Towards an Index of Sustainability for Agriculture

Language matters. The words we choose can greatly impact what we communicate. If I say “I see a car” most everyone who speaks English will get the exact same message. If I say “I support local foods” the interpretation will likely be highly variable. Let’s explore some of the language that accompanies society’s current heightened interest in agriculture and the food system and whether we are sharing the same message.

First, let’s talk “natural.” Many food products carry this term on their label, in their advertising, or as part of their image. But the first thing to recognize is that very little about agriculture is “natural.” Farming displaces the “natural” ecosystems just about everywhere it is practiced and is highly disruptive of many natural processes. So to suggest that there is some ultimate “natural” form of agriculture is not very accurate. Yes, agriculture can be changed to have fewer unintended consequences on natural processes (e.g., on water quality and wildlife), but there won’t be much farming in many natural ecosystems. Most of our food products are from plants and animals that would not exist in a “natural” state. We have greatly modified them through selection and breeding over dozens to thousands of years. Perhaps natural foods should probably be called “unadulterated” instead, as this term is generally used to suggest the lack of added ingredients beyond what was in the harvested raw material.

On to a more challenging term: “sustainability.” I have worked with this one for decades and have come to my own conclusions. But you probably have, too. Definitions abound, with many referring back to the UN Brundtland Commission report that described sustainability as “meeting the needs of today without compromising the ability of future generations to meet their needs.” Sounds good, but how do we determine “need” and, more particularly, how do we distinguish “need” versus “want”? Do we all need cell phones, strawberries in January, or our daily latte? Estimates have been made of the ecological footprints of various countries, with the U.S. requiring 23.7 acres of resource land per person, compared with 12.6 acres per person for Switzerland, and 4 acres per person for China (based on 2003 data). Which level of resource use represents “need” and which will we choose for our sustainability definition?

Often, sustainability as applied to agriculture is defined as “economically viable, environmentally sound, and socially equitable.” Imagine a three-legged stool. If all legs are of similar length, the stool it stable. If one leg is broken or too short, the stool falls over. I interpret this to mean that profitability is a necessary but not sufficient condition. An unprofitable farm will go out of business and cannot tend to the other two “legs.” But to be profitable along with serious resource degradation on the farm is not a viable long-term condition either. So sustainable agriculture encourages the “triple bottom line” idea commonly used by businesses.

I would like to suggest that sustainability represents a long-term goal that we cannot precisely define. We can confidently say that soil erosion is generally negative for sustainability, while increasing soil organic matter is positive. So we are able to confidently measure improvements in sustainability for a number of aspects of farming. However, I don’t think we can say there is a line that is crossed that makes a farm “sustainable.” Thus I suggest we avoid using phrases such as “that is a sustainable farm” and instead talk about farms becoming more or less sustainable over time.

Another aspect to consider is that sustainability is relative. Think about irrigation in eastern Washington. Most of the water used comes from snowmelt that is annually renewed. This is a renewable resource, in contrast to water from deep wells in which the water table is measurably falling due to irrigation withdrawals. In our rivers, we have irrigation withdrawals that generally maintain stream flows at levels that provide for other processes, such as fish habitat and recreation. To me, this type of irrigation can be sustained over time. But what happens as the climate changes and the winter snowpack is significantly diminished? Summer flows are expected to be much lower. While we may remove the same amount of water as we do today, it becomes unsustainable at that level if minimum flows for fish are no longer provided. Same behavior, different sustainability outcome.

Then we have “organic.” I have spent many years working in organic agriculture. This term has gone from a vague notion of farming “more naturally” without synthetic inputs, and maximizing ecological processes, to a very detailed Federal rule that is constantly being tweaked by the National Organic Standards Board. Some synthetic materials are allowed, and some natural materials are not, so organic is certainly not the absence of synthetics. Organic growers have access to a variety of pesticides, chemicals and fertilizers that are compliant with the standards, so organic is not the absence of these inputs. The organic standards do strongly encourage soil improvement, reduction of toxins, and increased biodiversity, and research supports these claims in general. However, despite following the same standards, organic farms can vary greatly in their practices and their outcomes. Organic farms have had documented contamination of soil by copper, which is both an essential micronutrient and a toxic heavy metal, from its extended use as a fungicide. At the same time, biosolids (the solid fraction resulting from municipal wastewater treatment) are excluded from organic production in part because of potential heavy metal content. Ironically, recycling of nutrients from cities back to the farms that feed them is a core ecological principle of organic farming. The organic standards are complicated and not easily reduced to sound bites that are very accurate.

