International audience | Nitrogen (N) fertilizer is an important yield limiting factor for sunflower production. The correlation between yield components and growth parameters of three sunflower hybrids (Hysun-33, Hysun-38, Pioneer-64A93) were studied with five N rates (0, 60, 120, 180, 240 kg ha−1) at three different experimental sites during the two consecutive growing seasons 2008 and 2009. The results revealed that total dry matter (TDM) production and grain yield were positively and linearly associated with leaf area index (LAI), leaf area duration (LAD), and crop growth rate (CGR) at all three sites of the experiments. The significant association of yield with growth components indicated that the humid climate was most suitable for sunflower production. Furthermore, the association of these components can be successfully used to predict the grain yield under diverse climatic conditions. The application of N at increased rate of 180 kg ha−1 resulted in maximum yield as compared to standard rate (120 kg ha−1) at all the experimental sites. In this way, N application rate was significantly correlated with growth and development of sunflower under a variety of climatic conditions. Keeping in view such relationship, the N dose can be optimized for sunflower crop in a particular region to maximize the productivity. Multilocation trails help to predict the input rates precisely while taking climatic variations into account also. In the long run, results of this study provides basis for sustainable sunflower production under changing climate.

Mechanical recovery for large offshore oil spills (defined as the marine environment over 10 km from shore outside of bays, lagoons, and marinas) depends on oil behavior, environmental conditions, equipment specifications, and operational issues. These factors limit oil recovery with booms and skimmers. The “rule of thumb” has been that 10–30% of the total oil spilled can be recovered. This paper describes a review of historical oil spills that found only between 2 and 6% of the total oil spilled was recovered.The limiting factors affecting mechanical recovery in offshore settings include environmental conditions, oil behavior, and logistics. Mechanical recovery will always be an important tool for spill response, especially in nearshore and in-port settings, as well as locations with sensitivity to chemical dispersants and/or in situ burning. However, its application in large offshore spills will generally result in recovery of only a fraction of the spilled oil.

International audience | Accumulated sediments in a 32,000-m3 detention basin linked to a separate stormwater system were characterized in order to infer their health hazards. A sampling scheme of 15 points was defined according to the hydrological behaviour of the basin. Physical parameters (particle size and volatile organic matter content) were in the range of those previously reported for stormwater sediments. Chemical analyses on hydrocarbons, PAHs, PCBs and heavy metals showed high pollutant concentrations. Microbiological analyses of these points highlighted the presence of faecal indicator bacteria (Escherichia coli and intestinal enterococci) and actinomycetes of the genus Nocardia. These are indicative of the presence of human pathogens. E. coli and enterococcal numbers in the sediments were higher at the proximity of the low-flow gutter receiving waters from the catchment. These bacteria appeared to persist over time among urban sediments. Samples highly contaminated by hydrocarbons were also shown to be heavily contaminated by these bacteria. These results demonstrated for the first time the presence of Nocardial actinomycetes in such an urban context with concentrations as high as 11,400 cfu g-1.

Paper presents an overview of wastewater treatment systems with macrophytes. It is concluded that application of these systems in Mediterranean countries is feasible, especially for treatment of smaller and remote wastewater point sources.