Micro-Topological Effects on Redox-Sensitive Nutrient Availability of Manganese, Iron, Sulfur, and Phosphorus

The working hypothesis for this study was that small elevation differences in field depressions affect the availability of redox active nutrients because the bottom of the depression remains waterlogged and in reducing conditions longer than the edge of the depression. Mn, Fe, S and P availabilities were investigated in a field depression with a 20 meter radius and 0.5 meter depth on a flood-prone, organic vegetable farm. One depression (Depression 1) was sampled seven times during three field seasons (May 2012-June 2014). The last two dates included sampling in an additional three depressions to allow a comparison among depressions on the same date. Sampling dates were categorized by the severity of flooding into the three following kinds of events: Post-Irene, Peak, and Non-Peak. The Post-Irene category includes sampling dates in the agricultural season following prolonged snow melt and flooding from Tropical Storm Irene in 2011. Sampling dates in the Peak category occurred within 30 days after one of the the top 12 greatest rainfalls, snowfalls, or heights of Winooski River Gage in the 30 month sampling period. Sampling on Non-Peak events occurred at least one month after a preceding Peak event. Repeated waterlogging events can increase redox cycling directly affecting the interchange of Mn, Fe, and S oxides and the soil solution. Indirectly, waterlogging can increase phosphorus release into the soil solution by reduction of iron. The results of this experiment indicate that some redox-sensitive soil nutrients correlated with elevation on some dates regardless of event type. Mn was more consistently affected by waterlogging events than Fe and S. Any relationship between sulfur and elevation may have been obscured by the strong relationship of sulfur with organic matter. This data suggests that phosphorus availability depended to some extent on available iron concentration

The State of Soil Health in Vermont: Summary statistics from Vermont agriculture in 2021

This report shares the summary statistics of the soil health indicators evaluated in the 2021 State of Soil Health project on farms in Vermont. The aim of this report is to share the data in a simple format that can be accessed by farmers, advisors and policy makers. The State of Soil Health in Vermont is an initiative to measure soil health and soil carbon on farms across the state of Vermont. This project is coordinated by UVM Extension and has relied on field support, in kind- donations and data sharing from partnering organizations. The project has five primary objectives: Establish a baseline of soil health indicators, carbon stocks, and associated ecosystem services in Vermont’s agricultural landscapes Create soil health soil sampling standards across management types Provide farmers with contextualized information about soil health on their participating fields Support collaboration among the many organizations that work with farmers towards shared goals around soil health Build skills and capacity for measuring soil health and soil carbon stocks Collaborators include UVM Extension, UVM Department of Plant & Soil Science, the Gund Institute for Environment, Dartmouth College, the Vermont Environmental Stewardship Program of the Vermont Agency of Agriculture, Food & Markets, the White River Conservation District, Vermont Association of Conservation Districts, Ben & Jerry’s Caring Dairy Program and The Nature Conservancy Vermont

Whole Farm Net Zero: approaches to quantification of climate regulation ecosystem services at the whole farm scale. Vermont Payment for Ecosystem Services Technical Report #7

In this report, approaches to the quantification of climate mitigation ecosystem services at the whole farm scale are reviewed and summarized for easy comparison. Eight quantification tools, and three case studies demonstrating possible tool applications, are summarized to fulfill the requirements of the Technical Services Contract—Task 7. Information from a combination of literature review and expert interviews served to document the inputs, outputs, strengths, weaknesses, opportunities, and threats for each quantification tool. This research was conducted in service to the Vermont Soil Health and Payment for Ecosystem Services (PES) Working Group (VT PES working group). It is our hope that this report provides productive information and insights for the implementation of whole farm scale payment for ecosystem services programs, Vermont’s Climate Action Plan, and similar efforts elsewhere. Emissions reductions on farms are of interest to farmers in Vermont and will be required by the implementation of the Global Warming Solutions Act (GWSA). Management changes that reduce emissions at the farm scale could possibly be supported and encouraged through a PES program. Given the work and goals of the PES Working Group and the requirements to implement the GWSA it is critical to understand the degree of accuracy and scope of currently available greenhouse gas assessment tools that could possibly be implemented to measure and monitor outcomes from VT agriculture. Section 2 of this report describes the methods used to collect information reviewing eight tools for quantifying agricultural greenhouse gas emissions and sequestration rates, including the CarbOn Management & Emissions Tool (COMET)-Farm, COMET-Planner, COOL-Farm, DayCent, DNDC (DeNitrification-DeComposition), Environmental Policy Integrated Climate (EPIC) & APEX Agricultural Policy / Environmental eXtender (APEX), Holos, and the Integrated Farm Systems Model (IFSM). These eight tools were each reviewed using a systematic literature review, interviews with experts who are well-versed in using the specific tools, and a Strengths-Weaknesses-Opportunities-Threats (SWOT) analysis. Section 3 presents some larger-context considerations for choosing an appropriate tool. Section 4 gives a high-level overview of the SWOT analysis performed for each tool reviewed for this task. Section 5 describes three example applications of emissions modeling tools.Section 6 contains concluding remarks. The report’s Appendix section includes the SWOT analyses for each tool to allow for more in-depth review, as well as a series of tables to present a high-level comparison of the tools

