Strategic tillage in Conservation Agriculture : consequences on weed communities and winter wheat productivity

ISBN: 978-84-09-37744-2International audienceIn Europe, Conservation Agriculture is currently challenged by higher weed pressure, potential glyphosate ban andreduced crop yield. The introduction of strategic tillage could be a viable option to diversify selection pressures onweeds and increase crop yield. Three types of fallow management (ploughing (CT), reduced tillage (RT), no-till withglyphosate (NT)) were compared on four fields after 17 years of no-plough, which ended with 7 years of NT. Weeddensity, weed composition, crop productivity and yield components were assessed in the following winter wheat.The reintegration of tillage after 17 years of Conservation Agriculture proved to be a major driver of weed communities before weeding (density, richness and composition). Weed density and species richness before weeding wasgreatest in RT, intermediate in CT and lowest in NT. Density of Alopecurus myosuroides, the most problematic weedof the experiment was higher in RT than in CT or NT. Differences in weed community composition were discussedin terms of weed seed longevity and weed seed movements associated to RT and CT. The number of grains perear and crop yield increased with tillage intensity (+11% for RT, +31% for CT). Specific weight and protein contentwere not affected by tillage treatments. Differences in winter wheat productivity were possibly related to enhancedsoil structure and increased mineralization of soil organic matter. Strategic ploughing could be a viable solutionto manage herbicide-resistant weeds in no-till cropping systems. Potential benefits will depend on the density andcomposition of the newly upwelled weed seedbank

Interdigitated conducting tetrathiafulvalene-based coordination networks

Assembly of a novel ethylenedithio-tetrathiafulvalene (EDT-TTF) derivative bearing two adjacent 4-thiopyridyl groups with M(NCS)2 nodes (M = Fe, Co) leads to two isostructural 1D coordination polymers showing an enhancement of their electronic conductivity by six orders of magnitude (10[superscript -6] vs. 10[superscript -12] S cm[superscript -1), upon surface oxidation by iodine and subsequent generation of EDT-TTF-based radicals.National Science Foundation (Award 1122374

Weed dynamic in Conservation Agriculture: experiences from the Isite-BFC regional network of farmers and cropping system experiments on agroecology in France.

ISBN: 978-84-09-37744-2International audienceConservation Agriculture (CA) relies on three fundamental pillars: diversified crop rotation, permanent soil coverand no soil disturbance. Weed control relies on few tools because pre-sowing tillage, pre-emergence herbicidespraying and in-crop mechanical weeding are not possible. This could lead to drastic changes in weed communitiesand quickly after the transition to CA, with fewer annual species (weed seeds remain on the soil surface, a conditiondeemed to be unfavourable to weed germination) and higher perennial species. However, the implementation ofCA principles could be transcribed into a wide array of cropping systems because the objectives of farmers differ,and/or because systems are implemented in different production situations (e.g., associated or not to livestock, soiltype, irrigation). Therefore, the Isite-BFC regional network gathers CA farmers and experimenters from cooperatives and research institute (INRAE) to share their experiences, detailed practices and weed surveys initiated since2007 in some sites. Weed diversity was high in all systems compared to what is known from tillage-based agriculture. Weed community changes over time depending on the diversity of crop rotation tested and initial weedingpressure. Since CA is challenged by potential glyphosate ban in Europe, the application of glyphosate was stoppedin 2018 in some sites and thus, cropping systems were redesigned accordingly to ensure weed management overthe long run, economic profitability and multiperformance

Selective gas adsorption by calixarene-based porous octahedral M32 coordination cages

Giant octahedral M32 coordination cages were prepared via self-assembly of sulfonylcalix[4]arene-supported tetranuclear M(II) clusters (M = Co, Ni) with hybrid linker based on tris(dipyrrinato)cobalt(III) complexes appended with peripherical carboxylic groups. Due to intrinsic and extrinsic porosity, the obtained solid-state supramolecular architectures demonstrated good performance as adsorbents for the separation of industrially important gases mixtures.peerReviewe