Are we near peak farmland?

January 5, 2013

The spectre of a peak in the supply of a necessary resource is generally reason for concern.

This might not be the case for peak farmland:

The amount of land needed to grow crops worldwide is at a peak, and a geographical area more than twice the size of France will be able to return to its natural state by 2060 as a result of rising yields and slower population growth, a group of experts said on Monday.

Their report, conflicting with United Nations studies that say more cropland will be needed in coming decades to avert hunger and price spikes as the world population rises above 7 billion, said humanity had reached what it called “Peak Farmland”.

More crops for use as biofuels and increased meat consumption in emerging economies such as China and India, demanding more cropland to feed livestock, would not offset a fall from the peak driven by improved yields, it calculated.

If the report is accurate, the land freed up from crop farming would be some 10 percent of what is currently in use – equivalent to 2.5 times the size of France, Europe’s biggest country bar Russia, or more than all the arable land now utilized in China.

“We believe that humanity has reached Peak Farmland, and that a large net global restoration of land to nature is ready to begin,” said Jesse Ausubel, director of the Program for the Human Environment at the Rockefeller University in New York.

“Happily, the cause is not exhaustion of arable land, as many had feared, but rather moderation of population and tastes and ingenuity of farmers,” he wrote in a speech about the study he led in the journal Population and Development Review. . .

Improved yields are usually the result of improvements in management, breeding and weed and pest control, and the mitigation of climatic challenges such as drought or flood.

These include genetic modification and irrigation and usually means intensification which aren’t universally popular.

. . . Gary Blumenthal, head of Washington-based agricultural consultancy World Perspectives, said the report’s conclusions were not surprising as technology already exists to dramatically boost crop production. But achieving “peak farmland” would depend on the technology being made available globally, he added.

“If we could just get yields in the rest of the world at levels that they are in the U.S. or Europe, we would have substantially more food,” Blumenthal said. “Just using existing farmland more efficiently, would substantially increase supplies. Yields are rising.” . . .

It’s not as simple as transferring methods from one country to another.

There are often political, financial and practical challenges to overcome before what works well in one place can be applied in another.

. . . Ausubel’s study admits to making many assumptions – rising crop yields, slowing population growth, a relatively slow rise in the use of crops to produce biofuels, moderate rises in meat consumption – that could all skew the outcome, if not accurate.

It also does not factor in any disruptions from significant climate change that U.N. studies say could affect farm output with rising temperatures, less predictable rainfall, more floods or droughts, desertification and heatwaves.

Still, it points out that both China and India have already spared vast tracts of land in recent decades.

In India, for instance, wheat farmers would now be using an extra 65 million hectares – an area the size of France – if yields had stagnated at 1961 levels. China had similarly spared 120 million hectares by the same benchmark. . .

Just as cities can go up rather than out, so can production.

Crops could soon be grown in greenhouses the size of skyscrapers in city centres across the country, it has been claimed.

Birds Eye and other food producers are investigating building ‘plantscrapers’, which could accommodate hundreds of storeys worth of crops, in a bid to make farming more economical, sustainable and meet increasing demand.

The ‘vertical farms’ would use an innovative feeding system which nourishes plants with enriched water, therefore cancelling out the need for soil – and the need for food to be grown  and harvested in the countryside. . .

Then there’s hydroponics using sea water:

The seawater greenhouse developed by UK-based Seawater Greenhouse is a low-cost solution for year-round crop production in some of the world’s hottest and driest regions. It does this using seawater and sunlight. The technology imitates natural processes, helping to restore the environment while significantly reducing the operating costs of greenhouse horticulture.

The first project was in Tererife, Spain, in 1992 where a prototype was built in England and shipped to Spain. This was a pilot project, which validated the concept and demonstrated the potential for other arid regions.

In 2000 another greenhouse was built in Abu Dhabi to try out the concept in a different climate, where humidity is higher than in Spain. Again, this was a success. The greenhouse provides a cooler climate that enables crops to be grown year-round, even in the extreme heat of the summer months. It also allows for the reclamation of salt-infected land by not relying, at all, on groundwater resources. It is a major benefit to local agriculture.

Seawater Greenhouse is now nearing completion of a new greenhouse to tame the harsh Australian outback. The greenhouse uses a natural distillation process to turn seawater, pumped from the nearby Spencer Gulf by solar powered pumps, to grow tomatoes hydroponically. The 2500m² greenhouse is capable of producing 100% of the energy needed, but also has a back-up power system in case of malfunction. The first crop will be ready to harvest in October. . .

More food can be produced from less land but the real test is whether it can be done sustainably.

Hat tip: Tim Worstall at the Adam Smith Institute.


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