. The first day I started thinking about my experiment and what I wanted to do, I thought I would do a continuation of my previous years project. I was originally going to test a red worms capability of decomposing different combinations of compost waste such as grass, tomatoes, lettuce and hay. This would have been my project if it had not been for some research that I had done. I had found that by changing the variable to the actual decomposer instead of it being an additive, it would benefit my community more. Doing this made me have more confidence in my experiment, making it more enjoyable do complete.

The fact that people are looking for a fast and easy way to decompose their yard wastes, intrigued me. I thought about the situation and realized that knowing what decomposes the quickest will benefit many gardeners and citizens of the community who just wish to rid of their yard wastes without polluting the earth. My thought process after this realization helped lead me to my current science project idea.
 
 

Hypothesis

My hypothesis was that the red worms would be the most effective decomposers. I believed that they would produce the best quality of compost and in the least amount of time.

This hypothesis was based on research done in previous years. Many web sites and books suggest red worms as a number one decomposer. Knowledge from previous years also helped form this hypothesis.
Last year, I created a project that utilized red worms and I discovered that, when given the correct supplements, worms can produce a very rich soil product.
 
 

Experiment Design

The items kept constant in this experiment are as follows:

ALL TEST GROUPS:
* Throughout the experiment, the container size was the same.
* A same amount of leaf-grass mixture added to each container.
* The same amount of water was added to each container during the same time period   once the experiment was underway.
*  Every two days the contents of the containers were turned.
*  The same amount of compost was tested during each test.
*  Each test was done the same way for every soil component.

NEMATODES:
* In all nematode test groups, the nematodes were from the same culture.
* Similar numbers of nematodes were used for each petri dish.
* The agar used for nematode growth in each petri dish was from the same bottle.
* The E. coli used for nematode growth was from the same vile.
*  When adding the E. coli, the same amount was placed into each petri dish.

WORMS
* The red worms were all brought from the same garden and were chosen randomly.
* A same exact number of worms were placed in each container.
* The worms all had bedding in their containers.

AMMONIUM SULFATE
* The same amount of ammonium sulfate was used for the individual containers.
* The ammonium sulfate used was taken out of the same package.

MANIPULATED AND RESPONDING VARIABLES
The manipulated variable for this experiment was the added decomposers. These were the nematodes, worms, and the ammonium sulfate.

The responding variables for this experiment were the temperature at which the composting took place, and the agents that were used to measure the nutrient levels of the compost. These agents were pH, potash, nitrogen, and phosphorus.

To measure the responding variables, I used thermometers for temperature testing. I used a pH kit to measure the pH level, a nitrogen kit for the nitrogen level, a potash kit to measure the amount of potash in the compost, and a phosphorous kit to measure the phosphorous.
 Materials
 
 

Materials

Quantity      Item Description
20               three gallon containers
60               liters leaf-grass clippings
1                 squirt bottle
125             ml nematode growth agar
5 ml            Escherichia coli K-12 strand nutrient broth
1                culture Caenorhabditis elegans N2
5 9             cm diameter petri dishes
1                 sterilized box knife
1                 Thermolyne hot plate
125             red worms
750 ml        damp shredded newspaper
20               metal backed thermometers
250 ml        Whitney Farms Sphagnum Peat Moss
9.07 kg.      Perfection brand ammonium sulfate
1                 200 ml Beaker
1                 large garden rake
10               liter  plastic pitcher
250             ml Starbucks coffee grounds
1                 Hold All Moisture, Light and pH meter
1                 volumetric pipette
20               plastic 100 ml cups
1                 glass dropper
1                 glass stirring rod
1                 Rapitest soil testing kit with Nitrogen, Phosphorus, pH and Potash tests.
 
