|Prof. E. Ann Clark challenged Farmer to Farmer participants to design systems that will make their farms more perennial and sustainable.
By E. Ann Clark, Professor, University of Guelph, Ontario
The premise of Ann Clark’s keynote speech at the 2009 Farmer to Farmer Conference was that agriculture, including organic, is not ecologically sustainable because it was never designed to be sustainable.
“The concept of designing something and expecting it to work even if you didn’t design it that way came to me from hearing Bill McDonough speak. I was very impressed with him when he said he does not support recycling of paper, because paper was never designed to be recycled.” So recycling paper uses a lot of water, toxic chemicals and added fiber. The book Cradle to Cradle, by William McDonough and Michael Braungart (North Point Press, 2002), is published on a type of plastic that looks and feels like paper but is designed to be recycled: The ink can be removed from the pages to make a new book.
So design is an issue that we in agriculture, particularly in organic agriculture, need to be thinking about, said Clark. We can use the principles that sustain nature as the foundation for designing agriculture, by, for example, integrating perenniality and livestock far more than in the past.
“I think one of the worst crimes of institutional agricultural thinkers,” said Clark, “has been to encourage farmers to specialize, to become hay producers and dairy producers and vegetable producers, but not integrating crops and livestock.
“The premise is, ‘Design is the first sign of intention,’” said Clark, quoting McDonough and Braungart. “So I ask you, what was agriculture designed for?”
Her answer: Agriculture (or logging, fishing, trapping) in colonial America was designed to produce vast quantities of bulk, homogenous product for export to the mother country, so that those countries could feed themselves, produce value-added goods, etc.
“Originally it was the mother country, and now, we’ve taken the same model and reapplied it to ADM, Cargill, IBP, Smithfield, Whole Foods Market or Earthbound Farms, or Aurora, or any of those others. So organic is following very much in the same production and marketing model … as conventional. We do it a little differently. We impose a little less harm; but in many respects it is modeled on exactly the same paradigm, and to our detriment.”
Agriculture was also designed for sustenance, so that we could eat; for export, taxes, tithing or obligation to others; to provide an income and/or a healthy, independent lifestyle; and for recreation – but not for sustainability.
Annual Agriculture: Unnatural and Unsustainable
McDonough asks why a toothbrush takes 500 years to decompose in a landfill. The answer: It wasn’t designed to decompose.
“I’m arguing today that agricultural sustainability is in the same boat,” said Clark. As an example, we have a 20,000-square-kilometer hypoxic (low oxygen) zone at the mouth of the Mississippi (and in countless other places) “not because we intended it to be that way, but because we didn’t intend for it not to be that way. It wasn’t a design driver.” The so-called Dead Zone in the Gulf of Mexico is due mostly to nitrogen (N) and phosphorus (P) runoff, primarily from Midwestern corn fields.
Clark argued for a fundamental change in the design of organic agriculture. “For thousands of years,” she said, long before synthetic biocides, fertilizers and genetically engineered crops, “humans regularly farmed themselves to oblivion” in many places because of “over-dependence on food crops with an annual growth habit.
“Annual crop agriculture is inherently unnatural and unsustainable, for many reasons,” Clark explained. “It lends itself to linearizing nutrient flow in the form of exported crops. Annual grains in particular lend themselves to that, because they dry and store well, they are transportable – they don’t move very much water. So we’ve evolved a system that’s based on export-oriented agriculture, and that intrinsically depletes soil nutrients to a deficit level at one end, while concentrating them to an excess level at the other end – as in a feedlot.”
Vegetables, too, carry large amounts of nutrients with them when they leave the farm.
Annual crops usually result in bare soils for long periods. “Nature has evolved many strategies to keep the ground covered,” yet when annual agriculture keeps the ground bare, “we’re fighting with nature for the whole time.”
In most places in the world, the native vegetation is perennial: trees in our area, grasses in others. Only in very dry climates did annuals evolve. Perennials are sinks for all kinds of nutrients, not just N, as long as they’re alive, said Clark; so nutrients accumulate under perennial forests.
