Search results for "PRATIQUE CULTURALE"
showing 10 items of 19 documents
Méta-analyse sur l’impact des modes de production agricole sur la qualité écologique du sol
2022
Le modèle d’agriculture productiviste, développé après la seconde guerre mondiale, a permisd’augmenter les rendements de façon à répondre à la demande alimentaire croissante mais il aaussi profondément affecté les propriétés physico-chimiques des sols et leur biodiversité. Pourréduire l’empreinte environnementale de l’agriculture conventionnelle et intensive, les acteurs dumonde agricole ont développé des modes de production alternatifs comme l’agriculture biologique(AB), la biodynamie (ABD) ou l’agriculture de conservation (ACS) qui visent tous à améliorer laqualité physico-chimique et biologique des sols. Si de nombreuses publications et synthèsesbibliographiques ont évalué l’impact des p…
Mapping and determinism of soil microbial community distribution across an agricultural landscape.
2015
Article en open access; International audience; Despite the relevance of landscape, regarding the spatial patterning of microbial communities and the relative influence of environmental parameters versus human activities, few investigations have been conducted at this scale. Here, we used a systematic grid to characterize the distribution of soil microbial communities at 278 sites across a monitored agricultural landscape of 13km(2). Molecular microbial biomass was estimated by soil DNA recovery and bacterial diversity by 16S rRNA gene pyrosequencing. Geostatistics provided the first maps of microbial community at this scale and revealed a heterogeneous but spatially structured distribution…
Six années de suivi du flux d'érosion éolienne sur un sol sableux cultivé au Sahel : Impacts des résidus de culture et de l'encroûtement
2013
In the Sahel, wind erosion occurs particularly in cultivated fields. This work was leaded at Banizoumbou in Niger where wind erosion fluxes have been measured for six years. The aims of this study was i) to monitor crop residues cover on traditional field and to quantify its influence on wind erosion ii) to characterize the impacts of soils crusting on erosion flux, iii) to characterize the impact of herbaceous strips on wind flux. Results showed that crop residues efficiently prevent cultivated fields from wind erosion during the dry season (January to April) and considerably reduce erosion fluxes at the beginning of the rainy season (May to July). Under a minimal crop residues cover rate …
RVVS 2013
2013
Changements à court terme de la composition des communautés de champignons mycorhiziens à arbuscules et des populations de Rhizophagus irregularis en…
2014
La mycorhize à arbuscule a un important potentiel d’amélioration de la nutrition minérale des plantes, fort utile dans le contexte agricole. Cependant, certaines pratiques culturales sont connues pour avoir un effet néfaste sur la diversité des champignons mycorhiziens à arbuscules (Glomeromycètes). Il est donc nécessaire de mieux comprendre les dynamiques de leurs communautés et populations pour pouvoir préserver et gérer le potentiel symbiotique. Dans cette étude, nous avons étudié les effets séparés et conjoints du retournement du sol et des fertilisations phosphatée et azotée du sol sur la structure des communautés des Glomeromycètes et sur les populations de l’espèce Rhizophagus irregu…
Impacts of Integrated Weed management in cropping systems on N2O emissions from soils
2014
International audience
Direct seeding mulch-based cropping increases both the activity and the abundance of denitrifier communities in a tropical soil
2009
International audience; This study evaluated the impact of direct seeding mulch-based cropping (DMC), as an alternative to conventional tilling (CT), on a functional community involved in N cycling and emission of greenhouse gas nitrous oxide (N2O). The study was carried out for annual soybean/rice crop rotation in the Highlands of Madagascar. The differences between the two soil management strategies (direct seeding with mulched crop residues versus tillage without incorporation of crop residues) were studied along a fertilization gradient (no fertilizer, organic fertilizer, organic plus mineral fertilizers). The activity and size of the denitrifier community were determined by denitrifica…
Biodiversité des sols viticoles: un héritage des modes d'occupation et des pratiques culturales anciennes?
2018
3 pages; National audience
Morphological characterisation of soil structure in tilled fields: from a diagnosis method to the modelling of structural changes over time
2004
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…
Raisonnement des pratiques et des changements de pratiques en matière de désherbage : regards agronomique et sociologique à partir d’enquêtes chez de…
2008
To ensure successful, more sustainable weed management practices, it is crucial to take account of farmer’s decision-making processes. Agronomists revealed that interviewed farmers had complex and various weeding programmes, and that, when designing these programmes, they integrated different time scales: the current year, the rotation, and the long term. They gave some light, too, on the decision-making processes and how it changes over time. Sociologists analyzed the way wine-growers bring about change from the cognitive angle and its bearing on interactive dialogue between the wine-growers themselves as well as with technical advisors