Monday, 14 December 2015

A Political Fantasy, Part 7, Agriculture: Details

We'll get to the "political fantasy" part of agriculture in my next post, but for now I think it's important to set down a clear idea of what traditional agriculture was like and how it has changed in the last couple of centuries with the emergence of modern agriculture.

As I said in my last post the industrialization of our society, driven by abundant cheap energy from fossil fuels, made possible better nutrition, cleaner water supplies, improved sanitation and medical advances including vaccines which resulted in a quickly growing population, mainly due to reduced infant mortality.

The industrialization of agriculture is the main thing that has allowed us to feed the ever growing human population. But because that industrialization is dependent on non-renewable resources, we find ourselves in an overshoot situation, where the fast approaching depletion of those resources will leave us unable to feed a large portion of humanity.

Let's look at traditional and modern agriculture in greater detail.

Land

In 1750, there were around 750 million people in the world, all of them feeding themselves by various traditional means: hunting and gathering, fishing, nomadic herding, swidden (slash and burn) agriculture or fixed field agriculture. Most civilizations were quite isolated and if they did not practice sustainable agriculture and forestry, they would collapse back to a lower level of energy use and a lower population that the local environment could support sustainably.

Western Europe had been running out of forests for some time. They could have adopted the more rigidly regulated forestry and more sustainable agriculture used in some parts of the far east and got by for a few thousand more years, but instead chose to use coal instead of firewood, and with the invention of the steam engine, to industrialize.

Improved sailing ships opened up large areas of "empty" land in North and South America, Africa, Australia and New Zealand to Europeans. The indigenous people in those areas no doubt think we had a strange idea of what "empty" means, but that is another story. Those same sailing ships, and eventually steam ships and railways made it possible to grow food, especially grains (which store and ship well) in these new agricultural areas and ship them to areas of high population density where there was not enough farm land to feed the people.

Eventually, refrigeration and fast transportation made it possible to do the same with more perishable forms of food, even between the north and south hemispheres, enabling us to have fresh produce flown in from half way around the world in the middle of winter.

Of course, in the process of bringing so much new land under the plough, a great many habitats were destroyed along with the species who inhabited them. Despite our supposed mastery of the planet, even the most modern economy relies to a great extend on services provided by the naturally occurring biosphere: fresh air, clean water, fertile soil, forests full of timber and rivers, lakes and oceans full of fish. The cost of providing those services by our own efforts would be crippling. We have already placed so great a burden on the environment that its continued ability to support us is in serious question. If we continue to convert what little is left of the as yet untouched environment into farms and cities, there will be no question left.

Of particular concern is the acidification and heating of the oceans due to increased CO2 levels in the atmosphere. Ocean phytoplankton (plants) are largely responsible for maintaining the oxygen level of the atmosphere. If conditions reach the point where they start dying off, we will have a serious, well nigh insoluble problem.

And yet our population still grows. Currently, about 370,000 new hungry mouths being born every day and only about 150,000 people dying to make room for them. But those numbers get larger every year, with the margin between births and deaths increasing as well.

Worse still, in the developing world, land is being converted to growing foods to ship to the developed world (at a profit) while poor farmers who had previously been able to feed themselves are left with nowhere to go but the cities, where they become jobless, hungry urban poor. It may be true the that bringing this land under modern cultivation methods enables it to produce more food per acre, but this is of very little help to the people who are in greatest need of the food.

Traditional farms were, and still are quite small, a few acres at most. Modern farms are much larger. It is well established that small farms perform better. There is lots of discussion about why, but the answer is obvious to me: a small farmer can devote more concentrated attention and care to his crops and livestock.

Water

In many parts of the world the supply of water is a limiting factor for agriculture. Irrigation has been the solution to this problem for thousands of years, usually using gravity fed water from rivers that continue to flow during the dry growing season, also by using muscle powered pumps to move water to where it is needed. This has been possible because, at higher elevations where the rivers arise, precipitation falls as snow in the winter, accumulates and then melts gradually during the spring and summer. With climate change, warmer conditions mean more of the water falls as rain and what does fall as snow melts more quickly, reducing the amount of river water available during the dry season when crops need it.

In the last century or so, motor driven pumps have made it possible to tap into underground aquifers for irrigation on a scale that uses up fossil water much faster than it is naturally replaced. Already wells are running dry and soon large areas of highly productive irrigated land will have to be abandoned or switched over to much less productive dry land agriculture.

Soil and Fertility

Soil is much more than an inert medium in which to plant our crops. In addition to providing essential nutrients, good soil has a high content of humus, decaying organic matter that provides nutrients, holds water, resists erosion, and causes soil to clump and form soil aggregates, which improves soil structure. Humus is also a major reservoir of carbon and the reduction of humus content in soil under modern cultivation techniques has been a major source of the atmospheric carbon dioxide which is causing climate change. Farming techniques which increase humus content in soil hold great promise for sequestering CO2. This is one area where "organic" farming does show promise, but those methods could just as easily be applied to conventional farming.

