Maize
A broad overview of the origin, history, production, and future of a vital commodity crop that our world depends on.
Origins
Maize
In central Mexico, sometime between 7,000 and 9,000 years ago, maize was domesticated from a wild grass called teosinte (Drury, 2019). Originating in the Balsas River basin of southwestern Mexico, it quickly spread down the coast to Peru and into the Americas, quickly coming into contact with European explorers who then spread it throughout the world ( Wallace et al. , 2013). According to Tenaillon and Charcosset (2011), while maize was domesticated in the highlands of Mexico, it later became primarily grown by Indigenous people in the US. The diffusion of maize throughout the Americas occurred through diversification and adaptation, made possible by many genetic factors like inbreeding and hybridization.
Imports, Exports & Consumption
Presently, corn is grown mostly in the US where production is concentrated in what is referred to as the Heartland region, otherwise known as the corn belt. This area includes Illinois, Iowa, Indiana, eastern portions of South Dakota and Nebraska, as well as parts of Kentucky, Ohio, and Missouri which host large expanses of grassland biomes, the most suitable biome for growing corn ( USDA , 2021). On the global level, the United States accounts for 32 percent of the worlds production of maize, while China comes in second at 23 percent, Brazil being third at 10 percent, and the European Union, Argentina, Ukraine, India, Mexico, South Africa and Russia contributing small percentages and accounting for the remaining demands ( USDA , 2021). While most of the production of maize has and continues to take place in North America, its significance and prevalence has also been increasing in other areas in recent years. For example, production is increasing in Britain, where it is primarily grown as food for livestock and is also beginning to be used as an energy crop as the trend for green power increases ( Drury , 2019). This growth in production is occurring in many places, with no sign of slowing in the near future, presenting issues that will be discussed later.
The ranking of top exporters is similar to that of top producers; however, it does differ slightly. Among the countries that export the most maize are the United States, Argentina, Brazil, and Ukraine, of which these four combined together account for over two thirds of the worldwide market ( Mccormick , 2020; OEC , 2020). Beyond these top four countries, also contributing largely to exports are France, Russia, Hungary, South Africa and Canada. Turning now to imports, we see that the leading importers of corn include Mexico, China, Japan, Vietnam and South Korea ( OEC , 2020). The rankings continue, spreading to Egypt, Spain, the Netherlands, Colombia, Iran, Italy, Germany and more. Lastly, when looking to who consumes the most corn the United States and China as the leading producers, also top the charts as the leading consumers. In the case of China, the domestic consumption actually exceeds their level of production ( Mccormick , 2020).
Farming Techniques
Most corn production occurs through large scale commercial operations. Corn is planted (using a mechanized planter) when the soil temperature reaches 50 degrees Fahrenheit, usually late March or early April in the US. Depending on the weather, crops takes 2-4 months to reach harvest ( LCDM , 2022). When moisture levels are no <25%, field corn is ready to be harvested. In large scale operations, a combine is used to cut the plants down and thresh the kernels off the cob. Kernels are then transported by truck to a seed storage center for holding, or passed on for further processing.
Often times methods like intercropping or crop rotations are peformed to maximize yields. In the case of corn, crops are typically rotated with other crops like soybeans. Crop rotation of maize with soybeans is particularly beneficial and increases yields as soybeans are nitrogen fixing plants and corn demands high nutrient input. Therefore, rotation with soybeans decreases the fertilizer inputs required.
Production
Daly et al. (2017) map the value chain by breaking it down into five different sectors. These five sectors include first, inputs, second, production, then aggregation, processing, and lastly distributing and marketing. As depicted below, each of these 5 areas includes a number of different components that allow the process to progress on to the next step as quickly and efficiently as possible.
Consumption Breakdown
Corn is an important ingredient in food, seed, and industrial products. Corn is processed for human consumption in the form of high fructose corn syrup, glucose and dextrose, starch, corn oil, alcohol, flour, meal, and grits. In terms of industrial uses, corn is a key ingredient in ethanol and fuel products. Lastly, corn is the primary ingredient in animal feed products, accounting for more than 95 percent of the total feed grain production ( USDA , 2021).
