8+Science+4+Annie's+MSW+Project

Cost Benefit Analysis of Composting as Compared to Fertilizer Annie Whitney March 4, 2010

[|Click here for our VoiceThread]  I) Intro In order to produce less municipal solid waste, a challenge was given: find a way to produce less municipal solid waste, and implement it project form. This project's goal is to do a cost benefit analysis of switching to on campus composting instead of fertilizer. The hope is that compost will be both more effective and cheaper, and that it will produce less waste because the leftover food will be reused and turned into compost, instead of waste, and because plastic bags used for fertilizer will no longer be needed. The hypothesis is that if the school switches to compost, then the grass will grow faster, less waste will be produced, and money will be saved.

II) Materials

-10.6 grams of grass seed -1 large Tupperware -2 pieces of cardboard -Saran wrap -10 grams of compost -10 grams of fertilizer -1500 milliliters of soil -Scissors -Permanent marker -Ruler -Camera -Water

Safety- When using scissors or a knife to cut cardboard, please follow #20 in the safety guidelines list, which says the following: When using knifes or other sharp instruments, always carry with tips and points pointing down and away. Always cut away from your body. Never try to catch sharp falling instruments. Grab sharp instruments only by the handles.

III) Procedure

1) Find out how much the school spends on fertilizer in one year. 2) Calculate savings if the school switches to compost. 3) Fill a Tupperware with 1500mL of soil. 4) Spread 10.6g of grass seed. 5) Start growing the grass and water as needed. 6) After the grass has started to grow, create two partitions out of cardboard cut to fit the Tupperware, and wrap in Saran wrap. 7) Place the partitions so that there are three equal sections. 8) Leave one partition with no growth additives, one with 10g compost, and one with 10g fertilizer. 9) Continue to water each section equally. 10) Measure grass growth with a ruler and take pictures. 11) Continue gathering data for twelve days. 12) Compare growth rates. 13) Weigh the benefits, both cost and growth rates, of compost to fertilizer.

IV: Presence of compost or fertilizer DV: Rate of growth EG: Compost section and fertilizer section CG: Section with neither

IV) Data

Daily pictures of grass:

Wednesday, February 17, 2010 Thursday, February 18, 2010 Friday, February 18, 2010 Monday, February 22, 2010 Tuesday, February 23, 2010 Wednesday, February 24, 2010

Friday, February 26, 2010

Monday, March 1, 2010 Data of day to day growth:

All measurements are in centimeters.
 * Control ||  ||   ||   |||||||| Compost ||   ||   |||||| Fertilizer ||   ||   ||
 * || 1 || 2 || 3 || General |||| Average || 1 || 2 || 3 || General |||| Average || 1 || 2 || 3 || General || Average ||
 * 17-Feb || 6 || 8 || 7 || 7 || 7 ||  || 7 || 6 || 9 || 7 || 7.3 ||   || 9 || 6 || 6 || 7 || 7 ||
 * 18-Feb || 10 || 9 || 7 || 10 || 8.7 ||  || 7 || 10 || 9 || 10 || 9.3 ||   || 8 || 6 || 6 || 7 || 6.7 ||
 * 19-Feb || 12 || 10 || 11 || 11 || 11 ||  || 13 || 12 || 7 || 11 || 10.7 ||   || 8 || 9 || 7 || 7 || 8 ||
 * 22-Feb || 18 || 14 || 15 || 13 || 15.7 ||  || 18 || 16 || 14 || 17 || 16 ||   || 12 || 11 || 7 || 8 || 10 ||
 * 23-Feb || 17 || 18 || 12 || 15 || 15.7 ||  || 15 || 15 || 14 || 14 || 14.7 ||   || 10 || 9 || 10 || 8 || 9.7 ||
 * 24-Feb || 15 || 14 || 18 || 14 || 15.7 ||  || 20 || 13 || 16 || 14 || 16.3 ||   || 10 || 12 || 12 || 8 || 11.3 ||
 * 26-Feb || 16 || 15 || 11 || 15 || 10.7 ||  || 17 || 11 || 16 || 16 || 11.3 ||   || 14 || 7 || 7 || 8 || 9.3 ||
 * 1-March || 11 || 12 || 7 || 11 || 10 ||  || 22 || 20 || 15 || 14 || 17 ||   || 13 || 7 || 3 || 7 || 7.7 ||

Data of cost benefits:


 * || Compost Pile || Estimated Yearly Cost of Fertilizer at MS ||
 * Cost || $0 || $1129.43 ||

V) Analysis Line graph of daily growth of grass and slope of growth rate:



Bar graph of overall growth of grass:

The first two graphs showing growth data show that compost grew both the most and the fastest, the control group grew some, but not as much as the compost group, and the fertilizer group grew, but then died before the final data collection day. The control group did grow, and for a while it grew very quickly. However, it did not last as long as the compost group did. The final graph shows the cost benifits; a compost pile has no cost for materials, but fertilizer is over $1000 yearly. Obviously, the fertilizer is the much more expensive option.

VI) Conclusion The hypothesis was supported because compost is not only better for growing better plants quicklier, but also because the savings yearly switching to all compost instead of fertilizer is about $1130 each year. Some problems with the experiment, however, could've been with watering. It seems as if the grass could've watered more, and that can be seen in the graph, on days when the grass wasn't water all three groups have a dip in growth. That would be an experimental error, because the procedure did not say to water daily. Some challenges with the experiment was how to measure the grass, because it grows irregularly. Because of this, it was measured in each by randomly selecting three pieces and averaging them, along with taking the general, eye level height of each section. Also, a photo was taken each day. From the data, it can be concluded that switching to a compost pile that is used in place of fertilizer will not only reduce the middle school's solid waste, but it will also save money and be a better growth booster for grass.