The ComPOSTer: Studying compost use on campus farmland – project update

Continuing our review of Campus as Lab efforts, this post will provide an update on a project examining the environmental and economic implications of transitioning campus agricultural land from conventional to sustainable farming practices.

The project, led by Professor Daniel Rubenstein and assisted by me, involves engaging undergraduate students in measuring the relative importance of different soil amendments (including S.C.R.A.P Lab compost!) and weed control methods on crop productivity, soil health, and profit. Additionally, our team is analyzing the impact of low-cost fencing in reducing crop damage from deer overgrazing.

The ultimate goal of the project will be to develop a set of recommendations on how the University can farm in a more environmentally responsible and cost-effective way as the current industrial model of growing a rotation of corn and soybeans using fossil-fuel based inputs is carbon intensive, degrades soils, and pollutes waterways. Alternative and more sustainable practices that we are testing include diversifying the crop rotation, using natural soil amendments like compost, and ensuring ground cover over the winter with a cover crop in order to increase the soil’s ability to supply nutrients to crops without relying on excess use of chemical inputs.

Below is a photo essay describing the project and progress to-date:

This summer, soybeans were planted on a 5 acre farm plot in 8 sections, each of which received a specific combination of soil amendment and weed control treatments. Each soil amendment-weed control treatment is replicated twice both inside of and outside of the fence, with the exception of the compost-cultivation treatment due to a shortage of compost. Following harvesting of the soybeans in October, a winter cover crop, rye, will be planted in the horizontal strip through the middle of the field.
S.C.R.A.P. Lab compost being applied to plots #5a, 6a, and 7a via a manure spreader, two weeks prior to planting

After planting, a sloping electric fence system with a taller inner fence and shorter outer fence, was constructed in an attempt to keep deer out (deer can jump pretty high, but rather not scale two obstacles at once). Reflective tap was also added as a scare mechanism for both deer and geese.
After a few weeks of growth, the soybeans inside of the fence (on right) are noticeably taller than the soybeans outside of the fence (on left)
Arable Mark devices were set up in each of the treatment plots to measure plant growth and health in real-time. The height and greenness of the plants, measured through a metric called NDVI (or Normalized Difference Vegetation Index), is a good indicator of potential yield

Next Steps:

In a few weeks, the soybeans will be harvested using a yield counter to obtain accurate data on the productivity of each plot. We will conduct statistical analyses to determine the relative effectiveness of fencing, soil amendment, and weed control method on yield. In the spring, we will take soil samples and run the same analyses for initial impacts on soil fertility compared to baseline levels collected earlier this year. We hypothesize that the sections receiving compost and planted with winter rye will have a more favorable soil pH, a higher percentage of organic matter, and optimum levels of nutrients versus the sections that did not receive the compost or rye treatments.

In Other News

Today, September 29th, the United Nations celebrated the first ever observance of the International Day of Awareness of Food Loss and Waste

The ComPOSTer: Event Composting & Alum Profile: Ishy Anthapur ’20

Happy first day of classes!

Princeton’s fall semester officially begins today. Over the course of this semester, the ComPOSTer will provide updates related to the relocation of the S.C.R.A.P. Lab composting facility, and feature a Q&A series with Princeton faculty who are conducting research at the S.C.R.A.P. Lab or on other topics related to composting. But before we head into the new semester, this post will wrap up the unofficial end of summer with highlights from the past month. Read below to learn about event composting and an alum profile featuring former assistant, Ishy Anthapur ’20.

Waste Less Wednesday Zoom Social Series: Composting at Events

Earlier this month, my colleague, Lisa Nicolaison, and I co-hosted a session on Johns Hopkins University’s Waste Less Wednesday Summer 2020 Zoom Social series. Check out the video recording below to hear about Princeton University’s experience hosting low waste events through the collection and composting of food and compostable serviceware.

Alum Profile: Ishy Anthapur ’20

Ishy reflects on her time working at the S.C.R.A.P. Lab and discusses her post-graduation plans. Congrats Ishy!

I worked at the S.C.R.A.P. Lab for the summer of 2019 while I was also doing research on campus for my senior thesis in the EEB department. I learned a LOT about Princeton’s sustainability plan and all the strides forward we’ve made (the S.C.R.A.P. lab being a huge part of that)! I also realized that the campus could be doing a lot more to deal with the amount of food waste in general.

My current plans are to pursue a P55 Fellowship in Boston at the Community Day Charter Public School. The S.C.R.A.P. lab affirmed my belief that community-based projects and services are so important to making an impact in terms of environmentalism and sustainability. I’m looking forward to trying to live as green as possible as I start my new job and my new life as an alum!

