Where does corn come from?

Corn, called maize outside North America, is a tropical grass that farmers have pushed far into the temperate zone. It photosynthesizes by the C4 pathway, which makes it unusually efficient in heat and strong sunlight, and it wants a frost-free season of four to five months with rain or irrigation during summer. Give it deep, fertile soil and nitrogen and it outyields every other cereal. The world's corn therefore sits on the summer-rain plains of the mid-latitudes and on tropical uplands, not in the cool wheat country to the north or the flooded rice country of the monsoon.

In 2024 United States produced 377.6 million tonnes of corn, 31% of the world's 1.2 billion tonnes (FAOSTAT). The US Corn Belt (Iowa, Illinois, Nebraska, Minnesota, Indiana) is the densest corn landscape on earth, planted with hybrid seed on flat glacial soils. China (24%) grows corn across the northeast and the North China Plain, mostly for feed. Brazil (9.4%) is different: much of its crop is the safrinha, a second crop sown into soybean stubble in January and February and harvested in the dry season, which is why Brazilian exports arrive when the northern hemisphere is between harvests. Argentina (4.7%) rounds out the big four, and the top five together grew 73% of world output.

Corn is also a staple food, not just a feed grain. In Mexico and Central America it is eaten as tortillas; across eastern and southern Africa, from Kenya to South Africa, white corn ground into meal is the main source of calories, grown largely by smallholders on rain-fed plots with low yields. India, Indonesia and the Philippines grow it for both food and feed. 169 countries reported production in 2024, and 19% of the world's corn came from outside the top ten.

Two technologies made the map. Commercial hybrid seed, sold from 1926, raised yields far beyond what farmers could achieve by saving their own seed, and genetically engineered traits for insect resistance and herbicide tolerance, introduced in 1996, are planted on nearly all of the crop in the United States, Brazil and Argentina but are banned or restricted in much of Europe and Africa.

Corn is traded mainly as grain (HS 1005). In 2024 the largest exporter was United States with 28% of world export value (CEPII BACI), followed by Brazil and Argentina. The United States, Brazil, Argentina and Ukraine supply nearly all of what crosses borders; China grows a great deal but exports almost none. The largest importer was Mexico (9.8% of world import value), ahead of Japan and South Korea; world imports were worth $47.6 billion. Mexico, Japan, South Korea, Vietnam, Egypt and the European Union buy for feed mills, while China's purchases swing sharply from year to year with state policy.

The processed forms of corn travel under other headings and do not appear in this ranking: corn starch, glucose and high-fructose syrup, corn oil, ethanol and the distillers grains left over from ethanol plants. The distillers grains trade is large enough that it matters for feed importers, and the United States is its dominant source. Corn on this page means grain.

The world reference is the CBOT (CME Group) Corn futures contract (ticker ZC): 5,000 bushels per lot, quoted in US cents per bushel, deliverable at shipping stations along the Illinois River and in the Chicago area. A bushel of corn weighs 56 lb (25.4 kg), so about 39.4 bushels make a tonne. The Dalian Commodity Exchange in China and Euronext in Paris list corn futures, and Brazil's B3 lists a contract in reais, but they follow Chicago far more than Chicago follows them.

The series on this page, US No. 2 yellow, Gulf export, is an export quote for loading at the US Gulf: it stood at $224/t in August 2026, up 21% from a year earlier (World Bank Pink Sheet). The series' highest month on record was $348.2/t in April 2022, and its lowest $38/t in November 1960; over ten years it has moved +49%. A Gulf quote equals the futures price plus the Gulf basis, which covers barge freight down the Mississippi, elevation at New Orleans and the local balance of supply and ships. Brazilian corn is quoted FOB Paranaguá or Santos, Argentine corn FOB Rosario or Up-River, and Ukrainian corn FOB Odesa or, when ports are closed, at the Danube.

Grades matter less for corn than for wheat, but they matter. US No. 2 yellow, the contract grade, sets limits on test weight, moisture, damaged kernels and foreign material; importers also test for aflatoxin and, in some markets, for unapproved biotech traits, which is how a single detection can stop cargoes. Ambiguities: corn means maize grain, both yellow and white; sweet corn and popcorn are counted separately as vegetables; and the US Gulf price is one origin's export quote, not a world price.

The United States grows about a third of the world's corn and exports a large share of what is traded, so the July weather in Iowa and Illinois is the single most watched variable in grain markets. Heat and drought during pollination in July cut kernel set and cannot be repaired by later rain, as in 2012; a late spring delays planting and pushes the crop into a shorter season; and wind events such as the 2020 derecho can flatten millions of acres in an afternoon.

The ratio of ending stocks to total use sets how nervous the market is. USDA puts world corn stocks-to-use at 22% for 2026/27, against 24% in 2025/26 (USDA PSD). Because China holds a large and unexported share of world stocks, traders also watch the US ratio alone; when US ending stocks fall toward the level of a few weeks' use, prices react violently to every crop-condition report.

Roughly a third of the US corn crop is distilled into fuel ethanol under the Renewable Fuel Standard, which sets minimum blending volumes, and Brazil has built a corn ethanol industry of its own. Ethanol demand is therefore a policy variable: blending mandates, small-refinery waivers, E15 rules and tax credits shift hundreds of millions of bushels of demand, and crude oil prices decide whether refiners blend more than the mandate. High oil prices lift corn; policy reversals sink it.

Brazil's safrinha corn is planted after soybeans and harvested from June, arriving at ports in the northern hemisphere's off-season. Its size depends on how early soybeans were harvested and whether the rains held through April. Priced in reais, Brazilian corn gets cheaper in dollars when the real weakens, which pulls export business away from the US Gulf and caps Chicago rallies.