 

Procedures

Safety Procedures for the Following Experiment:

1. Conduct all experimentation in a work area isolated from the public.
2. Wear a lab apron, goggles and plastic gloves at all times when handling the material.
3. Wash hands after coming in contact with the material very thoroughly.
4. Sterilize work area and materials after completion, with a bleach solution.
5. When the project is completed, sterilize all material in an autoclave.

PART A
Preparation

1. Poke 40 holes in each plastic three-gallon container, 20 on the sides and 20 on the bottom. This is for drainage of the excess liquids.
2. Label the containers:  n1 w1 c1 s1
        n2 w2 c2 s2
        n3 w3 c3 s3
        n4 w4 c4 s4
        n5 w5 c5 s5
n = nematodes, w = red worms, c = control, s= ammonium sulfate

3. Arrange the containers so all of the labels are visible or so that you know where each test group begins and ends.
4. In an open cemented area, mix a garbage bag of leaves with a garbage bag of grass trimmings. Mix with a large rake and add water if necessary so the mixture feels like a wrung out sponge.
5. Place 3 liters of damp leaf/grass clipping mixture in each of the containers.
******
Before you continue with procedures 6 and 7, go to part B, C, D or E, depending on which container is being filling at this point.

6. Add 200 ml of water to each of the containers for moisture.
7. Using a folded black plastic bag cut sections that fit into the containers. Do this for each container.

******
Go back to Part B, C, D, or E, to finish that section

8. Check the containers to make sure everything is going properly and stir them. Do this every Monday, Wednesday, and Friday.
9. Every Wednesday add 200 ml of water to each container.
10. Let the compost decompose for twelve days then test everything and record the data. After this first testing, wait three weeks and three days until the last test is completed.
 
 

PART B
Safety Procedures when handling the Bacteria

1. Use only the k12 strain of E. coli.
2. Wash hands before and after handling the E. coli and composting material.
3. Wear safety goggles and lab coat at all times.
4. Wear gloves (latex or plastic) when handling the bacteria if a cut or rash is present.
5. Dave McMillen, my designated supervisor, will supervise the project and he will be present when any handling of the potential pathogens is done.
6. After the experiment is completed, my designated supervisor will sterilize all the bacteria in an autoclave.
7. Clean up work area with a bleach solution.
 

PART C
Adding the C. elegans

1. Melt the hardened growth agar using the hotplate.
2. Once the agar is liquefied, fill up the five petri dishes 2/3 full.
3. Let the agar harden overnight into a gel-type form.
4. After the agar has set for a day, use the pipette to suck out .9 ml of E. coli and spread it evenly over the agar. Do this for each petri dish.
5. Cut the petri dish with the nematodes into fifths and place 1/5 into each agar filled petri dish.
6. Close the petri dishes and let them sit in an isolated spot for three days.
7. When the experiment is ready to begin evenly spread the C. elegans around containers n1 to n5. Use one culture for each container.
8. Return to part A and continue with procedures 6 through 8.

PART D
Adding the red worms

1. Mix 50 ml peat moss and 150 ml damp newspaper in containers w1 through w5. Make sure the mixture is damp like a wrung out sponge so that the worms cannot harm themselves.
2. Gently place 25 worms in each container carefully spreading them out evenly over the area.
3. Sprinkle 50 ml of coffee grounds over the mixture so the worms can have something to grip on to when eating.
4. Follow the Part A, procedures 6 through 8.

PART E
Adding the ammonium sulfate

1. Open the bag of ammonium sulfate.
2. Using the 200-ml beaker, add 200 ml to each container.
3. Mix the compost and sulfate thoroughly.

PART F
Testing the nutrient levels of the compost

P.H. level

1. Push the switch to the pH position.
2. Insert the probe deeply into the soil.
3. Read what the meter points to and record as data.
4. Clean the probe with a wet washcloth.
5. Repeat testing until each container has been tested.

