6533b854fe1ef96bd12afb93

RESEARCH PRODUCT

Analysis and modeling of the role of nitrogen competition in weed control

subject

description

This project challenges the question of reducing herbicide use, considering that a concomitant reduction of nitrogen fertiliser use and a better choice of the sown species/varieties can help to design more sustainable cropping systems. Combining plant ecophysiology, ecology, agronomy and modelling, this project aims at analysing to which extent optimizing nitrogen fertilisation and crop species/cultivar choice can provide new ways to promote biological weed regulation via plant-plant competition, thereby reducing herbicide use. This project will use an original approach consisting in feeding and then using a mechanistic model, FLORSYS, predicting cropweed community assembly as a function of cropping systems, pedoclimate and plant functional traits. The first objective is to better understand the plant diversity related to competition for nitrogen, especially for weed species. For that purpose, experiments in controlled conditions will be conducted to characterize plant traits involved in the process determining the plants' ability to compete for nitrogen. Then, using FLORSYS upgraded in this first step, virtual experiments will be conducted to better understand the consequences of modifying soil nitrogen availability and the sown species/varieties for weed demography. Finally, we will identify new sustainable weed management strategies promoting biological weed regulation via competition for nitrogen, in multi-efficient cropping systems (agricultural production and environmental impact).