Survey on cereal resources in Wallonia according to their different uses. Survey on cereal resources in Wallonia according to their different uses. More than 60% of the arable cropped area in Wallonia is dedicated to cereals. Cereal chains were initially aimed at ensuring food security but are now progressively oriented towards new non-food uses. Walloon cereal chains are now having to face up to new global challenges: to ensure the competitiveness and sustainability of vegetal and animal chains, to match society's expectations and to meet the biomass needs for energy uses and bio-based products. Within this framework, this research aims to evaluate the environmental and socio-economic sustainability of future scenarios of current and potential food and non-food uses for Walloon cereals. This paper, the first in a series of two, presents the current picture of Walloon cereal crops and their uses. Various steps are analyzed: production, collection, wholesale and processing. Four main uses characterize cereal processing: the so-called "4Fs", representing Food (human food uses), Feed (animal feed uses), Fuel (energy uses) and Fiber (material uses). Data collected from stakeholders in the Walloon cereal chain enabled us to assess cereal flows for the "4Fs", drawing a qualitative and a quantitative picture of Walloon cereal resources including the key elements of the cereal chains. This approach serves as a basis for a prospective exercise, described in a companion paper, which develops potential uses for Walloon cereal resources at the 2030 horizon.