When we grow crops they take up nutrients from the soil, eventually depleting the soil of those nutrients if measures are not taken to replenish them.

Traditional agriculture used several different approaches.

  • When you farm on the flood plan of a river, the soil gets replenished every spring when the river floods.
  • Swiddening involves slashing down an area of vegetation in a forest or jungle, letting the "slash" dry and then burning it. The ashes enrich the soil, the slash and burn clears the area so minimal cultivation is required. After a few years the soil is depleted and you move on, slashing and burning a new plot. Your old plot gets over grown by the forest and after a few decades can again be slashed and burned. This actually works pretty well, provided the population density is low enough.
  • Maintaining fertility in fixed field agriculture is trickier. The main nutrients that are needed are nitrogen, phosphorous and potash (N, P, K), and organic matter to maintain the humus content of the soil. Legumes, working with microbes growing in nodules on their roots can turn nitrogen in the air into nitrogen compounds that can be used by plants. There are minerals that are high in potash and phosphorous, though most traditional farmers did not have access to them. But for the most part the idea was to recycle the nutrients used by the plants. This means that the waste from the animals and people who eat those plants must go back into the soil along with the organic waste (straw) left over when the crops are harvested. Nightsoil was traditionally used directly and in some places it still is. This can contribute to the spread of disease. Or waste can be composted, which if properly done eliminates disease micro organisms, and then applied to the soil. In parts of the Far East land has been under cultivation pretty much continuously for 4000 years. Even with nearly complete recycling of waste, some nutrients are lost, leached into the ground water and carried away, so they must be replaced from elsewhere, but at nothing like the rate we see in modern agriculture.

Modern agriculture uses "fertilizers" which contain the necessary nutrients. Phosphorous and potash come from minerals, which are mined using machinery powered by fossil fuels and shipped (again using fossil fuels) from where there are rich deposits to the farms where they are needed. Nitrogen from the atmosphere is converted to ammonia using the Haber–Bosch process. Fossil fuels (natural gas, specifically) provide energy and hydrogen for this conversion, and then nitrogen fertilizers are made from the ammonia. Using these fertilizers, plant nutrients can be supplied in quantities that ensure excellent yields.

There are, however, some problems with these fertilizers. This is a "once through" use of material resources, which has all the problems you might expect, primarily the depletion of non-renewable resources, and pollution of water courses downstream from the farm.

Modern fertilizers are highly water soluble and as such readily available to be taken up by plants, but also to be dissolved in rain water and washed away into water courses where they are potent polluters, fuelling the explosive growth of algae and eventually leading to dead zones such as the one in the Gulf of Mexico downstream from the Mississippi River. There really isn't a sweet spot where yield is maximized and runoff minimized—to get good yields you have to accept quite a bit of runoff. They also fuel growth of soil micro organisms, leading to more rapid breakdown of organic matter in the soil.

Of course these plant nutrients do not just disappear when they get washed out to sea. The nitrogen rich chemicals mostly end up breaking down and returning to the atmosphere as plain old N2. The phosphorous and potash end up in the sludge on the bottom of the ocean and via plate tectonics will eventually be accessible once more as minerals, but on a time scale of many millions of years.

The use of non-renewable resources to feed the human population and that of our domesticated animals has enabled a population explosion over the last few decades, to the point where we are in an "overshoot" situation. Those non-renewables are being rapidly depleted and the renewable resources that are available are no longer sufficient to support us, indeed they too are being depleted by overuse.

Pests

A farm or garden does not exist in isolation—it is part of an ecology and interacts with it. Organisms from that surrounding ecology see our crops as a wonderful source of food. We tend to see them as pests, especially in modern agriculture.

Traditional agriculture was less susceptible to pests because its crops were more diverse and planted in smaller plots. The pests' predators were allowed to thrive, as well. None of this resulted in a 100% elimination of pests, but it did lead to somewhat fewer problems than we have today.

Modern agriculture has specialized in crops with much less diversity and plants them in much larger fields. Often we have thousands of acres planted to genetically identical plants, and the same plants year after year. This is immensely attractive to pests and once a pest arrives that those identical plants are susceptible to, they may all succumb. This necessitates the use of pesticides.

The way modern agriculture interacts with pests is essentially an arms race. Whether farmers use "natural" pesticides as in organic farming or synthetic ones as in conventional farming, pests adapt, evolving resistance to whatever pesticides are being used. Then new pesticides are developed and work for a while, but eventually the pests develop resistance to them as well. And so it goes.