Nitrogen levels

1. Fill a clean 30 ml beaker with 2 ml compost and 10 parts water.
2. Thoroughly stir the solution in the beaker for one minute at the least.
3. Let the solution stand until everything settles. This could take 5 minutes to 24 hours.
4. Using the nitrogen color comparator, remove the cap.
5. Using a dropper, fill the test chamber to the marked line with solution from the beaker. Be sure to transfer liquid only.
6. Remove a capsule from the bag and open it.
7. Pour the powder into the test chamber.
8. Fit the cap back on the comparator and shake vigorously.
9. Allow the color to develop in the test chamber by letting it sit for 10 minutes.
10.  Compare the color of the chamber to the reference sheet on the comparator. Determine the level of nitrogen and record the data.
11. Rinse the chamber and repeat until all tests are completed.

Potash

1. Fill a clean 30 ml beaker with 2 ml compost and 10 parts water.
2. Thoroughly stir the solution in the beaker for one minute at the least.
3. Let the solution stand until everything settles. This could take 5 minutes to 24 hours.
4. Using the potash color comparator, remove the cap.
5. Using a dropper, fill the test chamber to the marked line with solution from the beaker. Be sure to transfer liquid only.
6. Remove a capsule from the bag and open it.
7. Pour the powder into the test chamber.
8. Fit the cap back on the comparator and shake vigorously.
9. Allow the color to develop in the test chamber by letting it sit for 10 minutes.
10. Compare the color of the chamber to the reference sheet on the comparator. Determine the level of potash and record the data.
11. Rinse out the chamber and repeat until all tests are complete.

Phosphorus

1. Fill a clean 30 ml beaker with 2 ml compost and 10 parts water.
2. Thoroughly stir the solution in the beaker for one minute at the least.
3. Let the solution stand until everything settles. This could take 5 minutes to 24 hours.
4. Using the phosphorus color comparator, remove the cap.
5. Using a dropper, fill the test chamber to the marked line with solution from the beaker. Be sure to transfer liquid only.
6. Remove a capsule from the bag and open it.
7. Pour the powder into the test chamber.
8. Fit the cap back on the comparator and shake vigorously.
9. Allow the color to develop in the test chamber by letting it sit for 10 minutes.
10. Compare the color of the chamber to the reference sheet on the comparator.
11. Determine the level of phosphorous and record the data.
11. Rinse the chamber and repeat until all tests are complete.
 
 

Research Report

This report will cover composting, soil nutrients and composting stimulants. Under composting, how and what to compost is included as well as what to add to the compost. The soil nutrients are mainly the ones that are being tested in this experiment along with some other nutrients that the soil needs. The composting stimulants include nematodes, ammonium sulfate, and worms.

GENERAL FACTS ABOUT WORMS

Some insects, such as caterpillars and larvae, are mistakenly called worms. To make sure that your creature is a worm, check to see if it has legs. All worms have no legs, everything else, such as caterpillars and centipedes, do. Worms have no backbone and are therefore classified as an invertebrate. They are also cold blooded, meaning they create their body warmth from their surrounding atmosphere.

Worms live in a variety of places. Some live in the ocean and some live in the soil, some species of worms even live inside humans or animals. Worms also come in various sizes. The roundworm can be microscopic while the giant Australian earthworm can grow to be 12 feet long.

If you turn a worm over it will right itself immediately. This is because a worm has a top-side and a bottom-side. Worms also have a front end and a back end, called the anterior and the posterior.

Worms are sensitive to the touch. If touched, the worm will wriggle or move slightly away from the area in which it was touched. Worms do not have vocal cords, but they have five hearts, a small brain and a well-developed nervous system. Although worms can not be called smart, they can use their brains to learn.

THE LIFECYCLE OF WORMS

The Spring season is the time in which the worm’s reproduction begins; it ends toward the closing of summer. Worms are hermaphrodite, which means that each worm has both male and female reproduction systems, though they need another worm to mate. Worms can be picky in selecting their mate and may travel a considerably large distance to find their mate, while others may choose their neighbor.

