Page 288 - Environment: The Science Behind the Stories

Whether we can feed several billion people in a global urbanized
society with organic agriculture is an open question, however.
Approaches toward sustainable agriculture differ greatly,
but all aim to address adverse environmental and social
impacts. These include soil degradation, overuse of water, fos-
sil fuel combustion, loss of crop diversity, loss of biodiversity,
loss of pollinators, overuse of chemical pesticides and ferti-
lizers, and pollution from feedlot and aquaculture operations.

Locally supported agriculture is growing

Many proponents of sustainable agriculture have called atten-
tion to the fossil fuel energy we use to transport food long
distances. Those who tally “food miles” say the average food
product sold in a U.S. supermarket travels at least 1600 km
(1000 mi) between the farm and the grocery. Indeed, our exten-
sive transportation infrastructure distributes a wide variety of
foods reliably to all areas but, in doing so, burns large amounts
of petroleum. Because of the travel time, supermarket produce
is often chemically treated to preserve freshness and color.
In response, increasing numbers of farmers and con- Figure 10.29 Farmers’ markets are flourishing as consumers
sumers are supporting local small-scale agriculture. Farm- rediscover the benefits of buying fresh, locally grown produce.
ers’ markets (Figure 10.29) are springing up throughout
North America as people rediscover the joys of fresh, miles from producer to retailer contributed just 4–5% of total
locally grown produce. At farmers’ markets, consumers greenhouse gas emissions of the entire process. Fully 83% of
buy meats and fresh fruits and vegetables in season from emissions resulted from production at the farm or feedlot. As
local producers. These markets generally offer a wide a result, the average consumer can reduce his or her ecologi-
choice of organic items and unique local varieties not cal footprint more effectively by shifting dietary choices (such
found in supermarkets. as eating more fruits and vegetables and less meat and dairy)
Some consumers are partnering with local farmers in
community-supported agriculture (CsA). In a CSA program, than by eating locally sourced food, these researchers main-
tain. In Calculating ecological Footprints (pp. 290–291), you
consumers pay farmers in advance for a share of their yield, will work with some of this data yourself.
usually a weekly delivery of produce. Consumers get fresh
seasonal produce, while farmers get a guaranteed income
stream up front to invest in their crops—a welcome alterna- Sustainable agriculture mimics natural
tive to taking out loans and being at the mercy of the weather. ecosystems
Farmers markets and community-supported agriculture help
strengthen local economies while giving the consumer access to The best approach for making an agricultural system sus-
fresher foods. They also often cut down on food miles. How- tainable is to mimic the way a natural ecosystem functions.
ever, the number of miles a given item has traveled is not in itself Ecosystems operate in cycles and are internally stabilized
a reliable measure of fossil fuel consumption. In many cases, with negative feedback loops (pp. 124–125). In this way they
shipping a food item far away as part of a large shipment may provide a useful model for agriculture. CHAPTER 10 • A g R i C ulT u RE , Bi o TECH nology, A nd THE Fu T u RE o F Food
result in less fossil fuel use per item than transporting the item One example comes from Japan, where some small-scale
a short distance but in small quantities. The heirloom tomato rice farmers are reviving ancient traditions and finding them
at the farmer’s market that was grown 20 miles away may be superior to modern industrial methods. Takao Furuno is one
more delicious than the conventional one at the grocery store that such farmer. Starting 20 years ago, he and his wife added a
traveled halfway across the country, yet its production, transport, crucial element to their rice paddies: the crossbred aigamo
and sale may sometimes involve more fossil fuel use, not less. duck. Each spring after they plant rice, the Furunos release
To determine which alternative involves less energy use hundreds of aigamo ducklings into their paddies (Figure 10.30).
overall, one needs to conduct a life-cycle analysis, a quantita- The ducklings eat weeds that compete with the rice, as well as
tive analysis of the inputs and outputs across all stages of an insects and snails that attack the rice. The ducklings also fer-
item’s production, transport, sale, and use. Performing a full tilize the rice plants with their waste and oxygenate the water
life-cycle analysis (p. 641) is a complex endeavor, and we can by paddling. Furuno and the scientists and extension agents
expect results to vary from case to case. In general, research who have worked with him have found that in rice paddies
so far has shown that fruits and vegetables consume the least that have ducks, rice plants grow larger and yield far more
fossil fuel energy, that grains use more, that eggs and chicken rice. Once the rice grains form, the ducks are removed from
use still more, and that beef and dairy products use the most. the paddies (because they would eat the rice grains) and kept
In the most comprehensive life-cycle analysis of U.S. food in sheds, where they are fed waste grain. They mature, lay
production and delivery so far, researchers found that food eggs, and can be sold at market. 287

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