Nowadays I think a lot of our food choices are defined by labels: is this apple certified organic? Was this chicken “free-range” and “humanely-raised” on a family-owned farm? Though labels are definitely helpful and important, in this post I want to point out that truly good farming might defy a label or a certain list of requirements. It is an entire holistic approach. And often the correct approach takes after nature in some way. This approach is effective because nature’s cycles are efficient, sustainable, and waste-free, which is exactly what we are looking for in farming. One example is Permaculture, which you can read about in my earlier post. Not only are these methods fascinating, I think they have a lot of potential for growth if applied to our current conventional agriculture model. One such method is management intensive grazing.
Management intensive grazing or MIG is the name for a variety of methods of rotating livestock on separate patches of grass (also known as paddocks). This might sound kind of boring but I promise it’s pretty cool! Joel Salatin of Polyface Farms famously implements MIG with his cattle. In this method, different paddocks are sectioned off by electric fencing so that cows only graze in one area for a certain number of days at a time. Cattle rotate between paddocks at a precisely calculated time based on the number of animals and size of the paddocks among other things. It may not seem incredibly innovative or complex, but there is a lot of science behind the technique. It offers many benefits to the land and animals.
In letting cows find their own food, fertilize the ground with their waste, and roam around with lots of room, farmers avoid costs and inputs like feed, fertilizer, and antibiotics. These benefits are similar to those of regular old grazing, but because the system is controlled and managed so precisely, the benefits are maximized to get the most out of a given area of land.
Grass-fed beef is often hailed as a sustainable alternative to more conventionally grown beef, but critics point out its huge space requirements. They claim that it would be impossible to feed the US on grass-fed beef because it would take too much space, about 35,000 square miles or 10% of US land according to one estimate. However, this estimate does not take into account the space-efficiency of MIG. With MIG, Joel Salatin can raise 85 cows on 100 acres, which is about 1.2 acres per cow, much better than the 2.5 acres per cow that the above figure was based on.
How can we fit more cows on the land by just moving them around? In rotating cattle through different paddocks, the animals are forced to eat grasses that might not be their favorite. They therefore get the most food out of a given area. Usually a cow eats the young, fresh grass closest to its comfy spot in the shade and ignores much of the rest. In a conventional system, each cow may need a few acres of land but it doesn’t eat all of the grass on those few acres, only 30-40% according to this paper. Though I can’t provide an exact number, I’m sure the figure is much higher on intensively grazed land.
Since the farmer is making the cows move around and eat differently, MIG might seem to go against the natural behavior and diet of the cows. Yet the cows’ diversified diet and increased movement is surely beneficial to them. And when MIG and other agricultural systems copy nature, they can’t do so exactly and completely because farmers are still aiming for production and practicality. In nature every loop feeds back into itself, but on our farms we take out the finished product to eat or use. That finished product is the goal of the endeavor so we can’t forget about it in the quest to mimic nature.
In subsistence farming, a family can effectively become part of the farm food chain because it produces only to feed itself. The loop is contained. But otherwise, and especially if a farmer is growing food for hundreds of people, the farm or pasture differs inherently from its wild counterpart because it extracts and distributes that finished product. The farmer must tweak nature to find a balanced technique that produces for us and still keeps the land and creatures healthy.
The use of cows’ waste to fertilize the land helps illustrate this balance. In a conventional feedlot, cows are so concentrated that their waste becomes a pollutive problem. But what can be toxic in such large amounts is healthy in more moderated amounts. Cowpies are a natural fertilizer for the grass and help return nutrients to the land. On conventionally grazed land, the cows’ waste is enough to benefit the land but not overwhelm it. And in MIG, with more cows per acre (known as a higher stocking rate), the cows’ waste is more concentrated to optimally fertilize the land. Whereas the conventional feedlot sacrifices the health of the environment to achieve its finished product most cheaply, MIG balances the need for productivity with a need to keep the land healthy.
MIG mimics nature in that it is designed to take advantage of the fascinating and surprisingly complex relationship between grazing animals and grass. This process starts when the cow takes a bite of grass. The grass plant likes to keep an equal balance of leaves and roots so it will shed some of its roots to make up for the lost leaves. In turn these roots decay into fertile soil, and provide room for air, water, and a variety of creatures which are all beneficial to the land. We wouldn’t see these benefits had the cow not eaten that bit of grass. The grass (and the land) are actually better off with the cow around. Yet this process would end if the cow were to come back, take another bite, and prevent the grass’s re-growth. Thus the cow must be moved to another paddock in order for the grass to recover, just as a field may lie fallow to replenish its soil’s nutrients.
MIG also increases the diversity of grass species in a field. Cows may eat and cut down taller grasses and in the process make room for shorter varieties. But the cow must be moved off the paddock before they can decimate any one species (as may happen on conventionally grazed land). This precise system helps to create a balance of several different species, each important to the function and fertility of the land. With this balance, we can maximize the land’s use of sun and water. For example, drought-resistant species can thrive in drier times and seasonal varieties can ebb and flow during different parts of the year so that the field’s grasses are making the most of the present conditions and resources. Keeping every patch of ground always covered in grass prevents weed growth and erosion to maintain a long-lasting fertile topsoil.
As Michael Pollan puts it in his book The Omnivore’s Dilemma, “the grazing of ruminants, when managed properly, actually builds new soil from the bottom up.” Though many studies show that mismanaged grazing can severely damage land, we can see that grazing indeed has a positive effect on the soil if managed properly. I find it fascinating that the most efficient and sustainable way to graze land includes the use of electric fences when the free-for-all roaming of cows may seem more natural. We might not picture tons of electric fences when we think of happy cows out on pasture, but in this case a technology so seemingly unnatural is indeed our best tool to keep nature healthy. Go MIG!
I was originally planning on talking about a number of other techniques like aquaponics and conservation tillage, but there is so much to talk about with MIG that I got a bit carried away. I’ll continue to talk about innovative farming techniques in another post. Thanks for listening to me talk about cows eating grass for so long. Below are my sources for this post:
The Omnivore’s Dilemma by Michael Pollan