Maize, Zea mays

Corn grows on the second largest area of land in the world, but only a small proportion of it is grown for human consumption today. The majority of maize is used as animal feed or in industry for the production of bioethanol.

Colorful corn diversity

Maize (Zea Mays in Latin) belongs to the sweet grass family (Poaceae) and is therefore a type of cereal. The maize plant is a dioecious plant – the male flower is at the top of the plant, which can grow up to three meters high, and blooms before the female flowers, from which the corn cobs develop. And the corn plant can not only shoot upwards, its roots also grow up to 2.5 meters deep. There are over 50,000 different varieties of corn with very different cob colors.

Corn likes it particularly warm and moist. – The plant does not tolerate frost. The plant is a so-called C4 plant, which means that it has the ability to efficiently convert CO2 into carbohydrates through photosynthesis. Other C4 plants include sugar cane and millet. A major advantage of these plants is that they produce a comparatively large amount of carbohydrates even in very hot and dry conditions.

From South America around the world

The genetic origins of the maize plant come from what is now Mexico. The name maize is derived from the word ‘mahíz’ from the Taíno language (indigenous people of the Caribbean) and means ‘that which sustains life’. The exact domestication history of maize is uncertain, but studies show that it was cultivated around 9,000 years ago. Even though no direct wild ancestor of maize has been found to date, it is considered certain that it is descended from the wild sweet grass teosinte.

Even in early times, maize became a staple food in regions of Central and South America and made it easier for people to settle down. Maize played a very important role for the populations of the time. This was evident not only in the dishes, some of which are still prepared (with slight variations) today, but also in rituals and religion. The Mexica and Maya even believed that humans were formed from corn dough and several peoples believed in a corn god or goddess.

Corn spread around the world through colonisation. Christopher Columbus brought maize to Spain on his second invasion in 1496. There, people began to cultivate maize – initially, however, mainly as an ornamental plant or as feed for livestock. Due to favorable tax conditions and the good climatic conditions for maize cultivation, the plant quickly spread throughout southern Europe and was also increasingly cultivated as a food crop.

Via the European colonies, the enslavement trade and Muslim trade routes, maize spread further into various regions of Asia and Africa, where it quickly became popular due to its high yields and low labor requirements until harvest. In the USA and Canada, maize cultivation had already spread before the European invasion and was also adopted by the colonisers, especially as the cereals wheat, rye and barley brought with them could not initially be planted in North America due to the dense forests.

Hybrid and genetically modified maize

At the beginning of the 20th century, the first experiments were carried out with hybrid maize (a cross between two homozygous parents). Through the development of hybrid varieties with higher yields and more cold-resistant varieties, maize became more widespread – even in northern regions. While the wild forms of maize were still able to reproduce independently, the modern, domesticated species are in fact no longer able to do so.

In 1996, Monsanto launched the first genetically modified maize (GM maize) on the market. Corn was also one of the first plants to be traded as genetically modified. Since then, more and more GM maize varieties have come onto the market with the aim of countering herbicide and insecticide resistance, increasing drought tolerance or modifying ingredients for certain uses. GM maize is now grown on a large scale in many countries.

Today, maize is the second most widely grown crop after wheat in terms of area and can be found in almost all regions of the world. The USA is currently the world’s largest maize producer (measured in weight), ahead of China and Brazil. Here, however, maize is primarily grown for industrial purposes and used accordingly.

Huge areas of maize – with hardly any for us humans

Corn is a versatile grain. While it originally served as a staple food, today only around 13 percent of maize production is used for direct human consumption – even though it is still an important staple food in many regions. More than half of the maize produced globally is used as feed for livestock and a fifth for energy and other industrial purposes. We need three kilos of feed maize to produce one kilo of pork – an enormous amount of land.

Agrofuel and biogas

Corn is the arable crop that is used most worldwide as the basis for agrofuel, bioethanol and biogas and has also overtaken sugar cane by far. In both the USA and Europe, corn is the most important arable crop for energy, while sugar cane dominates in countries such as India and Brazil.

The biogas boom in the EU began in the 1990s. In Germany in particular, the area under maize cultivation has more than doubled since then. As the electricity generated from biogas can be sold at state-guaranteed fixed prices under the Renewable Energy Sources Act (EEG 2017), many farmers switched their operations to biogas. While biogas farmers are enjoying very high profits, this has led to numerous problems: First of all, biogas production is enormously energy-intensive and the meadows, pastures and wetlands that fall victim to the extraction of new arable land are irreparably destroyed. Furthermore, the biogas trend is driving up land prices, which in turn is causing other farmers to struggle to survive. A battle for arable land is also raging in Germany. Organic farmers in particular are suffering from this trend. At the same time, the biogas boom has encouraged the cultivation of monocultures such as maize. It is not for nothing that the term ‘maize desert’ has become established in Germany.

Corn as packaging

Corn can also be used in the plastics industry – outside of the food, animal feed and energy industries. Bioplastics are used to make packaging material that does not have to be produced on the basis of crude oil. The maize germ oil obtained is not only used for the production of salad oil, but also as a raw material in the paint industry.

Sister of the bean and pumpkin – corn in the milpa

On many Global Fields you can see maize cultivation not only as a monoculture, but also as a ‘milpa’. This fascinating agricultural system has thrived for centuries in the heart of Central America on the fields of the Maya and other indigenous peoples. It is based on the community of three plants: Corn, beans and squash. These are affectionately known as ‘the three sisters’ because they not only grow side by side, but also support each other in a unique way. The sturdy maize stretches its stalks upwards and provides the beans with a natural climbing aid. The beans in turn enrich the soil with nitrogen, which benefits all plants. The pumpkin spreads its large leaves along the ground, protecting the soil from drying out and erosion and providing shade. This creates a harmonious coexistence that not only enables high yields on a small area, but also preserves biodiversity and the fertility of the soil. A living example of how mixed cultures, whether traditional or innovative, reveal future paths for our agriculture.

Sources

Sodi e.V.: Research report on maize. Link.
MDR: Milpa bed: A mixed crop that has been tried and tested for thousands of years. Link.
Skoufogianni, Elpiniki & Solomou, Alexandra & Charvalas, Georgios & Danalatos, Nicholaos. (2019). Maize as Energy Crop. Link.
Ehrenstein et al (2022): Global maize production, consumption and trade: trends and R&D implications. Link.
Transparency in genetic engineering: C4 plants. Link.