In 2010, there were almost 6.8 billion people living on the face of the earth. World population was quickly on its way to 9 billion by the year 2050. To feed all those mouths, farmers till a little over 21 billion acres worldwide. That seems like a lot, but that arable land is actually only 3 percent of the world’s surface.
To feed all those people, farmers in the 20th century turned to high-tech agriculture. But in the first decade of the 21st century, some farmers and researchers were wondering whether our high-tech system could be sustained over the long term. There were some obvious future challenges, but little agreement on how we should meet the challenges.
Historians have documented how ancient civilizations died because they could not sustain their agricultural systems. For instance, prehistoric city-states in Mesopotamia (now Iraq) saw successive buildups and failures as the irrigation systems around Baghdad failed.
Modern irrigation problems were just one of the challenges to sustaining today’s agricultural systems –
- Irrigation sustains modern agriculture, particularly in semi-arid regions like the American West. But the sources of surface water for irrigation have already been dammed and diverted, and groundwater irrigators are pulling out water from the earth faster than it can be replenished by rain or surface water migrating to underground aquifers. Inevitably, we seem to be running out of sources of water for irrigation.
- Salinity. Irrigation systems also contribute to salt buildup in the soils. Water in nature is never pure. Lakes, rivers and groundwater will have mineral salts dissolved in it. When that water is applied to the fields in a thin sheet, the water will evaporate leaving behind the salt, especially in dry climates. As the salt builds up in the soil, plants die.
- Nutrients are the other fundamental requirement for plant growth, along with water, air and sunlight. Artificial fertilizers have provided enormous increases in crop yields especially since the end of World War II. But most fertilizers are made from natural gas and potash ore, and both are non-renewable compounds that are running out.
- Fossil fuels are the predominate source of power for farm implements, like tractors and harvesters. They also fuel the trucks, railroads and ships that carry commodities and produce from local farms to distant markets – sometimes half way around the world. Again, fossil fuels are being depleted. The end of the “Oil Age” is approaching.
- Pesticides are used heavily by modern farmers to stave off competition from both insects and weeds. Sustainable farming advocates argue that the indiscriminate use of insecticides and herbicides is affecting human health and wildlife populations. They also suggest that the increasing cost of these chemicals make small scale farming impossible.
- Excessive soil erosion can result when farmers are forced to grow as much of a commodity crop as they can on as little land as they can. As the soil is depleted, more fertilizer is needed. The only other alternative seems to be to clear and plow under forested areas or marginal land. That can lead to a host of problems including global warming.
- Monocultures. In modern farming, everything is optimized to produce one crop as efficiently as possible. Planters, cultivators, harvesters, hybrid seeds, fertilizers and some irrigation systems are specialized for single crops. So, there are powerful incentives for farmers to plant all or most of their land in one crop. Miles of miles of these monocultures can hurt the diversity of the biology in the environment.
- Environmental health, economic profitability and social and economic equity. Some researchers are concerned with the ways in which modern farming practices damage the environment, hurt small farmers and rural communities and create inequities. These concerns have been added to the research into how modern agriculture can be sustained well into the future.
Dave Vetter is an organic farmer in Aurora Nebraska who believes high-tech agriculture has become wasteful. “When you look at the whole thing, it’s not very efficient,” he says. “We’re moving stuff all over the place… The production basis is so diffuse that to get it to market there’s a lot of transportation and that’s one of the reasons right now we’re seeing so much emphasis on local food and eating local.”
Dave believes that farmers can not be sustainable without becoming organic. “A well-managed organic system is going to strive to become the primary producer of its own inputs which means it’s self-sustaining, as much as you can be that way.”
But other researchers disagree. It all depends on how you define “sustainable.”
There is some debate over when the sustainable agriculture movement started and who coined the term.
In 1940, English Lord Christopher James Northbourne published the book Look to the Land and argued that farms should be treated as a dynamic, living, balanced, “organic” whole – in the sense that a farm should be like a single living organism. Northbourne introduced some of the concepts of sustainable agriculture, but in using the term “organic” may have muddled the discussion. Sustainable farms are not necessarily organic farms, and vise versa.
