Encyclopedic Entry

Whole grains are cereals that have not been processed to remove their natural tissues: germ (the seed's embryo), endosperm (nutrition for the embryo), and bran (outer layer).

Photograph by Glenn Upton, MyShot

Rice is Life
Rice is a staple food in much of Asia. The average person eats it two or three times a day. In Myanmar, the average person eats 195 kilograms (430 pounds) of rice each year. That's a lot more than the average American, who eats just 7 kilograms (15 pounds) or the average European, who eats only 3 kilograms (7 pounds).

Maize
In most countries, the grain of the Zea mays plant is called maize. In the United States, it's called corn.

Grain Elevator
A grain elevator is just what it sounds like. It's a large storage facility for grain that is equipped with lifting mechanisms, so large amounts of grain can be lifted and poured into trucks, railroad cars, or other storage facilities.

Grain
A grain (gr) is a unit of measurement based on the mass of a typical grain, such as wheat. A grain is 64.8 milligrams.

Grain is the harvested seed of grasses such as wheat, oats, rice, and corn. Other important grains include sorghum, millet, rye, and barley. Around the globe, grains, also called cereals, are the most important staple food. Humans get an average of 48 percent of their calories, or food energy, from grains. Grains are also used to feed livestock and to manufacture some cooking oils, fuels, cosmetics, and alcohols.

Almost half of the grains grown around the world are harvested for people to eat directly. People turn wheat flour into bread, steam rice, and make corn tortillas. Grains are a food staple in almost every culture on Earth. A food staple is food that is eaten frequently, often at every meal. Staple foods can be eaten fresh or stored for use all year. Rice, corn, and wheat are the most common staple foods on Earth.

Grains are so important because they are a good source of important nutrients called carbohydrates. Carbohydrates are a type of sugar that provides energy for organisms to function. Grains have carbohydrates as well as other important nutrients, such as vitamins. While grains fill many nutritional needs, they often lack some important proteins. In many cultures, grains are part of a staple diet when combined with protein-rich legumes, such as beans. Together, grains and legumes make a healthy diet: corn and beans, rice and tofu, wheat bread and peanut butter.

A third of the world’s grain supply is fed to animals. Most domestic animals, from cattle to dogs, are fed food rich in grains and grain products.

The rest of the world’s grain supply is used in the manufacture of industrial products. Biodiesel is a fuel used for vehicles. One type of biodiesel is ethanol, which can be made from corn.

Grains are annual plants. This means they have only one growing season per year, yielding one crop. Every growing season, grasses grow, reach maturity, produce seeds, and then die. Grains are harvested from dead, or dry, grasses.

Some grains are winter grains, such as rye. They are able to withstand cold, wet climates. Others are summer grains, such as corn. Corn usually grows best in warm weather.

Grains can grow in almost any climate. Rice is the most important grain in many tropical areas, where it is hot and humid year-round. Rice is especially common in Asia. In Southeast Asia, rice is grown and harvested in flooded fields called paddies. Rice paddies can be flat or terraced. Terraced rice paddies look like steps on a green hill. This type of grain agriculture has been used for centuries.

Unlike rice, sorghum does not grow well in a wet climate. Sorghum favors an arid climate. The nations of West Africa, including Senegal, the Gambia, Burkina Faso, and Cape Verde, are the world’s largest producers of sorghum.

In temperate areas—those with warm summers and cold winters—wheat is the most common grain. Wheat fields are common in the Great Plains of the United States and Canada, for instance. Corn, which is native to the Americas, is now grown in many temperate areas throughout the world. Oats, another grain that grows in temperate areas, are also used as a livestock feed.


Harvesting Grain

People first began eating grains about 75,000 years ago in western Asia. These grains, including einkorn and emmer, were ancestors of today’s wheat. Einkorn and emmer grew wild near the banks of rivers. People harvested the grasses that grew naturally near their communities.

People began cultivating, or growing, grain more recently. In 2009, scientists announced that they had discovered the world’s oldest known grain silos at Dhra in what is now the nation of Jordan. The silos, which date back 11,000 years, contained remnants of barley and an early type of wheat. 

