6 December 2011

The future of food

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Your great-grandkids may eat their greens, but also a carte du jour of lab-grown meat, GM crops and insect-derived proteins. Hal Hodson gets a taste of the future of food.
the future of food

Your great-grandkids may eat their greens, but also a carte du jour of lab-grown meat, GM crops and insect-derived proteins. This artist's conception illustrates buildings with house intensive farms using LED lighting, while vats of artificial meat are cultured alongside. Credit: Illustration by Jamie Tufrey

SCIENCE HAS MADE a patchwork of this field. Strips of wheat roughly 3 m wide run west, each treated with different amounts of fertiliser, making some full and lush but others sparse and wispy.

Herbicide has been held back from a 4 m stretch at the same point along each strip, allowing poppies and wild plants to spring up in a belt that cuts through the whole field, choking the wheat.

This is Broadbalk field at Rothamsted Research, north of London, the world’s oldest agricultural research centre. Scientists have tracked Broadbalk’s wheat through 150 years of drought, flood, harsh winters and fine summers. Their databank works like an ice core, allowing Rothamsted’s 200 scientists to explore the past.

The centre’s history is prolific with fundamental agricultural inventions: inorganic fertiliser and the world’s most widely used herbicide – 2,4-D (2,4-Dichlorophenoxyacetic acid) – have roots at Rothamsted. The payoff is the staggering abundance of food afforded to the West by modern farming, but the inventions haven’t been all good news. 2,4-D, for example, was a component of the notorious chemical weapon Agent Orange, which U.S. forces used to destroy Vietnamese crops during the Vietnam War, poisoning hundreds of thousands of people in the process.

Both the European Commission and the U.S. Environmental Protection Agency have found that 2,4-D is not harmful to human health when used correctly – in recommended amounts and on appropriate crops. Apart from being cheap, 2,4-D’s popularity is due to its ability to discriminate between broadleaf weeds and crop grasses, efficiently targeting unwanted plants.

Rothamsted is a hotbed of research on the critical question of how to feed the planet. Maurice Moloney, Rothamsted’s director, explains to me that one particular chemical reaction uses 1-2% of all the energy produced in the world every year – 2,000 TWh (terrawatt hours), the energetic equivalent of 200 thermonuclear bombs, each bigger than that which obliterated Hiroshima at the end of WWII. It’s called the Haber-Bosch process, a way of pulling nitrogen out of the air to make ammonia, which fertilises fields all over the world.

That energy directly increases crop yields and feeds a third of the population. It also contributes enormously to environmental pollution through run-off into rivers and greenhouse gas emissions associated with its production.

Some plants, including a family called legumes, have an inbuilt capacity to meet their nitrogen needs. Peas, clover and lentils can all source their own fertiliser by exploiting a symbiotic relationship with bacteria on their roots, that pull in nitrogen in a process known as fixing. “The question for us is whether it’s possible to mobilise the mechanisms of nitrogen fixation into crop plants,” Moloney says. “It’s a bit of a Holy Grail and we’re looking at a long-term research effort which will yield results before we get into the doomsday scenario of 2050, where we have nine billion people and not enough food.”

Agricultural scientists are also beginning to develop crops that directly benefit consumer health as well as the farmer, says Moloney. “There is one deficiency prevalent in [the diets of] the West – long-chain omega-3 fatty acids. The human body evolved close to the sea and there was a lot of fish in our diet. Nutritionally, we still have that necessity,” he says.

Omega-3 improves brain development, cardiovascular health and memory, but it isn’t made directly by fish, Moloney explains. Instead, it comes from the algae they eat. “We’ve gone to marine algae and cloned the genes associated with making omega-3, then mobilised those into oilseeds like linseed and canola – typical constituents of the oils we use for cooking,” says Moloney.

The United Nation’s Food and Agriculture Organisation (FAO) estimates there are almost one billion malnourished people in the world today. They, and many of the extra two billion people who will live on the planet by 2050, are likely to care little about omega-3 in the face of the basic need for calories. But Moloney says the calorie shortfall problem can be addressed too, by providing simple systems based on analysis of plant behaviour rather than expensive technologies.

Push-Pull is an exciting example. It’s a pest control system, co-developed by Rothamsted and the International Centre of Insect Physiology and Ecology, an international research institute headquartered in Nairobi. It’s designed to prevent damage caused to crops in eastern and southern Africa by corn borers – agricultural insect pests – and Striga, a parasitic plant genus capable of wiping out entire harvests.

Moloney says the Push-Pull system works by growing complementary sets of plants alongside the main crop. “[One crop] releases a deterrent chemical which pushes the corn borers away. [The other crop] attracts them, but once they land on it, they aren’t able to get sufficient nutrients, so they die off. It gets the corn borers off the corn.”