China is the second-largest producer and a large but erratic importer. Its purchases depend on state reserve management, the tariff-rate quota, domestic price supports, hog herd size and the approval status of biotech traits: cargoes have been rejected over unapproved traits, as with MIR162 in 2013, and imports have swung from small to enormous within a year. A Chinese buying program can absorb an entire Brazilian surplus; a pause leaves exporters looking for buyers.

In the Americas, corn and soybeans are grown on the same land and farmers choose between them each spring on the ratio of new-crop soybean to corn futures and on fertilizer costs, since corn needs far more nitrogen. A high ratio pulls acres into soybeans and cuts corn supply the following autumn. USDA's March planting intentions and June acreage reports are the market's first hard reading on the outcome.

Corn takes more nitrogen per hectare than any other major crop, and nitrogen fertilizer prices track natural gas. When gas and ammonia prices spike, farmers cut application, switch acres to soybeans or accept lower yields, and the cost of drying the harvest with propane rises too. Energy prices reach corn from both sides, through input costs and through ethanol demand.

Most corn is fed to animals, so the size of the world's pig, chicken and cattle herds sets baseline demand. Animal disease can remove it suddenly: outbreaks of African swine fever in China's hog herd cut feed demand and imports, and avian influenza does the same for poultry. Meat prices and profit margins for feeders decide how much corn they buy and whether they substitute wheat, sorghum or barley.

Corn is an annual planted from seed each year. In the US Corn Belt it is sown in April and May, pollinates in July, when a silk on each ear must catch pollen from the tassel, and is harvested from September to November once the kernels have dried in the field. Brazil's safrinha follows soybeans, sown in January to March and harvested from June to August; Argentina plants from September and harvests from March. Farmers buy hybrid seed every year, because saved seed loses the hybrid vigor, and in the Americas most of that seed carries biotech traits for insect resistance (Bt) and herbicide tolerance.

Types differ by kernel. Dent corn, with a soft starchy center, is the bulk of the world crop and of all trade; flint corn, harder and preferred by some millers, is grown in Argentina and parts of Europe; white corn is grown for food in Mexico and Africa; sweet corn and popcorn are separate specialty crops. At the elevator, grain is graded on test weight, moisture, damaged kernels, broken corn and foreign material, and dried with heat if it comes in wet. Aflatoxin, a mold toxin produced in hot, dry seasons, is tested because it makes grain unfit for food or dairy feed.

Processing takes three routes. Dry milling grinds the kernel into grits, meal and flour, or into masa for tortillas after alkaline cooking (nixtamalization). Wet milling steeps and separates the kernel into starch, which becomes sweeteners, modified starches and ethanol, plus corn oil from the germ and gluten feed and gluten meal for livestock. Ethanol plants ferment the starch and leave distillers grains, a protein feed, and recover corn oil. Whole grain goes straight into feed rations. By-products from the field include stover, used for silage, bedding and in some places cellulosic ethanol, and cobs. Yields span an enormous range, from irrigated Nebraska fields to rain-fed smallholder plots in East Africa that produce a small fraction as much per hectare.

Feed is the largest use of corn worldwide: pigs, poultry, cattle and fish eat it as whole grain, cracked or in compound feed, and the distillers grains and gluten feed left over from processing go the same way. Fuel is second in the United States, where the Renewable Fuel Standard channels a large share of the crop into ethanol, and Brazil has followed. Food comes third at the world level but first in Mexico, Central America and eastern and southern Africa, where tortillas and maize meal are the staple.

Industrial uses take the remainder: starch for paper, textiles and adhesives, sweeteners such as glucose and high-fructose corn syrup, corn oil, and bioplastics. The USDA Economic Research Service's feed grains balance sheets divide US use into feed and residual, food, seed and industrial (mostly ethanol) and exports, and feed plus ethanol account for most domestic use in every recent marketing year those tables cover.

Corn moves in bulk. In the United States, farmers deliver to country elevators, which ship by rail to the Pacific Northwest and by barge down the Illinois and Mississippi rivers to the export elevators around New Orleans, the largest corn export gateway in the world. Brazil's corn leaves through Paranaguá and Santos in the south and, increasingly, through the northern arc ports of Itaqui and Barcarena fed by long truck hauls from Mato Grosso. Argentina loads at Rosario and the Up-River terminals on the Paraná; Ukraine at Odesa, Chornomorsk and the Danube ports. Cargoes travel in Panamax and Supramax bulk carriers, and Mexico takes much of its US corn by rail and by ship across the Gulf.

Processing concentrates where the corn is. Ethanol plants are scattered across the Corn Belt near their feedstock; wet mills are large and few, run by ADM, Cargill, Ingredion and Tate and Lyle; feed mills sit near livestock. The trading layer is the same as for wheat and soybeans: ADM, Bunge, Cargill, Louis Dreyfus and COFCO, plus Brazilian cooperatives and Ukrainian exporters. Seed and traits are concentrated in a handful of companies, led by Bayer and Corteva.

Single points of failure: the Mississippi River, where low water or a lock failure strands barges and widens the Gulf basis; the Panama Canal, which carries Gulf corn to Asia and imposes draft limits in drought years; the Paraná River, whose low water limits Argentine loadings; the Black Sea, where war closed Ukrainian ports; and biotech approvals, since a single unapproved trait can halt trade with a major buyer. Because a few exporters supply most of the trade, weather in one of them is a world event.