In the 1950s, publisher J. J. Rodale popularized the idea of organic farming through his magazines and books. Again he tended the blur the lines between organic and sustainable.
In 1978, Wendell Berry published The Unsettling of America and called into question many of the tenets of industrial agriculture.
In 1980, Wes Jackson wrote New Roots for Agriculture, and his book is credited with coining the phrase “sustainable agriculture.” Jackson argued that farming based on annual plant varieties sowed in monocultures that are dependent on artificial inputs are not sustainable over the long term. He founded the Land Institute and began researching and demonstrating farming systems based on perennial plants grown in rotation.
In the 1985 farm bill, Congress provided the first mandate for research into sustainable agriculture and funding followed in 1989.
Yet after at least 20 years of research, conferences and debates, the government admitted in 2009 that it still needed to develop a single definition of “sustainable agriculture.” In July 2009, the National Standards Institute began a process of defining the phrase. The institute sought comments from farmers, the commodity groups (like the Corn Board), national farm organizations, environmentalists, food processors, marketers, and the public. If the group can come up with a consensus standard, it might lead to a new label on food indicating products that are grown in “sustainable agriculture” systems – similar to the “organic” label now used as a marketing tool.
In general, sustainable agriculture advocates promote stewardship of both natural and human resources in agricultural systems. Some “best practices” are emerging –
- “Minimum till” or “no till” cultivation schemes for crops were widely adopted during the 80s and 90s, and they meet some of the sustainability standards. No till systems promote soil conservation and less irrigation, but they may also promote heavier use of pesticides.
- Irrigation and other water management systems are being developed to most efficiently use water resources. Soil testing and crop growing research help farmers apply only enough water at the precise time that plants need it in their growing cycle. Careful water management can also reduce the impact of salts.
- Crop rotation systems can reduce reliance on artificial nitrogen fertilizer and promote biodiversity.
- Ethanol and biodiesel fuels may provide a renewable alternative to fossil fuels, but there is a huge debate over how efficient and environmentally friendly the production of these fuels really is.
- Natural pest management techniques are under study trying to find the enemies of insects and weeds that already occur in the environment. However, some past experiments have gone awry.
- Soil conservation techniques were introduced after the dust storms of the 30s, went out of style during the “plant fence row to fence row” ethic of the 70s, and are now coming back into vogue.
- Strip cropping, double cropping, cover cropping and intercropping are all being researched as alternatives to monoculture cropping practices.
- Manure and other biomass sources of fertilizer are being promoted by some sustainable farming advocates as a natural, time-tested source for plant nutrients. But others point out that manure has only a little nitrogen (the primary nutrient for plants) in it – between 0.5 percent and 2 percent nitrogen by weight. (The man-made fertilizer anhydrous ammonia contains 82 percent nitrogen by weight.) To put it another way, a ton of cow manure contains between 12 and 25 pounds of nitrogen. It takes around 200 pounds of nitrogen per acre to grow 150 bushels of corn on that acre. So, at 20 pounds of nitrogen per ton of manure, it would take 10 tons of cow manure per acre to grow a typical field of corn. On a 160-acre field, that would be 1,600 tons of manure in the first year. The nitrogen in manure carries over, so the second and third years would require less. Some researchers, including Dr. Norman Borlaug, argue that there aren’t enough cows or other livestock in the world today to provide enough nutrients to grow our current food output and feed the world’s population.
In addition, all manures produce a small amount of methane gas, and methane is a potent greenhouse gas.
Community Supported Agriculture. One approach to sustainability are CSAs. They have become a popular way for consumers to buy local, seasonal food directly from a farmer. Here are the basics: a farmer offers a certain number of “shares” to the public. Each share gives each member a box of vegetables or other farm products each week. The advantage to the farmer is that they get to market shares during the winter and they get their money up front, helping cash flow. The consumers get ultra fresh food – food that in some CSAs they pick themselves. They also get to know the farmer and the types of produce that grow in their area.
CSAs are more sustainable because they cut down on huge transportation costs that endemic in our large farm economy.
Just as we know that some high-tech agricultural practices are unsustainable, we also know that we don’t yet have all the answers. Sustainable agriculture will be a hot topic for researchers and farmers for the foreseeable future.