Worms mate with their bellies together while facing opposite directions. At this time a tube of mucus forms and holds the worms together. The clitellum discharges a mucus ring, which then slides down the worms reproductive systems and gathers the many sperms and eggs that have been expelled. The eggs are then fertilized inside the mucus ring while the ring is slipping over the worm and off into the soil. As it leaves the worms body, the ends of the ring close off, forming little tiny tips at either end. The ring turns soft and rubbery as well as the color yellow. This tiny capsule can be called a cocoon and may contain 1 to 20 eggs. The cocoon sets in the soil for 14 to 21 days as the baby worms hatch. Baby earthworms are very small, they are thin and are transparently whitish. When the worm is at breeding age, it should be about 90 days old, though the worms keep growing for another four to six months. Although it does not happen very often, earthworms can live up to 12 years. This is as long as the average dog.

HOW WORMS DECOMPOSE ORGANIC WASTE

Worms are nocturnal, so they eat at night. A worms diet consists of organic matter. This includes decaying veggies, fruits, leaves, grass, and dead or decaying insect matter. Before eating they pull the food into their burrows. They then slowly eat it along with some soil. Worms do have taste cells and although they have a mouth, they do not have teeth. Because of this, worms do not chew their food before swallowing. After they do swallow, muscles push the food along the pathway. This is through the esophagus to a sac called the crop. There it is stored for a short time and then passed through the gizzard where it is ground up by the strong muscles found there. The tiny stones that the worm has swallowed throughout its lifetime while eating soil also grind it up. The food then passes through the intestines where different glands discharge juices that help with the digestion. Some of this now digested material is soaked into the blood stream or spread throughout the worm’s body for nutrients. The rest passes out the posterior as waste. These deposits are called castings. This is because wherever they are cast, things begin to grow. Castings make a great fertilizer, which is high in nitrate, phosphate and potash. People have started businesses, which “grow” the worms and then sell their castings.

THE NUTRITION OF WORMS

When they eat, worms show a definite preference for certain foods. By setting out different kinds of food for worms to eat, the worms will have a choice. When given a choice, they will almost always choose carrot tops over anything. Worms also seem to like oatmeal, cornmeal, chick starter food, laying mash, and coffee grounds. They can not eat oily foods or anything poisonous. The basic thing to remember when feeding worms is that they like to eat the "leftovers" from dinner - the healthy leftovers that is.

EARTHWORMS

The best known worm is called the earthworm. The earthworm has many segments and belongs to the group called Annelids meaning “ringed.” These rings help the worm to twist to the front and to the back. The common worm has 120 to 170 segments. Worms have two sets of muscles that they use to move with, no bones. One set connects the segments of the worm to each other.

The worm has four tiny pairs of bristles on each segment of its body. These help the worm to crawl around or to anchor itself in its burrow. Depending on the weather, the earthworm buries itself underground in its burrow or it comes up for some air.

An earthworm needs the dampness in the ground so in the summer heat, it burrows deeper into the ground. To keep its skin from getting dried out, the earthworm has developed a special gland that keeps the skin moist. They breathe through their skin. If the skin is too dry or it is exposed to light for too long, then the worm will die. Worms have no eyes or ears but they can, in a sense, hear and see. The earthworm has light sensitive cells, which help them see. They are also extremely sensitive to vibrations.

ROUNDWORMS

Roundworms are also called nematodes. There are more than 10,000 species of nematodes, making them the most broad and plentiful groups of animals. One acre of rich farmland can contain several hundred billion nematodes, as can decomposing plants or animal bodies.

A nematode is a slender worm, that when observed from the side angle or cut crosswise is round, thus the name roundworms. The nematode has no segments, the body of the nematode is normally pointed at each end. Some nematodes are microscopic while others can grow up to three feet long. The males are smaller than the females. Nematodes live in soil and in water. They can be parasites in plants and animals and cause disease in humans, plants and domestic animals. Their life span is a average of two weeks.

