About the World Fertilizer Monitor

The World Fertilizer Monitor tracks the impact of fertilizer shortages on global food production, and the resulting risks to food security, by country.

The World Fertilizer Monitor is being developed by Gro Intelligence, with support from the Bill & Melinda Gates Foundation. The tool is freely available to all.

What Is the World Fertilizer Monitor?

The World Fertilizer Monitor is a scenario explorer tool developed by Gro Intelligence that shows the relationships between fertilizer and production across wheat, corn, soy, and rice for all countries worldwide for different fertilizer shortage scenarios.

For the current version of the World Fertilizer Monitor, we focus exclusively on nitrogen because of its relative immediate impact on plant growth.

We feature nine nitrogen shortage scenarios that can be explored both globally and at the country level.

Globally, for each scenario, we translate nitrogen shortage into a production loss estimate by crop in metric tonnes. We then aggregate across wheat, corn, soy, and rice in caloric equivalents given that aggregating in metric tonnes across multiple crops does not provide the full picture from a nutritional standpoint. From calories, we derive the number of people who can be fed over a year, using 2,000 calories as the average typical daily food intake for a human being and multiplying by 365, to show the risks to global food security.

At the country level, we provide (i) a world map view per scenario with production changes in calories and production changes in tonnes per crop, and (ii) a country page table with production changes per crop, with respect to the 2021 production baseline for each scenario.

Our Methodology

Using data in Gro's platform and input from our partners, the International Fertilizer Association and CRU Group, we developed a methodology to calculate projected changes in yield caused by a given nitrogen fertilizer shortage scenario for a given country and crop. From yield, we derive a production change. We then aggregate this production change across four major crops - wheat, rice, corn, and soybeans - by converting production to calories.

The model

We estimate the yield change using quadratic nitrogen response curves from scientific literature referenced below. Parameters α, β and γ are specific to a given crop and Nav represents the nitrogen availability.

For soybeans, we use a long-term modified response curve from [1]. For cereals (corn, rice and wheat), we use response curve models from [2]. Both scientific papers [1,2] present studies that compiled data from local trials of crop yields N response curves in different soils, weather, and management conditions, and the results demonstrated a good level of generalization.

Model inputs

Our model is based on a combination of country-level crop yield, harvested area, and production data from Gro and the USDA PS&D, as well as nitrogen fertilizer application rates from the International Fertilizer Association (IFA), the world’s only global fertilizer association with around 400 members across fertilizer distributors, producers, NGOs, and more, and CRU Group, a leading independent authority on fertilizer. We also developed further hypothetical scenarios called Gro scenarios (1%, 3%, 5%, 7% and 10%), where we apply a uniform fertilizer application reduction across crops and countries.

We use crop-specific coverage provided by CRU Group for the major fertilizer consumption countries, namely Mexico, Brazil, Argentina, France, Germany, Italy, Spain, United Kingdom, Poland, Belarus, Russia, Ukraine, China, mainland, Malaysia, Thailand, Vietnam, Australia, Iran, Turkey, Bangladesh, India, Pakistan, Egypt, Canada and the United States, as of June 24, 2022.

In countries where fertilizer consumption amounts to less than 10% of global consumption, CRU Group nitrogen rates are estimates of fertilizer application to cultivated areas. Thus, we assume the average application rate for all crops in those countries in the absence of crop-specific nitrogen rates.

We take IFA’s forecasts of total nitrogen use and allocate to each crop depending on each region’s history of nitrogen application, using historical IFA data. When IFA data is only available at the super-national region level (e.g “Sub-Saharan Africa minus South Africa”), we allocate the total nitrogen fertilizer according to the USDA’s 2022 national crop area for each country.

Model outputs

We use the output from the nitrogen response curves to calculate the ratio of the yield response to nitrogen fertilizer application shock over the yield response to no nitrogen fertilizer application shock. To determine the impact of fertilizer shortage on yield, the yield ratio is multiplied by the baseline yield. While yield is not currently featured on the tool, it is used to calculate projected production change.

Based on the projected yield reduction impacted by global uniform nitrogen rate reductions (1%, 3%, 5%, 7%, 10%), nitrogen rate reduction based on CRU Group's April forecast, and nitrogen rate reduction based on IFA’s “optimistic,” “middle ground,” and “pessimistic” scenarios, we propagate the impacts to national production by multiplying the projected yield reduction by the crop harvested area.

CRU Group's and IFA’s country-specific variations in percentage from the current year versus last year are used in our quadratic models in order to derive the yield ratio. Therefore, instead of assuming a uniform level of decline in nitrogen rates, CRU Group's or IFA’s percentage changes can be either positive or negative, resulting in potential increases or decreases in yield and, thus, production.

We aggregate this production change across the four crops by converting production to calories. From calories, we derive the number of people who can be fed over a year, using 2,000 calories as the typical daily food intake for a human being and multiplying by 365.

Acknowledgements

Gro would like to thank the International Fertilizer Association (IFA), CRU Group, and the authors of the cited papers for their contributions to this analysis. Without them, this would not have been possible.

References

• [1] van Grinsven, H.J.M., Ebanyat, P., Glendining, M. et al. Establishing long-term nitrogen response of global cereals to assess sustainable fertilizer rates. Nat Food 3, 122–132 (2022). https://doi.org/10.1038/s43016-021-00447-x
• [2] Chan Guo, Xufei Liu, Xuefei He, A global meta-analysis of crop yield and agricultural greenhouse gas emissions under nitrogen fertilizer application, Science of The Total Environment, Volume 831, 2022, 154982, ISSN 0048-9697, https://doi.org/10.1016/j.scitotenv.2022.154982