In the case of insects, insecticides have a tendency to kill not just the pest, but the pest's natural predators, which were keeping the pest somewhat in check. Take the predators away and the pests multiply out of control unless you use even more pesticides. Or in one case, when a very specific pesticide which only kills insects was used, slugs, which are mollusks and not bothered by that pesticide, increased in number, doing as much damage as the insects had been doing.

And of course, pesticides are largely made from fossil fuels and using fossil fuel energy, so the day is coming when we won't be able to use them so generously, if at all. Their availability also depends on modern infrastructure, finance and shipping. And modern labs to keep developing new versions when pest evolve and the old one are no longer effective.

There is something called "integrated pest management" which seems to have potential to control pests without the arms race, but it isn't gaining acceptance very quickly in modern agriculture.. Perhaps because pesticides are so much easier to use in the short run. Wikipedia has an excellent article on IPM, with abundant references for further reading.

Seeds and Breeding

Traditionally farmers saved seed from this year's crop to plant the next year. Such seeds are what is known as a "landrace", well adapted to the local conditions, but still having quite a bit of diversity to cope with varying conditions. They practiced selective breeding—saving seeds from plants with the desired characteristics, so that the landrace improved. Using this technique, domesticated plants underwent some pretty drastic improvements over their wild ancestors. The same can be said of the animals we have domesticated and selectively bred.

Modern plant breeding, developing along with the science of genetics, found new ways to increase variation and select for desired traits.

One of the major advances of the twentieth century was hybrid seed: two inbred strains of a crop are crossed, producing a hybrid with greatly improved characteristics. The large increases in yields during the latter half the last century (the green revolution) were achieved through the use of hybrid seeds.

There are a couple of downsides to hybrid seed:

  • the improved characteristics are not preserved in the next generation of plants, so farmers can't save their own seed and must buy new seed each year, an added cost and off-farm
  • dependence. In the context of modern farming, of course, this is not a major issue.
  • there is very little diversity within any particular strain of hybrid seed—all the plants grown from it are pretty much genetically identical. This means less resistance to pests and less resilience to varying growing conditions, compared to the traditional landraces.

It took only a few decades after the discovery of the molecular basis of genetic inheritance (DNA), before we began to directly engineer genes. Genetically modified crops offer great potential, even though most of the ones developed so far have been an integrated part of the "arms race" against pests. But it is possible to use genetic engineering to introduce almost any trait you might wish.

Genetically modified seeds have usually been welcomed by both modern traditional farmers, who are a pragmatic lot. Organic farmers have greeted them with fear and loathing, which is largely unjustified. It is important to note that each new genetically modified organism is just that, a new organism, and needs to be to be evaluated on its own merits. But in the years since genetic engineering started our understanding of genetics has grown immensely and we now have a much better idea of what problems can be caused by inserting new genes in an organism. In fact, variations caused inadvertently by genetic engineering are no more than what occurs in conventional breeding techniques. It appears to be time for a relaxation of testing standards for genetically modified crops. The scientific consensus is that the genetically modified organisms that are currently available commercially posed no threat to human health and no more threat to the environment than any other aspect of agriculture. Which one must admit is not zero, but we're hardly going to give up on the whole project of agriculture at this point, not intentionally, anyway.

With all these advances in plant breeding, we have concentrated on producing new strains of crops which produce well when given ideal conditions: adequate water, no pests, and lots of fertilizer. Modern farming has succeeded so far by providing all these conditions. There is good reason to doubt that it can continue to do so, in the face of financial disruption, resource depletion and climate change. That being the case, it is likely time to switch the focus of plant breeding to coping with the challenges that lie ahead.

Meat

Humans are omnivores, and we certainly seem to have a built in love of meat. Traditionally farming included the raising of livestock and provided meat, though in relatively small amounts. Meat is a concentrated source of nutrition, easily digested when cooked, and it provides some nutrients that are hard to get from vegetarian sources.

Modern agriculture has responded to the demand for meat by industrializing its production in CAFOs (confined animal feeding operations), making generous portions of meat available to all but the poorest of people in the developed nations. But it takes a lot of inputs, grain and soybeans mainly, and it is not good for the animals, who are grazers and evolved to eat grass, not grain.

Since it takes ten pounds of feed to produce one pound of beef (somewhat less for a pound of pork or poultry) this is a pretty inefficient way to feed people. If the food used to produce meat was used to feed people instead, we could feed a larger population. This is true on the whole and I would agree that we should stop using CAFOs to produce meat, and eat less meat on the whole. But there is considerable land that is not suitable other crops, but can grow pasture for animals. And grassland ecologies need herbivores, so they had might as well be used to feed people. Dairy and eggs can be raised on pasture as well, with only a small amount of grain added to increase production.

And as a the ocean fisheries become more depleted by over fishing, aquaculture offers a way to maintain that high protein food source.