There are two types of nematodes, the beneficial (which will be called beneficials) and the root feeding. The beneficial nematodes will be killed by the heat of thermal compost, as will all of the root-feeding ones. The nematodes can “sleep” during the heating process and wake up when the temperature drops down below 135 F. The beneficials then begin to multiply and populate the area quickly. Although if the temperature drops quickly, the majority of the beneficials will not survive and less nematodes will live than was expected.

Good compost will contain 30 to 100 beneficial nematodes per gram. Several hundred nematodes per teaspoon of compost would be most desirable. There should be no root-feeding nematodes, if there are than the compost is not desirable quite yet.

CAENORHABDITIS ELEGANS

Caenorhabditis elegans, also known as C. elegans, are a member of the phylum Nematoda. They are a free-living nematode.

C. elegans are small, about 1mm in length, and live in the soil. This is especially true for rotting vegetation, probably because there are so many living organisms to feast on there. C. elegans eat the microbes living in the vegetation or soil.  Because it is only 1 mm long, C. elegans are to be handled as microorganisms and are grown on petri dishes. The body contains 959 cells and 81 muscle cells. It is transparent and when viewed with a microscope, the interior of the nematode can be seen. The C. elegan moves the same way as a worm, flexing and relaxing its muscles to propel itself along. The adult body is basically a tube, which holds two smaller tubes, the pharynx, gut and the reproductive system. The majority of the nematode’s body is the reproductive system.

The C. elegan has two sexes. There is a self-fertilizing hermaphrodite and a male. They mate and reproduce with sperm and egg. They are born as a single cell organism, which then goes through a complex cycle of development to become an adult. After reproduction the nematode slowly ages over an average of two to three weeks. After this, it dies.

The C. elegan has a nervous system as well as a brain and exhibits behavior and can be capable of rudimentary learning. It is assumed that C. elegans do not have consciousness but that has yet to be proven. The C. elegan has sense organ in its head, which sends acknowledgements to taste, smell, temperature and touch. A worm, the C. elegan has no eyes but responds slightly to light.
 
 

AMMONIUM SULFATE

Ammonium sulfate is a chemical compound - (NH4 )2 SO4.  It is a colorless or gray colored substance that is natural in the form of mascagnite. Ammonium sulfate is soluble in water but insoluble in alcohol or liquid ammonia.  When made by humans, ammonia is obtained from the distillation of coal then is added to sulfuric acid. It is then used as a fertilizer in other ammonium compounds and for fireproofing.
 
 

WHAT IS COMPOST

Compost is partially decomposed organic material that is used to improve the condition of the soil in gardens. Compost enhances the movement of water, dissolved nutrients, and oxygen through the soil, thus giving plant roots an easier way to reach the vital nutrients for growth and survival. Compost can improve the condition of many types of soil. When added to clay soil, compost breaks up the small particles and enables more room for roots to access water and nutrients, while when added to sandy soil, the compost closes up the large air holes and helps the water and nutrients from draining too quickly. Compost is added to soil and the roots of plants are able to creep deeper into the soil and access more nutrients. Compost adds small amounts of zinc, boron, copper, and some other essential nutrients to the soils.

COMPOSTING

The process in which organic waste is combined in a bin creating good food for bacteria, worms and other organisms, is called composting. As soon as the organisms began to eat this material, it slowly decomposes and over time becomes a rich soil product used to fertilize gardens and yards. For a simple gardener, composting is just a matter of adding the correct materials in a bin with drainage and breathing room, then letting the bacteria and fungi start eating.

WHAT TO ADD AND WHAT NOT TO ADD TO A COMPOST PILE

Although it is not recommended, compost can be made purely of table scraps. But when adding table scraps to a compost pile, only use vegetables and non-citrus fruits. Meat and oily foods are not good for compost along with dairy products and citrus fruits. If these are added, then the compost pile will prove to be an unhealthy additive to the soil. If the pile is in need of nitrogen, add manure (from plant eating animals only), meal, or greenery to generate heat.

