One real problem with monoculture is that it is often used as a strong argument but in a poorly defined way. The influential food journalist Michael Pollan has gone as far as to claim that monoculture is the “real problem”, the “great evil in american agriculture”. Another common worry is that modern biotech crops lead to “more monoculture”. A major problem with these arguments is that monoculture as a concept is very broad. Before we specify which type and degree of monoculture is the issue, we don’t really know what we are talking about. What is monoculture, and what is it not? In this piece I take a look at this ominous method and its role in modern farming.

Some wineries may have been growing nothing but grapes for hundred(s of) years. Are they the crown of all the ills in agriculture? No, but they are extreme examples of monoculture – which does not equal terrible farming. On the other hand, 90 % of modern farming area is actually not practiced as a monoculture year after year, but they routinely rotate crops.

What is monoculture?

Practicing monoculture means you grow (culture) only one (mono) crop. Monoculture can be defined in two aspects: time and space. That is, one crop is grown in a certain area for a certain amount of time. How big an area or for how long, however, are actually important details which the word tells us nothing about, nor does it give us any information on what would be optimal for the environment, the crop, or the farmer in each situation. That all depends.

The Weed Ecology Professor Andrew Kniss has written an excellent post, The problem with monoculture, on his blog Weedcontrolfreaks where he comments on this lack of detail in the term. He writes:

 So if you grow a single crop, you are growing a monoculture. Simple as that. The problem with this term is the scale. How much “given area” or “land” is required before we call it a monoculture? How long must a single crop be grown on the same area of land before it is considered a monoculture? The word is very imprecise. It seems to be used far more often by people criticizing modern agriculture than those who actually practice agriculture; I presume it is due to the non-specificity of the term. It doesn’t really convey enough information to be very useful to practitioners. It is the scale of the monoculture (both temporal and spatial) that determines whether monoculture is useful or problematic (or both) from an agronomic point of view.

What people often may be referring to when they name monoculture as the problem, is the practice of growing the same crop on the same field year after year after year, that is, monocropping. This could indeed in many cases have bad consequences. Let’s look a bit closer at whether modern farmers practice this kind of monoculture.

Crop rotation – not monocropping – is the norm

Using crop rotations means that the farmer alternates the type of plant grown on one land area – the opposite of what is often meant when referring to ‘monoculture’. Crop rotations have several advantages. They help avoid build-up of pathogens and pests that favour one type of crop, and they can improve soil structure and composition of nutrients by alternating deep-rooted and shallow-rooted plants, or including nitrogen fixing legume crops, for instance. The practice of rotating crops actually qualifies as one of the characteristics of a polyculture, though this term is more often reserved for the labour-intensive practice of growing multiple crops in the same space at the same time, one row each for instance, like on my grandma’s garden plot, or for very small scale subsistence agriculture in developing countries.

Data from the USDA tells us that currently the majority of crops in the US is farmed using crop rotations (82-96 % of cropland for most crops). That means the same crop is not grown for more than maximum two years in a row. A report from the European Commission paints a similar picture, where most farmland is managed with 3-5 year crop rotations, and gives exact figures for France and Poland, where only 1 and 5 % of farming area, respectively, is not under crop rotation. They further state that not rotating crops – practicing monocropping – is common for crops which are naturally resistant to pests. As with all tools of agriculture, benefits of rotating crops vs monoculture is situation-dependent. Talking of the whole concept of monoculture as bad gives us no insight into the specifics of any of the valuable details. The Europan Commission report Environmental Impacts of Different Crops Rotations in the European Union notes that crop rotations also have both pros and cons. From page 11 of the report :

Sometimes monoculture is the natural choice

It is good to remember that there are a number of crops where crop rotation on yearly basis is simply impossible. These include tree crops like wineries, olive and fruit orchards, tree nuts, berries like raspberries, and or any other perennial crop plants. Some wineries may have been growing nothing but grapes for hundred(s of) years! Are they the crown of all the ills in agriculture? No, but they are extreme examples of certain kind of monoculture.

