Monday, September 24, 2012

THE AGRICULTURAL REVOLUTION

Better Farms and Farmers Made the Industrial Revolution Possible and Have Defeated Malthus (so far)

Farming looks mighty easy when your plow is a pencil and you're a thousand
miles from the corn field. ~ Dwight D. Eisenhower

Gathering – which eventually evolved into farming and agriculture– is probably the world's oldest profession – despite the commonly-held idea, I doubt it was possible to "exercise" while famished by an empty stomach; food always comes first. Human gathering of wild plants (and beasts) has been around since our very beginning. Our domestication of plants and animals began about 10,000 years ago. As the most essential human activity, farming has allowed humans to become "civilized" and satisfy the caloric needs for our daily existence. Because of its key role in human development, I've long been fascinated with agriculture, especially the ways it has changed and advanced during the past several centuries.

For all but the most recent 200 years of human existence, agriculture (ag) has been the only line of work that the vast majority of humanity has undertaken. As shown in Figure 1 below, 90% of the US labor force worked on farms in 1790, as was true for all nations at the time. This vast preponderance of ag workers had been the norm for centuries. It wasn't until 1880 that less than half of our labor force worked on farms. Figure 1 shows the steady decline in agricultural work force over the past 200 years. This is largely why rural areas are now over-represented in the US Congress and other political bodies whose representation rules were established in the 18th and early 19th centuries. By 1900 40% of the US labor force worked on farms; in 2000, less than 2% worked on farms. The revolution in agriculture allowed the farm population to decline so significantly.
History students learn that the Middle-East's "fertile crescent" was the cradle of early civilization. There are several grounds for this, including that this region's cultivators, together with productive water and land resources, provided valued sustenance for more than just themselves. As cuneiform tablets document, these farmers sold their goods to other people; perhaps for the first time they were not subsistence farmers. Markets for food products were part of their every-day existence.
The arc of agricultural change has moved from manual agriculture (during the vast majority of human history), to mechanized (starting in the 18th century), to industrial agriculture (beginning in the mid-20th century). This continued advancement in agricultural practices has been dramatic and revolutionary. Historic examples of improvement in the ag sector include harnessing water- and wind-power to mill grains more efficiently that have been used since Roman times. The agricultural revolution in large part allowed its counterpart, the 19th century Industrial Revolution, to be possible. Even today, these two revolutions remain inextricably linked.
Since the late-18th century, much of this advancement originated in the US. Since then, significant American ag improvements have changed the fabric of our society. Table 1 identifies a number of them. Although it was not first applied in the US, the renowned Green Revolution, begun in the 1940's by Nobel Laureate Norman Borlaug, has dramatically improved the lives of millions of people in developing nations around the globe by increasing crop yields for rice, wheat, corn and other staple crops.
Table 1:  Major Inventions in US Agriculture,
18th through 20th Centuries[1]
Ag Invention  (Inventor)
Year
Cotton Gin  (Eli Whitney)
1793
Cast Iron Plow  (Charles Newbold)
1879
Mechanized Reaper  (Cyrus McCormick)
1834
Steel Plow  (John Deere)
1837
Self-governing windmill  (Daniel Halladay)
1854
Use of horses, not humans, for power – Considered the 1st US ag revolution
1860
Barbed Wire  (Lucien B. Smith)
1874
Internal combustion engine tractors
1915
Rubber-tired, all-purpose tractors with complementary machinery came into wide use – The 2nd US ag revolution
1930's
Irrigated agriculture becomes more prominent, especially in the Western US
1930's
More tractors than horses used on farms for motive power
1954
No- and low-tillage agriculture popularized
1970's
Low-impact sustainable agriculture (aka, organic) increases popularity
1980's
 Virtually all of the technological change that has occurred in US agriculture has been capital-using and labor-saving. This is both unsurprising and expected because historically the US has been resource "rich" (especially land and minerals) and labor "poor." Creating better, more efficient machines remedied our nation's relative lack of labor. These machines allowed the rather scarce workers to become much more productive.
The enormous increases in agricultural labor productivity were realized by adopting a series of new technologies including hybrid seed; iron/steel plows; mechanical planters, reapers, thrashers, harvesters and combines; barbed wire; mechanical tractors, fertilizer and irrigation.[2] Interestingly, it wasn't until 1954 that US farmers used more tractors than horses for motive power on the nation's farms. By the 1990's, farm labor and land productivity had increased 100-fold in 150 years.
Figure 2 illustrates this substantial growth of efficiency in producing corn, one of the most important ag crops grown on Earth. It now takes far less labor and land to grow corn for a box of Corn Flakes (or as feed for the beef in a Big Mac) than it ever did before. Comparable efficiency improvements have been realized in the production of the other 2 primary grains of humanity, wheat and rice, as well as other crops.

In 1850, it took 82 labor hours to produce 100 bushels (Bu) of corn on 2.5 acres of land; by 1987, it took less than 3 labor hours to produce 100 Bu of wheat on 1 1/8 acres. These advances had 2 important, inter-related consequences. First, they allowed ag workers to leave the farms, move to the cities where many became urban, often industrial, workers. As described above, agricultural workers were "displaced" by machines that allowed crop production to increase using less labor. In the US this process of substituting machines for labor continues today beyond the farms, as it has for generations.
Second, at the same time as ag workers were leaving the farms, ag output was increasing. This is illustrated in Figure 3, where ag productivity is measured by the number of non-farm people one US farmer produces food for. In 1930 one farmer supplied 9.8 persons in the US and abroad with their food; by 1970, a single farmer supplied 75.8 people. This represents an amazing 774% increase in this measure of ag productivity during only 40 years.