HOW TO ASSEMBLE A COMPOST PILE

 Compost piles can be built by layering different kinds of organic waste in a tub or an open space. If in a tub, leave space between the layers for air to circulate and make sure that there is a type of drainage system. Any type of tub will qualify for the job although there are certain types of tubs made specially for composting. Layering the organic waste is not always necessary as a regular turning of the contents is required for quicker completion of decomposition. Another way to speed up the decomposition process is to cut the pieces of added material into small sizes. This will enable the bacteria and fungi to eat the individual pieces faster.

HOW COMPOSTING WORKS

Heat makes possible the rotting of the contents and kills all unwanted organisms. Dampen the pile and cover it with a lid for the tub or a simple plastic bag. As heat and steam build up, the waste decomposes over time into a nutrient-rich substance called compost. The compost is then applied to plants as a fertilizer.

THE TEMPERATURE OF A COMPOST PILE

When composting, it is critical to have heat. It is so necessary because the heat is what kills all of the potential pathogens, root-feeding animals, and weed seeds. The temperature should not go so high that the beneficials are killed. When starting a compost pile, the heat should get to 135 F in 24 to 48 hours. The pile should be turned to cool it if it gets too hot.
 

NUTRIENT NEEDS OF PLANTS

Each plant has its own tolerance level of what nutrients, heat, cold, and moisture it can hold and what it needs. Plants use nutrients to build new tissues and cells, furthering their growth. The main nutrients plants need, in the largest amounts are oxygen, hydrogen, carbon along with other minerals but in smaller amounts. The other minerals are cobalt, chlorine, boron, iron, zinc, molybdenum, nickel, manganese, and copper. In this experiment not all of the above nutrients were tested. The nutrients that were tested are nitrogen, phosphorus, potash, and the pH.

NITROGEN

Nitrogen is very important in plant growth. The nitrogen in the soil is what makes the plants leaves turn green and grow. If there is a nitrogen deficiency, the plant will turn yellow and will not grow to its full potential.  If too much nitrogen is present, there will be too much foliage and the blooming will be delayed.

PHOSPHORUS

Phosphorus helps the plant with genetics and seed development. It also helps with plant maturity, the seeds yield, fruit development, vitamin content, and plant resistance to disease and being killed in the winter. If there is a lack of phosphorus, the plant will be stunted and there will be a case of seed sterility.

POTASH

Potash is in a sense, the food for the plants. Without potash, the plant would be stunted, have a poor root system, and would have yellow, spotted, curled leaves. Potash helps the plant with the fruits flavor and color. It also helps with the formation of carbohydrates and protein.

PH

The pH level of the soil helps the plant grow. It determines how well the plant can acess the nutrients in the soil. Each plant has its own pH level that it can perform its best in. By testing the soil, it can be determined which plants will grow to their fullest potential.

SOIL TYPES

There are three soil types; sand, clay and silt. Sandy soil contains large particles, allowing for good drainage but is not good at retaining water nutrients and minerals needed for plant growth. Clay soil is made of small particles, which are good at retaining water and its nutrients, but not good at draining the excess materials. This can lead to oxygen starvation for the plant, which happens when water is taking up the plants normal air space. The third type of soil is called silt. The silt particles are smaller than sand but larger than clay, making an ideal soil perfect for drainage and keeping in the needed nutrients. The most common type of soil is loam. Loam is made of 50% sand, 25% clay and 25% silt. This combination is the preferred soil combination if silt is not obtainable.
 

SUMMARY

Composting is a very good way to recycle the organic matter that is no longer needed by people. Compost is helpful to the environment, people and to the plants and soil. Everyone who is concerned with the environment should find some way to compost be it decomposed by worms, nematodes, ammonium sulfate, or just a natural decomposition cycle.
 
