Crops That Feed The World | Rice

Bibimbap, Biryani, Jollof Rice, Nasi Lemak, Paella, Risotto, Sushi – the list of delicious rice dishes from around the world is truly endless. But how did this humble grain become a ubiquitous, universally loved food? Let’s look at the origins of rice and scientific innovation that made rice one of the most produced grains on the planet.

How did rice become a global commodity?

Rice, as a food crop and commodity, has played an important role in creating the early-modern world economy. An ancient food crop once synonymous with Asia and its prosperity, today, the story of rice is intricately linked to the rise of industrial capitalism and international trade. About four to five centuries ago, the popularity and trade of rice was limited to Asia. It was grown for subsistence in several regions of the continent, with excessive production often exported to neighbouring regions in need. Accounts from as early as the 8th century indicate some level of international rice trade between South Asia and Eastern Africa.¹

As early as some 1,300 years ago, the Hani people developed a complex system to bring water from the mountaintops to the rice terraces. Now they sing and dance to celebrate the "Kaiyangmen" festival to pray for a good harvest and fortune in the coming year. Honghe County, China. (Photo by Liu Ranyang via Getty Images)

In Europe, rice was first imported from Syria, Persia, and India by the Greeks and the Romans, though not as the staple food it’s known for today. At the time, rice was used as a rare medicine to treat ailments of the digestive tract.¹ During this period, international trade was dominated by luxury goods such as spices, printed cottons, silks, and porcelain, and exchange of subsistence goods like rice only occurred on a small scale.² As a result, rice was not yet established as a staple food crop in Europe.

Nevertheless, European traders took note of the thriving rice agriculture in Asia and were keen on venturing into cultivation themselves.² Through the colonisation of the Americas, European imperialists began to realise this ambition. During the 18th and 19th centuries, rice became one of the driving forces of colonial expansion into Burma, Brazil, Carolina, and Indochina.² Rice grown in the colonies would be traded and used for domestic consumption in Europe. Imperial China, Mughal India, and Meiji Japan also invested heavily in their rice production capacities to remain competitive in the global market.² The decades that followed saw colonial expansion, two World Wars, and political revolutions leading to decolonisation that would see considerable shifts in who dominated rice cultivation and trade during these tumultuous times. The value of rice as a staple food and trading commodity has remained strong since the 18th century.

Today, rice is cultivated on every continent except Antarctica.³ With over a hundred countries producing rice, over 715 million tons of the cereal are harvested each year.³ Half of this rice comes from China and India, with an additional 40 per cent coming from other Asian countries including Indonesia, Bangladesh, Vietnam, Myanmar, Thailand, the Philippines, Japan, Pakistan, Cambodia, the Republic of Korea, Nepal, and Sri Lanka.³ A few other significant producers outside of Asia include Brazil, the United States, Egypt, Madagascar, and Nigeria.³ Despite 22 species of rice being grown today, two key species – Oryza sativa and Oryza glaberrima – are relevant for human consumption.³ Except for certain African varieties, most rice we consume today are subspecies of O. sativa.

Discover how the System of Rice Intensification could make rice cultivation significantly more sustainable

Workers drying paddy grains by creating long columns of rice before spreading the piles with feet and rakes. By reducing the moisture level of the grain, the risk of bacteria is kept to a minimum. (Photo by Avishek Das via Getty Images)

Has science changed rice over the years?

Science has undeniably changed rice, and many of those changes are for the better. Up until the end of World War II, efforts to improve the rice crop were limited to selective breeding and developing more effective farming techniques. However, after World War II, severe famine coupled with sharp population growth in Asia prompted international efforts to use synthetic fertilisers and pesticides, agricultural mechanisation, and biotechnology as a means to fast-track improvements around rice crop production. Here are some ways in which science has helped feed a rice-hungry world:

Higher yield

Conventionally, early rice crop varieties had a tall and weak stem with considerable foliage. Once harvested, the biomass contained 30 per cent grain and 70 per cent straw.⁴ Since straw cannot be used for human consumption, foliage from the rice plant is either used as a lower-quality animal feed or disposed of as waste. Until the 1950s, rice breeders focused on improving the amount of rice a single plant could produce. When Chinese breeders successfully engineered the first ever semi-dwarf rice variety ‘Guang Chang Ai’ in 1959, it was considered a breakthrough in the field.⁵ The dwarfing gene successfully doubled the yield potential of the crop, making it the single most important architectural change in modern rice varieties.⁴ The dwarfing gene was then used by researchers across Asia to breed high-yield rice varieties, thus heralding Asia’s Green Revolution.

Shorter growth duration

Traditional rice varieties from the tropics took 150-200 days to mature.⁴ They were also photoperiod sensitive and could be grown only during the monsoon season in Asia. To allow farmers to grow more than one crop cycle in a year, scientists engineered rice varieties unaffected by photoperiods. These new varieties could be grown in a span of 110-120 days and during any season with the help of advanced irrigation techniques.⁴

Disease resistance

In rice-growing regions, humid and nutrient-rich environments enable the spread of several plant diseases. These diseases, caused by a host of pathogens and insects, greatly reduce the yield of semi-dwarf rice varieties, causing huge economic losses to rice-growing countries.⁵ The yellow stem borer and brown plant hopper, along with pathogens like blast and bacterial leaf blight, have caused much destruction to rice agriculture over the years. By breeding rice crops that are more resistant to these diseases, plant breeders have been able to provide some relief to rice farmers.⁵

Grain quality

Consumers in different parts of the world have different preferences regarding the qualities they desire in their rice. Some prefer long, slender grains that retain their structure after cooking. Others enjoy short-grained rice that turns sticky after cooking. By employing advanced plant breeding techniques that allow for improving, reducing and even omitting various traits, scientists have enhanced desired characteristics in rice and removed or toned down undesirable taste or texture traits, such as chalky and brittle grains.⁴ These modifications have helped rice-producing countries price their rice competitively in the global market.

Nutrient enrichment

Rice provides 50 per cent of the dietary caloric supply for the population in Asia, a continent severely impacted by malnutrition.³ After the success of high-yield varieties, rice research has focused on developing varieties that can provide better nutrition to consumers. Several breeding endeavours since then have worked on developing varieties that are more rich in protein and micronutrients such as iron, zinc, and vitamin A. In 2017, scientists were even able to develop a protein-enriched variety of rice using gene-editing CRISPR technology.⁶ In 2000, a beta-carotene-rich variety popularly known as ‘Golden Rice’, believed to offer several health benefits, was successfully engineered for production.⁵

Will we continue eating rice in the future?

The short answer is yes, most likely. Rice is a staple food for close to half of the world’s population, making it an indispensable part of many Asian, African, South American, and even European cultures. However, despite all past and present biotechnological innovations, it is not immune to climate change. In fact, rice grows in some of the most vulnerable parts of the world to climate change and faces increasingly serious threats from flooding, rising salinity of soil and water, and heat stress. Current rice cultivation practices are extremely water-intensive and produce higher greenhouse gas emissions than any other crop.^7,8 To tackle both issues, breeders are working towards developing rice varieties that require less water to grow and at the same time are more immune to flooding and high temperatures.⁴ Developing better tillage practices, efficient fertilisers, and using methane-ingesting bacteria are likely to help as well.⁹