Annuals, “unless you’re really good at it with cover crops, can never compete with perennials in terms of nutrient retention.” Annual crop land loses substantial amounts of nutrients in our area in spring and fall, when annuals are planted and harvested, because precipitation exceeds potential evapotranspiration.
Monoculture is another problem with annual agriculture. Monocultures are rare in nature, which is almost always very biodiverse, which tightens nutrient cycling and suppresses diseases. “Any of these organisms we call pests are really pests because they’re out of context. They’ve lost the normal elements that keep them in their place.”
The process of succession in nature, Clark continued, accumulates nutrients, organic matter and biodiversity, which together sustain nature. “We lose that in annual agriculture, which starts over every year with high end-stage succession.”
In contrast, perennial forages (grasses, legumes, forbs) mimic nature, and grassland leys (a few years of forage followed by a few years of grain, then a few years of forage) are the closest we’ve come in this part of the world to mimicking nature while sustaining human nutrition and minimizing dependence on fossil fuels.
Clark discussed a 20-year study she did on rotations involving corn in which some plots included a red clover plowdown crop, and some had alfalfa hay as a following crop. The more perennial forage was included in the rotation, the more organic matter accumulated, because perennial forages withhold the land from cultivation, which slows decomposition of organic matter and pumps carbon (C) into the soil through roots and plant parts that die and return to the soil every year. If you include on- and off-farm sources of greenhouses gases, acknowledging all the energy consumed to make and transport synthetic fertilizers, biocides, etc., then you get very large differences in emissions of CO2 and nitrous oxide. Every rotation except those with alfalfa was a net greenhouse gas emitter.
So, said Clark, perenniality confers advantages that are very suitable for a post-oil future. Including perennial forages in rotations replaces the C lost in years when annuals were grown.
Conservation tillage, she noted, does not reverse C loss. In addition to depending on herbicides or new crimping devices, conservation tillage slows the rate of breakdown and redistributes C vertically but doesn’t actually increase soil C in this part of the world. “It works in dry places – Wyoming, Kansas, Alberta – you do see a net increase in soil C under conservation tillage, but not in wetter areas.”
Clark shared British data showing that when you sell animal products from a hectare of land, you sell much less nutrient off your farm than when you sell a grain or vegetable crop – and hay is worst. “So part of the logic of mixed farming, historically, having some of your land in forages, where you’re marketing an animal product, versus having some of your land in (and selling) grains or vegetables, is reducing the total implied nutrient loss from your farm that you may have to recover from somewhere else. One approach is to lose less – e.g., selling that acre as meat or milk or eggs rather than as grains, vegetables or, especially, hay; the latter leads to large losses of N and K.”
Clark recommended the book Farmers of Forty Centuries, written by agronomist F. H. King, who noticed that the United States had lost half its topsoil after farming for only 100 years, while China, Korea and Japan had been farming for thousands of years, had much greater populations than the United States, and their soils were still robust and healthy. Touring those countries in 1909, King saw that nothing was wasted. People pushed a steady stream of wheelbarrows from the city to the countryside, returning human waste to agricultural areas, where it was rigorously composted and returned to the land. Farmers put outhouses along their roads for passersby to use.
Modern American systems, however, are designed “so everything ends up in the ocean or the air; it doesn’t come back to the land, even in organic systems when they ship crops off their land.”
More than Feed
As opposed to annual crops, which degrade the soil, export nutrients, detract from long-term sustainability, and hence, challenge the future of agriculture, perennial forages are more than just livestock feed, said Clark. Grasses and legumes “perform a lot of services” that benefit the farm and the planet.
They provide year-round ground cover, which suppresses weeds – not through competition but by modifying the quality of light coming through the canopy; they add and retain organic matter and scavenge N from deep in the soil, because the deeper roots of grasses recycle nutrients vertically that got below the rooting depth of other crops; they provide nutrient “sinkness” by keeping the ground covered all year rather than having it bare and subject to leaching for long periods; they provide biodiversity and successional benefits and cycle more nutrients on the farm (since far less nutrition leaves the farm in animal products); provide greenhouse gas abatement and animal health and welfare.