The ComPOSTer: Alum Profile – Kiley Coates ’20

This week at the ComPOSTer we take a quick break from Campus as Lab updates to catch up with the second S.C.R.A.P. Lab operational assistant to graduate this spring – Kiley Coates ’20.

Read below about how Kiley’s time working at the S.C.R.A.P. Lab has framed her views of sustainability on different scales and has helped in her transition to the workforce as a lab technician processing COVID-19 test samples.

Kiley’s involvement with the S.C.R.A.P. Lab can’t be overstated – she worked 220+ hours over the course of 10 months and wrote an analysis of the composting process for her senior thesis.

“I worked at the S.C.R.A.P. Lab starting May 2019 and continued there until my time was unfortunately cut short due to COVID in March 2020. The S.C.R.A.P. Lab was a great way of learning about sustainability on a variety of scales. The S.C.R.A.P. Lab itself was a larger-type operation and I was able to learn about how institutions like Princeton could use this machinery to improve their in-house sustainability practices. On smaller scales, I learned a lot about various projects on Princeton’s campus and how to apply them even when I left Princeton (having my own compost pile, using reusable silverware even outside the home, etc.). Gina Talt, my supervisor, was a champion at promoting sustainability in practical ways, recognizing the nuances of environmentalism and the importance of doing what you can, while still acknowledging the class and cultural differences that may limit someone’s ability to participate in sustainable practices. 

After graduating, I started working for LabCorp in Durham, NC in their COVID Lab. My position as a lab technician involves primarily working on the queue of pending samples and ensuring we maintain our turn-around time and process priority samples efficiently. It’s definitely pretty different from my work with the S.C.R.A.P. Lab, but I definitely utilize problem-solving skills I grew during my time with Scrappy.”

Congrats Kiley!

Thank you for being such a dedicated composting champion at Princeton. Best of luck going forward!

The ComPOSTer: Alum Profile – Milan Eldridge ’20

Happy dog days of summer everyone,

In about a month, classes at Princeton will resume, but before we head into the new academic year, the ComPOSTer caught up with one of the S.C.R.A.P Lab’s most recent alumni – Milan Eldridge ’20!

Although relatively new to the team, Milan was a fast learner whose passion for sustainable living made her an invaluable and dedicated assistant who took on multiple shifts even during her last semester at Princeton. Read more about Milan’s experience working at the S.C.R.A.P. Lab in her own words below:

I started working at the S.C.R.A.P. Lab at the beginning of my spring semester during my senior year. After becoming more involved with sustainability on campus, I wanted to continue to explore ways that I could be involved with sustainability within the campus community. I also wanted to learn more about sustainability on a larger scale so that I could carry what I had learned with me after graduation.

During my time on campus, I had seen the university change the company through which they composted. All of a sudden, we weren’t allowed to compost everything we had previously been allowed to compost in the dining halls. Soon, after spending some time in the Frist Late Meal Gallery, I started seeing bins labeled ‘S.C.R.A.P. Lab’. For a long time, I had no clue what the acronym stood for, only that we were meant to put our compost in the bin. After reading more about the S.C.R.A.P. Lab, I thought it would be a great opportunity to expand my knowledge of what the university was doing to combat food waste and help contribute to the goal.

“Sustainability can take many forms and may look different in different places depending on the limitations of each place” Milan Eldridge ’20

While working at the S.C.R.A.P. Lab, I quickly learned that, while the university produces a great deal of food waste, people are willing to do what they can in order to reduce the impact this has on the planet. This ranged from various academic departments keeping compost buckets to student groups like Coffee Club searching for ways to keep their business as sustainable as it could be by searching for a way to compost their used coffee grounds. However, at the same time, there are also people on campus who occasionally get really ecstatic about composting and want to compost everything they receive at late meal, down to the utensils and plastic condiment cups.

Nevertheless, I believe that the Office of Sustainability has been doing a great job on campus in order to educate students about what they can do to live more sustainable lives. I have learned that sustainability can take many forms and may look different in different places depending on the limitations of each place. For example, some products that are marketed as compostable aren’t always easily converted into soil by our composting system and it takes time, dedication, and patience in order to ensure that every member of a community understands the limitations that may be present. All in all, I have learned lessons that I believe will be extremely beneficial in the future as I continue to integrate sustainability into my living habits and encourage others to do the same. 

We wish Milan the best of luck in her future endeavors!

