February 8, 2016, by Tim Radford
Scientists say nature conservation and protecting the planet from global warming can both be achieved if land is used sustainably, not just for immediate profit.
LONDON, 8 February, 2016 − Here is the big challenge: can 21st-century agriculture deliver the right levels of nourishment for nine billion people by the end of the century, and at the same time protect nature, save on energy and soak up ever more carbon from the atmosphere to limit the impact of climate change?
The answer in two recent research studies is yes. But both require human society to think again about what it wants from the land it occupies. And each addresses a different approach.
John Reganold, professor of soil science and agroecology at Washington State University in the US, and a colleague argue in Nature Plants journal that organic farming – that is, farming without pesticides or commercial fertilisers − could deliver the necessary calories, make a profit for the farmers, and protect the environment all at the same time.
And Andrew Balmford, professor of conservation science at the University of Cambridge in the UK, and colleagues propose another solution in Science journal. They think the world should concentrate on higher yields per hectare so as to leave more land free for nature to do its thing − which is absorb carbon, deliver clean water and oxygen, and limit the impact of climate change.
The two solutions sound mutually exclusive, but they may not be. In essence, both require human society – from national agencies to village smallholders − to think again about how to manage the future.
Organic farms cover only 1% of global agricultural land, but their produce is big business in Europe and America.
Professor Reganold and his co-author acknowledge that no single answer can solve the planet’s problems, but they analysed 40 years of scientific comparisons of both organic and conventional agriculture, and then matched the outcomes against the four goals of sustainability: productivity, economics, environment and community wellbeing.
They argue that in some circumstances – in severe drought conditions, for example – organic farms have the edge because their soils have higher water-holding capacities. And even when yields may be lower, consumers are prepared to pay more, so profits are sustained.
The real costs in agriculture are concerned not with food yield but with food waste.
“Reconciling agriculture and conservation is one of the century’s greatest challenges”
“Hundreds of scientific studies now show that organic agriculture should play a role in feeding the world,” Professor Reganold says. “If you look at calorie production per capita, we’re producing more than enough food for seven billion people now, but we waste 30% to 40% of it.
“It’s not just a matter of producing enough, but making agriculture environmentally friendly and making sure that food gets to those who need it.”
Professor Balmford has already made the case for “land-sparing” in the UK. This time, he and his co-authors want to see the rest of the planet address the problems of farming and the environment.
They do not directly advocate organic farming. In fact, they want to see better advice on soil, nutrient and water management, better seeds, multiple crops and integrated pest and disease control − but only in certain areas and not in others.
They suggest that a planet really concerned with greenhouse gas emissions, biodiversity loss and food security should stop thinking about immediate profits and look for mechanisms that would enhance sustainable approaches.
So they want to see land-use zoned, and restrictions on crops for export rather than on staple foods. It worked in Costa Rica, where forest protection encouraged farmers to abandon cattle pasture and switch to high-yielding fruit.
The researchers suggest payments, land taxes and subsidies to encourage farmers to conserve wildlife habitats. And they cite success in the Indian Himalayas, where farmers leave land for wild sheep, upon which the snow leopards depend. This also reduced predation by the leopards on farmed livestock.
They want to see good science and agricultural practice encouraged. In part of the Philippines, for example, irrigation advice to lowland rice farmers means they are now getting two crops per year.
In addition, they want to see agencies impose certified standards that could link yield growth to habitat protection. In one such scheme in northern Cambodia, villagers are getting both technical assistance and a price premium − and have increased harvests and reduced deforestation.
“Reconciling agriculture and conservation is one of the century’s greatest challenges,” says the study’s lead author, Ben Phalan, a zoologist with the Cambridge University Strategic Initiative in Global Food Security.
“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.”
And Professor Balmford says: “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.
“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.” – Climate News Network