Crumb Trail
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Saturday, August 30, 2003

This New Scientist essay by Debora MacKenzie criticizes agricultural practices by painting a scenario of a great die off of humanity during the 21st century due to agricultural collapse on a global scale. The scenario is presented as an address to the Edinburgh Science Festival on the first day of the 22nd century.

By the 1990s it was apparent that population growth had slowed, and in 1994 demographers predicted that numbers would stabilise at 9 billion by 2050. Many people stopped worrying about a population crisis.

As we all now know, the demographers were half right. The population did reach 9 billion. But it didn't stay there long. By the 2050s, food production was declining sharply, and in many places, high-yield agriculture collapsed completely. This led to the great famines. Meanwhile, population density triggered two other agents of decline: the great migrations and the plagues. World population plummeted.

For many people these sorts of pseudo-scientific screeds are as close as they ever get to actual scientific knowledge or agronomic practice. Such essays just seem silly to those who have a smattering of knowledge but the majority of people can't refute them and tend to give them credence since they are published in decent quality popular periodicals which also publish sound popularizations of recent scientific papers.

This is an example of political subversion of science of the kind posted about in Creative Darwinism. MacKenzie is not an environmentalist, she's a politician using environmental doom scenarios as a wedge issue to advance a political agenda. Fomenting an atmosphere of crisis and impending disaster to persuade people to empower authoritarian governments that promise to save them from calamity is a practice as old as civilization but still sometimes successful.

As MacKenzie demonstrates it's really quite easy to do. All that is required is an assumption of worst case outcomes for all current issues and a careful selection of cited data points to omit any contrary information. In doing so the scenario can be defended as being plausible, though it's not, and immunize the creator of the scenario from criticism. She will not be held accountable for her public assertions though she has done harm to society by releasing a mental plague virus. We do not consistently punish this crime and have no good methods to do so that would not stifle social speech. It is interesting to note that this wanton act of destruction could well be more dangerous to humanity in the coming decades than any biological replicator.

A few extra data points may help slow the spread of this virus. The most important one is that though all of the threats to agriculture noted by MacKenzie are real they are all well known and techniques to alleviate them are already in use. Agriculture is not static or monolithic. New methods emerge from universities as well as other public and private research centers faster than anyone can consume them. Some ideas are at the theoretical stage, some are in laboratory test, some are in field trial, some are in tentative commercial use and some are current state of practice on a regional basis. Each region has its own current evolutionary state and changes at different rates. This broad diversity of practice and continuous state of change reveals the naivety of scenarios like MacKenzie's.

I won't do a full frontal fisking of the essay but a few specific data points to refute MacKenzie's overwrought assertions may be useful.

Chemical fertilisers could replace the mineral nutrients taken by the plants, but couldn't restore the soil's fine microstructure.

True, but they help quite a lot when used as part of an integrated system. Agricultural soils are exhausted only a few years after first being put into cultivation. For thousands of years farmers coped with this by serial use of land, first by slash and burn migration of field use and later by rotation and fallowing. It wasn't until the fifteenth century in Europe that western farmers began to consciously amend their soils by importing fertility. They added chemicals such as lime and gypsum to increase calcium and sulfur, rock dust to increase phosphorous, and grew nitrogen fixing legumes as a cover crop, inter crop or sub crop. They consciously managed their fields by rotating from crop back to pasture and so further improved their fields by the beneficial addition of dung and urine from grazers.

These farmers grew quite skilled in the chemical analysis of soil using the most sensitive instruments available - their noses and tongues. An experienced farmer can tell you the PH of soil and it's calcium content to a high degree of accuracy by taste of the soil and the plants growing there. Scientists and naive observers often misunderstand this due to conflicting terminology and ways of knowing. When a farmer says that soil is sweet or sour he is commenting on the PH.

Not surprisingly, some of the best farmers using these new methods were accused of witchcraft, especially if there was an existing grievance such as religious conflict. These good farmers were driven off and their lands seized. One especially competent group, the various sects of Anabaptists, fled Europe for the new world and can still be found in many parts of north and south America, often with prosperous and healthy farms.

Recent advances in the development of soil analysis equipment have made sophisticated chemical testing widely and cheaply available, and continuing progress with remote sensing and communication capabilities allow continuous real time monitoring. When used as part of integrated systems specifically designed to optimize soil fertility and structure it becomes possible to maintain fields in good tilth while in continuous use.

By 2000 we had pushed the plants to their limits.


Thirsty farm animals increased the demand for water. But their major impact was on grain reserves: it takes 3 kilograms of grain to produce 1 kilogram of meat.
Nonsense. A full grown cow drinks 30 gallons of water on a hot, dry day. The average urban American uses over ten times that much, often 20 times as much, just for domestic purposes. The inflated claims for livestock water use are based on the water used to grow the grain fed to them. But, they are only fed grain because it is abundant, cheap and high in carbohydrates that make them fat. Slow maturing animals, such as cattle, only get grain for a short period while they are finished (fattened) for market.

