Contribution de l'agriculture de conservation des sols à la transition agroécologique. Discours introductif de la séance.

Prospective Agriculture et Biodiversité - Inra - Département Environnement Agronomie

Rapport sur expertiseEA; CT3; absent

Effets du mode de travail du sol sur les microorganismes à l'échelle du profil cultural

Soil tillage modifies the location of crop residues and soil structure and affects microbial populations and activities such as mineralization of soil organic matter. The aim of this work was to compare the effect of two tillage systems (traditional mouldboard ploughing, LT, and reduced tillage, TR) on crop residues distribution and soil structure as well as their consequences on soil microbial biomass (BM), the potential activity of C mineralization (Cmin) and soil bacterial community structure (through T-RFLP). In order to study simultaneously the effects of soil structure modifications and crop residues distribution on these microbial parameters we used a stratified sampling scheme based…

Does grassland cover limit the replenishment of weed seed banks during seed rain?

International audience

Biomes cultures : filières alimentaires et valorisation non alimentaire

La satisfaction des besoins alimentaires n’est toujours pas assurée pour une part importante de la population en régions tropicales. Les changements climatiques sont susceptibles d’aggraver cette situation et d’induire également des irrégularités de production conséquentes dans les régions agricoles tempérées. Globalement l’insécurité alimentaire pourrait donc s’accroître dans le temps et l’espace. Par manque d’études prédictives précises et considérant différents niveaux d’échelle (plante, exploitation, bassin et région de production), on perçoit encore très mal les évolutions futures par filière et aire géographique, notamment sur le plan quantitatif (estimation des impacts, de leurs des …

Raisonner le choix d’un itinéraire d’implantation des cultures

Prod 2020-1c pole EA pole SPE GESTAD AGROSUP; International audience; L’itinéraire d’implantation Diversité des modes de travail du sol Diversité des outils de semis et de plantation Typologie des itinéraires d’implantation Comment choisir un itinéraire d’implantation ?

Modelling crop rotation including temporary grasslands for weed management

Session 3 - Crop modellingEAEcolDur; absent

Assessment of tillage systems in organic farming: influence of soil structure on microbial biomass. First results. Improving Sustainability in Organic and Low Input Food Production Systems

International audience

Modelling vertical and lateral seed bank movements during mouldboard ploughing

Abstract The vertical distribution of weed seeds in the soil is of fundamental importance because seedling emergence depends on seed depth. The lateral displacement of the earth during mouldboard ploughing contributes to the dispersal of the weeds inside the tilled field. In order to model vertical and lateral seed displacements during ploughing, an existing model describing soil particle movements for different ploughing characteristics (depth and width) and soil structures was tested on a multilocal field trial. The trials were carried out in 1996 and 1997 and comprised two soil textures and three soil structures; tillage was performed with a mouldboard plough at varying ploughing widths …

Morphological characterisation of soil structure in tilled fields: from a diagnosis method to the modelling of structural changes over time

Characterisation of soit structure within the tilled layer of cultivated fields is crucial because the importance of this soil characteristic on the biological, chemical and physical properties of the soil and its repercussions on water cycle, root growth and functioning. We present in this paper a method for field characterisation of soil structure. This method, practised since the 1970s, was designed for field diagnosis of the effects of cropping systems on soil structure. It is based on a stratification of the observation face of a pit dug perpendicular to the direction of tillage and traffic: spatial compartments are distinguished, according to the nature of the mechanical stresses they…

Parameterizing the "grassland" module in the multispecific model FlorSys

EAEcolDurCT1; The multispecies model FlorSys can predict the effects of cropping systems on the dynamics of weed communities in annual crops ; however, it is not configured to predict the fate of weeds in permanent cover such as grasslands. We realized the simulation of a weed seed rain in controlled conditions to estimate the percentage of weed seeds intercepted by a grass cover. Parameters of this linear model will be used to develop a new sub model in FlorSys to be able to simulate weed dynamics in temporary grasslands. We used twelve weed species selected on the basis of specific morphological characteristics and observations made in the experimental set up of SOERE ACBB (Observatory En…

Modelling vertical and lateral weed seed movements during mouldboard ploughing with a skim-coulter

Abstract The vertical distribution of weed seeds in soil is crucial because seedling emergence varies with seed depth, whereas lateral soil displacement during mouldboard ploughing contributes to weed dispersal within the tilled field. In order to model vertical and lateral seed displacements during ploughing, an existing model describing soil particle movements for different ploughing characteristics (depth and width) and soil structures was adapted to integrate the effect of a skim-coulter. This model was tested in two field trials, in Northern France, using coloured plastic beads to imitate weed seeds. The trial in Dijon was set up on an eutric cambisol and comprised both compacted and u…

Effets du mode de travail du sol sur les microorganismes à l'échelle du profil cultural