Science Fair Project “Best Compost Fertilizer for Growing Marigolds”

1. Science Fair Project“Best Compost Fertilizer for Growing Marigolds” Luke McClurg 9th Grade Biology

2. Explore My Project! • Standards • Problem and Hypothesis • Procedures • Supplemental Research & Procedures • Data Sheets • Conclusion • Picture Tour • Resources & Links

3. Academic & Technology Standards • California Content Standards for Science: Ecology – 6d, 6e, 6f Cell Biology - 1, 1f • Technology Standards (NETS): Productivity Tools – 3a,3b Communication Tools – 4b Research Tools – 5a, 5b, 5c Problem-Solving & Decision-Making Tools – 6a, 6b, 6c

4. Problem and Hypothesis • Problem: Which composted materials will produce the healthiest plants when growing marigolds? • Every year my mom grows marigolds throughout our backyard and especially around our vegetable garden to repel insects. My father has several different types of compost piles in our yard. He uses a compost bin for kitchen waste and an open pile for garden clippings. I thought it would be interesting to figure out which type of compost my mom should use as fertilizer for her marigolds. • Hypothesis: Marigolds will grow best and produce the most blooms in the soil fertilized with the compost made from a mixture of kitchen waste and garden clippings.

5. Procedure • Time Table • Step 1 • Step 2 • Step 3 • Step 4

6. Time Table • Step 1 (March 1st-April 8th)-Measured and bagged the three variable compost mixtures with fresh ingredients; bagged sample dirt; and recorded observations weekly. • Step 2 (April 1st- April 8th)- Germinated marigold seeds. • Step3 (April 8th- May 19th)- Combined compost mixtures with dirt and filled planting trays: planted seedlings in planting trays; and recorded growth weekly. • Step4 (May 19th)-Analyzed final data results

7. Procedure: Step 1 • First I located an area in my backyard with relatively untreated soil. Two five gallon buckets were filled from the same area. Five liters of dirt were measured and placed into three commercial strength, clear plastic garbage bags. The fourth bag was filled with 15 liters of plain dirt. The backyard dirt was used for an activator for the compost bags using a ratio of 2/6, activator to compost materials. The compost materials were chopped up with a shovel inside a bucket before being measured and added to the bags. • Variable-Bag I- Kitchen waste (15 liters of approximately equal amounts of fruits, vegetables, oatmeal, and coffee grounds) • Variable- Bag II- Garden Clippings (7.5 liters of lawn cuttings and 7.5 liters of brown leaves) • The bags were sealed and thoroughly mixed, then placed inside a large plastic trunk. Inside the trunk, a low voltage heating pad was placed on top of the bags in order to speed the decay process. The trunk was kept in a protected work shed. Weekly checks were made and recorded on the “Weekly Observations of Compost” data work sheet. The compost bags were mixed and rotated, the heating pad was checked, and observations of the smell and visual appearance were made.

8. Procedures: Step 2 • Germination- In order to control the possibility of non-viable seeds being the cause of poor or no growth in the compost mixtures, germination was done in a controlled environment. The best seedlings with the most extensive roots were selected after germination to be planted in the experimental soils. • For details on germination process

9. Procedures: Step 3 • The compost bags were opened and each was mixed separately in a bucket with a ratio of 1/1, dirt to compost. The large pieces of undecomposed material were removed and six planting containers were filled for each of the variable compost mixtures and the dirt group. • The seedlings were planted in the planting packs. The packs were kept out doors in full sunlight up off the ground. They were watered every day and never allowed to completely dry out. On the “Weekly observations of marigolds” data sheet, I recorded the height, number of leaves, and the total blooms on each plant in each group.

10. Procedures: Step 4 • After the final results were recorded, the raw data was averaged for each group and each category. Graphs were made for the final averages on height, leaves, and blooms.

11. Supplemental Research • Nutrients needed for healthy plant growth • Compost Make-up • Soil pH • Germination

12. Nutrients Needed for Healthy Plant Growth • A good compost mixture should be made of certain nutrients. There are three nutrient categories for healthy plant growth: • Primary- nitrogen (N), phosphorus (P), and potassium (K) • Secondary- Calcium (Ca), magnesium (Mg), and sulfur (S) • Micronutrients- Zinc (Zn) and manganese (MN) • Primary nutrients are needed in large quantities and secondary nutrients are needed in lesser quantities. Micronutrients are only needed in very small amounts. Compost is a source for all of these categories. Nitrogen is one of the primary nutrients needed. Plant roots take up nitrogen from the soil in the form of nitrate (NO3-) and ammonium (NH4+). Nitrogen is needed for healthy growth and reproduction. Phosphorous promotes flowering, strong root growth, and the transfer of energy from one point in the plant to another. Potassium is important for regulating the use of proteins and starches that make sturdy plants. Please click to continue.

