Corn, Compost and Cutlery

September 21, 2011 12:00 am0 comments
Paige Roosa

Located just two miles from the Cornell campus, the Cornell compost facility collects compost from a multitude of sources, such as the College of Veterinary Medicine, dining facilities, greenhouses, plantations and polo fields. In 2006, Farm Services, the organization that manages the compost facility, reported that the Cornell campus generated 6,337.84 tons of organic waste.In recent years, Cornell Dining adopted compostable cutlery in all of itsß dining locations.  

Biodegradable cutlery is made from all different blends of corn and potato starches, combined with hardeners and polylactic acid from corn sources. These products break down under high-heat conditions, such as a compost pile.

But many of these biodegradable products still have trace amounts of plastic in them, according to Jean Bonhotal, a compost specialist for Cornell Extension within the department of crop and soil sciences.

“The compounds that are biodegradable will disappear in six to nine months in the compost pile, and the tiny fragments of plastic are left behind,” Bonhotal said.ß

Fragments that are so tiny they cannot be seen by the naked eye, but will show up in chemical analysis tests performed on the soil. As a result, organic certification organizations, such as NOFA-NY, do not allow the use of any biodegradable cutlery in compost sold for organic purposes.

Compost is an important environmental resource, therefore cutlery that can decompose into organic matter contributes more to the environment than cutlery that ends up in a landfill.

“[Compost’s] role in the environment is basically that of a recycled organic material. This material, and the decomposition process, reduce mass, release nutrients ­­–– in essence a slow release fertilizer ­­–– and acts to effect climate on top and within the soil,” Prof. Jonathan Russell-Anelli, crop and soil sciences, said.

“As to [biodegradable cutlery] being more eco-friendly than plastic – in the grand scheme of things, yes, but non-compostable, non-plastic cutlery is far more sustainable that either plastic or compostable… if you look at the life cycle anaylsis of the object, the amount of compostable forks that you would use compared to say, a metal fork (even with washing it) comes out to an energy usage well beyond that of a metal fork,” Russell-Anelli said.

“At present both corn growing and soil extraction use significant amounts of energy to produce. So all in all, right now they basically are the same, but corn has a distinct advantage over oil in that we don’t have to use unsustainable oil products to make it, granted that today, we are still using oil to grow corn,” he said.

According to Ava Ryan, ‘13, dining sustainability coordinator, and certified “master composter” in Tompkins County, food and material waste is picked up from all of the major dining halls on campus by Farm Services and is transported to the 3.5-acre compost facility, located about two miles away.

Upon entering the compost pile, the waste is placed into windrows. There are zero month, three month, six month and nine month piles, depending on the compost’s age. It takes about nine months for waste to degrade into compost.

Some of the compost generated by the facility is spread on farms. Certain piles are designated to be certified organic so that they can be used on organic farms, said Bonhotal. A portion of the compost is also used for research purposes.

“Cornell Dining switched to using biodegradable cutlery not because it’s environmentally friendly, but because it’s easier –– it means that Farm Services will actually pick up the compost,” Ryan said.

But contamination between biodegradable and non-biodegradable waste is an issue. According to Bonhotal, if plastic ware makes it to the compost pile, it will not break down.

“There is some confusion about what can and can’t go into the compost, which is why Cornell wanted to go all degradable [in the dining halls]. If you have plastic ware that you want to recycle, and you have degradable plastic mixed in with it, then that becomes a problem because then the recycled material won’t function as intended,” she said.

To help reduce contamination, Ryan works as a “Compost Monitor” at Trillium three days a week. Compost monitors are responsible for helping people sort their trash into the proper receptacles.

“I think everyone should use reusable everything … but obviously that can’t happen in the dining halls, or at least not in places like Trillium, where they don’t have a dish belt or even a dishwasher,” Ryan said.

Prof. Anil Netravali, fiber science and apparel design, studies green composites that are “fully biodegradable and fully sustainable.” These products come from fibers and plastics or resins that are developed from sustainable sources, such as plants, that are grown every year.

Netravali and co-workers modify plant proteins so that they behave like polymers in plastic.

These plant materials, according to Netravali, are more sustainable because they are renewable, unlike petroleum. Plant proteins and starches also require less heat energy to process –– for example, polyethylene, one of the lowest energy-requiring petroleum based compounds, still requires an input of 30 degrees more than soy protein.

“When we take the protein and cross-link them by using a cross-linker, they become more thermally stable. We use compounds from a plant to cross link these plant proteins, as we don’t want to use petroleum-based cross linkers. This somewhat limits us- we cannot use these plant products as high temperature polymers, the technology is just not there yet,” Netravali said.

While biodegradable compounds are a step up from petroleum based plastics, Ava, Bonhotal, and prof. Jonathan Russell-Anelli, crop and soil sciences, all agree – reusable metal forks and knives are probably the most ecological.

“As an agricultural science major studying sustainable ag, I have an issue with the fact that [most biodegradable cutlery] is made of corn and soybeans, grown in monocultures… corn grown for cutlery definitely isn’t organic, and is full of GMOs,” Ryan said.

The debate over which materials and processes are most ecologically sound is complex; and as Bonhotal stated, “there are no simple answers in the highly populated world that we live in.”

While the choice of whether to use corn plastic or paper, aluminum or polyethylene, is debatable, it is easier to agree that compost is a valuable resource. According to Ryan, it is important that the dining halls make efforts to promote compost.

“Nutrients are a really precious resource … why should we be tying them up in an unsafe place like a landfill, sitting there generating methane, when we could be composting them and reusing them?” she added.

 

Comments