The sweet-rice mixture was probably the world's first composite mortar, according to the American Chemical Society.
Food scientists are furiously racing to come up with new rice varieties and growing techniques to meet the rising demand presented by a growing population in Asia.
To discuss the challenge, rice scientists and world officials met at a symposium in New York last week, where the International Rice Research Institute (IRRI) and the Asia Society jointly released a task force report, "Never an Empty Bowl: Sustaining Food Security in Asia."
Agricultural research has already made huge leaps in feeding the world's hungry: Most of the rice strains grown globally today are modern varieties that have been bred by scientists in the last 40 years, said Achim Dobermann, IRRI's deputy director general for research. But with the population of Asia set to grow substantially in coming years, there is much ground left to cover.
"We know that for the next 10 years, we need to produce 8 to 10 million more tons [of rice] each year," Dobermann told LiveScience. "That would essentially enable us to keep pace with the growing population."
And that increase needs to be achieved with the same amount of land – or less – devoted to growing the crop.
"As a consequence of economic growth, current rice cultivation areas are likely to be lost to urban expansion and land conversion to biofuels. Accordingly, sufficient production to meet future demand will have to come from smaller and smaller areas," the report read.
While some parts of Asia have experienced economic growth, others are stuck in cycles of poverty. Asia accounts for about 65 percent of the world's hungry population, and in many Asian countries, rice contributes more than 30 percent of people's total caloric intake on average, the experts said.
This single crop plays such a vital role in the welfare of so many people, that advances in rice science could reap global benefits, while a disruption to the rice supply could wreak major havoc.
And population growth is not the only looming challenge to the rice supply.
"Population growth, increasing demand from changing diets, dwindling land and water resources for agriculture, higher energy costs, and the huge uncertainties regarding the effects of climate change present scientists and policy makers with additional challenges," wrote Vishakha N. Desai, president of the Asia Society, in a foreword to the report.
Sun and rain
To tackle the problem, scientists are looking to make significant changes to the humble rice plant.
For example, IRRI researchers are trying to reengineer the photosynthesis mechanism in rice that converts sunlight and water into crop. They want to make it more comparable to the C4 photosynthesis process in crops like maize and sorghum, both of which can produce up to 50 percent more biomass given the same input, Dobermann said.
They also want to improve the nutritional quality of rice, so that the same amount of food might impart more sustenance and nutrients to people.
IRRI scientists can search through their inventory of more than 100,000 different varieties of rice to find some that contain special benefits.
"There may already be rice kinds that naturally have higher zinc content, for example," Dobermann said. "We try to identify genetic reasons for this and use this information to upgrade modern varieties with this trait."
Another goal is to create rice that contains vitamin A, a nutrient important for eye health; lack of vitamin A is a leading cause of childhood blindness. Approximately one-third of the world's preschool-age population is vitamin-A deficient, and the problem is especially serious in Southeast Asia, according to a 2009 report by the World Health Organization.
There are no natural sources of vitamin A in rice, so scientists are looking to other crops like maize to find the genes necessary to produce the vitamin, Dobermann said. When such traits from non-rice crops are needed, scientists use genetic engineering methods to transfer over the necessary genes.
Genetically modified rice has not yet been approved for human consumption by any country.
"The vitamin A enriched rice is the first one that we will bring to the market," Dobermann said. "If everything goes well then we should be reaching the stage of approval in one country — probably the Philippines — in about two years."
After that, it could still take several years to get the new rice into the hands of farmers around the nation, he said.
Finally, researchers are working to make rice more resistant to pests, diseases and environmental threats, such as rising temperatures, floods and drought.
For instance, to combat flooding, IRRI scientists have created a rice strain that can be submerged under water for longer than traditional counterparts. (This strain is not considered genetically engineered rice, because rather than tweaking the genes directly scientists bred various types together to form the final version.)
"That's one we're rolling out big time in India and Bangladesh now," Dobermann said.
Climate change also presents risks. Temperatures – especially at night – are increasing in many parts of Asia. Most rice varieties aren't adapted to this kind of heat, and can become sterile if exposed to too-high temperatures at critical stages in the growing process. Researchers are still in the beginning phases of looking for fixes to this issue.
Overall, scientists say the rice shortage problem is not insurmountable. The goal of producing 8 million to 10 million tons more of rice per year is possible, Dobermann said.
"I think it is very achievable if people make the right decisions and the right investments," he said. "It means that on average, the rice yield needs to grow by about 50 to 60 kilograms per hectare each year. That is essentially within the range of the yield growth rates we've had in the past."
Though it will take some ingenuity, "I believe we have enough interesting solutions already in hand," he said.