Up on the Roof

Making global cities sustainable with rooftop farming

By Amy Wagner

Forget about farm-to-table foods. If earth and environmental studies Professor Robert Taylor has his way, roof-to-table dining might be the wave of the future. “Urban rooftop agriculture can produce significant amounts of food at reasonable prices and is a sustainable way to reduce a city’s carbon footprint. Local rooftop agriculture can significantly complement the traditional farm-to-city food supply chain,” he says. 

“It’s also a great way for cities to hedge against extreme weather events, acting as a type of ‘back-up generator’ for local food supplies.”

Putting belief into action, Taylor has collaborated with J.S. Carandang, the chair of the biology department at De La Salle University in Manila, Philippines, on a research project exploring rooftop hydroponics in Manila as a key strategy for urban sustainability.

Funded by the Angelo King Foundation in 2011, the researchers spent 14 months on the project, which concluded with the publication of “Making Global Cities Sustainable: Urban Rooftop Hydroponics for Diversified Agriculture in Emerging Economies,” in OIDA International Journal of Sustainable Development. They are currently in the process of expanding the project to Bangkok, Thailand, and Ho Chi Minh City, Vietnam. 

“The blend of hydroponics and rooftop farming brings two sustainable initiatives together that are of particular significance in crowded, urban environments,” says College of Science and Mathematics Dean Robert Prezant. “Dr. Taylor’s work in this area of sustainable practices offers an outstanding model that we hope will not only garner wide support but will also become a global model.”

How does your rooftop grow?

“Hydroponics technology has been around for a long time,” Taylor explains. “What’s new is that urban rooftop agriculture utilizes underused space in very space-constrained Asian cities and can be integrated into the local food supply as a supplement to traditional farm-to-city supply systems.”

The researchers installed a hydroponic setup for growing lettuce and micro greens on a six-story building at De La Salle University.

“Generally, in Manila, commercial buildings have flat rooftops that are strong enough to support rooftop agriculture,” Taylor notes. A shed made of steel pipes and three layers of nets sheltered the plants. Waterproof canvas sheeting offered additional protection in the event of the extreme winds and rains of a typhoon.

For cities in emerging economies, like Manila, food security is a growing challenge, as traffic congestion, poor roads and inadequate infrastructures make it increasingly difficult --- and expensive --- to get food from rural farms to the tables of urban consumers. Rooftop farming shows promise as a means to increase food security.

The Manila project yielded significant results. “If high-value vegetables like herbs are grown, it definitely is a profitable business model, as sales of these vegetables to local restaurants reflect the most profit,” Taylor says. “For mainstay vegetables like lettuce, the benefits come from a reduced carbon footprint, since the produce doesn’t have to be transported long distances to market.”

Professor Robert Taylor is a the forefront of rooftop agriculture and sustainability science.

In Manila, the team also increased sustainability by using the sun to power the rooftop system’s water pumps and aerator.

Hydroponic farming also conserves water and reduces greenhouse gas emissions. “Water will be a big issue for the 21st century, and agriculture is the world’s largest consumer of fresh water,” he says. “If we can reduce the amount of water to grow one pound of vegetables by 75 percent, we will have achieved a considerable environmental good.”

Consumers will also benefit by knowing where and how their produce is grown, while tremendous long-range opportunities exist to engage urban residents in local agricultural production.

“I’m convinced rooftop agriculture and other sustainable and organic approaches to urban agriculture will become more widespread,” says doctoral student and researcher Catherine Alexander, who is completing her dissertation under Taylor’s guidance and co-authored the paper on the Manila project. She is currently working with Taylor to develop spreadsheet metrics to compare the effectiveness of rooftop hydroponics with traditional industrial agriculture.

Taylor and fellow researchers in the Philippines explore rooftop farming as a way to "produce significant amounts of food at reasonable prices" and as a way to reduce a city's carbon footprint.

Things are looking up all over

Alexander also served as tech support for a groundbreaking course in “Current Issues in Sustainability Studies” that Taylor taught in 2013 for Montclair State graduate students and graduate students at Ho Chi Minh City University of Natural Resources and Environment in Vietnam (HCMUNRE).

Taylor had received a Vietnam Educational Foundation grant to teach the course, which linked Montclair State graduate students to students in his class at HCMUNRE, one of two universities under Vietnam’s Ministry of Natural Resources and Environment, which regulates and manages the natural environment.

“I also provided five workshops to governmental officials, academics and other professionals over a five-month period, including one on urban rooftop hydroponics,” Taylor recalls.

In addition, he worked to develop a partnership between Montclair State and HCMUNRE that will offer students a joint BS/MS degree in sustainability science beginning in September 2014.

While in Vietnam, Taylor met with research groups interested in using rooftops for agriculture production, and he is currently working with city planners and other professionals in Ho Chi Minh City to develop an agricultural plan for food security in the region.

Because Ho Chi Minh City is at sea level and vulnerable to the flooding caused by global climate change, it is an excellent candidate for this sort of development. Concerned planners and government officials are open to changes like rooftop farming as a way to lessen the impact of extreme weather, he says.

Bringing it all home

While Asia is the focus for Taylor’s ongoing research projects, urban rooftop farming has begun to take root in the United States, too. New York City, Boston and San Francisco are places with a number of existing commercial rooftop projects. “I believe that urban rooftop agriculture will be integrated into more urban agricultural strategic plans for cities,” he says.

Closer to campus, Taylor is working with the Passaic County Planning Department to develop urban agricultural applications and plans.

“We will be working with Passaic County to look at potential sites for commercial farming emphasizing the use of underused urban space, older buildings and other potential sites for urban hydroponics.”

This semester another graduate student completing an MS in Applied Sustainability Science is working with Passaic County on this study in a project-based internship.

Rooftop gardening will soon come to campus as well. There will be one atop the University’s Center for Environmental and Life Sciences building when construction is completed. While the garden is designed to be ornamental, Taylor has high hopes for the rooftop. “Perhaps we can use this space to develop a model agricultural project in the future.”