Most people would easily go as far as to agree that monoculture is something that only exists because of us humans, and would never otherwise appear in nature. Right? Well, not entirely. Humans may only have been putting to a more wide-spread use a phenomenon that naturally appeared around them in the existing conditions of the era when agriculture was born. Professor Thomas DeGregori, a scientific advisor of the organisation American Council on Science and Health, who has studied and written about technology, agriculture, and economic development, talks about this in his piece The Anti-Monoculture Mania:

Ironically, it can be argued that humans developed agriculture in what could well be considered an era of “monocultures.” In the transition from the Pleistocene to the Holocene, “climatic changes in seasonal regimes decreased diversity, increased zonation of plant communities, and caused a shift in net antiherbivory defense strategies” (Guthrie 1984, 260). The ecological richness of late Pleistocene in many of the areas where humans were first to develop agriculture, gave way to “relative ecological homogeneity during the succeeding Holocene” (Guilday 1984, 251).

The warming climate meant that areas in many latitudes began once again to experience spring thaws and run-off, which frequently caused erosion. These areas were often colonized by single strands of hardy weeds with nutrient rich seeds whose botanical weediness required aerated soils which the erosion created. The fact that there were monodominant stands of these grasses meant that humans could form small clusters of relatively permanent habitation as they regularly harvested nature’s monoculture seed crop.

So while things are not as clear-cut as they may seem to many who consider monoculture exclusively an unnatural and detrimental method, it has been clearly demonstrated that crops which are susceptible to pests may suffer from drawbacks when one variety is grown in large scale in one area for an extended period of time.

Steve Savage writes about ancient examples of monoculture on his piece on Sustainablog and his own blog, Applied mythology. He writes:

Farmers’ voices

For some fresh farmer perspectives on how they choose the best methods for their situation, please see this excellent post titled Are conventional farmers doing it wrong? In the part two, five american farmers tell us about the crop rotations on their farms:

• Yes, we rotate crops. We’re in a ten year battle over raising canola because we’re
  looking for crop rotations that are good fits
• Don’t most people? Grow too much of the same thing, and it is like watching inbreeding!
• Oh yes. We grow ten different crops. We rotate according to market demands, crop history, weed history, soil needs. Our soils are in excellent condition.
• Yes, we rotate our corn and soybeans every year, and we no-till.
• Yes, intensively. Typically winter wheat, corn, safflower or sunflowers, malt barley. If needed we’ll then go to summer fallow or back to wheat. Also this would be when we’d put ground in alfalfa and leave it for a few years.

I’d like to thank the farmers on Food and Farm Discussion Lab for their input above. Most of us are no longer farmers, and farming knowledge is becoming obscured in myths and concepts that lack a magnitude of detail necessary for a real understanding of the nuance of the actual issues at hand. Steve Savage makes this succinct point in his piece “Monoculture” May Not Mean What You Think It Means:

How does biodiversity relate to monoculture?

Another topic which people sometimes connect to the problem with monoculture is one of crop- or biodiversity. The general idea is: the more diversity, the better, and the worry is that it has diminished. More diversity being better may often be true, and is argued to help with ecosystem stability, but this concept too is more complicated than what a simple bidirectional scale can express. As an example Professor DeGregori’s article points out that grassland ecosystems are often not very diverse, but can still be very stable ecologically speaking, and they create unique habitats like the one that gave rise to the bison.

These arguments of worry over biodiversity tend also to be quite loosely defined. Let’s look at some different ways to approach the topic in order to make the issues more clearly outlined.

Not all diversity is good

Monoculture, as in, having a field of one crop, does reduce the biodiversity of that area if we would compare it to, say a forest, or a polyculture in its place. By planting one type of plant on one field instead of five or ten, you will have less diversity on that field. Is this unequivocally bad? It also happens to solve a lot of problems (like getting enough of that crop to eat). So many, in fact, that farmers have favoured this method for grains and many other crops since times immemorial. If someone could come up with an efficient (especially: not extremely labour intensive) way to get the same results from a polyculture, they would certainly get the farmers attention (as well as mine!).