These vast improvements in agriculture have achieved the significant benefit of providing more food for the Earth's ever-growing population. Without these advances, it would be impossible to be feeding as many of the 7.04 billion humans inhabiting the Earth as is now possible. Since the 19th century, to a large degree these ag advances have stayed the bleak, famished future prophesized in 1798 by Thomas Malthus. In this sense, the industrialization of ag has been a keystone advance for ever-more urbanized humanity.
Nevertheless, modern industrial-scale agriculture's advances have several consequences.
First, industrial ag is heavily dependent on fossil energy. Such energy includes direct uses like diesel fuel for tractors, combines and irrigation pumps, as well as sizeable indirect uses like the energy needed to produce chemical fertilizers, principally from natural gas. Chemical fertilizer usage in ag has almost tripled during the past 50 years.
Industrial ag has become more energy intensive. The energy input to ag has increased 4-fold over the past 40 years, as crop yields have increased 3-fold. Between 1997 and 2002, overall per capita energy use in the US declined almost 2%, but per capita food-related energy use in the US increased by 16.4%. As a share of the national energy budget, food-related energy use grew from 12.2 % in 1997 to 14.4% in 2002. Ag's share has continued rising during the past decade.
Second, industrial agriculture costs taxpayers considerable money. The US Department of Agriculture (USDA) provides farmers (especially the largest ones) with significant direct and indirect subsidies. These subsidies include direct payments, marketing loans, crop and price insurance, export subsidies and disaster aid. One assessment indicated that total farm support by the Federal government has been between $15B and $35B annually. These costs don't include the effects of US government tariffs on foreign ag imports nor the $4B to $5B annual Federal ethanol subsidy/tax credit that thankfully expired in January 2012.
Third, the organic food movement that had its beginning after WWII is a direct response to the industrialization and increased energy dependency of agriculture. This alternative method of growing food has steadily become more prominent and accepted in the US and other countries. In a sense, organic methods have turned the clock back to more "traditional" means of planting, growing and harvesting crops and raising animals, where natural fertilizers, feeds and heirloom seeds are used. Organic food consumption has rapidly grown over the past decade because of many desirable features, most centrally its more wholesome taste and purity.
However, despite the prominence organic food has gained for a growing number of consumers – especially in California where much of the movement started – it accounts for a very small sliver of US food expenditures. In 2010, organic food consumption was $12.4B, 1% of total US food consumption. Less than 1% of US cropland is certified organic; just 26% of US food consumers regularly buy some organic food. The foremost reason for organic's minute slice of the US food market is its higher cost. Recessions, like the one we've been stuck in, don't help grow organic's market share.
Fourth, associated with the increased energy and chemicals used to produce our food are the possible environmental consequences of industrial agriculture. Here's a well-known example of what can go wrong environmentally in an area characterized by highly-intense industrial agriculture.
The Kesterson Reservoir is located in one of the most productive agricultural regions of the world, California's San Joaquin Valley (SJV). More than 12% of all US agricultural output (by value) is produced in this valley. This area stretches between California's Coast Range on the west and the Sierra Nevada mountains on the east for 400 miles. The valley receives on average about 10 inches of rainfall, but due to the hot, dry climate over 90 inches of evaporation annually. Irrigation is thus a necessity. So Sierra rivers were damned and diverted and reservoirs were created to supply California's growing demand for year-round fresh water. In California, ag uses about 75% of the state's total available fresh-water resources. For decades, significant amounts of chemical fertilizers and pesticides have been applied by California growers (like others) to increase crop yields.
What happened? With dramatically increased irrigation usage and the SJV's physical characteristics, parts of the valley's water table increased over time that in turn threatened crops (their roots could drown). The Kesterson Reservoir was created in 1968 in the SJV to relieve this water "imbalance." Unfortunately, given the nature of Coast Range's geology, the water quality of the area and this reservoir changed. By the late 1970's water in this region of the valley became more saline and concentrated with selenium. Wildlife and waterfowl that used the reservoir (the SJV is on the Pacific flyway of migratory birds) were adversely affected. Selenium toxicity is well-understood and includes several severe metabolic disorders for wildlife and humans. Wildlife, waterfowl and plants were decimated by the changes to the reservoir's ecological balance. Remediation of the Kesterson Reservoir involved filling in the reservoir with more than 1 million cubic yards of dirt. This was completed by the end of 1988; but it's not clear that even this sizeable effort has mitigated all the environmental problems.
Finally, and looking to the future, have the impressive advancements of the ag revolution mentioned above continued? Unfortunately not. The ag revolution has slowed since the 1990's. Prior decades' productivity increases have not been sustained and crop yields have not risen as they once did. And yet humanity's demand for food continues to grow. A variety of factors may be responsible. A 2011 study published in Science, examined the effect of climate changes on crops. This study concluded that wheat yields are down 5.5% compared with what they would have been with no climate change, and corn yields are down 3.8%. Crop yields for soybeans and rice were not affected. Although there may be means of countering these yield growth reductions (such as eliminating ethanol/biofuel subsidies, improved infrastructure and ag practices in developing nations and continued ag R&D), this is a clear cause for concern. Will Malthus be kept at bay in the 21st century? Let's hope so; and for good measure, we should provide offerings to Demeter.



[1] These seminal improvements do not include the horse-drawn seed drill invented in 1701 by the Englishman Jethro Tull, who 3.6 centuries later lent his name to one of the most distinctive British progressive rock bands in the mid- to later-part of the 20th century. A stellar double act, from the ground up.
[2] About 15% of all US farmland is now irrigated. But in the more arid Western US, 78% of farmland is irrigated.

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