The global importance of maize diversity

By Lauren Baker


I recently visited Mexico in preparation for a strategic convening the Global Alliance for the Future of Food is planning on resilient seed systems. While in Oaxaca, I saw first-hand how the deep historical connection to the milpa (maize system) is tied to socio-cultural and culinary traditions, local livelihoods, as well as the region’s ecological diversity.

Corn is a centrally important crop, both to local communities and the global food system. As the world’s most dominant and productive crop, with extensive areas of land dedicated to global production yields of over 1 billion metric tons, corn is used for a variety of purposes — including animal feed, grain for human consumption, ethanol, as well as for high fructose corn syrup, sweeteners, starch, and for beverage/alcohol production.

Identifying more sustainable models for corn systems
A recent report launched by the National Commission for the Knowledge and Use of Biodiversity (CONABIO) and TEEBAgriFood, funded by the Global Alliance, explores the true cost of maize in Mexico. The report, titled “Ecosystems and agro-biodiversity across small and large-scale maize production systems,” compares maize production in Mexico to production in Ecuador and the U.S., looking at dependencies and impacts across different regions and production systems.

“If we better understand how corn production, and its use and consumption, impacts biodiversity, water use, ecosystem services, livelihoods, food security and health, we can more effectively shape policies and choose practices that minimize the negative impacts and enhance the positive ones.” CONABIO 2018

The CONABIO report recognizes maize as indispensable to the future of the global food system and inextricably entwined with Mexican national and Indigenous identities. It makes explicit the web of social, cultural, and environmental factors that influence maize production and consumption. There are several findings that stand out.

Smallholder farmers are critical to the management of biodiversity
The report demonstrates the importance of evolutionary services provided by maize systems high in genetic diversity and highlights the dependence of the wider food system on these essential services managed over generations by small-scale farmers. As well, the report outlines the cultural contributions of maize landraces (local, traditional variety of corn) and provides some monetary estimates about their positive value for smallholder farmers in Mexico.

For example, in the Mexican context, the value of maize extends beyond the market value of the harvest. The significance of maize diversity to the local culture of farmers and communities is illustrated by shadow prices of maize landraces that are between 20 and 25 times higher than the prices given to the crops by mainstream markets (2011 and 2016 prices respectively).

In Mexico, maize landraces are produced by smallholders who represent 85% of the farmers in the country. These farmers follow traditional practices, relying on and perpetuating the genetic diversity of landraces. The climatic and geographic variability of these smallholder systems both depends on and results in diversity. Genetic diversity in traditional systems has been maintained by these farmers over time through the practices of in-field experimentation, seed selection and exchange, ensuring the process of diversity generation.

Genetic diversity is central to climate resilience and the future of food
Maize diversity exceeds that found in any other species, and is used and preserved by smallholder traditional maize farmers. As maize systems globally adapt to changing climatic conditions, the future depends on existing and future sources of genetic variability. This variability is reflected in the wealth of diversity existing in the wild relatives and cultivated forms of maize. Hybrid maize varieties that seek to enhance yield, build pest and pathogen resistance, and adapt to drought are also reliant on maize diversity. Changing climatic conditions, both at the field level and at the broader ecosystem level, underscores how important the broader pool of genetic diversity is to ensure resilience. This diversity is a global public good and must be valued as such.

“In situ conservation of genetic diversity including maize wild relatives, the maize landraces, and the existing intricate relationship of farmers and users with the biological resources, through their traditional practices, must be strongly supported…to assure the continuous generation and evolution of the necessary genetic combinations to feed future maize production worldwide.” CONABIO 2018

Crop management practices should enhance positive benefits and reduce negative impacts
The report highlights how crop management practices can either enhance the positive impacts of food systems or perpetuate negative impacts. These include impacts to terrestrial and aquatic ecosystems from pesticide and fertilizer residue to soil fertility, pollination, water absorption, and pest and disease control. Maize productivity is impacted by key variables, including rainfall and the availability of irrigation, soil fertility, nutrient cycles, and weather. The report’s central recommendation is that we take advantage of the positive benefits provided by smallholder farmers by supporting local, in-situ breeding of native maize and consider how to enhance and support these management practices while minimizing negative ecosystem impacts.

The CONABIO report contributed to the evidence base for TEEBAgriFood, and to the development of the holistic food system evaluation framework launched in early June.

Building on the results of the CONABIO report, the Global Alliance is investing in the application of the TEEBAgriFood valuation framework to two other corn systems, including: 1) Maize in Malawi and 2) Corn in the Mississippi Basin, U.S.
Dr. Stephanie White from Michigan State University is carrying out a holistic true-cost analysis of the maize food system in Malawi to shed light, not only on monetized costs and benefits inherent in this system, but also on the environmental, health, and social externalities. Dr. Harpinder Sandhu from Flinders University is undertaking a comparative analysis of different corn systems (e.g., conventional and diversified/agroecological) in the Mississippi Basin in order to describe and value (where appropriate) the dependencies, impacts, and externalities related to these systems (positive and negative).

From these studies, we will be able to better understand opportunities for shifting practices, policies, programs and subsidies to improve environmental, health, and socio-cultural outcomes across corn systems.