Even if fields tend to have only one crop variety, it does make great sense to include different crop varieties close to one another (on the same field) in some cases, when that plant diversity helps avoid evolution of resistant bugs, like in the case of need for Bt-refuges. Bt-resistant diamondback moths were originally found on organically farmed fields that used Bt-toxin as a spray back in 1989 (you can read DeGregori’s article for references), so the farming world has been aware of the potential for a time and has taken precautions to counteract the spread of that resistance. Transgenic seeds that have the Bt-gene can produce their own pesticide (which is very safe for other animals save the target caterpillars), and these seeds come with the recommendation to plant a refuge area of plants without the trait alongside the main crop in order to ease off on the local evolutionary pressure driving resistance.

Now that we mention pests, it is worth noting that while some kinds of diversity are beneficial for the farmer, other types may harm your crop (too many pests). It all depends on the specifics of the situation.

Biodiversity of untouched nature will almost always far surpass that of farmland, and it’s important to keep as much of that nature intact as possible. Efficiently farmed land helps reduce the area of farmland needed. Efficiency in farming also means avoiding a multitude of organisms which would contribute as diversity: namely, all weeds and pests. By reducing weeds and pests (and thus also diversity), we guarantee that the resources poured into the field do not go to waste. Whether the best and most efficient type of farming is monocropping or some type of crop rotation always depends on the type of crop and the larger situation.

GMOs, monoculture, and biodiversity

A very common claim related to biodiversity is that modern biotech crops would lead to ‘more monoculture’. Well, in one perspective, genetically engineered crops have actually lead to ‘less monoculture’, because they have increased yields, which means they have produced the same amount of food on smaller field area. (A field of one crop is, in one out of two definitions, a monoculture.) I’ve written more about these advances in efficiency in GMOs and the environment. To mention one recent review, The impact of agricultural biotechnology on supply and land-use, published 2014 in the journal of Environment and Development Economics, finds the following result of the use of Genetically Engineered crops:

…altogether, GE saved 13 million hectares of land from conversion to agriculture in 2010.

Heterogeneity in the product sure can be fun for me as the balcony gardener at home though!

That’s a whole lot of diversity saved from farming (nature that hasn’t been turned into fields). Okay, so maybe biotech crops don’t lead to more monoculture in that aspect. Another interpretation of the biotech ‘monoculture problem’, which is not actually connected to the term monoculture at all, is the worry that biotechnology would lead to diminished genetic diversity within the crop plants themselves. But fact is that farmers do plant a very genetically homogenous batch of seeds already when they buy traditional hybrid seeds. Arrays of different varieties are available, and farmers have the advantage of choosing carefully to suit their particular needs. The benefits in the form of vigour of the plants (healthier, bigger) far outweighs the pros of diversity in planting seeds with more randomly distributed characteristics – more heterogenous size, pest tolerance, etc also means smaller yields, in turn requiring larger farming area for same amount of product.

Meanwhile, neither these hybrid or biotechnology crops created in the last century may mean bad news for crop diversity. Professor Thomas DeGregori, a scientific advisor of the organisation American Council on Science and Health who has studied and written about technology, agriculture, and economic development, talks about this in his piece The Anti-Monoculture Mania:

“For both wheat and rice “components of genetic diversity other than spatial diversity have improved over time.” This includes:

“temporal diversity (average age and rate of replacement of cultivars); polygenic diversity (the pyramiding of multiple genes for resistance to provide longer lasting protection from pathogens); and pedigree complexity (the number landraces, pureline selections, and mutants that are ancestors of a released variety)” (Rosegrant and Hazell 2000, 311-312).

