This week with Park & City composting students learned how to measure various parameters of the compost pile (weight, porosity, bulk density, temperature and more!). Students also observed/recorded any changes that may have occurred in the compost pile since the last visit. Some discoveries included, mycelial activity (mushroom “roots”) as well as fully fruited mushrooms which is a fairly good indicator of microbial activity and that the breakdown process is in the works. The class also noticed that some of the seeds and bulb plants (such as onions) have sprouted roots and new shoots (the seedlings were referred to as, “volunteers”)! These “volunteers” were removed from the compost pile and transplanted into some of the raised beds in the hopes they will root successfully. Now we are getting down and dirty! The scholars were reminded how big our compost pile is in cubic meters and gallons (1 cubic meter or 200 gallons). Temperature was the only parameter where we could use the main pile directly to get our information, we simply stuck in a thermometer. All other parameters required us to use a 5-gallon bucket to acquire the data. The 5-gallon bucket was filled with compost material from our pile. As the bucket was filled, the material was packed by dropping the bucket on the cement to ensure any empty air pockets were filled with compost material. After the bucket was filled and packed to the brim, students weighed the 5-gallon bucket to record the weight of the material (we were sure to subtract the weight of the bucket). This weight was then multiplied by 40 (40 5-gallon buckets make up the 200-gallons of the compost pile) which gives us the bulk density of the compost pile. If the number is between 800 and 1200, we know that the compost pile has enough material to withstand the yearly maintenance process (we got 940)! The next step was to identify the porosity of the compost pile. Students figured out the porosity of the compost pile by using that same 5-gallon bucket filled with the compost material from the previous step. We also had a couple gallon jugs of water, each gallon of water would represent 20% of porosity (if a whole gallon is used, 20% of open space is taken up by water). Students simply added gallons of water to the 5-gallon bucket until the water was just visible at the surface of the compost material. Again, for every gallon of water added, we knew 20% of space was taken; in the end we ended up pouring just about 3 gallons of water into the 5-gallon bucket. This means that our porosity of the compost pile is roughly 58%. This is important information so we know how much airflow there is in the compost pile which will aid in the breakdown process. Lastly, students added about 80 pounds of new compostable material to the compost pile which was mixed thoroughly and will begin to breakdown and add more nutrients to the pile. All of the participants are eager to return in the coming weeks to see what new surprises await in the compost pile!!