Smashing pumpkins

Richardson Adventure Farm invites visitors to smash pumpkins from a tall tower.

    
     Unlike the Internet, stories printed in a newspaper are finite. You can't fit everything in.
     For instance, my column on pan de muerto in Tuesday's paper, focusing on a Jewish-Mexican bakery called Masa Madre, originally included a three-paragraph digression into the history of Jews in Mexico, which I ended up cutting because the column was just too long. Anyone who read the abbreviated story and thought "Jews in Mexico? Tell me more!" was flat out of luck, and had to dig on their own.

     Or the article Wednesday on page 10, "Pumpkin disposal—a smashing (green) idea to consider," a fun piece by Indira Khera at WBEZ about breaking up pumpkins for compost.

     When simply thrown away, "pumpkins end up in landfills as food waste," she wrote. "Buried under heaps of trash, they rot and release methane — one of the most potent greenhouse gasses."
     But smashing and composting pumpkins "reduces methane creation and transforms the pumpkins into useful, organic nutrients for soil or mulch."

     Which is fine, as far as it went. But the story left me wondering: smashing pumpkins and composting pumpkins reduces methane creation how? Why is it that pumpkins buried under  old diapers and other garbage vent lots of methane, while those diced and mixed with coffee grounds put out less? What physical process is at work? 

     I formed theories — exposure to air, light, certain bacteria — then poked around the Internet looking for confirmation. Finding much about the alternates of making those pumpkins into beer, or drawing off the methane to create energy, but nothing that would explain the differing methane output. Granted, I didn't look very long. 

     Giving up, I queried Khera. What's going on here? Honestly, just asking seemed fraught. We were colleagues, true, now, in theory. But didn't know each other. I wasn't sure she'd even respond, or if she did, she might feel somehow criticized, that I was questioning her article, calling it deficient.  I took the risk, since I was curious, and the Sun-Times and WBEZ are  supposed to be covalently compounded now, our atoms intermingled, bound together by the strong force of media synergy. Seemed worth a try.

     Khera, a recent graduate from the University of Chicago with a degree in biology, welcomed the question  and answered fully:

     "When food waste goes to a landfill, it sits in these giant heaps — there's no oxygen, and the microbes present use anaerobic digestion (digestion done in the absence of oxygen). This process produces something called biogas, which includes quite a bit of methane.

     "In compost (most common type, aerobic compost) — food waste isn't piled. It's mixed together and turned over on a regular basis. The microbes use aerobic processes (digestion in the presence of oxygen), and produce far less methane due to the chemical nature of the process. There is some literature that has found a small amount of methane production at the bottom of compost heaps (naturally, things are a little more piled up and there's less oxygen). But much less than a landfill / driven by the nature of aerobic vs anaerobic processes."

     My hunch about air was right (anaerobic = without oxygen; aerobic = with oxygen). She then shared a number of resources — something from the heretofore unimagined Agency for Toxic Substances & Disease Registry (unimagined by me that is; obviously Khera is clued in) and some general information on composting from the Environmental Protection Agency.
     Funny. I had lunch Wednesday on the balcony of the Cliff Dwellers Club with a well-known business executive who had a hand — actually, a central role — in marrying the paper with the radio station, and she asked me how I thought the union is going.
     I almost replied, "Just great; I contacted a 'BEZ reporter today asking for clarification about her story on rotting pumpkins and she didn't get ruffled or act like I had somehow threw shade on her work, but enthusiastically shared the information I was looking for!"
      But that seemed, oh, small ball compared with the vast world of tectonically shifting money that my friend dwells in, so I kept mum. But it seems a hopeful sign.