Forecasting hourly evapotranspiration for triggering irrigation in nurseries

Predicting water requirements for plants is crucial in constrained nurseries during periods of intense sunlight. The temporal variations of evapotranspiration, an irrigation indicator, are described using a time series model with a seasonal component, whose parameters are identified. The resulting hourly time-scale predictive model, which makes it possible to anticipate crop water requirements, was applied to two climatic zones in steady-state weather with good accuracy. As the proposed predictive model only requires storing previous data without a significant computational effort, it can be easily used in real time. We compared predictive and real-time irrigation triggering algorithms on two plots with different irrigation thresholds in a typical nursery, and showed that the predictive approach could avoid crop exposure to water stress. In order to validate our approach, both algorithms were implemented in real-time field experiments using a standard input–output terminal to trigger the automatic irrigation of two rose plots (Rosa sinensis). When water availability was unrestricted, irrigation took place earlier in the predictive case and thus maintained the substrate properly moistened more frequently. When a midday no-irrigation period was imposed as a constraint in order to simulate water-limited resources or hydraulic network overload, irrigation was triggered slightly earlier in the “predictive“ plot, and water deficit peaks remained below irrigation thresholds more frequently than in the static threshold approach

Social Media, Gender and the Mediatisation of War: Exploring the German Armed Forces’ Visual Representation of the Afghanistan Operation on Facebook

Studies on the mediatisation of war point to attempts of governments to regulate the visual perspective of their involvements in armed conflict – the most notable example being the practice of ‘embedded reporting’ in Iraq and Afghanistan. This paper focuses on a different strategy of visual meaning-making, namely, the publication of images on social media by armed forces themselves. Specifically, we argue that the mediatisation of war literature could profit from an increased engagement with feminist research, both within Critical Security/Critical Military Studies and within Science and Technology Studies that highlight the close connection between masculinity, technology and control. The article examines the German military mission in Afghanistan as represented on the German armed forces’ official Facebook page. Germany constitutes an interesting, and largely neglected, case for the growing literature on the mediatisation of war: its strong antimilitarist political culture makes the representation of war particularly delicate. The paper examines specific representational patterns of Germany’s involvement in Afghanistan and discusses the implications which arise from what is placed inside the frame of visibility and what remains out of its view