Global Yield Gap Atlas: delivering data for sustainable crop yield growth

What is the growth potential of maize in Ethiopia? Why do farmers in different locations have different yields when the climate conditions are the same? And how can a region meet future food demand without crossing ecological boundaries? Together with partners Martin van Ittersum developed the frequently consulted Global Yield Gap Atlas (GYGA), a database which helps to find answers to these and other questions.

My dream on GYGA is to contribute to a better agriculture in the world.

GYGA is a collaboration between Wageningen University & Research and the University of Nebraska-Lincoln and is supported by a network of international partners. “The idea was born in 2008, when high food prices led to social unrest, especially in poor countries,” recalls Martin van Ittersum, professor of Plant Production Systems at Wageningen University & Research: “In the past, increasing production was always the solution to food shortages. The world had more to eat per person in 2010 than in the 1960s, even though the population had more than doubled. The question was: is increasing production still the answer when food security is at stake? And can this be done without a large-scale increase in the agricultural area, which is undesirable from an ecological and biodiversity protection point of view? In short: where in the world is food production reaching its limits and where is there still some room? We wanted to look at that systematically."

Reliable data

He developed the idea for a Global Yield Gap Atlas with Ken Cassman of the University of Nebraska-Lincoln. The first hurdle: how do you get reliable data? Van Ittersum: “The challenge was to find a reliable and rigorous methodology without spending a lot of time and money on compiling local data. We chose to compile enough data country by country for a representative picture, in collaboration with national experts and agencies. We published the data in an online Atlas and other specialists soon came forward with additional reliable data, including from new countries. That's how the ball started rolling.”

Local accuracy and a globally consistent method is the strength of GYGA, according to Van Ittersum: “Other data sources may offer better global coverage at the moment, but if you zoom in, you quickly come across inaccuracies because the data has not been validated locally.”

Making good judgements

The GYGA now contains data from about 70 countries, and new countries, crops, and other indicators are continuously being added. The GYGA is not a means of intensifying agriculture, Van Ittersum emphasises: “It is a tool to make good judgements between agricultural production and other purposes, such as a clean environmental and biodiversity all requiring good use of land, water and nutrients. Furthermore, GYGA is useful to find explanations for differences in yields between similar regions. For example, researchers found that the yield gap of wheat in an Australian region was smaller than that in a comparable Argentinean region. It turned out that farmers in Argentina grew a second crop every year. Although this reduced the wheat harvest, the second crop was economically very appealing. As a result, Australian farmers started experimenting with a second crop.”

GYGA is a tool to make good judgements between agricultural production and other purposes, such as a clean environmental and biodiversity all requiring good use of land, water and nutrients.

Commercial sponsors

Non-profit organisations, such as foundations, government agencies and public bodies, universities/research institutes, and NGOs, can use the GYGA database free of charge. Private companies pay an individual licence or sponsorship fee to support the maintenance and further development of the GYGA. A conscious choice, Van Ittersum explains: “Public funding in scientific research usually has a scope of four years and, with a bit of luck, a few years longer. But we want to keep the GYGA going for more than 10 years. Private financiers can help us get the resources we need.”

GYGA currently has nine sponsors and licensees, including the Bill and Melinda Gates Foundation. Commercial partners also include the International Fertilizer Association and fertiliser producer Yara. There is much going on concerning fertilisers. Van Ittersum realises that the participation of fertiliser companies in GYGA can therefore also raise critical questions: “But during our years of collaboration I have become confident that they are using GYGA to promote efficient and socially responsible use of products and want to advance food production. With GYGA we really target to improve responsible production of food in locations where this is most feasible.”

Future of GYGA

Thanks to the funds from the sponsorship programme, the GYGA project can look to the future. It is most welcome, according to Van Ittersum, who still has plenty of wishes for the future: “We are now working hard to add climate change as an indicator, partly thanks to funding from the Dutch Organisation for Scientific Research NWO. I would also like to see the effects of pests and diseases incorporated into the GYGA. Along with nutrients, these determine to a large extent the yield gaps in the world. My dream is for GYGA to contribute to better agriculture in the world. So that countries in Africa and South Asia can meet their own needs for important food crops and no longer depend on imports. And for Western countries to better understand how they can develop a cleaner agriculture, saving natural resources.”