Where our food grows

The bread, rice and fruit we eat grew somewhere.

Farmers grow them in fields and orchards. Different foods grow in different places. Some like hot weather. Some like cool weather.

Almost everything on your plate started on a farm, in a field, an orchard or a pond. There are more than 50,000 kinds of plants that people can eat, but just a few feed most of the world. A 1995 atlas by FAO, the United Nations food organization, found that three grains, rice, maize (corn) and wheat, gave people 60 percent of the energy they got from food.

Foods that people eat most days, like rice, bread, corn or potatoes, are called staple foods. Where each one grows depends on the weather, the soil and the water in that place.

The Food and Agriculture Organization of the United Nations (FAO) noted in its 1995 atlas Dimensions of Need that, of more than 50,000 edible plants, just three, rice, maize and wheat, provided 60 percent of the world's food energy intake, and that these three were staples for over 4,000 million people. A staple is a food eaten regularly and in such quantities that it supplies a major part of a population's energy and nutrients.

FAO added that staple foods are typically well adapted to the growing conditions where they come from, tolerating drought, pests or poor soils, and that farmers often rely on them to reduce risk. Most people's diets are based on one or more staples: rice, wheat, maize, millet, sorghum, roots and tubers such as potatoes, cassava, yams and taro, and animal products.

Plants need warm days to grow.

Rice needs lots of warmth. Wheat can start growing when it is cooler. Near the Equator, it is warm all year.

Crops need enough warm days in a row to grow, sprout and ripen. This time is called the growing season, and most crops need at least 90 days. Each crop has its own needs: rice needs a temperature of at least 20 degrees Celsius (68 degrees Fahrenheit) to grow, but wheat will sprout at just 5 degrees Celsius (40 degrees Fahrenheit).

In the tropics, where it is warm all year, the growing season can last the whole year. Farther from the Equator, summers are shorter. In Alaska, the growing season is only about 105 days on average.

National Geographic Education defines the growing season as the period of the year when crops grow successfully; most crops need at least 90 days. In temperate regions it is usually measured as the average number of days between the last spring frost and the first severe autumn frost, or by the days warm enough for a particular crop: rice needs at least 20 °C (68 °F), while wheat sprouts at 5 °C (40 °F).

The season shortens with distance from the Equator and with height. Near the poles it can be under two months, and Alaska averages only 105 days. In California, it lasts about 50 days high in the Sierra Nevada but 365 days along the southern coast. In the tropics it can last all year, though a rainy season can interrupt it: coffee is harvested all year in Colombia, while heavy rains often interrupt the coffee season in Indonesia.

Chocolate is made from cocoa beans.

Cocoa trees only grow where it is hot and rainy all year. They grow near the middle of the Earth, close to the Equator.

Some crops can only grow in a very narrow band of the world. Cocoa trees, whose beans are used to make chocolate, grow in a belt about 10 degrees north and south of the Equator. They like it hot and humid, with plenty of rain spread through the year.

In the wild, cocoa trees grow in the shady lower layer of the rainforest. The biggest cocoa growers today are Côte d'Ivoire, Ghana and Ecuador. So the chocolate in your snack may have come from a farm thousands of kilometers away.

The International Cocoa Organization (ICCO) explains that cocoa is produced in a belt between 10° N and 10° S of the Equator. The tree's natural habitat is the lower story of evergreen rainforest, and temperature and rainfall matter most: average annual maximums of 30 to 32 °C and minimums of 18 to 21 °C, and 1,500 to 2,000 mm of rain a year, well spread, with dry spells (under 100 mm a month) lasting no more than three months. Relative humidity is often 100 percent by day.

ICCO names Côte d'Ivoire, Ghana and Ecuador as the three current largest producers. Because cocoa is so particular, a chocolate bar eaten in a cold country depends on farms in a narrow tropical belt, a clear example of how climate fixes where a crop can be grown.

Plants grow in soil.

They drink water from rain. Where there is not enough rain, farmers bring water to the fields. This is called irrigation.

Good soil is a farmer's treasure. FAO, the United Nations food organization, says that 95 percent of our food comes from soils.

Crops also need water. Where rain is too little or comes only at some times of year, farmers bring water to their fields through pipes, canals or sprinklers. This is called irrigation. National Geographic estimates that about 18 percent of the world's cropland is irrigated. Drip irrigation, which lets water drip from holes in pipes right onto each plant, is one of the most efficient ways to water crops.

FAO's World Soil Day campaign states that 95 percent of our food comes from soils and that up to 58 percent more food could be produced through sustainable soil management. Irrigation, bringing water to crops by pipes, canals, sprinklers or other means rather than relying on rain alone, makes farming possible where rainfall is sparse or seasonal; National Geographic Education estimates that about 18 percent of the world's cropland is irrigated, after the irrigated area doubled during the 20th century.

The cost is water. FAO's AQUASTAT finds that 69 percent of all water withdrawals worldwide are for agriculture (12 percent municipal, 19 percent industrial), rising to 91 percent in South Asia. Overuse can be severe: diverting the Amu Darya and Syr Darya rivers to irrigate cotton, melons and citrus shrank the Aral Sea from 68,000 km² before the 1940s to three separate lakes.

Different places are linked with different foods.

Rice is linked with Asia. Potatoes and tomatoes are linked with South America. Corn is linked with Mexico and Central America.

Every region of the world is linked with its own crops. An atlas made by FAO in 1995 lists, for example, rice and tea in the China-Japan region, mango and rice in the region FAO calls Hindustani (South Asia), wheat, grapes and lentils in the Near East, maize (corn) in Central America and Mexico, and potatoes, tomatoes and cacao in South America.

Next time you eat a meal, try to guess where each food grew.

FAO's 1995 atlas groups selected food crops by world region: bamboo, millet, rice, soybean and tea for the Chinese-Japanese region; banana, coconut, mango, rice and sugar cane for the Indochinese-Indonesian region; banana, chickpea, eggplant, mango and rice for the Hindustani region; apple, apricot, carrot, onion and wheat for Central Asia; almond, barley, fig, lentil and wheat for the Near East; olive, oats and wheat for the Mediterranean; coffee, millet, sorghum, teff and yam for the African region; maize, pepper and squash for Central America and Mexico; and cacao, cassava, potato, sweet potato and tomato for South America.

FAO also noted shifts in what people eat: since 1970, root and tuber consumption in the Pacific Islands had fallen by 8 percent while cereal consumption rose by 40 percent, from 61 to 85 kg per person, and cassava had become a basic food for around 500 million people.