The argument that the Green Revolution crops have led to a diminution of genetic diversity, with a potential for a disease or pest infestation engendering a global crop loss catastrophe, is taken as axiomatic in many circles as one more threat that modern science imposes upon us. In fact, there is a sizeable and growing body of solidly based, scientific, peer-reviewed research that finds the exact opposite of the conventional wisdom (CIMMYT 1996, Evenson and Gollin 1994 & 1997, Gollin and Smale 1998, Rice et al. 1998, Smale 1997 & 1998, Smale et al. 1996 & 2002 and Wood and Lenné, 1999). Findings for wheat for example, “suggest that yield stability, resistance to rusts, pedigree complexity, and the number of modern cultivars in farmers’ fields have all increased since the early years of the Green Revolution” (Smale and McBride 1996).”

Yet another commonly held belief is that development of biotech seeds has lead to a dramatic reduction in the variety of seeds available to the farmers. Some people seem to perceive that monoculture refers to the idea that todays farmers only grow crops of a few genetically uniform types, the only kinds ‘left’. The claim that available crop diversity would have suffered was put forth by an activist organisation RAFI which reported on majority of old plant varieties having disappeared from seed catalogues. (Under their new name, ETC, they also contributed to a questionable UN report, which I have written about at length here: Myth: The UN calls for small-scale organic farming.) Like many myths, this one is curiously persistent, considering that if you actually look into it, it does not hold up. This piece from The Genetic Literacy Project reports on that in detail. While creation of new varieties creates more diversity, the ‘disappearance’ of most old varieties has been of virtual nature – same variety previously sold under many names is nowadays found under one name only:

…many varieties noted in the early 1900s did not represent different species; rather they were just the same rose (or tomato) by another name.

For example, while Tracy found 578 named varieties of garden beans, only 185 of those were truly distinct. So wiping out nearly 400 varieties represented zero loss of diversity; it was just a book clean up.

Farmers still have a rich choice of crop varieties available to them, and they are often the
best informed party for deciding which variety works best for their land and situation. No manner of practice of monoculture (or Big Ag-business) has stolen that choice from them.

Know what you critique

There are many mistaken ideas that circulate about modern farmers, and the role of monoculture in farming is one of those. Weed Ecologist Andrew Kniss makes a succinct point in the piece on his blog about Michael Pollan putting the blame on monoculture. (My interpretation is that Pollan uses the word here in way that most likely refers to the growing of whole fields of crops instead of rows. See the frustration when dealing with such an ill defined concept?)

I suppose one could argue that Pollan is correct when he says “Monoculture is at the root of virtually every problem that bedevils the modern farmer,” but only because that is how modern farmers grow crops. If modern farmers universally adopted polyculture, a new set of (equally bad) problems would result. And then polyculture would be at the root of virtually every problem farmers faced.

Are monocultures problematic? Sure, if the geographic or temporal scale is large enough. But the problems solved by using monoculture on a field-scale tend to far outweigh the problems they cause.

Before you criticise monoculture as a farming method, it is best to make your argument specific. Do you mean monoculture in time or space? Which crop and which context is particularly problematic for monoculture? How? Or perhaps you mean to say more diverse rotations are needed when it comes to certain crops or farms? It’s also good to be specific about what the specific problems are that you are hoping to find a new solution for with your criticism. Is it about specific weeds, or pests, or nutrient availabilities, and where? Is there another crop or special schedule of rotation you know about that has evidence of serving certain type of farmers better in their situation?

Most western farmers are using very sophisticatedly tuned methods for balancing the best outcomes for their individual farms. I’ve noticed that the more I know about agriculture, the more complex and fascinating the topic turns out to be. Instead of adding to the cloud of confusion around farming with vague comments on the ills of monoculture, it would be far more fruitful to concentrate on understanding what actually lies behind the grand-sounding concept.

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If you would like to ask questions or have a discussion in the comments below, you are very welcome, but please take note of my Commenting policy. In a nutshell:

1. Be respectful.
2. Back up your claims with evidence.

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This piece has also been published at the non-profit site Genetic Literacy Project.