It worked very well for the insects, but then scientists also noticed that a problematic Striga species wasn’t growing any more, he says. “It turned out that in addition to this mechanism of pushing and pulling the insects, there was a hormone released by one of the co-cropped plants which caused a premature germination of the seeds of the Striga plant, not allowing it to establish and become a parasite.”

Yields on demonstration plots in Africa have doubled, Moloney continues. He slides the farmers’ manual for the Push-Pull system across the table to me. The co-crops are self-propagating, so the farmer only needs to purchase seeds once. One of the co-crops is also nitrogen fixing, meaning farmers can save on fertiliser. “It’s a very clever system, based on hi-tech, but converted into something that anybody could use,” Moloney says.

Much of the increased yield delivered by plant science gets swallowed by livestock … literally. In pursuit of maximised yields, intensive farming stacks animals and feeds them precise amounts of food at optimum times. This practice helps fulfil the global demand for meat, but requires huge amounts of water and feed. The FAO predicts the demand for meat will rise 9% by 2050 as the diets of the developing world begin to approach those of the West. This will multiply the burden on crops and water.

One small group of scientists is aiming to mass-produce meat without fields of feed that stretch to the horizon or require the 50,000-100,000 litres of water it takes to raise 1 kg of beef. Mark Post, vice dean of biomedical technology at Maastricht University, in the Netherlands, says that no matter how advanced traditional livestock farming gets it will always have one fundamental drawback: “You still have to work with the relatively inefficient system called a cow.”

Post is trying, along with a loosely gathered team of scientists worldwide, to take meat production out of fields and abattoirs and into the lab. This isn’t merely an academic exercise: cultured, or in vitro, meat is made by growing muscle cells, either on a bioscaffold or in a self-supporting chunk. Both methods can provide meat for processing, but only the chunk method has the potential to fill future plates with ‘steak’.

“I think it will be a viable food for humans,” Post says. He seems wary of coming across as a champion for an unproven technology, but his Dutch-accented English doesn’t hide his enthusiasm. “We still have to address a number of issues, but I believe this is going to happen and eventually even replace the current meat industry,” he says.

If cultured meat did replace conventional livestock – in the distant alleys of 2050 – the amounts of energy, greenhouse gas emissions and land saved would be vast, according to a life cycle analysis by Hanna Tuomisto, a University of Oxford PhD student.

I ask Post about his team’s goal. He laughs: “To make a hamburger. It’s going to be a $200,000 hamburger and someone is going to eat it, yeah. If nobody wants to, I’ll eat it myself.” Currently, Post and his team are only able to make a structureless sludge of ‘meat’ and there are unknown challenges involved in scaling up the laboratory process. “The pieces of meat we’re making right now are wasted muscle, so their protein content is not what we’d like. The texture [of the hamburger] will be somewhat different, as will the taste,” Post says.

Tanks of grow-your-own T-bone steak may still be some way off; what Post’s team is addressing is the underlying structure of the culture, working on ways to get nutrients to the centre of larger chunks of growing meat. “For a big chunk of meat, you need a channel system or the inner part of the ‘steak’ will die during the culture,” Post says.

Cutting out cows and producing meat in vats on an industrial scale may seem unnatural, even bizarre, but then there’s really nothing natural about growing rows of edible grass and regularly slathering it in chemicals to ward off creepy crawlies.

While researchers at Rothamsted are developing pest-resistant crops that could lead to reduced chemical use and healthier biospheres, another order of scientists believes those pests are among the best food sources available.

University of Oxford professor George McGavin, one of Britain’s foremost entomologists, says insects are the perfect food for humans. “Insects are probably the ideal food for hominids in terms of protein, carbohydrates, fats – they contain thiamine, niacin, calcium and all kinds of things that we need. That’s what we evolved eating – fruits, berries and bugs.” McGavin says.

Getting our protein from insects would not only be better for us, it would be better for our planet. A life cycle analysis conducted by scientists at the Wageningen University, in the Netherlands, showed that insects produce significantly less greenhouse gases and nitrous oxide than conventional livestock, per kilogram of mass gained.

Promoting insect consumption in the developing world where they are already eaten could also help fill the growing demand for protein-rich food. “Large numbers of humans already derive their major food input from insects,” McGavin says.

The Balinese, for example, enjoy dragonflies boiled in coconut milk infused with ginger and garlic; the sautéd larvae of aquatic flies are a Japanese delicacy; and beetle larvae, known as witchetty grubs, are an important dietary component of many traditional Australian Aborigines.

It’s clear just from their superior energy conversion abilities that insects represent an extremely clean route to food, adds McGavin. They don’t belch methane like farm animals, for one thing.

I ask him if he thinks there is potential to farm insects on an industrial scale. “Yes I do. Absolutely. We’re at seven billion people, heading for eight or nine. We can’t feed the world on beef, yet our cultural food habits are so ingrained that we’d ‘die’ before we’d eat worms.” McGavin sees insects as a key component in providing food for the future. “There are 40 tonnes of insects for every human alive at any one time – that’s four or five African elephants,” he says.