Ancient people ate grains in much the same way we do today. Wheat grains were made into flour and used in breads. Rice was steamed and eaten hot or cold. Oats were mashed with water or milk to make oatmeal. Beer, one of the oldest manufactured beverages in the world, is made from grain such as barley. Ancient beers had a very low alcohol content, but were good sources of carbohydrates.

In some ancient civilizations, grain products served as wages or forms of currency. Many of the workers who built Egypt’s pyramids at Giza, for instance, were often paid in bread and beer.

Today, grain silos are a familiar sight to many people in the developed world. Harvesting is done almost entirely with enormous, expensive machinery. The most important piece of agricultural machinery for grain crops is the combine harvester. This remarkable machine does three jobs: it cuts the grain, threshes the grain, and winnows the grain. Cutting, of course, is removing the grain from the stalk of grass. Threshing is loosening the edible grain from its casing, called the chaff. (Chaff is inedible; organisms cannot digest it.) Winnowing is the process of removing the grain from the chaff. Combine harvesters help farmers expand the amount of grains they can harvest by combining three activities into one.

In the developing world, few farmers have the huge fields of grain that agribusinesses in the developed world do. Farmers in the developing world typically have a few acres, and provide grain for their local community. These farmers usually thresh and winnow with separate machines (threshers and winnowers) after harvesting the field. In many places, harvesting is still done with hand tools such as the sickle, a long, curved blade used for cutting many stalks of grain at once.

Vocabulary

Term Part of Speech Definition Encyclopedic Entry

acre

Noun

unit of measure equal to .4 hectares.

agribusiness

Noun

the strategy of applying profit-making practices to the operation of farms and ranches.

agriculture

Noun

the art and science of cultivating the land for growing crops (farming) or raising livestock (ranching).

Encyclopedic Entry: agriculture

alcohol

Noun

chemical compound, usually ethanol or methanol, generated by fermentation and used for fuel, hygiene, medicine, and food.

ancestor

Noun

organism from whom one is descended.

ancient

Adjective

very old.

annual

Adjective

yearly.

arid

Adjective

dry.

bank

Noun

a slope of land adjoining a body of water, or a large elevated area of the sea floor.

barley

Noun

grass cultivated as a grain.

bean

Noun

edible seed of legumes.

beer

Noun

alcoholic beverage made from grain.

beverage

Noun

liquid for drinking.

biodiesel

Noun

fuel made at least partly from renewable sources such as soy oil, palm oil, or animal fats.

calorie

Noun

unit of energy from food, equal to the amount of heat required to raise the temperature of one kilogram of water by one degree Celsius.

carbohydrate

Noun

type of sugar that is an important nutrient for most organisms.

casing

Noun

material on the outside of a substance, usually there to protect the material inside.

cattle

Noun

cows and oxen.

cereal

Noun

type of grain, including wheat.

chaff

Noun

the dry, usually worthless, husks of grain or grass.

civilization

Noun

complex way of life that developed as humans began to develop urban settlements.

Encyclopedic Entry: civilization

climate

Noun

all weather conditions for a given location over a period of time.

Encyclopedic Entry: climate

combine harvester

Noun

farm machine that cuts, threshes, and winnows grain.

cooking oil

Noun

liquid fat taken from plants such as olives and soy. Also called vegetable oil.

corn

noun, adjective

tall cereal plant with large seeds (kernels) cultivated for food and industry. Also called maize.

cosmetics

Noun

substances applied to the body to make it appear more attractive.

cultivate

Verb

to encourage the growth of something through work and attention.

culture

Noun

learned behavior of people, including their languages, belief systems, social structures, institutions, and material goods.

currency

Noun

money or other resource that can be used to buy goods and services.

developing world

Noun

nations with low per-capita income, little infrastructure, and a small middle class.

diet

Noun

foods eaten by a specific group of people or other organisms.

Encyclopedic Entry: diet

digest

Verb

to convert food into nutrients that can be absorbed.

discover

Verb

to learn or understand something for the first time.

domestic animal

Noun

animal that has been tamed for work or to be a pet.

edible

Adjective

able to be eaten and digested.

einkorn

Noun

type of wheat.

emmer

Noun

type of wheat.

energy

Noun

capacity to do work.

enormous

Adjective

very large.

ethanol

Noun

type of grain alcohol used as biofuel.

expensive

Adjective

very costly.

familiar

Adjective

well-known.

feed

Noun

processed food for livestock.

flour

Noun

ground grain, usually of wheat.

food

Noun

material, usually of plant or animal origin, that living organisms use to obtain nutrients.

