Progress 10/01/20 to 09/30/21
Outputs
Target Audience:Scientists, students and policy makers interested in atmospheric deposition, acid rain, and other related subjects. Changes/Problems:Several lines of research provide strong evidence that dust transport is increasing in large areas of the western USA, which can increase the transport and deposition of phosphorus and particulate nitrogen. Yet, direct measurements of the total atmospheric dust load to ecosystems are rare, only cover small areas, and are typically of short duration.To address this data and knowledge gap, dry deposition monitoring through the NADP network began in 2017 and expanded to our site in December 2021. Dry deposition is collected monthly and processed for total mass deposition as well as composition. This effort will continue for the duration of this project. What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?Results have been disseminated by the National Atmospheric Deposition Program (NADP) to a wide range of scientific communities. Data are also available on the NADP website. What do you plan to do during the next reporting period to accomplish the goals?An atmospheric deposition monitoring station will be maintained at the University of Nebraska Eastern Nebraska Research and Extension Center (ENREC), Mead. An automatic wet/dry precipitation collector and recording rain gauge will be employed for this purpose. Samples will be collected on a weekly basis and shipped to the Wisconsin State Laboratory for Hygiene in Madison, WI for detailed chemical analysis. We will follow the NADP guidelines in collection of precipitation samples and participate in the NADP quality assurance program. Concentration and deposition rates of chemical substances (e.g., SO4, NO3, NH4) and precipitation pH will be characterized. At the end of every year, the PI will analyze the data and compare with previous years' results to ensure quality control and progress toward objectives. Concentrations and deposition rates of chemical substances and precipitation pH will be quantified. Annual progress reports will be submitted to the NRSP003, Agricultural Research Division, and the University of Nebraska.
Impacts
What was accomplished under these goals?
The mission of the National Atmospheric Deposition Program (NADP) is to provide quality-assured data and information in support of research on the exposure of managed and natural ecosystems to acidic compounds, nutrients, mercury, and base cations in atmospheric deposition. For crop and livestock systems specifically, our work is providing basic knowledge with respect to multiple factors including a) measuring precipitation quality and quantity as it enters an agriculture system, b) measuring the flux of important agriculture compounds input to systems, c) providing data for fertilizer balance studies (N, P, and S) to crops, soils and agricultural waters, d) providing data for the chemical balance of soils and crops, and e) measuring the flux of agriculture compounds exported from agricultural systems to others (as listed in "A Science Roadmap for Food and Agriculture - 2010"; http://escop.ncsu.edu/docs/ scienceroadmap.pdf). Furthermore, the chemistry of precipitation is an important indicator of the quality of our environment. Monitoring precipitation chemistry over time and space allows us to understand how natural and human factors are affecting our environment. This master project has been instrumental in meeting the needs of many research projects nationally. Through this project, we may contribute to the sustainability and profitability of U.S. food and agricultural systems (food, feed, fiber, and fuel) as they adapt and mitigate to the impact of climate change to continue to produce a safe, secure and abundant food supply. The Nebraska objectives were to operate the atmospheric deposition station at the University of Nebraska Eastern Nebraska Research and Extension Center, Mead, NE on the western edge of the "Corn Belt." An automatic sensing wet/dry precipitation collector and a recording rain gauge was employed for this purpose. Samples were collected on a weekly basis and shipped to the Wisconsin State Laboratory of Hygiene (Madison, WI) for detailed chemical analysis. We followed the NADP guidelines in collection of precipitation samples and participated in the NADP quality assurance program. Concentration and deposition rates of chemical substances (e.g., SO4, NO3, NH4) and precipitation pH were characterized. This year marked our 44th year of operating a station in this network. Total precipitation for 2020 was 432 mm (note data become available from NADP a few months after collection so annual results provided here are from 2020). This is 54% below our long-term average. This is the least amount of total precipitation measured since we began measurements. The second lowest total precipitation measured at our site was 467 mm in 2012. The laboratory measured mean pH of the precipitation was 7.11, 18% greater than the average of the entire period. There has been a strongly increasing trend in the pH since 2008 with the trend over the last 5 years slightly decreasing, or becoming more acidic. In 2020, as in previous years, total inorganic N (wet deposition from nitrate and ammonium) were higher over the "Corn Belt" states with eastern Nebraska and a large portion of Iowa having some of the highest annual deposition rates. Most of the deposition at our site (4.23 kg/ha) is from ammonium and occurs during summer months as expected from an agriculturally intensive region (including a substantial livestock industry). This was a significant decrease from last year's deposition of 6.93 kg/ha consistent with the lower rainfall. The highest was 9.05 kg ha-1, measured in 2011 and the second highest measured in 2015, was 8.14 kg ha-1. The trend in total inorganic N ion deposition since 2000 has been increasing at approximately 0.08 kg ha-1 y-1. The total inorganic N is made up of nitrate (NO3) and ammonia (NH4). The 2020 annual NO3-N ion concentration was 0.23 mg L-1, 13% greater than the NO3-N ion concentration in 2019 and 23% less than the overall average NO3-N ion concentration measured at our site. The 2020 annual NH4-N ion concentration was 0.75 mg L-1. This was 38% greater than the NH4-N ion concentration in 2019 and 41% greater than the overall average NH4-N ion concentration. Our station measured the third highest annual NH4-N ion concentration in the network. The 2020 annual NH4-N ion deposition was 3.25 kg ha-1. This was 36% less than the NH4-N ion deposition in 2019 and 13% less than the overall average NH4-N ion deposition. This was the second lowest NH4-N ion deposition measured at our site. The lowest was 1.98 kg ha-1 measured in 1988. The sulfate wet deposition is relatively low at our site and in the surrounding states (about 2 kg ha-1). The 2020 annual SO4-S ion deposition was 0.76 kg ha-1. This is 56% less than the deposition in 2019 and 74% less than the overall average SO4-S ion deposition. This was the lowest SO4-S ion deposition measured at our site. The 2020 annual SO4-S ion concentration was 0.18 mg L-1. This was 4% less than the concentration in 2019 and 59% less than the overall average SO4-S ion concentration at our site. This was the lowest SO4-S ion concentration measured at our site. In general, our sulphur deposition is gradually decreasing while our nitrogen deposition, through ammonia, is gradually increasing. National trends of these species are illustrated in NADP year-to-year map animations, available online at http://nadp.isws.illinois.edu/data/animaps.aspx.
Publications
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