Next week, we will hear from one of our long-standing team members, Wesley Wiggins ’21. Wesley will be the ComPOSTer’s resident blog writer for the next several weeks during which he will use his operational expertise to provide insightful updates on all of the exciting coursework and research happening around the project through our Campus as Lab program.

The ComPOSTer: Juneteenth Reflections

Good morning ComPOSTer subscribers,

Yesterday, July 19th, Princeton University offered all faculty and staff a fully paid day off to recognize the significance of Juneteenth – the day 155 years ago when the last enslaved African Americans in the country learned of their freedom – and to provide space to contemplate how we can all do our part to eliminate structural and overt racism and other forms of discrimination on our campus, in our communities, and in our country.

As such, this post aims to raise awareness about how waste management and the larger food system have contributed to racial injustice and how composting can be a part of the solution to achieve a more equitable society.

The sustainability movement is not complete without racial equity

Along with violence and police brutality, the food system is another, yet under-acknowledged, area in which systemic racism against Black people exist. From the allocation of farm subsidies and marketing of fast food, to the siting of waste disposal facilities, the U.S. food system has economically discriminated against Black communities while unequally exposing them to environmental harms and diet-related diseases.

According to Black food justice leaders, the solutions to eliminate food system inequities are not solely a matter of access or education, but rather that of poverty alleviation. Funneling capital into Black communities and allowing the people to own their own land and businesses will provide Black people with the financial stability and empowerment to grow and consume accessible, affordable and nutritious food.

How does composting fit into the equation?

First off, it is important to note that indigenous people and African Americans, such as early civil rights figure, George Washington Carver, knew about the importance of composting and using compost to promote sustainable agriculture practices long before the organic farming movement became popularized by the Rodale Institute in the mid-1900’s.

That point aside, composting uneaten food at a local scale not only diverts material away from landfills or incinerators (which have been disproportionally sited near low-income and minority communities), but provides a soil amendment to support community food-growing operations, while also offering other benefits such as job creation, stormwater management, and more.

Shown below is a photo of Leah Penniman (far left) leading a youth group in maintaining a compost pile at Soul Fire Farm. Leah is one of the aforementioned food justice pioneers, and co-founded Soul Fire Farm in Grafton, NY with the intent of ending racism and injustice in the food system by reconnecting people of color to the land on their own terms.

Photo credit: OMD blog

To learn more about the intersection of food and/or composting, health, and race, see below for recommended readings:

Why Food Belongs in Our Discussions of Race 

The Good Food Revolution: Growing Healthy Food, People, and Communities

Farming While Black

The ComPOSTer: SCRAPPY on the move; National Learn about Composting Day

The month of May began with a week-long celebration of International Compost Awareness Week (ICAW) and now it comes to a near end with

National Learn about Composting Day!

During ICAW, we highlighted 5 composting facts, but for a deeper dive into the benefits of composting, check out this series of infographics developed by the Institute for Local Self-Reliance.

S.C.R.A.P. Lab Updates

Phase 1 of the S.C.R.A.P. Lab facility relocation began earlier this week when “SCRAPPY” was dismantled and transported to a temporary storage location. SCRAPPY will remain there until our new permanent location is finalized and the facility is reconstructed. We will post more updates here, but in the meantime, check out a few photos from the move which took about half a day:

Dismantling the screw conveyor auger
SCRAPPY being rolled out on a wooden “sled”
Two forklifts raise the composting system onto the flatbed truck
All parts of the composting system are strapped securely to the flatbed
The flatbed arrives at the storage site and the forklifts are back to lift SCRAPPY off of the truck
SCRAPPY stored safely in the storage barn

The ComPOSTer: ICAW Recap

Hi everyone,

Thanks for celebrating International Compost Awareness Week (virtually) with us!

In case you missed some of our featured content, here were some of our favorites from last week:



The ComPOSTer – International Compost Awareness Week!

Good evening everyone,

Did you know that the first full week in May is International Compost Awareness Week (ICAW)! This year celebrates the 25th anniversary of the event which aims to increase public awareness on the benefits of compost and organics recycling.

To celebrate ICAW, we’ve made a few updates to the blog. You’ll find:

  1. A new “Resources” section that provides readers with information on how to compost at home
  2. The background story behind the S.C.R.A.P. Lab which can be found in the “About” section

Additionally, be sure to follow the Office of Sustainability’s social media accounts (tigersgogreen) this week for learning and engagement opportunities including fun videos from our staff and student EcoReps:




Happy composting!

The ComPOSTer: New Video, Gov. Signs Food Waste Bill, How to Plant a Victory Garden

Happy Friday everyone!