13. The secondary nutrients are already found in most soil and don’t need to be added with most fertilizers or composts. Calcium helps cell formation, growth , and roots. Magnesium helps form the chlorophyll molecules in the cells of green leaves. Sulfur acts with nitrogen in producing protoplasm for plant cells. The micronutrients (ZN and MN) or trace elements are also needed but in very small quantities. They help plants be able to use the other nutrients that are present and help with chlorophyll formation (Fe) The research shows that compost made from multiple organic substances should hold a higher nutrient content and therefore promote growth and flowering the best. This nutrient theory is what I based my hypothesis on. The compost pile with garden clippings and kitchen waste should provide the soil with the most nutrients.

14. Compost Make-Up • The definition of compost is “partially decomposed organic material used in gardening to improve soil and enhance plant growth”. Many organic substances can be used to create compost, such as kitchen waste, garden clippings and manure. There are three important considerations when attempting to compost. They are pH, nutrient contents, and carbon to nitrogen ratio. • The pH and nutrients are discussed in other sections, here I will report on the C:N. A good compost pile should have a 30:1 ratio of carbon to nitrogen (C:N). You can determine the approximate C:N ratio of your compost by using a formula after looking up the ratio of each of your materials used. The formula is the % of the material used X its C:N + any other materials calculated. • So 50% clippings grass= 20:1 • 50% leaves=40:1 • 50% x 20/1=10 or 10/1 ratio • 50% x 40/1=20 or 20:1 ratio • 10:1 + 20:1= 30:1 C/N ratio • Therefore the C/N ratio of my garden clippings compost was approximately 30:1. The kitchen waste ingredients were harder to find and add up. • In order to fit the time frame of my experiment I used a method of composting described in Let it Rot! by Stu Campbell. He states that composting or decomposing can be done by using a plastic bag. The advantage of this is that it can be a faster process and can be done in a small space or even indoors. A disadvantage is that it is mostly anaerobic (doesn’t use oxygen) and therefore can have a pungent odor and may become slimy. • In my research of compost I found that using an activator speeds up the process of decomposition. The bacterial activator I chose was dirt. A ratio of 2:6, activator to compost was suggested in the research and used in the experiment.

15. Soil testing • Soil pH is a measure of how acid or alkaline your soil is. To find the availability of nutrients in the soil a pH test is done. The nutrients that are available in the soil can’t be used unless the soil is the proper pH for the plant. The pH scale goes from 0-14, 7 being neutral. If a number is less than 7, it indicates acidity. A number higher than 7 indicates an alkaline soil. Different plants need different pH ranges to thrive in. Marigolds thrive best in soil with a pH of 5.5-7.0. • For this experiment I used the Rapitest pH Soil Tester kit to measure the PH of each of the compost mixtures and the soil. The sample had to be crumbled up and free of undecomposed materials. A small sample was placed in the container, the activator tablet was poured on top , then a plastic pipette was used to put the correct amount of distilled water in the container. Next, the contents were shaken then left to settle so that the color of the water could be compared to the pH chart.

16. Germination • Germination is the process in which the dormant embryo or seed of the plant resumes growth. Seed embryos need three specific conditions in order to germinate. The emergence of the embryos root is the first step in germination. As the roots continue to grow, the embryo shoot grows upwards, sprouting into the first two leaves. • Through my research, I discovered that different flowering plant seeds germinate under different conditions. For example, some seeds germinate better in the dark and others do better in the light. • The only research that I could locate on germination outside a soil medium stated that the seed packet would specify any special light conditions needed. The marigold seed packet used did not. One of the gardeners at Luis Nursery in Visalia, California stated that for marigolds, germination would probably be faster if done in indirect sunlight, not in complete darkness. Please click to continue.

17. Another condition for germination is temperature control. A steady temperature is critical during the early stages of germination. Also seeds must be kept constantly moist and in a loose medium. The materials used were a 38 x 25 x 4 cm glass baking dish, paper towels, plastic wrap, and two packets of Ferry Morse Petite Yellow Marigold seeds. The pan was lined with paper towels to provide a loose fiber medium. The seeds were spread out so they weren’t touching. The towels were soaked in water from a spray bottle and the pan was covered with plastic wrap to keep the moisture in. The pan was kept on a kitchen counter with access to indirect sunlight and kept at a constant temperature of between 67- 73 Fahrenheit. Within two days the roots were breaking out of the seed coat and on the third day young shoots had formed in more of the seeds. The seedlings were planted in the compost mixtures on the 8th day after they were approximately 5cm in length from the end of the root to the tips of the leaves.