Where grain is not abundant or cheap livestock eat natural diets. Ruminants such as cattle, sheep and goats - animals with cloven hooves that chew their cud - evolved to eat grasses and thrive on them. Birds, such as chickens, do eat seeds but specialize in bugs and worms which are sources of high quality protein, as well as getting a significant percentage of their diet from grasses. Pigs are omnivores, like people, and can be pastured just like cows. Supplementing these animals with grains is a marketing decision, a way to fatten them faster and increase productivity that makes sense when the cost of grain is low.

In many parts of the world animals get little or no supplements. They are grazers all their lives. The fields they graze are among the most healthy and fertile agricultural lands on the planet. New Zealand, Australia and S. America are masters at pastoral agriculture and produce some of the finest meat, dairy and fiber products. In many parts of N. America and Europe the post WWII practice of massive grain supplementation is being curtailed or abandoned. Animals are being let out of confinement and returned to pastures for both economic, agronomic and nutritional reasons. These animals are healthier, more flavorful and produce more healthful meat and milk.

As this practice increases less land is cropped. Returning tired crop land to pasture restores it and increases total biomass produced as well as biodiversity. What makes this transition viable is the development of a suite of techniques and technologies. The techniques involve close coordination of pasture growth and consumption to maximize nutritional content and volume.

Pastures and grazers coevolved, adapted to one another, and both thrive in the presence of the other. It may seem contradictory that grass thrives when grazed, that it needs its predators, but grass evolved in the (anthropomorphizing) expectation of being grazed, trampled, shat upon and then abandoned for a time to recover while the grazing herd moved on to greener pastures.

Herd migration is not possible where there are cropped fields, roads and other human land uses. Land is fenced and livestock have less room to roam. Migration can be simulated by subdividing fields into small paddocks and moving animals from one to the next in rotations that allow the herd effect - intensive use followed by periods of rest. But, fences are expensive and the required size of a paddock varies with the season as grasses grow at different rates depending on day length, temperature and moisture. Recent advances in portable electric fence technologies have solved this problem. Grazing managers can quickly and cheaply set up light weight temporary fences and vary paddock size as conditions require.

This is a management intensive activity that requires skill, knowledge and attention but it requires comparatively few resources. Some managers simulate natural conditions to an even greater extent by managing multiple species on the same land. For example cattle, goats and chickens can be rotated through the same paddocks and each species finds their own type of preferred foods. They benefit one another because they don't share diseases or parasites. Gut worms that infect cattle spend part of their lives in the grass and depend on being consumed along with grass to get into a host. When a goat eats them they are foiled. The opposite is true for goat parasites. Chickens eat every bug and worm they can catch. They'll pick apart dung pats to get at any larvae excreted by cattle or deposited in the pats by flying insects such as flies. This further reduces the parasite load. Multi-species grazing increases the productivity of the land and the health of all species.

At the end of the article MacKenzie finally gets to the real subject; world domination.

Sometimes I wonder whether it would have been different if, when industry globalised at the start of the millennium, political power had globalised too. I know the idea of global government is a heresy. But so many of our crises were outside the realm of corporate concern, and beyond the power of national and regional governments. A global authority might have been able to monitor and perhaps stem the spread of human, animal and crop diseases.

This is pure rubbish. People, corporations and governments are all aware of the issues and are actively working to address them. Their diversity and personal interest in the issues is the perfect match for the types of problems they face. They are quicker to identify problems and quicker to respond. Diversity in analysis and response is a discovery machine that allows parallel development of varied methods and selection of superior solutions which can be shared about. The absolute worst thing we could do is to impede this form of organization which so perfectly matches the natural systems in question which are themselves developing new attacks in a distributed fashion.

The natural threats of globalization arise from increased communication and transportation. Pests have more contacts in more places with more various life forms. This presents them with more challenges and more opportunities from which they develop more varied methods to thrive. The same factors operate for farmers. They get more information at lower cost about varied techniques and technologies they can use to pursue their interests. The competition between life forms is eternal.

MacKenzie's worst case exaggerations for political purposes are foolish and despicable but so would be an opposite scenario of some fantasy future where all problems are solved by some combination of technology and organizational wisdom. It won't happen either way, the future will be like the present and the past. People will continue to have problems and continue to develop solutions. There will be material progress as there has been in the past, the trend to do more with less will continue, the trend of substituting knowledge for material resources will continue but things will never be easy.

We are our only worthy opponents. The only truly dangerous threat is people like MacKenzie. If we come to ruin it will be for social reasons not natural or technological reasons. We have the choice. We can learn to live well together as we must to be so numerous and powerful or we can shrink from the task and retreat into seductive utopian illusions that will end in grief.

posted by back40 | 8/30/2003 10:08:00 PM


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