“If you look at organic standards,” said Clark, “the emphasis on allowing animals access to outdoors and to grass is really premised on maintaining their own health, their own ‘pigness’ or their own ‘chickenness’ or their own immune system, getting access to wind and light…grass lets that happen.”
Forages also enable water table management. “You can select forages for depth of rooting to keep the water table down to prevent salinization.”
Green pastures between trees are aesthetic, and crops such as switchgrass can provide bioheat. You can give grazing animals anthelminthics and other medicinals that you cannot give them under other conditions.
Benefits of Livestock
So perennials are good – but why livestock? For those who enjoy livestock and are willing to manage and feed them 365 days of the year, livestock are desirable “because humans do not do well on grass, while livestock bridge what the planet needs (all the benefits of perennials cited above) and what we need – to convert that land into a salable product that also sustains human nutrition,” said Clark.
Clark described a system in the damp areas of Nicaragua where people collect termite nests and burn them at night to ward off mosquitoes. As the nests burn, termites run out, and chickens eat the termites. Later the chickens provide eggs and meat to the families.
“That’s what livestock can do on a sustainably managed farm,” said Clark. “They give an economic justification for doing the right thing by the planet.”
Grass ley farming – interspersing intervals under perennial grass and red clover plowdown with intervals of annual cropping – is the closest analogy to that, and only dairy farmers do that today.
Clark and her coworkers surveyed 12 organic farms for three years. Half were grain and livestock farmers; the others grew horticultural crops and had no livestock. “We found that the soils on the horticultural farms that had no livestock were at least as good, if not better than, the neighbors’ who were also organic but had livestock and grains – because the six horticultural farmers without livestock grew their crops only four years in 10; the other six years were forages – red clover, alfalfa, hairy vetch, different forages, or grain crops – winter wheat, fall rye, spring oats, which they incorporated into the soil or sold off the farm, but the purpose of those crops was to provide services to the horticultural farm, e.g., to improve the soil, bring nutrients back, control nematodes, etc. They were designed to prepare the site for the horticultural crops.”
Although these farms did not have livestock, they depended on livestock farms, to buy the hay or grain coming off the farm or to provide manure to replace the nutrients and organic matter that they were losing when they sold their horticultural crops. So livestock were essential to these farms. However, most of the manure the horticultural crop farmers were importing was not from organic livestock, and “all kinds of stuff comes out in manure that you don’t want on your farm,” said Clark. Composting deals with some but not all of it, she added.
Livestock typically means ruminants – cows, beef, veal; pigs can be pastured but must graze mostly on legumes; chickens can get up to about 15 or 20 percent of their feed as forage, but they depend on grains or some other energy-rich nutrient source for the rest of their diet.
So “grass is the forgiveness of nature,” said Clark, “a role that is made compatible for contemporary agriculture because of livestock. But in order to make grass work in contemporary agriculture, you have to have a way to turn it into money. That’s what livestock is.
“It’s more than that, though. I emphasize the idea that grass provides services to the farm and to the planet. But more than that, it enables enterprise stacking (Joel Salatin’s term) to capture the economic and ecological synergies that will sustain agriculture and rural communities into the future.”
|Toki Oshima drawing|
Clark ended her keynote with ways to integrate animals with other crops. For example, at Tony and Fran McQuail’s 2-acre apple orchard in Lucknow, Ontario, Tony discovered that earthworms take the leaves of apple trees underground over winter and eat them – thus removing the major source of inoculum for apple scab. So he now spreads compost from the livestock part of his operation under each tree to increase earthworm populations. This produces a lot of grass growth, so he strip grazes sheep through the orchard – and the sheep eat downed apples, thus removing codling moth larvae. By raising sheep and apples, the McQuails get income from two enterprises from the same piece of land.