Encyclopedic Entry: food

food staple

Noun

food that is eaten frequently, either fresh or stored for use all year.

Encyclopedic Entry: food staple

frequent

Adjective

often.

fuel

Noun

material that provides power or energy.

grain

Noun

harvested seed of such grasses as wheat, oats, and rice.

Encyclopedic Entry: grain

grain elevator

Noun

large storage facility for grains, equipped with lifting mechanisms.

grain silo

Noun

large storage facility for grains.

grass

Noun

type of plant with narrow leaves.

Great Plains

Noun

grassland region of North America, between the Rocky Mountains and the Mississippi River.

growing season

Noun

period in the year when crops and other plants grow rapidly.

harvest

Noun

the gathering and collection of crops, including both plants and animals.

humid

Adjective

containing a large amount of water vapor.

inedible

Adjective

not able to be eaten or digested.

legume

Noun

type of plant with a pod that splits, with seeds in the middle, such as peanuts.

livestock

noun, plural noun

animals raised for sale and profit.

machinery

Noun

mechanical appliances or tools used in manufacturing.

maize

Noun

corn.

manufacture

Verb

to make or produce a good, usually for sale.

millet

noun, adjective

a type of grain.

nutrient

Noun

substance an organism needs for energy, growth, and life.

Encyclopedic Entry: nutrient

oatmeal

Noun

rolled or ground oats mixed with water or milk.

oats

Noun

type of edible grass.

protein

Noun

molecule necessary for all living organisms.

raw material

Noun

matter that needs to be processed into a product to use or sell.

remarkable

Adjective

unusual and dramatic.

remnant

Noun

something that is left over.

rice

Noun

grass cultivated for its seeds.

rice paddy

Noun

rice field.

river

Noun

large stream of flowing fresh water.

Encyclopedic Entry: river

rye

Noun

cereal grain grown for food.

seed

Noun

part of a plant from which a new plant grows.

sickle

Noun

long, curved blade attached to a handle, used for cutting many stalks of grass at once.

sorghum

Noun

type of grain.

stalk

Noun

stem of a plant.

steam

Verb

to heat something by placing it over boiling water.

sugar

Noun

type of chemical compound that is sweet-tasting and in some form essential to life.

summer grain

Noun

grass that is harvested during the summer or autumn.

temperate

Adjective

moderate.

terrace

Noun

flat surface created on a steep hillside for the purposes of agriculture.

thresh

Verb

to loosen the grain from its casing, called chaff.

tofu

Noun

thick, soft substance of varying consistency made from soybeans.

tortilla

Noun

flat, round bread made from corn or flour.

tropical

Adjective

existing in the tropics, the latitudes between the Tropic of Cancer in the north and the Tropic of Capricorn in the south.

vehicle

Noun

device used for transportation.

vitamin

Noun

chemical substance that is necessary for health.

wage

Noun

money or goods traded for work or service performed.

weather

Noun

state of the atmosphere, including temperature, atmospheric pressure, wind, humidity, precipitation, and cloudiness.

Encyclopedic Entry: weather

wheat

Noun

most widely grown cereal in the world.

winnow

Verb

to separate the grain from the inedible casing, called chaff.

winter grain

Noun

grass that is harvested during the winter or spring.

yield

Verb

to produce or result in.

Credits

Media Credits

The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited.

Writers

Melissa McDaniel
Erin Sprout
Diane Boudreau
Andrew Turgeon

Illustrators

Tim Gunther, Illustrator
Mary Crooks, National Geographic Society

Editors

Jeannie Evers
Kara West

Educator Reviewer

Nancy Wynne

Producer

Caryl-Sue, National Geographic Society

Sources

Dunn, Margery G. (Editor). (1989, 1993). "Exploring Your World: The Adventure of Geography." Washington, D.C.: National Geographic Society.

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