18. Data Sheets • Explanation • Marigold Height • Marigold Leaves • Marigold Bloom

19. Explanation: Data Sheets/Graphs • On the “weekly observations of compost” data sheet observations were made of each compost mixture. During the observations I noted the smell and the looks of the mixtures without opening the bags. Also noted was a heat check of the heating pad used and a physical rotation of each bag to mix the compost. • Also used was a “weekly observations of Marigolds” data sheet. The first recorded observation took place one week after the germinated seedlings had been transplanted to the different compost mixture plant trays. At this point one plant from each group was removed for being the “outlier” or underdeveloped plant. The height, number of leaves, and number of blooms were recorded. The height was measured from the soil to the top of the tallest leaf as the leaf was held upward. The number of leaves was counted by the leaf stem and even the smallest buds were counted. Under “observations” I also noted things such as moisture retention in the different mixtures and the overall look of the plant. • The final data on the marigold observation sheet at the end of the sixth week was analyzed and graphed. The raw numbers for each plant in a group were averaged so that the group had a mean score for each of the three observation categories.

20. Marigold HeightFrom Seedlings To Six Weeks Of Growth • Average height in cm. is the measurement on the value axis. • The four different compost test mixtures are on the category axis. • Plant I - Kitchen waste compost • Plant II - Garden clippings compost • Plant III - Mix Kitchen / Garden compost • Plant IV- Dirt

21. Marigold LeavesFrom Seedlings To Six Weeks Of Growth • Average number of leaf stems is the measurement on the value axis. • The four different compost test mixtures are on the category axis. • Plant Group I - Kitchen waste compost • Plant Group II - Garden clippings compost • Plant Group III - Mix Kitchen / Garden compost • Plant Group IV - Dirt

22. Marigold BloomsFrom Seedlings To Six Weeks Of Growth • Average number of blooms in measured on the value axis. • The four different compost test mixtures are on the category axis. • Plant Group I - Kitchen waste compost • Plant Group II - Garden clippings compost • Plant Group III - Mix Kitchen / Garden compost • Plant Group IV - Dirt

23. Conclusions • After the raw data was analyzed, it was apparent that test group II, garden clippings, grew the best marigolds. However it should be noted that both test group I and III were only slightly behind test group II. All compost test groups grew better marigolds than the control group of dirt. The garden clippings/ kitchen waste group performed second best. • Some short comings of my experiment were that I didn’t need to put control dirt through the decomposing procedure because a gardener wouldn’t be using cooked dirt to mix with compost or to plant marigolds in. Also a longer term observation of plant growth would have been helpful in seeing if the difference between the test groups would widen or disappear over time. It would help to see if the nutrients in a certain group continue to be released in the decomposing materials. Lastly, a complete laboratory analysis of the different compost mixtures would be interesting to see the final products true content of pH, nutrients, and C/N ratio. • I was hoping to show that by using the plastic bag method of composting, people who live in apartments or homes with little or no backyards can successfully decompose their kitchen waste and use it for fertilizer in pots, planters, or small gardens. Also, if my experiment can inspire people to compost waste, the growing problem of garbage in the U.S. would be slowed. Most importantly, is that my mother won’t have to use my dad’s kitchen compost when planting her marigolds. She prefers using the garden clippings compost and my experiment showed that this alone does as well or better than kitchen compost alone or a combination of the two.

24. Picture Tour Please click here to continue.

25. More Pictures

26. Resources & Links • Books: • 1) Compbell, Stu. Let It Rot!. Story Publishing, 1990. • 2) Johnson George and Raven, Peter. Biology-Principles and Explorations, Holt, Rinehart, and Winston, 2001 • 3) Western Garden Book. Sunset Publishing Corporation, 2001. • On-line Sites: • 1) www.backyardgardener.com • 2) http://www.citygardening.net • 3) http://hgic.clemson.edu/factsheets/HGIC1652.htm • 4) http://www.fantasy-gardening.com • 5) http://www.mastercomposter.com • 6)http://encarta.msn.com/encnet/refpages/SRPage.aspx?search=composting&x=13&y=18