Fred Reid of Abbotsford, British Columbia, integrates 9,000 organic laying hens with raspberries. He noticed that chickens are creatures of edge: They don’t like grasslands or going into forests, but they do like edges. So he creates edge with rows of raspberries. Half of his 20-acre farm is in productive raspberries and half is growing up to be producing. When raspberry plants in the producing half are up high enough that the chickens can’t reach them to eat them, he plants cereals between the rows to give the chickens something green to eat, which is required under organic standards.
The chicks are raised in an open barn. Once they’re laying and they know where home is, he opens the door at 11 a.m. (after they’ve laid their eggs for the day) to let all 9,000 out. The half of the farm that is in raspberries is divided with chain link fence into grazing paddocks. He rotates the chickens from paddock to paddock over the summer, where they voraciously eat greens and scratch out weeds, roll in the dust, deposit manure (reducing the amount he has to remove from the barn).
The chickens return to the barn on their own at night. Four big dogs guard the barn. Reid has a similar system for greenhouse-grown vegetables. His wife grows vegetables between raspberry rows in the half of the farm that isn’t producing berries yet and sells them off the farm, helping maintain the correct nutrient balance. Otherwise nutrients from the chicken manure would eventually build to excess levels.
At the Abbey of Regina Laudis in Bethlehem, Connecticut, three weaned Tamworth piglets are placed in a paddock made with Flexinet fencing on the perimeter of hay or pasture fields to control woody weeds such as barberries, multiflora rose and poison ivy that grow from under the trees into pastures and hay fields. A small trailer holding grain and water moves with the pen. The pigs root around, cleaning the area thoroughly of woody plants and suckers, and are moved around the edge of the field throughout the season.
Greg Gunthorp of Le Grange, Indiana, finishes 1,000 hogs on grass all year. Gunthorp has no barns, but individual sows live in small quonset huts with straw on the ground in winter. Weaned pigs that are going to become meat live in larger quonset huts that are open on both ends and are packed with straw. Part of the reason Gunthorp makes money with pigs is that he doesn’t own all the land he grazes. He undersows red clover on a neighbor’s grain land, and after the grain is harvested, Gunthorp’s pigs strip graze that land all winter, consuming red clover and stubble. He buys in corn and minerals. In spring he picks up the pigs and his moveable fence, and the neighbor has a nicely manured field.
The Armours of New York integrate livestock with about 50 horticultural crops on 25 acres. The husband and two summer employees are the only labor. They sell thousands of pounds of heirloom tomatoes at farmers’ markets (manned by their two children) and through their CSA. They let their big pile of very strawy manure sit for about two years. Then they pick up the pile with a front-end loader, back the tractor down the raised beds, and fork the compost onto the surface of the raised beds. Every bed gets covered about every two years. They never step on the beds, and they never work the compost into the beds. Instead, the very coarse, open fluff stays on the soil surface. This mulch prevents weeds in the soil seedbank from getting enough light to germinate; and the fluffy nature of the compost prevents incoming weed seeds from making good contact with the soil, so they don’t germinate. Thus, the Armours’ beds have no weeds.
Clark concluded that sustainability has to be a design driver if agriculture, including organic agriculture, is going to sustain us in the future. “We have to incorporate more perenniality in our farms. If we don’t have enough excess land where we can economically turn it under and not make any use from it, if you need to get some income from all your land each year, that means livestock. And you don’t want to be selling hay, because you’re selling a lot of nutrition off your farm. It doesn’t have to be you [raising livestock]. If you have a neighbor who loves pigs, let them be the ones who raise pigs on your land. You have to have intervals of grass or perennial forage in the system in order to be sustainable.” Clark believes that livestock are the glue that enables ecological and economic synergies in the post oil era.
E. Ann Clark is an associate professor at the University of Guelph in Ontario, where she specializes in pasture and grazing management and in organic agriculture. She is an outspoken critic of genetically engineered crops. She wrote a chapter called “Forages in Organic Crop-Livestock Systems” in Organic Farming, The Ecological System, edited by Charles Francis and published in 2009 by the American Society of Agronomy.
– Jean English