 

Results

The original purpose of this experiment was to determine which decomposer was the most efficient and produced the best quality compost. I used a simulated compost pile and then tested those “piles” for the nutrients; nitrogen, potash, phosphorus, and pH.

According to the results, the redworms had the most consistent pH level throughout the experiment. The only changes were from a 7 to a 7.5 and from a 7.5 to a 7 (refer to graph). The average of test one compared to the average of test two showed that the averages stayed the same, at 7.1. Almost all of the phosphorus tests decreased during the second trial by at least one number, although redworm 3 stayed the same. When the averages were compared, the phosphorus level decreased from 3.8 to 2.2. Nitrogen levels were decreased and raised by the second test. Redworm 1 decreased by two, redworm 2 decreased by one and redworm 3 stayed the same. The tests that did go up were redworm 4, which increased by one and redworm 5, which increased by three. The test one and two average showed an increase from .8 to 1. Redworm potash test results were all different except redworm 1 and 5, which stayed the same throughout both tests. Redworm 2 increased by one while redworm 4 increased by two. Redworm 3 was the only test that decreased for the potash, doing so by two. Looking at the graphs that show the averages of test one and two compared shows that redworms increased the potash result from 3.2 to 3.4. Comparing the overall averages, redworms placed highest with potash and phosphorus, second with nitrogen and third with pH.

Although the first nematode pH test showed a difference of levels, from seven to eight, the graph shows that the pH levels all came to 7.5 by the second test. The average graphs show a decrease from 7.6 to 7.5. Six out of the ten phosphorus tests stayed the same. The changing tests, nematode 3 and 5 both decreased 3 by two and 5 by one. The average shows a decrease from 3.2 to 2.6. The nitrogen tests for nematodes are very diverse. Two tests stayed the same, nematode 3 and nematode 5, while nematode 1 increased by one. Nematode 2 and 4 both lowered from one to two. These averages show a decrease from .6 to .4. Test results for potash all show an increase except for nematode 3, which stayed the same. Nematode 5 increased the most from 1 to 4. The average of test one and test two show an increase from 3.2 to 3.4.  Overall, nematodes were the highest in pH, second in phosphorus and potash, and third in nitrogen.

Like the nematodes, control has a varied first pH test, which then levels out to 7.5 by the second test. Test one and two averages for pH shows an increase from 7.2 to 7.5. Phosphorus control tests all show a drop by the second testing, control 1, 2, 3 and 4 dropping by three and control 5 dropping by one. The average graphs show a decrease from 3.8 to 1.2. Nitrogen control tests show no real pattern. Control 1 increased by one while control 2 decreased by two. Control 3 increased by two, control 4 stayed at two for both tests, and control 5 decreased from two to one. The graph comparing test one and test two’s average shows an increase from .8 to 1.2. The potash test results also show no real pattern, it is varied. Control 1, 2, and 5 decreased while control 3 stayed the same and control 4 increased. The average graphs indicate a drop from 3 to 2.8. The overall results for control was that it was the highest for nitrogen, second highest for pH and third for phosphorus and potash.

The ammonium sulfate pH test shows an increase by the second test for every container. They all increased by at least one and by four at the most. The graphs that show the average of test one compared to test two shows that the pH level increased from 4.4 to 6.7 by the second test. Almost all the phosphorus levels decreased for the ammonium sulfate tests. Ammonium sulfate 1, 3, 4, and 5 decreased while ammonium sulfate 2 increased. The average graphs show that there was a decrease from 2.2 to .8. The nitrogen results indicate that ammonium sulfate 1, 4, and 5 stayed the same and ammonium sulfate 2 and 3 increased. The nitrogen averages for the tests show that there was an increase from .8 to 1.2. The potash tests for ammonium sulfate indicate that by the second test, the amount of potash in the simulated compost increased considerably.  The average graph also shows a large increase from .8 to 3.2. Overall, the ammonium sulfate had the lowest amounts of nutrients out of all four possible tests.

