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Out of space July 28th, 2019 by

Celebrating 50 years after landing on the moon, a series of weekly TV broadcasts nicely illustrates the spirit of the time. One interview with a man on a New York City street drew my particular attention. The interview showed why so many people supported the NASA programme: “We have screwed up our planet, so if we could find another planet where we can live, we can avoid making the same mistakes.”

History has shown over and over again how the urge to colonise other places has been a response to the declining productivity of the local resource base. In his eye-opening book “Dirt. The Erosion of Civilizations”, Professor David Montgomery from the University of Washington made me better understand the global and local dynamics of land use from a social and historical perspective.

Out of the many examples given in his book, I will focus on the most recent example: the growth of industrial agriculture, as the rate of soil erosion has taken on such a dramatic proportion that it would be a crime against humanity not to invest all of our efforts to curb the trend and ensure food production for the next generations.

The Second World War triggered various changes affecting agriculture. First, the area of land cultivated in the American Great Plains doubled during the war. The increased wheat production made more exports to Europe possible. Already aware of the risks of soil erosion, in 1933 the U.S. government established an elaborate scheme of farm subsidies to support soil conservation, crop diversification, stabilize farm incomes and provide flexible farm credit. Most farmers took loans to buy expensive machinery. Within a decade, farm debt more than doubled while farm income only rose by a third.

After the Second World War, military assembly lines were converted for civilian use, paving the way for a 10-fold increase in the use of tractors. By the 1950s several million tractors were ploughing American fields. On the fragile prairy ecosystem of the Great Plains, soil erosion rapidly took its toll and especially small farmers were hit by the drought in the 1950s. Many farmers were unable to pay back their loans, went bankrupt and moved to cities. The few large farmers who were left increased their farm acreage and grew cash crops to pay off the debt of their labour-saving machinery. By the time the first man had put his foot on the moon, 4 out of 10 American farms had disappeared in favour of large corporate factory farms.

At the same time that the end of the Second World War triggered large-scale mechanization, the use of chemical fertilizer also sharply increased. Ammonia factories used to produce ammunition were converted to produce cheap nitrogen fertilizer. Initial increase in productivity during the Green Revolution stalled and started to decline within two decades. By now the sobering figures indicate that despite the high yielding varieties and abundant chemical inputs, productivity in up to 39% of the area growing maize, rice, wheat and soya bean has stagnated or collapsed. Reliance on purchased annual inputs has increased production costs, which has led in many cases to increased farmer debt, and subsequent farm business failures. At present, agriculture consumes 30% of our oil use. With the rising oil and natural gas prices it may soon become too expensive to use these dwindling resources to produce fertilizer. 

Armed with fertilizers, farmers thought that manure was no longer needed to fertilize the land. A decline in organic matter in soils further aggravated the vulnerability of soils to erosion. As people saw the soil as a warehouse full of chemical elements that could be replenished ad libitum to feed crops, they ignored the microorganisms that provided a living bridge between organic matter, soil minerals and plants. Microorganisms do not have chlorophyll to do photosynthesis, like plants do, and require organic matter to feed on.

A 1995 review reported that each year 12 million hectares of arable land are lost due to soil erosion and land degradation. This is 1% of the available arable soil, per year. The only three regions in the world with good (loess) soil for agriculture are the American Midwest, northern Europe and northern China. Today, about a third of China’s total cultivated area is seriously eroded by wind and water.

While the plough has been the universal symbol of agriculture for centuries, people have begun to understand the devastating effect of ploughing on soil erosion. By the early 2000s, already 60% of farmland in Canada and the U.S.A. were managed with conservation tillage (leaving at least 30% of the field covered with crop residues) or no-till methods. In most other parts of the world, including Europe, ploughing is still common practice and living hedges as windbreaks against erosion are still too often seen as hindrance for large-scale field operations.

In temperate climates, ploughing gradually depletes the soil of organic matter and it may take a century to lose 10 centimetres of top soil. This slow rate of degradation is a curse in disguise, as people may not fully grasp the urgency required to take action. However, in tropical countries the already thinner top soil can be depleted of organic matter and lost to erosion in less than a decade. The introduction of tractor hiring services in West Africa may pose a much higher risk to medium-term food security than climate change, as farmers plough their fields irrespective of the steepness, soil type or cropping system. In Nigeria, soil erosion on cassava-planted hillslopes removes more than two centimetres of top soil per year.

Despite the overwhelming evidence of the devastating effects of conventional agriculture, the bulk of public research and international development aid is still geared around a model that supports export-oriented agriculture that mines the soils, and chemical-based intensification of food production that benefits large corporations. Farm subsidies and other public investments in support of a more agroecological approach to farming are still sadly insufficient, yet a report from The High Level Panel of Experts on Food Security and Nutrition published this month concludes that the short-term costs of creating a level playing field for implementing the principles suggested by agroecology may seem high, but the cost of inaction is likely to be much higher.

With the reserves of oil and natural gas predicted to become depleted before the end of this century, changes to our industrial model of petroleum-based agriculture will happen sooner than we think. And whether we are ready for it is a societal decision. With all attention being drawn to curbing the effects of climate change, governments, development agencies and companies across the world also have a great and urgent responsibility to invest in promoting a more judicious use of what many see as the cheapest resource in agriculture, namely land. We are running out of space and colonising other planets is the least likely option to save our planet from starvation.

Further reading

David R. Montgomery. 2007. Dirt: The Erosion of Civilizations. Berkeley: University of California Press, 285 pp.

HLPE. 2019. Agroecological and other innovative approaches for sustainable agriculture and food systems that enhance food security and nutrition. A report by The High Level Panel of Experts on Food Security and Nutrition. www.fao.org/fileadmin/user_upload/hlpe/hlpe_documents/HLPE_Reports/HLPE-Report-14_EN.pdf

IPES-Food. 2016. From uniformity to diversity: a paradigm shift from industrial agriculture to diversified agroecological systems. International Panel of Experts on Sustainable Food systems. www.ipes-food.org

Pimentel, D.C., Harvey, C., Resosudarmo, I., Sinclair, K., Kurz, D., M, M., Crist, S., Shpritz, L., Fitton, L., Saffouri, R. and Blair, R. 1995. Environmental and Economic Cost of Soil Erosion and Conservation Benefits. Science 267, 1117-23.

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