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Feeding more people with less energy

by Magdalena Mis | @magdalenamis1 | Thomson Reuters Foundation
Wednesday, 22 February 2012 00:00 GMT

* Any views expressed in this opinion piece are those of the author and not of Thomson Reuters Foundation.

From biofuel changes to using algae and no-till farming, plenty of opportunities exist to boost food production at a smaller energy cost

By Magdalena Mis

 Experts predict that by 2050 food production will have to double to feed an estimated population of over 9 billion people.
 
However, boosting food production requires using more carbon-based fuels and nitrogen-based fertilizers. Those increases could help drive global warming.
 
Is it possible to produce more food while reducing the energy needed to do so?
 
Michael E. Webber tries to answer this question in the January issue of Scientific American magazine.
 
Let’s take a quick look at the energy efficiency of two key ingredients of our diets: plants and animals.
 
Photosynthesis converts only about 2 percent of incoming solar energy into stored energy in plants. Converting plants to beef – by feeding cattle – is also inefficient, as it takes about nine units of plants to produce one unit of beef. Chicken is only marginally better – eight to nine units of plant matter to produce one unit of chicken.

The energy that is used to produce food is much greater than the amount of energy that we get out of it. It is estimated that a country like U.S. expends about 10 units of fossil energy to produce one unit of food energy.
 
A steady rise in food production in recent decades was possible thanks to extensive use of energy through innovations such as diesel-fueled tractors, electric irrigation pumps, and fertilizers and pesticides. Cheap energy has also allowed the creation of transportation networks that have improved food distribution all over the world.
 
But now that the fuel prices are higher and many countries are looking for ways to reduce their emissions of climate-changing gases, we need to improve the food-energy ratio. It’s a task even more challenging when one considers the effects of climate change on crops: food production gets get hurt by droughts and floods, higher temperatures that decrease photosynthesis in many regions, and competition for grains from biofuel companies.
 
How can the energy consumption be reduced, then?
 
Some popular solutions that have been introduced to in recent years might not help at all, the article suggests.
 
BUY LOCAL?

The trend of ‘buying local’ may, in some cases, hurt the environment more than shipping products from far-away places, Webber argues.
 
The value of spending money in the local community is obvious. However, in order to grow food locally, farmers sometimes use marginal land that requires more fertilizers and more irrigation. In such cases shipping food from far-away places where growing conditions are easier may require less energy, emit less carbon dioxide and, in effect, do less environmental damage than growing food locally.
 
Similarly, biofuels may not be the answer they once seemed. Biofuels made from foods such as maize, soy, palm or sugar create growing demand for farmland and can raise food prices as competition for food grows between biofuel companies and food consumers.
 
However, Webber insists, there is a cause for optimism. Certain innovations, policies and cultural choices can reduce the food-energy ratio and, at the same time, lessen environmental damage.
 
One of the options Webber proposes is to stop using maize kernels to make ethanol. Instead, he says, maize kernels should be used to feed people and livestock and only the stalk and the leaves of the plant should be used to make fuel.
 
MANURE POWER

Another alternative is to convert agricultural waste products - such as livestock manure - into power. The amount of manure created by large-scale animal farms greatly exceeds any local demand for fertilizer and is too expensive to ship to other destination that might use it. The manure also emits methane, a powerful climate-changing gas.
 
But manure can be put into a digester and converted into biogas, a source of power, while at the same time reducing greenhouse gas emissions. Juehnde, a German village, for instance, now generates enough biogas for heating and cooking that it has became independent from the national gas grid.
 
Another option to save energy and grow more food is to mix carbon dioxide from smokestacks at coal plants with sea water to grow algae, Webber says. Algae can be used to produce biofuel and potentially as food for humans and animals. However, it may be decades before this kind of solution could be implemented at a large scale, despite a range of testing and pilot programs now underway.

Certain innovative agricultural techniques also could help.
 
Drip irrigation spares freshwater and the energy needed to distribute it. Long sections of tubing laid at the bottom of the plants delivers water directly to the roots, cutting the losses to evaporation when water is sprayed into the air or directed into open channels during conventional irrigation.
 
No-till agriculture – drilling seeds into the undisturbed soil with special equipment rather than plowing the earth – also reduces the amount of labour, irrigation and energy needed to grow food, while also cutting erosion and carbon emissions. More than half of the farms in Argentina now use this technique, making the country the world leader.
 
As many fields have a gradual slope, which causes water and fertilizer to pile up in some areas while others receive too little, farmers often over-irrigate or over-fertilize the entire field to ensure all areas remain productive. But using laser technology to help level fields can minimize erosion, irrigation and fertilizer runoff, and cut the amount of fertilizer needed, as well as energy to run irrigation pumps.
 
REDUCING FOOD WASTE

Another approach proposed by Webber to reduce energy consumption and greenhouse gas emissions is to reduce the amount of food that is being wasted – a move that might have a bigger environmental impact than expensive or controversial energy supply policies.
 
One of the methods proposed includes investing in diagnostic methods that could monitor food spoilage instead of relying on use-by date labelling, which can result in still good food being discarded. One way to improve food monitoring may be to better track its temperature, perhaps by using inks on food packaging that change colour if the food is exposed to the wrong temperature levels.
 
Finally, every-day dietary choices are important, too. If we can eat less energy-intensive meat and more energy-efficient products like fruits, nuts, vegetables and grains, more food will be available. Simply serving leftovers – rather than throwing the remainder of a meal away – can also make a difference and doesn’t require a bit of innovation, only new thinking.
 
As the so-called ‘Green Revolution’ that boosted food production in Asia and Latin America a few decades ago showed, big changes in food availability are possible. But as the world looks for a new revolution in food production by 2050, technology alone may not be enough. Hunger lingers around the world. What may be critical is reducing energy waste in food production – a global effort build on new behaviours, attitudes and policies.

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