PhD position OT-11678

Crop diversification in France: impacts on the use of plant protection products, biodiversity and the balance of agricultural production

78850 Thiverval-Grignon

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INRAE presentation

The French National Research Institute for Agriculture, Food, and the Environment (INRAE) is a public research establishment. It is a community of 12,000 people with more than 200 research units and 42 experimental units located throughout France. The institute is among the world leaders in agricultural and food sciences, in plant and animal sciences, and is 11th in the world in ecology and environment. INRAE’s main goal is to be a key player in the transitions necessary to address major global challenges. In the face of the increase in population, climate change, scarcity of resources and decline in biodiversity, the institute develops solutions for multiperformance agriculture, high quality food and sustainable management of resources and ecosystems.

Work environment, missions and activities

French agriculture is facing nowadays an increasing number of challenges to ensure the sustainability of the sector (Tilman et al., 2002). This requires a transition of cropping systems towards agroecology.
This innovation implies that these new systems rely on diversification and make use of biological regulations, with the aim of reducing the use of synthetic inputs (Doré et al., 2011). Crop diversification over time, the rotation, or in space with intercropping of different species or varieties in the same plot (crop mixtures), is a change of cropping practice which leads to environmental, economic and social benefits at farm and territorial scales (Malézieux et al., 2009).
Crop diversification at field scale introduces multiple advantages increasing crop yield in terms of quantity and stability concerning biotic and abiotic stress (Lin, 2011; Hufnagel et al. 2020). By providing a heterogeneous environment in space and time, crop diversification promotes the development of auxiliary biodiversity which improves the resistance of agricultural systems to pests, limits weed development and plays a fundamental role in reducing the dependence of agriculture to plant protection products (Lechenet et al., 2016). Moreover, diversification offers direct benefits on soil biogeochemistry (carbon, nitrogen and water cycles) helping to reduce the use of nitrogen fertilisers and non-renewable resources (Barot et al., 2017; Adeux et al., 2019; Jensen et al., 2020). Finally, in continuous adaptation of production systems to multiple disturbances (market floating, public policies, pests, climate), the advantages of crop diversification lead to an increase of the socio-economic sustainability of agricultural production (Bedoussac et al., 2015; Raseduzzaman and Jensen 2017).
Despite these potential benefits, the use of crop and variety mixtures in France are limited in 2021 to mixtures of species (fodder) in mixed livestock systems and mixtures of varieties (wheat) in the cereal systems. This is mainly due to a set of constraints related to the quality of the seeds used for mixtures and to the difficulties to integrate such mixtures into animal and human feed systems, which are designed for standard mono-specific productions (Meynard et al., 2018). In addition, these effects are often measured at the field scale while the integration at farm scale requires a better investigation. Finally, the induced reduction of plant protection products by crop diversification needs to be evaluated at territorial scale.
The PhD thesis aims to assess the potential of crop diversification (rotations and crop mixtures) to reduce the use of plant protection products, considering the diversity of production systems. Scenarios of diversified cropping systems will be evaluated and extended to the national scale to investigate the effects on biodiversity and crop productivity.
This research will combine surveys to farmers and experts with the analyses of national databases regarding (1) the land use in agriculture (Land Parcel Identification System; Levavasseur et al., 2016) (2) the use of plant protection products (surveys on cropping practices, Dephy network, sales of plant protection products at French scale) (3) the effect on biodiversity (French Farmland Biodiversity Observatory). Among the scenarios for increasing diversification, those concerning the development of seed mixtures (results of the MoBiDiv project) will be mainly tested. The results of this research aim to make a direct contribution to
the identification of the levers and obstacles to the integration of diversified crops into the French national production systems, and contribute to the formulation of new public policies aimed toward an effective ecological transition.
The PhD be hosted at INRAE SADAPT AgroParisTech (Department ACT) in Thiverval-Grignon (25 minutes from Paris) until September 2022, then at Saclay. The student will be enrolled in the PhD school ABIES (AgroParisTech, University Paris-Saclay) and financially supported by the MoBiDiv grant.

 Eligibility and application
Send a cover letter and a CV with two references to:
Philippe Martin
Marco Carozzi
Nicolas Munier
Emmanuelle Porcher

Training and skills

Master's degree/Engineering degree

• M.Sc. in Agronomy / M.Sc. in Environmental Sciences or Geosciences with a keen interest in system and territorial approaches;
• Proficiency in statistical treatment/modelling software (R, Python,...) and spatial analysis (QGIS, ArcGIS,...);
• Ability to communicate and work in French and English (written and oral) with an interdisciplinary research team and non-academic actors (elected representatives, farmers, policy makers).

INRAE's life quality

By joining our teams, you benefit from (depending on the type of contract and its duration):

- up to 30 days of annual leave + 15 days "Reduction of Working Time" (for a full time);
parenting support: CESU childcare, leisure services;
- skills development systems: trainingcareer advise;
social support: advice and listening, social assistance and loans;
holiday and leisure services: holiday vouchers, accommodation at preferential rates;
sports and cultural activities;
- collective catering.

How to apply

I send my CV and my motivation letter
Offre d'emploi INRAE_ENG.pdfpdf - 207.73 KB

Offer reference

  • Contract: PhD position
  • Duration: 3 years
  • Beginning: 01/10/2021
  • Remuneration: 1417€/month net
  • Reference: OT-11678
  • Dealine: 28/06/2021
Centre Ile-de-France - Versailles-Grignon

SADAPT 78850 Thiverval-Grignon Website