Can science help improve food security?

Global crop yields face an uncertain future amid projected changes to the world's climate

Farming and retail experts warn that this year's poor UK's harvest is going to trigger a rise in food prices on supermarket shelves.

The past 12 months have seen a range of extreme weather not just in this country, which experienced its second-wettest summer on record, but around the globe, such as the droughts in Russia and the US Midwest that effectively devastated these regions' wheat yields.

The UN Food and Agriculture Organization (FAO) latest figures showed that global food prices had risen by 1.4% in September as a result of fears of food shortages following poor harvests.

Projections of future changes to the planet's climate and its impact on the agriculture sector's ability to feed a rising global population has made the issue a priority for scientists.

The Biotechnology and Biological Sciences Research Council (BBSRC) is one of the UK's leading funding bodies for crop research and it has listed food security as one of its strategic priorities.

In 2010/11, it provided £100m - accounting for 36% of its funding - for research projects looking at improving food security.

BBSRC chief executive Douglas Kell acknowledged that food security was a complex, wide-ranging challenge but said science had an important role to play.

"For example, wheat yields were one tonne per hectare in the middle of the 19th Century but improved farming methods and agri-science research now sees us closer to nine tonnes per hectare in the UK today," he told BBC News.

"Research programmes, like the 20:20 Wheat Programme (which aims to increase yields to 20 tonnes per hectare in 20 years), hope to improve this further and in a number of ways, such as improving the way wheat uses the Sun's energy, better tolerance to stress or resistance to pests and disease."

Slow growth

Wheat has become a vital staple around the world since a chance hybridisation 10,000 years ago enabled humans to start harvesting and domesticating the cereal.

It is the UK's largest crop, and worldwide more land is used to grow wheat than any other crop. It has overtaken rice to become the second most-produced cereal after maize.

Prof Neil Hall, from the University of Liverpool's Centre for Genomic Research and part of the team behind the decoding of the wheat genome, said it took a long time for experiments in a laboratory to make it into the fields.

"The challenge crop breeders are facing is that they have to deal with rapid climate change that is not only affecting sunlight, temperature and rain but also crop pests.

"In wheat the breeding process, from identifying a desirable trait to generating a new variety that can be used in agriculture, can take more than 10 years," he told BBC News.

The challenge of using crop varieties available to farmers to feed the world's growing population in a rapidly changing climate was "humanity's greatest challenge in the 21st Century", according to Colin Osborne, a reader in plant biology at the University of Sheffield's Department of Animal and Plant Sciences.

"We need to increase crop yields using less land, irrigation and fertiliser," he explained.

Plant scientists involved in the university's Project Sunshine are looking for "innovative new solutions to these problems", Dr Osborne added.

"One ambitious project aims to boost crop growth by introducing a 'turbo-charger' that evolved many times in wild plants.

"We are also discovering new ways to reduce crop losses to pests and diseases."

He observed: "Our research looks at ways to prime natural plant defences, and to exploit partnerships with fungi to reduce crop dependence on fertiliser."

Gnawing problem

But attention must not just be focused on what is happening in the field.

Rodents can decimate harvested crops while they are stored in farm buildings

The NFU recently warned that the wet summer had waterlogged rodents' usual habitats, increasing the risk of rats and mice seeking refuge in grain stores and farm buildings.

So not only do farmers have to contend with poor yields, they also face the problem of what they are able to collect from their fields being eaten before it passes the farm gates.

On a global scale, the problem of rodents eating grain is considered to be a serious threat to global food security and it is estimated that reducing the amount of crop lost in this manner by just 5% could help feed one third of the world's undernourished people.

In an attempt to find a way to deal with such infestations, a team of researchers from the University of Liverpool and Rothamsted Research is looking at ways to manipulate rodent behaviour.

The £4.7m project is investigating the scent signal mechanisms that rodents use to navigate around their habitat, communicate with each other, and reproduce.

It is hoped that the research will deliver more effective ways to control rodents, which can reproduce very quickly to plague proportions if a reliable source of food is available.

One of the UK's leading crop research organisations is the John Innes Centre (JIC).

The centre's director, Dale Sanders, said plant science offered new ways to "sustainably increase crop yields, while at the same time reducing inputs such as fertiliser and pesticides".

"This will be achieved through a greater understanding of plants, how they grow, and how we can exploit the latest genomic technologies," he told BBC News.

"One focus of research is to reduce yield losses from pests, diseases and other stresses such as drought and climate change."

Prof Sanders said that wheat breeders had been working to increase productivity without a detailed knowledge of the genetics behind the changes they have made.

"Breeding has increased yields, but recently those increases have slowed. The possibilities for improvement are reaching their limit. New sources of genetic diversity are needed to revitalise wheat breeding."

He added that in research being led by the JIC, scientists would seek to identify "lost" diversity and valuable traits from wild wheat and other grasses, from primitive varieties adapted to different conditions worldwide and from commercial bread wheat.

"This diversity will be incorporated into elite UK varieties ensuring breeders can quickly use it to make improvements in the field."

Just as drought can decimate yields, so can flooding.

Researchers have developed a "waterproof" rice variety that can withstand being submerged in water for prolonged periods, which would kill traditional varieties.

Rice is the primary food for three billion people, and more than 25% the world's harvest is grown in areas that experience extreme weather conditions.

'Valuable tool'

The BBSRC is part of the Global Food Security Programme, a partnership between UK research councils, government departments and agencies that aims to " meet the challenge of providing the world's growing population with a sustainable, secure supply of good quality food from less land and with lower inputs."

Global food security champion Prof Tim Benton said that even tiny changes in crop prices could have a big impact when it came to buying food.

"While some people can cope with an increased shopping bill, for others it can be devastating," he observed.

"A sudden and unexpected price change can be difficult for poorer households to cope with, particularly in developing countries.

"Scientific research provides a valuable tool for addressing these challenges."

Not everyone supported the idea that increasing yields through scientific advance will deliver food security.

Tim Lang, professor of food policy at City University London and former member of the government's Food Council, said just focusing on the role science can play in increasing food production was "nonsense".

"I belong to a school of analysis that says the problem is not just scientific or technical, the problem is societal, cultural and economic," he told BBC News.

Food 'folly'

Prof Lang called for a greater focus on the social dimension of food policy - behaviour, consumption, expectations - and not "repeat what has gone wrong from the 20th Century, which has been to say we will resolve the problem of feeding people adequately just by producing more food".

He said policymakers in the 1930s and 1940s had assumed that people would just eat what was good for their health.

"They said 'let's just unleash science and technology, and if we invest enough and get distribution right, prices will come down, markets will be full of food and people's health will improve'.

"The appeal being made that science will resolve this problem is folly. It is bad policy.

"A food policy that is dominated by the biosciences is heading into a new version of problems.

"We must learn the lessons of the last time that the science and technology arguments dominated food policy - it led us into the mess we are now in."