Common language divides agriculture into “organic” and “conventional.” In this taxonomy, conventional simply means “not organic,” and that would be a more accurate description. The diversity among conventional farms is likely much greater than among organic farms. Conventional farms are evolving along with new science, technology, regulation, and consumer demand. Some of the changes, such as cover crops, reduced tillage, biological pest control, and composting of wastes represent significant improvements in sustainability.

We often see the words “sustainable” and “organic” coupled together, implying that all organic farms are “sustainable” and that the only path to sustainability is through organic. I propose another way of looking at this. If we could develop a meaningful sustainability index for agriculture (which we have not) and could measure the various farms, we would then be able to plot them on a frequency curve. I have drawn a hypothetical example below (Fig. 1).

Figure 1. Hypothetical distribution of organic and conventional farms on a hypothetical sustainability index.
Figure 1. Hypothetical distribution of organic and conventional farms on a hypothetical sustainability index (100=perfect). Y-axis is % of farms at a given level of sustainability

Let’s assume we have two populations of farms, conventional (“not organic”) and organic. I’ll assume their distribution in terms of sustainability is roughly normal, with a few very low sustainability farms, a few very high ones, and many in the middle. I’ll assume this is true for both groups. I’ll assume that conventional farms will tend to score lower on the scale than organic, since the organic standards do require certain practices that will lead to better sustainability outcomes. But I think these two curves would probably overlap, with some high sustainability conventional farms scoring higher than the lower sustainability organic farms. We can determine the average sustainability of the two groups and would conclude that organic is more sustainable than conventional. But I can also find conventional farms that are more sustainable than some organic farms; thus organic status is not a guarantee of higher sustainability.

This becomes important when we look at results from research studies that compare organic and conventional farms. It is obvious that the choice of farms to compare can have a pivotal impact on the conclusions drawn. This choice can be conscious (in other words, those doing the study have a predetermined outcome they desire, and choose farms that will lead to this outcome), or random (for single farm pair comparisons, it is very influential). So if I want to prove that organic farms are more sustainable than conventional, I can choose an organic farm on the high end of that curve (c), and a conventional farm lower on the curve (a). If my desire is opposite, I choose a low sustainability organic farm (b) and a higher sustainability conventional farm (a). This exercise is meant to point out the hazards of trying to equate a vague and hard to define goal (sustainable) with a clearly defined standard (organic).

The last term to look at is “local.” Media reports suggest that many consumers consider this of equal or greater importance than organic. We hear about food miles, the 100-mile diet, and “buy local” campaigns. The desire to buy local is based on the promise of fresher food, a lower carbon footprint, more money staying in the local economy, a closer relationship between consumer and farmer, and more. But as you probably know, the definition of local is hugely variable, and always somewhat arbitrary. Is local 10 miles, 50 miles, 100 miles, within state, or grown in USA? All of these definitions are used.

At a recent meeting, I listened to two presentations on market trends. One showed how the interest in local foods was growing. The other showed data on the growth of the fresh berry sector in grocery stores, where strawberries, raspberries, and blueberries are now available year round and sales are exploding. Of course, this increased supply of berries is only possible by sourcing product from a range of production regions, meaning supply is local for only a short time each year. Yet consumers are readily buying these non-local products. When I asked a speaker about this apparent contradiction, I was told that there is a difference between “local” and “locale,” and that the consumer can have the same positive feeling as with a local purchase when they buy an imported product that describes its place of origin and perhaps a bit about who grew it. That explanation leaves me wondering how much practical meaning “local” has.

Natural? Sustainable? Organic? Local? They can all mean different things to different people. Despite having to create a world of black and white when setting standards, or when marketing products, most of agriculture comes in complex shades of grey that don’t fall neatly into the categories of the words we use. Because of this, it is important to talk about specifics rather than generalities. In talking about improving our food systems, let’s all choose and use our words carefully, both in our criticisms as well as our praises. And let’s keep up the conversations!

Thanks to the reviewers who provided many helpful comments.