Assessing the environmental impact of different crop protection strategies

The original publication is available at: www.agronomy-journal.org. Copyright INRA / EDP Sciences [Full text of this article is not available in the UHRA]In 1993, a project was established to develop more sustainable arable farming systems. Fields were divided into two plots to compare the environmental and economic performance of conventional and integrated farming systems (IFS). As environmental impact assessment (EIA) techniques were, at that time, in their infancy, differences in crop protection strategies could only be evaluated using quantity of pesticide applied. EIA techniques are now more sophisticated and using data from the original project, potential impacts have been re-assessed using the p-EMA model. The results show that using the quantity of pesticide applied as a surrogate indicator of risk is unsound, and that where the site has few sensitive habitats there may be little difference in predicted environmental impact between the different strategies. However, if the site is habitat-rich, IFS strategies can significantly lower the predicted risk. The results also demonstrate the need for substantial site and pesticide information to improve IFS strategies.Peer reviewe

A Multimessenger Picture of the Flaring Blazar TXS 0506+056: Implications for High-energy Neutrino Emission and Cosmic-Ray Acceleration

Detection of the IceCube-170922A neutrino coincident with the flaring blazar TXS 0506+056, the first and only ∼3σ high-energy neutrino source association to date, offers a potential breakthrough in our understanding of high-energy cosmic particles and blazar physics. We present a comprehensive analysis of TXS 0506+056 during its flaring state, using newly collected Swift, NuSTAR, and X-shooter data with Fermi observations and numerical models to constrain the blazar's particle acceleration processes and multimessenger (electromagnetic (EM) and high-energy neutrino) emissions. Accounting properly for EM cascades in the emission region, we find a physically consistent picture only within a hybrid leptonic scenario, with γ-rays produced by external inverse-Compton processes and high-energy neutrinos via a radiatively subdominant hadronic component. We derive robust constraints on the blazar's neutrino and cosmic-ray emissions and demonstrate that, because of cascade effects, the 0.1-100 keV emissions of TXS 0506+056 serve as a better probe of its hadronic acceleration and high-energy neutrino production processes than its GeV-TeV emissions. If the IceCube neutrino association holds, physical conditions in the TXS 0506+056 jet must be close to optimal for high-energy neutrino production, and are not favorable for ultrahigh-energy cosmic-ray acceleration. Alternatively, the challenges we identify in generating a significant rate of IceCube neutrino detections from TXS 0506+056 may disfavor single-zone models, in which γ-rays and high-energy neutrinos are produced in a single emission region. In concert with continued operations of the high-energy neutrino observatories, we advocate regular X-ray monitoring of TXS 0506+056 and other blazars in order to test single-zone blazar emission models, clarify the nature and extent of their hadronic acceleration processes, and carry out the most sensitive possible search for additional multimessenger sources. © 2018. The American Astronomical Society. All rights reserved.