How 'more food per field' could help save our wild spaces

January 28, 2016
Credit: SC Department of Agriculture

Agricultural expansion is a leading cause of wild species loss and greenhouse gas emissions. However, as farming practices and technologies continue to be refined, more food can be produced per unit of land - meaning less area is needed for agriculture and more land can be 'spared' for natural habitats.

While this may sound like good news for nature, conservation scientists warn that, without the right policies, higher farm yields could be used to maximise short-term profits and stimulate greater demand, resulting in less wilderness and more unnecessary consumption and waste.

Now, leading conservationists writing in the journal Science are calling on policymakers to harness the potential of higher-yield farming to spare land for conservation, instead of solely producing more food and profit. By minimising the footprint of farming in this way, vital land could be spared for maintaining and restoring the rapidly dwindling natural world.

The authors describe a series of "land-sparing mechanisms" that link yield increases with habitat protection, such as land-use zoning and smart subsidy schemes, along with real-world examples that show how they can work - from India to Latin America.

They write that replicating these mechanisms elsewhere depends on "the political will to deliver strong environmental governance".

"Reconciling agriculture and conservation is one of this century's greatest challenges," said Dr Ben Phalan from Cambridge University's Department of Zoology.

"To help meet that challenge, we need to move on from thinking about higher yields simply as a means to produce more food, and to use them to free up land for conserving biodiversity and ecosystem services," said Phalan, who authored the policy paper with colleagues from Cambridge, the RSPB and Brazil.

Previous research from Cambridge and elsewhere has shown sparing land for nature by producing more food per field is the "least worst option" for both biodiversity and , says co-author Andrew Balmford, Cambridge professor of conservation science.

"Sparing tracts of land as natural habitat is much better for the vast majority of species than a halfway house of lower-yielding but 'wildlife-friendly' farming, and we have recently shown that in the UK land spared through high-yield farming could even sequester enough greenhouse gases to mitigate the UK's agricultural emissions*," said Balmford.

However, Phalan says that policies to encourage higher farm yields need to avoid the 'rebound effect'. First identified by William Jevons in 1865 - when he noticed more efficient engines increased rather than reduced coal use, as engines were put into more widespread use - the rebound effect for higher yields could see food prices drop, encouraging greater consumption, more food waste and even more conversion of habitats to farmland.

Higher yields may also increase the cost of conservation if they allow farmers to earn more per field. "If a hectare of farmland is producing higher profits, farmers will charge more to give it up for conservation," said Phalan. He says that conservation efforts can be undermined by unintended consequences. "Halting agricultural intensification or expansion in one area may just shift pressure to farm in others. Increasing farm yields can help counter this 'leakage'."

The land-sparing approaches advocated by the researchers are designed to address both rebound effects and leakage. Examples from around the world show how these approaches can work, although researchers caution that further work is needed to improve and test each of them.

Designating "land-use zones" for both conservation and farming would safeguard habitats, while incentivising higher yields to compensate for limits on the extent of farmland. Researchers say that restrictions should target export commodities rather than staple foods.

In Costa Rica, for example, the clearance rate of mature forests halved after the government zoned forests as off-limits for . Food production for export shifted from cattle farming toward high-yielding pineapple and banana crops.

Economic incentives can be tailored to increase yields and prevent destruction of wildlife, with payments conditional on conservation. Himalayan herders are rewarded for setting aside pastures for wild sheep - a food source for snow leopards - and insuring against loss of their livestock. This has dramatically improved yields and eliminated killing of the endangered cats for livestock protection.

To encourage land sparing in developing countries, help with enhancing yields should focus on smallholder farmers growing staple crops. Researchers say that technical advice on water management and multiple cropping should be balanced with advice on reducing any side-effects: by using natural pest control and other agro-ecological methods, for example, instead of pesticides.

Policies and practices to minimise pollution are essential. "If yields are increased using large quantities of fertilisers and pesticides, they can pollute the air and rivers. It is even possible that the effects of this pollution could cancel out the benefits of sparing ," said Phalan.