Sounding a little like the Agent Smith character from the movie The Matrix, McGavin compares humanity’s current situation to a germ growing on an agar plate; everything is fine until it reaches the edge. “We are now, as a species, able to see the edge of the agar dish,” McGavin explains. “[Overpopulation] is the elephant in the room – everyone is thinking about it but nobody is doing anything.

“If we’re not prepared to cull ourselves or reduce our numbers, we’re going to have to find new and innovative ways of feeding ourselves. That may well be a completely new approach to farming, one element of which must be insects as food.”

Food production needs to jump in capacity by 70% by 2050 to feed two billion extra mouths, according to the FAO. One way of growing more food is to use more land and Dickson Despommier, a microbiology professor at Columbia University, in New York City, believes this is the answer. What’s unusual is that he thinks we should do this by building vertically, not horizontally, using space within and on skyscrapers and other urban and city constructions. His idea – the vertical farm – has gone viral, attracting huge amounts of interest and enthusiasm as well as a rainbow of criticism, mainly focussed on the energetic requirements of such a setup.

British environmentalist George Monbiot has derided vertical farms as “magical thinking”, saying that marijuana would be the only crop capable of turning a profit from such expensive urban space. If Monbiot is right, then several new businesses are doomed to failure. Despommier says there are now seven vertical farms up and running, from Korea to Holland. Most of them are growing lettuce; hardly hydroponic dope.

“There’s a Dutch group now that claims that by growing crops with LEDs indoors, not using any natural light at all, they get a growth rate three times what can be achieved outdoors,” Despommier says. “They believe that sunlight contains inhibitory as well as stimulatory wavelengths.”

The group, called PlantLab, has embraced the concept of growing food indoors, using multiple layers in a closed environment. Conventional greenhouses are outdated, the company says, and permit too much interference from the outside world. Their entire operation is built around LED bulbs that allow them to deliver only the specific wavelengths of light their crops need, preventing the rest of the spectrum from being wasted.

Jason Matheny, the founder of research organisation New Harvest, says cultured meat would easily fit into the vertical farm model: “Given the reduced land requirements, one could imagine cultured meat being produced in vertical farms. The facilities and raw ingredients, such as algae, could be organised in tall buildings. There would be no need for cropland or pasture. That land could be converted back [for] wildlife.”

Rothamsted’s Moloney has another arrow to add to the vertical farm quiver – increasing the photosynthetic efficiency of arable crops. Typical food crops convert just 2% of their incident light into biomass but, Moloney says, corn and sugar cane have a mechanism by which they convert 8%, four times higher than the main arable crops.

“We’re now learning enough about [corn and sugar cane] at the genetic level to actually have a chance of engineering other crop plants to do something similar,” Moloney says. Better photosynthetic efficiency would mean staple crops could grow in less light. Combined with energy efficient LEDs, vertical farms could pump out food at unprecedented rates.

The new indoor models, which have sprung up around Despommier’s idea all have one thing in common – they are closed systems. Where GM crops seek to tame nature, Despommier’s vertical farms and Matheny’s cultured meat try to shut it out.

Back at Broadbalk field, my guide has been Rothamsted’s head of plant pathology and microbiology, John Lucas, a cross between a scientist and a farmer who looks like he’d be just as comfortable on a tractor as in a lab.
He points out that the 2011 drought in Britain meant there wasn’t enough water to dissolve some fertiliser pellets into the soil. When I ask about the potential of nitrogen-fixing arable crops to get around this dilemma, he pauses. “The problem with the [nitrogen]-fixing wheat is that it’s an energy requiring process; you’re not getting it for nothing. There will be a trade-off between the amount of energy going to the nitrogen fixation and the amount of energy going to the growth and development of the crop.”

Nothing comes for free, but existing systems – like fields of wheat – can be made more efficient if more photosynthetic energy can be found to facilitate nitrogen fixation. No stone can be left unturned in the search for the future of food, because today one billion people and counting are hungry.

Six-legged protein packets

Every year, 38 billion tonnes of warming gases such as carbon dioxide, methane and nitrous oxide enter the atmosphere as a result of human activities. According to the FAO, the livestock industry produces 18% of those gases, a massive six billion tonnes. As Mark Post makes clear, cows are relatively inefficient at converting plant matter into protein.

Insects do that very efficiently. An analysis from Netherland’s Wageningen University shows that rearing house crickets produces almost zero greenhouse gas emissions, just 1.5 grams per kg of body weight gained. This compares to the nearly 3 kg of greenhouse gases that beef cattle emit for every 1 kg gain.

“Greenhouse gas emissions of four of the five insect species studied was much lower than documented for pigs when expressed per kilogram of mass gain and only around 1% of the GHG emission for ruminants,” reports the analysis, published in the journal PLoS ONE in 2010. Insects are also a healthy food, as they contain less saturated fat than conventional meat.

Hal Hodson is a London-based science writer and photographer.
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