Urban Agroecology

What would urban agriculture look like if it were industrialized? Everything on this site approaches urban agriculture from an ecological perspective. As urban agriculture becomes more popular, we find entrepreneurs looking at opportunities in the field. Some of those entrepreneurs will follow the current trends towards local, sustainable agriculture. But, others will see the opportunities and approach urban agriculture from the industrial approach. What will their agriculture look like?

We can take a guess by looking first at existing non-urban industrial agriculture. It is characterized as:

1. Capital intensive, energy intensive, and highly automated (ie, not labor intensive). This is typically described as productive when measured on an output per unit of labor or an output per acre basis.
2. Based on reductionist sciences, not systems sciences. That is, it uses monocropping to produce a single output given a set of inputs and does not use integrated plant or plant/animal cropping systems (polycropping). It is not concerned about systemic level ecological or human relationships that are part of the food chain.
3. Uses industrially produced chemicals, such as fertilizers and pesticides.
4. Large scale (ie, not human know-your-local-farmer scale).
5. Subsidized by taxpayers via regulations that favor factory farms, cheap water from government projects or direct subsidies.
6. Marketed with hyperbole about how its alleged benefits will save the world from environmental catastrophe and/or future increases in population, while ignoring or downplaying its problems.

When we look at current proposals for urban agriculture, there is one set of proposals that fits the above characteristics. These proposals are focused around intensive production using hydroponics. Hydroponics has been around for quite a while, but large-scale proposals have been popping up in the past few years, more frequently as urban agriculture (and the trends towards local and sustainable agriculture) have accelerated.

First, some background. Hydroponics is a technology that grows plants in water-based nutrient solutions instead of soil. It is well-documented that hydroponics is a highly productive method of growing plants. For maximum production, hydroponic techniques require highly controlled growing conditions, controlling temperature, humidity and lighting. Because of this, hydroponics is almost always practiced indoors. These highly controlled conditions allow production to be done year-round. Hydroponic operations can recycle water, so they offer the benefit of efficient water usage. Hydroponics is by no means, however, ecological. As generally practiced, it requires industrial chemicals and large capital outlays for equipment to maintain necessary growing conditions. It does not integrate with local ecosystems, but excludes them to create its own closed system.

The first article I saw proposing large-scale urban hydroponics was a theoretical proposal in the Science section of the New York Times, in July 2008. The article presented the possibility of “vertical farms” powered by alternative energy (wind and solar). The article was short on economic and production details and heavy on “pie-in-the-sky” speculation. The estimates provided, however, are suggestive. Professor Dickson Despommier, of Columbia University, believed that a 30-story vertical farm capable of feeding 50,000 people would cost in the hundreds of millions of dollars to build. Despommier acknowledged that this idea needs more research

By August 2009, just 13 months later, the topic had moved to the Op-Ed pages of the Times. No longer being interviewed, the piece was written by Professor Despommier. He was forthright in disclosing that he has a financial stake in vertical farms, since he has started a company to build them. So, it isn’t surprising that the piece was typically Op-Ed, opening with the assertion that

If climate change and population growth progress at their current pace, in roughly 50 years farming as we know it will no longer exist. This means that the majority of people could soon be without enough food or water. But there is a solution that is surprisingly within reach: Move most farming into cities, and grow crops in tall, specially constructed buildings. It’s called vertical farming.

That’s certainly attention-getting. After a little finger-pointing at climate change, topsoil loss, voluminous water use and polluted runoff in traditional agriculture,  and expected population growth, he moves on to the hard sell. Sky-scraper agriculture will save us all, especially if we live where water is in short supply.

He claims that “Vertical farms are now feasible, in large part because of a robust global greenhouse initiative that has enjoyed considerable commercial success over the last 10 years.” It’s unclear what this means or what it has to do with vertical farms. He also claims that vertical farms would “revolutionize and improve urban life,” but doesn’t explain how. In a flash of Arcadian vision, he claims that vertical farms would also “revitalize land that was damaged by traditional farming.” Farms would be abandoned as every indoor farming acre replaced 10-20 acres of existing farmland, which would revert to a natural ecological state.  Vertical farms would act as ecosystems by recycling waste and water.

The availability of fresh food would improve diets and reduce Type II diabetes and obesity. Reduced transportation costs would reduce fossil fuel use. Crops damaged by weather would be a thing of the past. Pollution from agricultural runoff would end. Jobs would be created. Buildings would be “things of beauty and grace.” There would be less carbon dioxide and more oxygen in the air. Gawd, what’s not to like? (I did warn you of the marketing hyperbole in these proposals!)

Finally, he gets to the main point. In order to prove that this concept works, he needs money. In particular, he needs a massive handout from the City of New York to build a prototype. Once the prototype (subsidized by taxpayers, of course) demonstrates the economic viability of high-rise agriculture, venture capistalists will rush into the market. Apparently, however, the benefits aren’t so obvious that private investors are willing to risk their capital on the prototype. Venture capitalists will take risks, but they’re not stupid.

Looking at this proposal, we see that it meets all the above criteria for industrialized agriculture. A more critical look would raise some key questions that might explain the dearth of private capital. The proposed  systems are heavily energy-dependent, so I’ll focus on energy, although other issues could be raised. Protecting crops from the weather in high-rise buildings and producing food year-round would require massive investments of energy to construct the buildings and the internal production systems. Operationally, temperatures would have to be maintained at crop-determined levels, ie, heating in the winter and cooling in the summer. We already know that commercial buildings are massive users of energy, so maintaining the proposed vertical farms would have similar energy requirements. (What would happen, incidentally, to the crops–not to mention the people dependent upon them–when a major power outage occured? The requisite backup systems to prevent total crop loss would likely be prohibitively expensive.) Finally, energy costs associated with the production and transport of industrial chemicals used in hydroponic operations need to be considered.

I am, to say the least, skeptical. Most of the proposals I’ve seen so far appear to be sky-scraping pies in the sky. That’s not to say that large-scale hydrop0nic operations won’t find a place. But, that place is likely to be a small, niche market, where such projects have particular benefits dovetailing with local factors. In particular, in locations where temperatures are moderate year-round and water is in short supply, the energy requirements for structures would be low and savings in water would be valuable.

I do believe we need more experimentation with these systems. Although they are definitely industrial and not ecological, the lines between the two systems can and will be blurred, with some features of sustainable systems moderating the negative features of hydroponic systems. Basically, we’re in the process of reinventing urban agriculture and we need to experiment wildly to find ways of producing food in cities in ways that are sustainable. It’s possible that hybrid systems will be developed for economic and/or ecological reasons, depending on local circumstances.

For example, aquaponics is similar to hydroponics, but instead of industrial chemicals, it uses waste from fish to grow food, providing both plant and animal products. (Of course, where does the fish food come from?) See this discussion of a possible commercial aquaponics operation. A recent New York Times blog post discussed a variety of urban agriculture developments taking place, including a hydroponics production test facility on the Hudson River that uses alternative energy sources. A fellow blogger recently sent me a link to an article about an aspiring entrepreneur in the hydroponics field. You know the topic has hit the collective consciousness when bloggers begin to promote the approach. The important point here is that people are exploring possible ways of producing food in urban settings. While I believe the best ways of doing this will be ecologically sound, we won’t know what those ways are without experimenting. In the end, I believe that agroecological systems will be more viable, as they integrate with local social and natural systems using time-tested production methods.