In Axe 3, we address the following questions:

(i) Does climate change induce higher yield instability?

(ii) It is possible to reduce production instability by a crop diversification?

(iii) How climate change will impact cropping zones?

A first challenge concerns the assessment of climate impact on crop yields. A large number of public and private institutions have developed weather-based and satellite-based indices to anticipate yield losses. In addition to these simple indices, a flurry of aggregated indices based on statistical methods, machine learning techniques, and process-based models have been produced, and little is known about their effectiveness to actually anticipate yield loss. It is becoming urgent to conduct an in-depth evaluation of their accuracy and to determine their ability to analyze risk of yield loss under contrasted climate change scenarios and under several diseases or pests’ attack, potentially increased with climate change.

A second challenge concerns the evaluation of the capacity of crop diversification to mitigate production instability. Monocultures and the intensive use of synthetic inputs are often seen as factors increasing vulnerability of cropping systems to climate change. It has been hypothesized that a diversification of the agroecosystems (longer crop sequences, mixing of species and varieties etc.) will reduced adverse climate change impacts. But the ability of crop diversification to reduce the vulnerability to climate change has not been clearly demonstrated.

Finally, there are now evidences that climate change will have an impact on the distribution area of crops in the next coming decades. Although several agricultural regions are threatened by climate change, the warmer climate expected in high latitude regions may offer new opportunities for agriculture expansion in the north. It is important to explore potential distributions of cropping areas for informing major stakeholders on benefits or disadvantages of alternative land use scenarios, in particular scenarios based on diversified cropping systems. Therefore, the key question is not only “how to crop” but, also, “where to crop".

Example of project

How is climate change changing the geographical areas adapted to arable crops?
Maps of areas of potential diversification in Europe in the future, which can be used to contribute to the development of scenarios 

Example of publications

Chen M, Brun F, Raynal M, Makowski D, 2020. Forecasting severe grape downy mildew attacks using machine learning. PLoS ONE 15(3): e0230254. https://doi.org/10.1371/journal.pone.0230254

Chen, M., Brun, F., Raynal, M., Makowski, D., 2020. Delaying the first grapevine fungicide application reduces exposure on operators by half. Scientific Reports. DOI: 10.1038/s41598-020-62954-4 

Beillouin D, Ben-Ari T, Makowski D, 2019. A synthesis of meta-analyses on crop diversification at the global scale. Submitted in Data in Brief

Cernay, C., Makowski, D., Pelzer, E., 2018. Preceding grain legume increases cereal yields under low nitrogen input conditions. Environmental Chemistry Letters, https://doi.org/10.1007/s10311-017-0698-z

Lesur C., Malézieux E., Ben-Ari T., Langlais C., Makowski D. 2017. Lower average yields but similar yield variability in organic versus conventional horticulture. A meta-analysis. Agronomy for sustainable development 37, 45

Current doctoral and post-doctoral work

Analysis of the risk of downy mildew in the vine based on regional data and local information collected during the season

Mathilde Chen

Supervision: David Makowski et François Brun (ACTA)

Statistical analysis of on-farm research data

Anabelle Laurent

Supervision: David Makowski et Fernando Miguez (Iowa State University).