Energy

Traditional farming uses mainly human and animal muscle power and very little in the way of other energy inputs. This is part of what limited the size of farms. My father did not acquire a tractor until the early 1950s, and managed to work a 100 acre farm with a team of 2 horses, but that is close to the limit.

Machinery powered by fossil fuels has greatly increased the amount of land that a farmer can work and freed up the 1/4 to 1/3 of farm land that had been used to grow feed for draught animals. This is what is meant when it is said that the efficiency of modern agriculture has greatly increased.

But labour efficiency is only one measure. if you look at energy efficiency, or EROEI, modern farming is much worse than traditional farming. For every unit of food energy produced, modern farming uses about 10 units of energy, mostly from fossil fuels. That's an EROEI of 0.1 — yes, "point one". This works well enough in a context of expensive labour and abundant and cheap fossil fuels.

But we are in a situation where energy is growing short in supply and we have an excess of people looking for work. It's well established that small farmers get better yields, so I think it's time we reconsidered the wholesale automation of farming. More on that in my next post.

Waste

Currently, about one third of food grown is wasted. When you start looking at different regions of the world, it is somewhat surprising that the less developed areas, where traditional agriculture is still practiced to a greater extent, actually waste less food per capita than the developed parts of the world. And there is a much less waste once food reaches the consumer. I would guess this is because poorer consumers simply can't afford to waste food.

In the developed world where modern agriculture dominates, even with better equipment for harvesting, shipping and storing food, there is still more waste per capita in those stages of the process than in the less developed parts of the world. And consumers in the developed world, who can afford to be lazy about making every crumb of food count, waste even more again.

Tempting as it is to think about eliminating waste altogether, it probably isn't realistic and more important, optimizing for efficiency tends to make a system less resilient. Our food system is going to face a lot of challenges in the next few decades from things like climate change, resource depletion and financial breakdown. It would be a good idea to leave some slack in the system, rather than optimizing it to the point where it is extremely fragile.

Finance

Traditional agriculture was (and still is) mainly a subsistence activity—even when it produces a surplus to support the rest of society, traditional farmers usually eat what they grew and grow much of what they eat. Most of the inputs for traditional farming come from the farm itself and this sort of farming is not highly dependent on the financial system for its continued operation

This is not the case with modern agriculture. Machinery, fuel, seed, fertilizer, pesticides and labour all must be purchased before a crop can go in the ground, and credit from the bank is necessary to get the process going. Farmers also rely on markets which are part of the financial system to sell their crops. When the financial system is not functioning well, modern farming suffers.

Well, I could go on at considerably more length, but I think the information I presented here sets us up nicely for my next post, in which I will discuss what lies ahead for agriculture. And returning to the theme of political fantasy, I'll consider what governments can do to improve the situation.

3 comments:

Anonymous said...

Irv: This is a very interesting article. You mention that a significant input is fossil fuels and it is declining. Another significant input is water and it is falling in a less consistent manner in many parts of the world.

We are not getting the snow pack which delivers water in the dry season as you mentioned. On top of that places like California get long periods of drought with intermittent deluges. Farmers can't use this type of water.

I think agriculture will have to evolve to more green house growing and hydroponic farming where water is conserved and nutrients can be directed entirely to the plant.

And we may eventually see more desalinization plants and water pipelines to deal with the decline in the water levels in our aquifers.

Will this drive up the costs of our food. Yes it will. Global Warming is upon us and we are paying the price. The survival of the human race is being threatened and extreme measures will be required to assure a proper food supply.

You mentioned the inefficiency of beef production. We will have to migrate to a plant based diet to assure that there will be enough food to go around.

Irv Mills said...

I see by a separate e-mail that "Anonymus" above is actually my friend Mike Smith.
Well, Mike, in my next post I talk abut where agriculture appears to be going and where it really has to go. Techno-optimism is leading us in a certain direction, including toward greenhouse towers and hydroponics, but the cost of these (along with other low EROEI renewables) is such that it will entirely cripple our economy.
If you can maintain an average EROEI above 15 you can't maintain a growing industrial economy. Most countries are already below 15 and it only seems to be getting worse. So we have to switch to an economy and lifestyle that uses less energy. It's as simple as that. Agriculture is no exception.
Climate change is going to make all this more challenging, but getting off fossil fuels will make climate change less of a problem, and the sooner we do it the better. This means needing less energy. And the best way to need less energy is to use less energy. All the things I am advocating are easily within the grasp of ordinary people, all that is required is a change of attitude, of goals. Which is a heck of a lot more probable than the high tech sleight of hand that people think will allow them to continue on as usual.

Irv Mills said...

In the second paragraph of my first comment, it is supposed to say "If you can't" not "if you can". Kinda changes the meaning...