Biodiversity in the kitchen, part III: the Green Revolution and its unintended fall-out

(This is the third in a series about eating biodiverse foods; having looked at the early history of food, and the mechanics and markets of Industrial Revolution agriculture, I focus here on Green Revolution and its unintended side effects.)

pivot irrigation monoculture monocrop industrial agriculture agribusiness

pivot irrigation in California

The biggest shave of agricultural genetics came during the mid-1900s, during a period known as the Green Revolution. While it overlaps with the Industrial Revolution, I distinguish the two because one is based on mechanical issues and the other on chemicals.  Yes, the Green Revolution caused a surge in agricultural productivity, lowered the price of food, and probably did save a lot of people from famine (not a couple hundred: from hundreds of thousands to millions).  BUT it did this in ways that are not proving to be sustainable; the Green Revolution has produced a lot of negative consequences that must be dealt with before agriculture can really move forward again. 

First, a little background: the advent of chemical agriculture

The atmosphere we breathe is filled with nitrogen, but it is in a form that plants cannot use.  Instead, tiny little organisms in the soil convert atmospheric nitrogen to plant soluble nitrogen.  There are plants known as nitrogen fixers, and they do a wonderful job of making those organisms very happy and prolific.   There are a host of other nutrients and minerals required by plants for health, but it is most often a lack of available nitrogen that thwarts plant growth.

how is fertilizer made natural gas haber-bosch process

Haber-Bosch process (click to enlarge)

In the early 1900s, two scientists (working argumentatively, this was not a collaboration) developed the Haber-Bosch process, which creates plant soluble nitrogen- in the form of ammonia- from atmospheric nitrogen, water, and natural gas.  The process is pretty involved, and includes changing both the temperature and the atmospheric pressure inside the reaction chambers, and that requires energy, beyond the initial natural gas requirement.

With the Haber-Bosch process, fertilizers containing higher than natural levels of nitrogen became commonplace.  Plants do indeed respond positively (except for my eggplants, which when too happy seem to produce more flea beetles than fruits) to the additional nitrogen.  But two problems crop up fairly quickly:

  1. the nitrogen fixing organisms disappear from the soil, and
  2. the crops become more prone to lodging.

Lodging happens when a high wind pushes the plants over and they cannot, for some reason, stand themselves back up.  One cause of lodging involves top heavy plants with big fat seed heads, bigger than the stalk can handle.

Enter Norman Borlaug.

What was the Green Revolution?

norman borlaug agronomist father of the green revolution

Norman Borlaug

Known as the father of the Green Revolution, Mr. Borlaug was an agronomist who spent a great deal of time in the 1940s and 50s working with wheat plants.  In order to save time, Mr. Borlaug went to Mexico where he could plant a crop in the highlands during one season and in the lowlands during the next, effectively doubling the speed at which he could work.

By crossing and re-crossing, he eventually arrived at a variety of wheat with shorter stalks that could handle the increased size of the seeds when the field was treated with the artificial nitrogen fertilizer.  Because of his two-locations technique, there was the side effect of that particular wheat variety being what I call ‘site agnostic’, meaning where it was being grown had little impact on how it performed.  The wheat also had an exceedingly narrow genome.

Typically the genetic variety within a single crop is fairly high.  This is how there is a broad enough genetic base to protect against total species devastation in the event of some new plant pathogen appearing.  For this particular wheat, each and every plant is less like cousins and more like identical twins.

When, in the early 1960s, Mr. Borlaug was invited by the Indian government to repeat this process with rice, the result was similar: a site agnostic, short-stalked rice with a very narrow genome that grew very well in the presence of synthetic nitrogen fertilizers.  The jump in rice productivity did indeed help more people eat more rice more cheaply.  Unfortunately, the side effects, though accidental, are by no means incidental.

Problems with the Green Revolution

biodiversity in rice varietiesSeeds used to be free– farmers simply saved from the previous year’s crop.  The hybrid seeds must be bought.  Fertilizer used to be free- the composted kitchen scraps, cover crop systems, and composted animal manure were all put to use.  The synthetic fertilizers must be bought.

After a few years of applying synthetic nitrogen fertilizers to the soil, the soil food web begins to break down as the nitrogen fixing organisms disappear.  The fields become, in effect, addicted to chemical fertilizer.  Reverting to prior methodologies becomes very difficult, more so the longer the field is engaged in this form of agriculture.

Because plants can only uptake food at a certain rate, fertilizer applied above that rate washes off in the next rain.  The increased nitrogen in the streams causes algal blooms, which deprives the water (and fish) of oxygen and blocks sunlight from reaching any aquatic plants.  Eventually the nitrogen breaks down into a variety of forms, a process known as the nitrogen cascade.  After wreaking havoc en route, some of the excess fertilizer ends up in the atmosphere as laughing gas, a potent greenhouse gas.

The crops are of course not the only plants intrigued by the abundant nitrogen.  Weeds grow with equal vigor.  This results in the application of herbicides.  The mass gathering of a specific crop in one place is seen by any insects or other creatures who find that crop tasty as a very convenient occurrence indeed.  This results in a need for pesticides.  Now there is a very large field growing a single crop with a tiny degree of genetic variability and no neighbors- the biodiversity is nil.  The fancy term for that is monoculture.  A monoculture is an economic gamble: should that crop fail, the farmer has lost a significant portion of that year’s revenue, perhaps all of it.

Mr. Borlaug’s crops were so successful in meeting their singular goal that a great deal of well-intended charitable money was put toward introducing them in other places.  The fact that wheat is a bit of a water hog did not seem to factor in when deciding where to grow it. The fact that other cultures have other crops (improvable, no doubt) that are both culturally and ecologically more suited to their landscape did not factor in. (This is part of why the Green Revolution never really reached Africa.)

Spraying fertilizer, image from Good Morning Columbia NewsThe fact that these high yielding seeds require the synthetic fertilizers (and thus require the farmer to buy said fertilizers) did not factor in.  Neither did fact that those longer stalks were indeed very useful- as roof thatching and animal fodder, amongst other things. Those needs now must be grown elsewhere, a phenomenon Vandana Shiva has dubbed “shadow acres”. (Shadow from not being included in efficiency calculations.)

The fact that a monoculture of rice is not a balanced diet did not factor in.  Nor did the reality that the caloric ratio of energy put into growing a crop compared the calories (energy) obtained from the crop had completely flip-flopped: we’re spending more energy to grow food than we are getting from the food!  Too bad we can’t eat oil or gas.

All of which is perhaps more than you wanted to know, but it gets me to what I wanted to show you: our contemporary diet is artificially narrow.  Part of the reason for this is the fundamental fallacy of the single-problem-to-solve mindset, and part of this is because farmers are people too.  The vast majority of farmers are not trying to make it big, they are just trying to make a living, so they keep taking what seems like the next right step, but the steps are piling up in the wrong direction.  Farmers who are seeing what is happening and trying to change the direction of agriculture need help, some of it from us, the eaters.

Next up: How biodiversity in the kitchen helps save the world


Many thanks to Kojomoe, who drew the Haber-Bosch diagram, to for the rice seeds picture, and to Good Morning Columbia News for the photo of the chemicals being sprayed.

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