Food in Winter: Eating Locally Means Preserving Locally

Food prices have been rising; between June and November 2010 the prices of staples such as wheat and corn have gone up by more than 25% (1). One likely reason is rising energy costs. Food production is energy-intensive, and if the cost of energy rises, so must the price of food. In the U.S., we consume over 10 quadrillion Btu (quads) of energy a year, about 10% of our total energy consumption, to produce the food we eat. Some of this energy is used to manufacture fertilizer and pesticides and to run farm equipment. Much of the energy is used to transport, process, package, distribute, and market food items. But the biggest chunk of energy used by the food system is for storing and cooking and otherwise preparing food, most of which happens in the home (2).

It’s looking increasingly likely that global oil production has peaked; even some previously skeptical commentators have come to this conclusion (3). If production has peaked, global oil supplies will eventually start to decline. It is not clear whether this decline will be steep or gradual or how soon it will begin. If the decline is steep, the price of liquid fuels such as gasoline and diesel could rise rapidly, and there could be shortages. The food system, with its many interconnected links dependent on liquid fuels, is vulnerable, and this means food itself could become more expensive or even scarce.

One solution, for areas with suitable land and enough rain, is backyard food production and local agriculture. Locally grown foods, less dependent on transportation and distribution networks, should be somewhat immune from the worst effects of price increases and possible shortages of fuels (4). But local food production cannot be depended upon if the supply ends when the growing season ends. Even with hoop houses and other technology to extend the harvest, in most of the U.S. locally grown food will not be available for half the year unless it’s been preserved. If shipments from California, Florida, and Mexico become expensive or unavailable, there better be something in the refrigerator, the freezer, the cold cellar, the smokehouse, the pickle barrel, or the pantry.

There are many tried-and-true methods of food preservation. An important aspect is energy use. Using estimates in the literature (5) and my own calculations I have estimated the energy consumption of a variety of these methods. Freezing and refrigeration score especially poorly, in part because electricity must include the energy required to produce it, and also because a freezer must run for an entire storage period whether it is full of food or down to one item. Drying requires a lot of energy. But once dried, foods will keep for many years if properly stored. Canning requires energy too but canned vegetables and fruits will keep well for several years. And some canned foods such as tomato sauce (pictured above), if made from home-grown, vine-ripened fruit by someone with anything like the skill of my wife Louise, are better than what you can buy.

Local food-growing systems will become more meaningful and important to the degree that they address the importance of food preservation.

(1) Foley, John, Food Prices Face a Perilous Rise, NY Times, 12/29/10
(2) CSS, 2007, Factsheets: U.S. Food System, http://css.snre.umich.edu/css_doc/CSS01-06.pdf
(3) See Krugman, Paul., The Finite World, NY Times, 12/26/10
(4) I am referring here to field-grown crops, not the extremely energy-intensive food production of heated greenhouses.
(5) Smil, Vaclav, 1991, General Energetics, John Wiley & Sons, NY

Lawns, the Price of Eggs, and Chicken Tractors

Lawns provide fine venues for sports, but why do people maintain big lawns that are never used for anything? Maybe lawns stimulate something deep in our psyches. Maybe at an unconscious level the smell of fresh cut grass equals “good” (food for a horse) or an expanse of close-cropped green surrounding the house equals “safety” (no snakes nearby). Lawns don’t come without some cost however. According to EPA, Americans burn 800 million gallons of gasoline yearly, about 0.6% of the total use of that fuel, to mow grass. Lawn care also uses water and pesticides.

A big lawn could become a useful resource for feeding chickens. There's an upsurge in interest in chicken-raising, perhaps related to the price of eggs, which has risen recently as shown in the chart. Agricultural commodities can be expected to rise in cost as energy prices increase, so eggs may get more expensive. Also, the grossly crowded conditions of today's industrial poultry operations raise questions about the quality of commercial eggs. Unfortunately, producing one’s own eggs with a small flock of chickens is only marginally cost-effective. The main cost is the price of feed. My calculations suggest that buying, housing, and feeding a dozen or so egg-laying hens for three years will cost in the range of $150 per bird, not counting the labor to take care of them. Each hen will produce approximately 50 dozen eggs during this period; so if the eggs are worth $3 a dozen the benefits more or less equal the costs.

However, if you have a flock small enough so that you can feed it largely with kitchen and table scraps, and if you can keep your chickens on good pasture a lot of the time, the cost picture improves. The scraps from a family of four could make up half the feed of four chickens. Good pasture would cut the feed bill further. Chickens will eat just about any food scrap that is at all edible. They are adept at catching flies and other insects and ticks. They love green matter so much that they will quickly defoliate a small fenced-in yard, reducing its pasture value to virtually nothing. The key to providing good pasture is to have a large enough area so that the birds can’t get ahead of plant growth. An ideal approach is to frequently move them to fresh pasture. It’s not hard to do this with a different kind of lawn tractor - a chicken tractor. The chicken tractor pictured was built by a co-worker of mine, Dave Bean. It houses several chickens and is not hard to move around on the lawn. It protects the chickens from predators, but it’s open to the grass below. With a chicken tractor making its rounds, the chickens eat, the grass gets chopped off and fertilized, lawn insects and ticks are obliterated, and there’s still a lawn area for a volleyball game.

Weeding Out False Positives

Weeds are unwelcome parasites in a garden, taking water, nutrients and light away from plants we want to grow. Individually or in low numbers, they aren’t a concern, but a weed infestation can be devastating. A false positive is a belief that things are connected when in reality they are not. In a way, a false positive is a weed of the mind. Like weeds, false positives seem to sprout naturally. We look for patterns and connections, and we file away memories of what look like cause and effect relationships. False positives are typically harmless, but if there are enough of them, or they are particularly influential, they can lead us astray. In his recent book The Vanishing Face of Gaia, James Lovelock points out that superstition and belief in magic – classic examples of false positives - are long-standing habits of human thought, whereas the scientific method, with its use of observation and measurement to circumvent false positives, is only a few hundred years old.

I had a chance to weed out a false positive three months ago. A person who seemed authoritative told me that it was getting time to plant peas, but that the Farmer’s Almanac said that peas planted on March 21 would rot in the ground. My plan had been to plant peas on just that day, and my first thought was to put it off to another day with a less ominous prediction. After all, it’s a strange world, and maybe the Almanac had some insight on peas and planting dates. But March 21 was a beautiful sunny day, and the seeds went in the ground, albeit with some trepidation on my part. I’m happy to say they sprouted and have produced the bountiful plants in the photo above. Did I tempt fate and get lucky? I don’t think so. More likely, I just stumbled on another pesky false positive and, this time anyway, was able to pull it out.