Improved can have a knock-on economic as well as environmental impact. In the Philippines, introducing irrigation helped lowland rice farmers produce two crops per year rather than one. The higher labour demands were met by employing upland farmers, who invested their new income in fertiliser, boosting their own yields and reducing farmland expansion.

Deforestation rates in the uplands halved, while larger and poorer households were those most likely to benefit.

Combinations of these mechanisms and more will make saving land from agriculture and sparing it for nature more likely, write the researchers. They point to Brazil as an example of multiple policy interventions working together:

"Zoning of protected areas and forest conservation on private land, combined with subsidising farmers to increase yields on degraded pastures rather than create new ones, has seen deforestation of the Brazilian Amazon decline steeply since 2004 - although it's too early to say if this success will be sustained," said co-author Dr Bernardo Strassburg of Brazil's International Institute for Sustainability.

Phalan says that, while these examples show land sparing can be achieved, making sure that higher-yield farming benefits nature at scales that matter will require commitment from senior levels of government.

"Making space for nature is largely a question of societal and political priorities," said Phalan. "The challenge is less whether it's possible to reconcile farming and , than whether those with power are willing to make it a priority."

Explore further: Boosting farm yields to restore habitats could create greenhouse gas 'sink'

More information: How can higher-yield farming help to spare nature? Science, DOI: 10.1126/science.aad0055

*A study published in Nature Climate Change earlier this month suggests that if the UK increased farm yields in line with what experts believe is possible, and turned spared land into forest and wetland, the resulting carbon 'sink' could balance out the nation's agricultural emissions by 2050 - in line with government targets.

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4 comments

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KelDude
not rated yet Jan 29, 2016
All these "side line" articles about food, lack of this or that etc are skirting the real issue with this planet. There are "too many people on it" period! We need to get population reduction into the mainstream conversations. We've turned the planet into an ant hill and we're the ants. On the personal level you can do something, limit your family size to "self replacement" IE: 2 kids (or less). I could go on but I think you get the point. We're doomed if we do nothing about population size.
Gigel
not rated yet Jan 29, 2016
KelDude, it all reduces to technology in the end. At the end of prehistory there were too many people too, they couldn't eat enough from hunting and gathering. So they invented agriculture. All of the sudden they weren't too many any more. The same today. But instead of looking for technological solutions we keep whining about how "too many" we are. We just need to reinvent civilization. My guess is on the way we'll end up with far higher energy production, with less impact on the environment and we'll get to go to other planets too. In many cases what you see is what you expect so it is important how you look at the whole issue.
KelDude
5 / 5 (1) Jan 31, 2016
Gigel, I understand we're very inventive at "moving on to the next level" BUT this planet can NOT support our population. Let's not forget that it's not only humans on the planet but all other life forms we know of in the universe. And we are wiping that out at a rate as high or higher than the "great extinctions" of the past. What will the world be like when all that's left is us, the few animals we raise for food and our pets? There are not enough resources on the planet to put us all into western style life. Sure we can go and mine asteroids but we still have to return to the dying planet. We think we're smart enough to defeat all challenges but nature is smarter and trying hard to slow us down. Zika virus, no anitbiotics work anymore etc etc. Our wasteful consumer based society will kill us off as fast as anything else. We don't even see our self destuction coming.
Gigel
not rated yet Feb 01, 2016
We should look for the next level, really. As long as we don't do that we simply sit and wait for old age at which point it will be harder to do something. Already curbing natality rate led to aging of the most prosperous countries. Fearing overpopulation proves disastrous for the human society, which naturally thrives when it increases. Whether Earth can support today's human population is highly debatable. With current technology, e.g. massive nuclear fission energy production the Earth can sustain at least ten times the current population. For this it is required that farming is done in closed spaces with man-made light and energy; that living is done on the vertical; oceans could be inhabited and so on. But it doesn't make much sense for the human race to try to live on Earth for another 100 years or more. It makes more sense to try to leave Earth for other planets. What is important is to concentrate on progress, not on defending the environment. On the way that will come too.

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