Data

Nitrogen Test for Redworms
             redworm 1     redworm 2    redworm 3     redworm 4             redworm 5
Test 1     2                 1                   0                     0                         1
Test 2     0                 0                   0                     1                         4

Nitrogen Test for Nematodes
             Nematode 1      Nematode 2      Nematode 3      Nematode 4      Nematode 5
Test 1     0                     1                         1                     1                         0
Test 2     1                     0                         1                     0                         0

Nitrogen Test for Control
             Control 1     Control 2     Control 3     Control 4     Control 5
Test 1         1             1                 0                     2             1
Test 2         2             0                 2                     2             0

Nitrogen Test for Ammonium Sulfate
             Ammonium         Ammonium        Ammonium            Ammonium        Ammonium
              Sulfate 1              Sulfate 2             Sulfate 3                 Sulfate 4           Sulfate 5
Test 1         0                         0                         0                             0                      0
Test 2         0                         2                         1                             0                      0
 
 

Conclusion

According to my results, it is shown that ammonium sulfate is the least desirable decomposer. The rest vary depending on the nutrients that your soil needs. If your soil is in need of nitrogen, add compost that has all natural decomposers, such as yard waste and organic matter, in it. Do not add any extra decomposers to the compost. If, to obtain a loam soil, you need phosphorus then add redworms. Last, if the nutrient that is most needed in your soil is pH, add nematodes.

The results of my experiment somewhat coincide with my hypothesis. I had inferred that redworms would be the most efficient and effective decomposers. The redworms are in fact the decomposer to be used to reach a higher phosphorus level, although they are not the best overall. Because I predicted that redworms would be the number one choice, I reject my hypothesis. If redworms had produced the most nutrients then my hypothesis would be accepted.

After viewing the results of my experiment, I wonder if this project was extend for one year, would the results change. Maybe the ammonium sulfate works better over a longer period of time rather than a short period. There was an increase in all of the nutrient levels for ammonium sulfate, so if it is allowed to compost longer, perhaps it will come up to the perfect levels of nutrients later on in the experiment. I also wonder if the nutrient levels that went lowered for all of the decomposers would keep going down or if they would come back up. If the phosphorus levels of the control group came back up, that would change the results of this experiment. This experiment might end up with very different results if the time period was extended.

Some sources of scientific error could have occurred during the testing. After all the testing was complete, I still had three phosphorus pills that were supposed to be used and I don’t know where I made the mistake. That could have changed the outcome of my experiment. Another source of possible scientific error was when I wrote down results after testing, I was always rushed. This could have caused a mix-up with some numbers and that could have altered the results. During the experiment I noticed that the back row and the top row of containers were much dryer than the front row even though I watered them evenly. This could be because the circulation in the room was not equal and it could have affected the experiment. If I were to do this project again, I would try to position the containers so they all received the same amount of circulation and none of them dried out any quicker than the others. I would also conduct my experiment for six months to a year to determine if long composting periods affect the nutrient level of the compost.
 
 

Bibliography

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"Why Test your Soil?." Woodstock, IL: Luster Leaf Products, Inc., n.d.

Ammonium Sulfate. Columbia Electronic Encyclopedia. 2 Feb. 02 <http://infoplease.com>.

C. elegans. 20 Dec. 01 <http://elegans.swmed.edu/>.

Edgley, Mark. Introduction to Caenorhabditis elegans. 8 Jan. 02 <http://www.biotech.missouri.edu>.

Freudenrich, Craig C. How Composting Works. How Stuff Works Inc. 7 Nov. 01 <http://www.howstuffworks.com>.

Oetinger, David F. "Nematode." World Book Encyclopedia. N.p.: n.p., 1999. N. pag.

Soil Food Web. 2 Feb. 02 <http://www.soilfoodweb.com>.