Today the ComPOSTer presents a few highlights and resources to bring some positivity to your day, as well as inspiration for sustainable action as we head into the weekend and Earth Week! In this post, you’ll get a virtual behind the scenes look into S.C.R.A.P. Lab operations, read an update about the NJ food waste recycling bill, and learn about a “toolshed” of resources to start your own Victory Garden (using compost, of course).


Follow the journey of campus food scraps as they travel from the kitchen in Frist Campus Center to the University’s onsite S.C.R.A.P. Lab for conversion into compost that is used to support plant growth and health on campus:


After passing in the Senate, New Jersey’s food waste recycling bill was signed into law by Governor Murphy earlier this week. Starting in 18 months, establishments in the state that generate 52 or more tons of food waste annually must arrange for separate recycling if an authorized facility is located within 25 road miles. On-site recycling is an allowable option as well. Additionally, a Food Waste Recycling Market Development Council will be established and tasked with developing recommendations for stimulating market demand for the soil amendments and energy products produced by recycling facilities. New Jersey is now the 9th US state to have some form of an organics recycling policy.


As a result of the COVID-19 pandemic, food waste losses across the country have increased significantly as US producers and growers can’t find buyers for their vegetables and dairy products. Approximately half the food grown in the US usually goes to restaurants, schools, stadiums, theme parks and cruise ships. Now that these food service operations are temporarily “closed,” vegetables are rotting in farm fields, and milk is being washed down drains. Growers are making efforts to fix the mismatch in supply and demand by donating surplus food to food banks and charities, but until more resources and partnerships are established, they are not enough to absorb the current surplus.

On the flip side, millions of Americans are now turning to “victory” gardening as a fun and productive outdoor activity to do while stuck at home.

Have you started your garden yet? If so, let us know and send some pictures by emailing

If not, you’ll gain the satisfaction of growing something yourself without having to go to the grocery store.

Here are some tips for getting started and maintaining your garden, adapted from resources provided by the U.S. Composting Council:

STEP 1: Prepare your “garden” whether that is a container garden on your balcony or patio, or a raised bed in your backyard. And remember to add compost! The foundation of growing healthy and nutritious food is healthy soil. By adding compost to your garden beds, you’ll build organic matter and provide your plants with key nutrients for healthy growth.

The difference in plant growth and health between soil with compost (right) and without compost (left)

STEP 2: Choose your seeds and plants!

STEP 3: Plant your seeds and nurture your plants through weeding, watering, and controlling pests.

STEP 4: Enjoy the harvest!

Have a question about your garden?

Contact your county’s Master Gardener representative or your state’s agriculture extension office. Link to Rutgers Master Gardener Helpline (NJ residents only).

The ComPOSTer: Status update amid COVID-19

Good afternoon everyone,

I hope this blog post finds you and those around you doing well during this difficult time.

As with many activities and events at the University, the S.C.R.A.P. Lab has closed for the remainder of the semester due to the COVID-19 restrictions. In the meantime, any food waste generated at Frist Campus Center will be picked up by our third-party organics recycler, Organic Diversion.

When S.C.R.A.P. Lab operations resume, the composting facility will no longer reside at the current location on FitzRandolph Road, but at a new site on campus. Due to Capital Planning efforts, we will be moving to a permanent location along Washington Road in May/June. Over the next weeks and months, the ComPOSTer will chronicle this journey, and will continue to provide research updates and information about all things composting and compost, so please keep reading along!

A big thank you to all of the students who assisted with composting during the ’19-’20 academic year! Pictured here: TOP from left to right: Wesley Wiggins ’21, Stanley Cho ’23, Joe Kawalec ’21; BOTTOM from left to right: Gina Talt (project manager) ’15, Reese Knopp ’23, Kiley Coates ’20

On that note and in better news – earlier this month, the NJ food waste bill that was referenced in the last blog post was passed by the Senate and currently waits to be signed by Gov. Murphy.

Under the bill, large food waste generators (e.g. establishments like prisons, hospitals, higher education institutions) will be required to source separate and recycle their food waste if they generate an average projected volume of 52 or more tons of food waste per year (i.e. 1 ton or more of food waste per week), and are located within 25 miles of an authorized food waste recycling facility.

The bill will advance the organics recycling industry in New Jersey by incentivizing the construction of either composting or food waste-to-energy facilities in the state, as well as the use of the associated soil amendments like compost for landscaping and construction projects. Read more here.


We end the academic year having composted a cumulative 91 tons of food waste since the start of the project. We look forward to continuing our journey in a few months!