The Corn Belt
Infrastructure in the corn belt region, sourced by Singular et al . (2017).
As an area of intense agricultural production pertaining to corn, this area experiences high amounts of environmental degradation in the form of soil erosion, air pollution and more. Scientists have found that about 35 percent of the region has completely lost its topsoil largely due to mechanization in the form of plowing and tilling, as well as intense fertilizer use ( Kimbrough, 2022 ). Natural disasters like the Dust Bowl have occurred in response to over-tilling. Bare soils also emit more carbon into the atmosphere, further contributing to the climate crisis.
Environmental Impacts
Environmental impacts of maize production includes issues surrounding land use, soil quality, and water usage. In terms of land use, erosion and land degradation are among the top concerns in this category. Over cultivation of degraded and marginal lands can harm the soil structure and intensify wind and water erosion ( Chew et al. , 2013). Additionally, farming on slopes can decrease the topsoil. Land degradation brings about habitat loss, which can threaten species and reduce the surrounding biodiversity of the ecosystem, causing a chain reaction in which the entire health of the ecosystem can become threatened. Increasing the scope and intensity of agricultural practices further intensifies these effects and can also lead to loss of genetic diversity within the crop. In general, a decrease in biodiversity increases an organism’s vulnerability to both abiotic and biotic stressors ( Chew et al. , 2013). Suitable land is a constraint due to the fact that many areas possess infertile soils and nutrient shortages that make them inadequate for crop production. In response to this, mineral and synthetic fertilizers are applied, posing additional impacts to the environment. Application can lead to things like fertilizer runoff and greenhouse gas emissions ( Chew et al. , 2013). Related closely to land and soil management is water management. Surface water depletion is an issue raising growing concerns, therefore conserving water is crucial. Practices like intercropping which can be beneficial in increasing both the soil water retention and soil nutrient content, using drought tolerant varieties, and designing crop rotation strategies that maximize water consumption and efficiency should be implemented.
Climate Destabilization
Increasing climate destabilization will only add to and intensify the problems we are currently facing in terms of maize production. Additionally, Wang et al. (2017) reveal some potential future effects associated with variations in the climate. These include effects that will alter crop yields, change crop phenology in terms of flowering dates and days of maturity, and influence CO 2 fertilization. Temperature and precipitation will likely increase, which will offset growing patterns, speeding up growth and shortening important life stages. However, an increase in atmospheric CO 2 could positively effect C4 crops by speeding up photosynthesis and increased stomatal resistance, which would decrease evapotranspiration and water loss ( Wang et al ., 2017). Effects will vary by region, but overall, the maize growing season will be shortened in many regions by 15-20 days and yields are projected to decline by 10-30%. In the world map below, we see that future changes in climate will impact crop yields significantly, threatening certain geographical areas more than others.
World map showing areas in red where yields are projected to decrease by 2070 provided from NASA/Katy Mersmann .
Food Insecurity & Growing Demand
The demand for maize will continue to grow in response to our growing population, increased food demand both with respect to corn and meat products, and increased use of biofuels. Overall, the growing demand for maize will lead to an intensification of the current environmental impacts associated with maize production as farmers work to increase yields and maximize production. This will result in increased fertilizer and pesticide use, increased irrigation, and efforts targeted at selective breeding practices to develop drought tolerant and high yield, low input varieties. As studied by Brisson et al. (2019), modern hybrid variations have a greater impact on the health of the below ground soil composition, compared to native and inbred maize lines. This can be attributed to the heightened focus on aboveground traits and lack of attention to below ground characteristics like root architecture in recent selection processes. The result is compromised soil and plant health, and decreased resiliency of crops, both of which will further add to the issue of food insecurity and an inability to meet demands.