We often hear of the concept of “peak oil”, where the idea is that the maximum rate of oil production has been reached. But the concept is vague: hydrocarbons are present in many fossil and remote or undersea formations, and there are continuous changes in extraction technology and the efficiency and nature of uses, so the ‘peak’ becomes an economic concept. Similar riders apply for most other ‘peak’ concepts when applied to natural resources such as minerals: with a will to pay, its near-impossible to run out of gold with its abundance in sea water.

What about “peak farmland”? The amount of land, give-or-take a small amount changing at coasts, is constant, but can be brought into production as farmland by ‘clearance’ of native vegetation, or taken out of use as farmland by building, conservation and other measures, not to mention salinity and erosion.

This paper from Ausubel, Wernick and Waggoner of Rockefeller University puts forward the view that we have now reached the peak of farmland area in the world. Their data (figure 9, reproduced above) show no increase in the last 20 years, and their prediction is a decrease in farmland area from now on. The consider that the increases in crop productivity over the last centuries will continue, with both genetic and agronomic components, while neither population nor meat demand will soar.

They are “expecting that more and richer people will demand more from the land, cultivating wider fields, logging more forests, and pressing nature, comes naturally. The past half-century of disciplined and dematerializing demand and more intense and efficient land use encourage a rational hope that humanity’s

pressure will not overwhelm nature. Beginning with the examples of crops in the large and fast-developing countries of india and China as well as the United States, we examine the recent half-century. we also look back over the past 150 years when regions like europe and the united States became the maiden beneficiaries of chemical, biological, and mechanical innovations in agriculture from the industrial revolution. organizing our analysis with the ImPACT identity, we examine the elements contributing to the use of land for crop production, including population, affluence, diet, and the performance of agricultural producers.”

Many blogs also discuss this paper: http://blog.ecoagriculture.org/2013/01/14/peak_farmland/

http://www.rationaloptimist.com/blog/peak-farmland-is-here.aspx

Original paper here

Local copy for local users here