Resource Magazine — March/April 2013
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Exploring Urban Agriculture

This special issue of Resource presents urban agriculture as one promising path toward the goal of feeding our planet’s growing, and increasingly urban, population. Many of the tools to make that path viable come from controlled environment agriculture (CEA). The contributors to this issue, many CEA researchers and practitioners, are explorers moving toward that goal.

Urban agriculture is a viable, sustainable strategy for local food production that can respond to global economic crises, food safety issues, and environmental stresses. Around the world, the number of cities embracing urban agriculture is increasing. However, most U.S. cities remain anchored to Industrial Age agriculture, with production confined to rural areas far from city markets. Lately, though, there has been a dramatic rise in the numbers of urban planners, architects, engineers, politicians, futurists, and consumers who support sustainable food production close to and even within city limits.

People are drawn to cities because cities are the world’s economic engines. Just 600 cities today account for about 60 percent of global economic output. In 2010, for the first time in history, the world’s urban population exceeded 50 percent of the total population, while occupying less than 4 percent of the available land area. Given current population trends, our cities will be home to billions more by mid-century. By the end of this century, more than 80 percent of the world’s projected population of ten billion will be urban dwellers. Disruptions due to climate change, higher energy costs, water shortages, and food production, distribution, and safety issues have also been projected.

Fortunately, we have choices. The explorers who contributed to this issue describe some of these choices, many of which are emerging from current technologies. With hard work, and a willingness to change some of our established methods, we can meet the challenges of the future. One promising area for future development is plant production, especially given our increasing understanding of plants’ complex responses to their environment. Food safety, quality, freshness, and nutrition are concerns, and there’s an increasing demand for locally grown, sustainably grown foods. Consumers want to know where their food comes from. Urban agriculture offers solutions for these concerns.

We believe that the current discussion about urban agriculture is important and needs to reach a larger audience. Part of this discussion concerns the role of controlled environment agriculture (CEA) and other technologies in urban agriculture. Another part of the discussion is the emerging importance of the bio-sciences, which is happening in production agriculture generally and in urban agriculture particularly. Overall, this is an exciting time for production agriculture.

We asked the contributors to discuss their research, experience, and practices, and to describe the challenges they see. We also asked what solutions, perhaps unique to their geographic region or their area of expertise, could help feed the growing number of people on our rapidly urbanizing planet. In particular, how can we balance the decreases in the numbers of farmers and farmable acreage, as well as decreases in the resources specific to food production, with the world’s increasing food requirements?

Many more contributors than we anticipated returned thoughtful responses, and we have tried to include as many as possible. We thank all who participated, and we regret that we were not able to include them all. For readers of Resource, we hope this special issue gives you some understanding of the diversity, the technologies, and the economies of urban agriculture, as well as how this emerging sector may influence other sectors of agriculture and food production.

Urban agriculture means food production in densely populated areas, and it includes many types of production systems, such as traditional open gardens, protected environments such as tunnel greenhouses, and self-contained systems such as hydroponics and vertical farms. Urban agriculture also includes intensive CEA systems on less valuable land with minimal transport distance to markets and rooftop greenhouses that increase the efficiency of the built environment. Large, fully enclosed growing systems within buildings, called vertical farms, and plant production in growth rooms that have been specially designed for efficient use of resources may lead to the ultimate in closed systems for food production: off-planet bases, perhaps on the Moon and Mars.

Urban agriculture also complements recent developments in field agriculture. In the United States, for example, we have begun to see increasing interest in farming, both as traditional family farms and as food production systems in urban areas. Many of these efforts have adopted controlled environment practices to make better use of small plots for highly productive and high-quality food production. New approaches have emerged in soil-less (hydroponic) agriculture and on traditional farmland in protected agriculture (such as high-tunnel greenhouses). Whether in community gardens, on traditional farms, or on urban rooftops, controlled environment methods extend the growing season and protect valuable crops from damaging weather, including frost. By allowing more control over the production process, these methods give the grower more predictable returns and provide the market with a more consistent product.

The contributions in this special issue also include some tentative answers to the question, “Can controlled environment agriculture save the world, or even feed the world?” High-volume staple crops such as wheat, corn, and rice, which form the basis of much of the world’s diet, are not suitable for CEA. But CEA can make a difference in people’s nutrition and quality of life while enhancing the remediation of resources. CEA complements, but does not replace, field crop production by extending the growing season and ensuring product quality. CEA therefore has a big role to play in urban agriculture and can help growers succeed in areas that would otherwise be food deserts, as well as in the greenbelts surrounding cities. Extreme environments and climate change are also on the minds of our contributors.

Technical issues that are essential to further developments in urban agriculture are treated throughout these contributions, such as energy, carbon footprint, water use, lighting, and advanced sensors and control systems. In addition, regulatory and policy initiatives will determine the future of urban agriculture in many locations, and political, social, cultural, and aesthetic concerns will help or hinder efforts to establish urban agriculture as well.

No discussion of urban agriculture is complete without considering vertical farming, which has come to represent urban agriculture, at least in certain media and to some venture capitalists. Over the past 200 years, various vertical farming concepts have been proposed, but none were practical. Today, with recent technological advances in CEA and hydroponics, vertical farming may be feasible. Japan is currently the leader in farming within buildings, particularly in the development of “plant factories with artificial light,” or PFALs. However, even the strongest advocates of vertical farming also encourage development of other production methods for urban agriculture.

The future of urban agriculture will proceed along whichever paths lead to success in feeding an increasingly urbanized, densely populated world. Feeding our global population is the primary goal, but nations with space programs can benefit from urban agriculture in another way as well. The efficient, self-contained production systems that revitalize our cities can also be the basis for permanent settlements in space. Someday we may realize the dream of contributor Silvio Rossignoli and “enjoy the tastes of long-forgotten food plant varieties, grown in a sustainable, chemical-free environment, both on Earth and on Mars.”