Showing papers by "James N. Galloway published in 2021"

The influence of crop and chemical fertilizer combinations on greenhouse gas emissions: A partial life-cycle assessment of fertilizer production and use in China

Abstract: Different crops and fertilizer combinations result in different greenhouse gas (GHG) emissions. To investigate GHG emissions among crops with different chemical fertilizer production and use processes, we use a partial life-cycle based greenhouse gas footprint approach to evaluate total GHG emissions, emissions per unit area, and emissions per unit yield of nine crops receiving applications of seven chemical fertilizers for the period 1998 to 2016 in China. Our results show that the life-cycle GHG emissions in China increased by 35% over this 18-year period. Chemical fertilizer use has a greater influence than chemical fertilizer production, as it emitted over half of total GHG emissions. Due to different fertilizer types/uses and cultivated areas, GHG emissions varied among crops. The three main grain crops including rice, wheat, and maize contributed half of the total GHG emissions, mainly due to their larger cultivated areas than other crops. Crops with smaller cultivated areas but larger fertilizer application rates also contributed nonnegligible GHG emissions. For example, vegetable production increased nearly two-fold and accounted for about 20% of total GHG emissions, due to high applications of urea, NPK compound fertilizer, and diammonium phosphate. Fruit crops contributed both much higher GHG emissions and GHG emissions per cultivated area than most other crops, resulting from high application intensities of urea and NPK compound fertilizer. Among the chemical fertilizers, urea generated the greatest GHG emissions (~60% of the total GHG emissions) due not only to its relatively high application across the crops, but also its relatively high GHG emission intensities for both production and application. Finally, we explore potential to mitigate the life-cycle GHG emissions of chemical fertilizers nationally, through varying fertilizer application rates, fertilizer types, and cultivated areas. For example, our scenarios modify the cultivated areas of the three main grain crops, reduce urea and NPK compound fertilizer for fruits and vegetables, and substitute some urea and diammonium phosphate with superphosphate and potassium chloride. Our study highlights the importance of different chemical fertilizer and crop combinations. It can help to mitigate the GHG emissions comprehensively and objectively.

The Human Creation and Use of Reactive Nitrogen: A Global and Regional Perspective

Abstract: More food and energy allow for more people who then require more food and energy, and so it has gone for centuries. At the same time, economic progress leads to a different lifestyle with an increa...

Improving the social cost of nitrous oxide

Abstract: The social cost of nitrous oxide does not account for stratospheric ozone depletion. Doing so could increase its value by 20%. Links between nitrous oxide and other nitrogen pollution impacts could make mitigation even more compelling.

High-frequency follow-up studies in musculoskeletal disorders: a scoping review.

Abstract: Objectives This scoping review identifies research in musculoskeletal disorders that uses high frequency follow-up of symptoms. The aim was to investigate whether symptom variability is investigated as a predictor of disease outcome and how intensive follow-up methods are used in musculoskeletal research. Methods Embase, MEDLINE and PsycInfo were searched using OVID, and the Institute of Electrical and Electronic Engineers was also searched using the Institute of Electrical and Electronic Engineers Xplore search engine. Studies were systematically reviewed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses, but no meta-analysis was done because the priority in this study is to identify gaps in available literature. Results Twenty-one papers were included. There was a mean of 54 patients per study (s.d. of 27.7). Two-thirds of the papers looked at how a symptom influences another in the short-term (subsequent assessment in the same day or next day), but none looked at the long-term. Only one study considered symptom variability investigating how higher variability in pain (defined by the s.d.) is associated with higher average pain severity and lower average sleep quality. Conclusion The methodology of musculoskeletal disorder research has changed from completing paper booklets to using electronic data capture (smartphones). There has also been a trend of collecting more intensive longitudinal data, but very little research utilizes these data to look at how symptom variability affects symptom outcomes. This demonstrates a gap in research where furthering understanding of this will help clinicians decide on the most important symptom to address in future patients.

Shenandoah Watershed Study-Virginia Trout Stream Sensitivity Study (SWAS-VTSSS): Stream water quality and hydrologic monitoring data for mid-Appalachian headwater streams

Abstract: The Shenandoah Watershed Study (established in 1979) and the Virginia Trout Stream Sensitivity Study (established in 1987) serve to increase understanding of hydrological and biogeochemical changes in western Virginia mountain streams that occur in response to acidic deposition and other ecosystem stressors. The SWAS-VTSSS program has evolved over its 40+ year history to consist of a temporally robust and spatially stratified monitoring framework. Currently stream water is sampled bi-hourly during high-flow events at 3 sites and weekly at 4 sites within Shenandoah National Park (SHEN), and quarterly at 72 sites and on an approximately decadal frequency at ~ 450 sites within the wider western Virginia Appalachian region. Stream water is evaluated for pH, acid neutralizing capacity (ANC), base cations (calcium, magnesium, sodium and potassium ion), acid anions (sulfate, nitrate and chloride), silica and ammonium, with a subset of samples evaluated for monomeric aluminum and dissolved organic carbon. Hourly stream discharge (4 sites) and in-situ measurements of conductivity, water and air temperature (3 sites) are also measured within SHEN. Here we provide an overview and timeline of the SWAS-VTSSS stream water monitoring program, summarize the field and laboratory methods, describe the water chemistry and hydrologic data sets, and document major watershed disturbances that have occurred during the program history. Website links and instructions are provided to access the stream chemistry and time-series monitoring data in open-access federal databases. The purpose of this publication is to promote awareness of these unique, long-term data sets for wider use in catchment studies. The water chemistry and hydrologic data can be used to investigate a wide range of biogeochemical research questions and provide key inputs for models of these headwater stream ecosystems. SWAS-VTSSS is an ongoing program and quality assured data sets are uploaded to the databases annually.

Identifying and assessing effectiveness of alternative low-effort nitrogen footprint reductions in small research institutions

Abstract: Concern over the ecological damage of excess nitrogen has brought increased attention to the role of research institutions and universities in contributing to this problem. Institutions often utilize the concept of the ecological ‘footprint’ to quantify and track nitrogen emissions resulting from their activities and guide plans and commitments to reduce emissions. Often, large-scale changes and commitments to reduce nitrogen footprints are not feasible at small institutions due to monetary and manpower constraints. We partnered with managers in the dining and facilities departments at the Marine Biological Laboratory (MBL), a small research institution in Woods Hole, Massachusetts, to develop five low-effort strategies to address nitrogen emissions at the institution using only resources currently available within those departments. Each proposed strategy achieved emissions reductions in their sector and in the overall nitrogen footprint of the MBL. If all modelled strategies are applied simultaneously, the MBL can achieve a 7.7% decrease in its nitrogen footprint. Managers at MBL considered strategies that required no monetary input most feasible. The intersection of carbon and nitrogen emissions also means the modelled strategies had the co-benefit of reducing the MBL’s carbon footprint, strengthening the argument for applying these strategies. This paper may serve as a model for similar institutions looking to reduce the ecological impact of their activities.