SMRs and AMRs

Saturday, January 01, 2011

How to feed 9 billion people? Try high-rise food production

Future of farming could be going vertical

By Don Gordon
Guest writer
Mankato Free Press
Saturday, January 1, 2011

I would estimate that most of the people reading today’s column will sit down to a holiday meal that contains more than enough calories to sustain them. Unfortunately, not so for the one billion residents of the world who are perpetually hungry and malnourished.

Despite some gains in reducing hunger in the past, we are faced with the reality of seeing the numbers increase each year. Each day we have 217,000 more people to feed, and that amounts to an increase of over 80 million a year. If this growth rate continues, the United Nations estimates that our population will increase from the nearly 7 billion today to 9.1 billion by 2050. To feed all these people, we will need to increase food production by 70 percent.

Since 1950 increases in food production have been largely due to the development of high yielding varieties (HYV), increased fertilizer use, and increased irrigation. Of the three, developing more HYVs seems to be our best option for increasing productivity because crops will only tolerate so much fertilizer and water tables are falling worldwide.

Farming more land is not given much credence because most of the economically viable land for growing crops is already being used; unless, of course, we decide to sacrifice diversity by clearing more (mostly tropical) wild lands.

Lester Brown, in his new book, World on the Edge, reminds us “as rapid population growth continues, cropland becomes scarce, wells go dry, forests disappear, soils erode, unemployment rises and hunger spreads.”

Compounding the hunger problem is the mass migration of people to cities. By 2050, the UN estimates that 70 percent of the world population will be living in urban areas. Getting food to cities means costly transportation costs and more fossil fuel use, thus adding to the global warming problem. Of course, there is the added loss of food due to spoilage. The journal Nature estimates that between one quarter and one-third of the food produced worldwide is lost or spoiled. Could there be a greener way?

There is no shortage of ideas concerning how to feed the world population.

Space does not permit listing all of these, but there is one being suggested that will be of interest to gardeners. This method is not going to solve the hunger problem, but it might help a bit in urban areas. This system is called vertical gardening (or farming), and it is really not new since forms of it have been practiced since the advent of agriculture.

When you run out of land in urban areas the answer is a no-brainer: go vertical, build upward. We have done it for housing, is it also possible for food production?

Just imagine, skyscrapers with multiple floors of fruit and vegetables. The latest issue of the Economists looks at the pros and cons of growing crops in vertical farms in urban areas. The biggest promoter of vertical farming is Dickson Despommier, professor of environmental science at Columbia University. In his new book, The Vertical Farm, Despommier points out that with this method pesticide, fungicide and herbicide use would be minimal.

Also, there would be no need to worry about soil erosion because the plants would be grown hydroponically. By recycling both water and mineral nutrients, there would no runoff pollution problems.

There are a number of designs for vertical farming in urban areas, but critics point out that without artificial light these designs will fail. Stacking plants limits the ability of natural light to reach all parts of the plant.

Peter Head, a British engineer, points out that “Light has to be very tightly controlled to get uniform production of very high-quality food.”

The cost of artificial light for growing plants is expensive. Here in Minnesota a number of indoor non-vertical hydroponic facilities have failed because of expensive energy costs associated with both light and heat.

The future for vertical farming in urban areas is unclear. Proponents say the light problem can be overcome by growing plants on just the sides of buildings sandwiched between glass and rotating on a conveyor belt. But, at this time construction of single story greenhouses on top of existing buildings seems more economically plausible. In 2011, an organization called Science Barge will open the world’s largest urban commercial hydroponic farm in Brooklyn. This is a 15,000 square foot facility that is expected to produce 30 tons of vegetables a year.

Vertical gardening, farming or growing plants in rooftop greenhouses may seem farfetched, but it is imperative that we investigate new and innovative methods of producing food.

To feed 9.1 billion we need another green revolution that is more successful than the first.

Don Gordon is professor emeritus of botany at Minnesota State University Mankato. Send questions concerning horticulture or the environment with a stamped, self-addressed, long envelope to 52794 Deerwood Trail, Mankato, MN 56001, or email him via this link. Posted by permission of the author.

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