February 19, 2009
The politics of food-9: Sustainable farming
(This series of posts looks in detail at some of the fascinating aspects of food production identified by Michael Pollan in his book The Omnivore's Dilemma (2006). All page numbers refer to that book, unless otherwise noted. Other related posts can be found here.)
For me, the most interesting part of the book (p. 190-237) was the section on sustainable farming, in particular what is known as 'grass farming'. Grass farmers grow animals for meat, eggs, milk, and wool. But the whole system is designed as a food chain based on grass. It is a surprisingly precise process, starting with understanding the life cycle of grass.
Grass has a growth cycle like an S-shaped curve, starting slowly, then rising rapidly and then leveling out after about fourteen days, depending on the season and the weather. The farmer has to know how long it takes for grass to reach its optimum height and then he allows cows to graze on that grass. The 80 cattle on Joel Salatin's Polyface Farm in Virginia are allowed into a section of the pasture at the very top of the blaze of growth in that pasture. The cattle are allowed to take one bite but not allowed to take a second bite of the same pasture, in order to avoid overgrazing. This means that the amount of cows per unit area of pasture per day has to be strictly controlled. As soon as they have done their one-bite grazing, they are moved to the next paddock where the grass has also reached its optimum height and might be thigh-high. And so on.
To carry out this strategy, Salatin divides his pasture into several dozen paddocks of about one to five acres, depending on the season and the weather, since those things affect the rate of growth of grass.
As they graze, the cows spread and fertilize grass seed with their manure, and their hoof prints create little pockets of exposed soil for water to collect and germinate grass seeds. After the cattle leave, that section of pasture is then left alone for the grass to grow back and to enable worms and grubs to enrich the soil. The pasture is then visited by broiler chickens in 10'x12', two-foot tall floorless pens, that are moved every day by 10 ft. This enables the chickens to feed on the grubs and other life forms that have fattened on the rich soil left behind by the cows. Chickens also get some corn, toasted soybeans and kelp along with the grass they eat. Chicken feed is the only important input for the farm that is brought in from outside and constitutes about 20% of the chicken's diet.
The layer hens are also taken in a mobile henhouse called the Eggmobile housing 400 hens into a pasture three days after the cows have left, and they are let out into the pasture so that they can eat the fly larvae that have grown into grubs. These provide the chickens with protein. The chicken droppings fertilize and replenish the soil and help more grass growth.
Rabbits and turkeys and pigs are parts of similar cycles to ensure that nothing goes to waste.
So the whole process is a closed loop where the output/waste of one part of the cycle becomes the input for the next. This means that you cannot scale up one part alone. As Joel Salatin says:
In an ecological system like this everything's connected to everything else, so you can't change one thing without changing ten other things.
Take the issue of scale. I could sell a whole lot more chickens and eggs than I do. They're my most profitable items, and the market is telling me to produce more of them. Operating under the industrial paradigm, I could boost production however much I wanted – just buy more chicks and more feed, crank up the machine. But in a biological system you can never do just one thing, and I couldn't add many more chickens without messing up something else.
Here's an example: This pasture can absorb four hundred units of nitrogen a year. That translates into four visits of the Eggmobile or two passes of a broiler pen. If I ran more Eggmobiles or broiler pens over it, the chickens would put down more nitrogen than the grass could metabolize. Whatever the grass couldn't absorb would run off, and suddenly I have a pollution problem. (p. 213)
This is why farms like Salatin's are incompatible with giant organic chains like Whole Foods. The chains want to be able to purchase large but varying quantities according to the needs of the national market. On Salatin's farm, the needs of the environment determine the range and amount of food that he produces. Such farms end up catering to those members of the local community that care about how their food is produced.
The rise of farmer's markets and the locavore/localvore movement (consisting of people who try to buy food produced in the local area) are signs that people are becoming more conscious of their food. Some parts of the country cannot practice year-round agriculture making it hard for people to be fully locavore, but doing as much as they can is a start.
POST SCRIPT: Please support Antiwar.com
One of the best news and analysis sites around is Antiwar.com. Started during Bill Clinton's war in the Balkans, it has taken a consistent stand against the many wars that have been conducted, irrespective of the ideological labels attached to the protagonists. It has correctly identified the pro-war/pro-business single party nature of American politics and steadfastly opposed its war-like policies. Although the people behind the site are mostly libertarian-conservatives, as a result of its principled stand, the site has attracted support from people all over the political spectrum.
The site does not take advertising and depends on reader support. It is currently running a fund-raiser so please support it if you can.