Field scale soil health scenarios. Vermont Payment for Ecosystem Services Technical Report #2

This report illustrates how changes in management on Vermont farms can influence soil health metrics at the field scale. We’ve used regionally relevant science-based scenarios to demonstrate how selected soil health metrics that are associated with ecosystem services could change on farms in response to management practices at the field scale. These field scale management scenarios demonstrate that many practices in use by farmers in Vermont can have positive impacts on the soil health indicators of interest to the Vermont Soil Health & Payment for Ecosystem Services Working Group. The scenarios document potential for tradeoffs among soil health properties. Specifically, some of the scenarios illustrate how bulk density and compaction can worsen in instances when other soil health properties improve. Long-term research that measures multiple indicators of soil health and ecosystem services on recommended soil health management practices in Vermont is needed to support the evidence-base for soil health and ecosystem services incentive programs

CMB-S4: Forecasting Constraints on Primordial Gravitational Waves

CMB-S4---the next-generation ground-based cosmic microwave background (CMB) experiment---is set to significantly advance the sensitivity of CMB measurements and enhance our understanding of the origin and evolution of the Universe, from the highest energies at the dawn of time through the growth of structure to the present day. Among the science cases pursued with CMB-S4, the quest for detecting primordial gravitational waves is a central driver of the experimental design. This work details the development of a forecasting framework that includes a power-spectrum-based semi-analytic projection tool, targeted explicitly towards optimizing constraints on the tensor-to-scalar ratio, $r$, in the presence of Galactic foregrounds and gravitational lensing of the CMB. This framework is unique in its direct use of information from the achieved performance of current Stage 2--3 CMB experiments to robustly forecast the science reach of upcoming CMB-polarization endeavors. The methodology allows for rapid iteration over experimental configurations and offers a flexible way to optimize the design of future experiments given a desired scientific goal. To form a closed-loop process, we couple this semi-analytic tool with map-based validation studies, which allow for the injection of additional complexity and verification of our forecasts with several independent analysis methods. We document multiple rounds of forecasts for CMB-S4 using this process and the resulting establishment of the current reference design of the primordial gravitational-wave component of the Stage-4 experiment, optimized to achieve our science goals of detecting primordial gravitational waves for $r > 0.003$ at greater than $5\sigma$, or, in the absence of a detection, of reaching an upper limit of $r < 0.001$ at $95\%$ CL.Comment: 24 pages, 8 figures, 9 tables, submitted to ApJ. arXiv admin note: text overlap with arXiv:1907.0447

Performance and characterization of the SPT-3G digital frequency-domain multiplexed readout system using an improved noise and crosstalk model

The third-generation South Pole Telescope camera (SPT-3G) improves upon its predecessor (SPTpol) by an order of magnitude increase in detectors on the focal plane. The technology used to read out and control these detectors, digital frequency-domain multiplexing (DfMUX), is conceptually the same as used for SPTpol, but extended to accommodate more detectors. A nearly 5× expansion in the readout operating bandwidth has enabled the use of this large focal plane, and SPT-3G performance meets the forecasting targets relevant to its science objectives. However, the electrical dynamics of the higher-bandwidth readout differ from predictions based on models of the SPTpol system due to the higher frequencies used and parasitic impedances associated with new cryogenic electronic architecture. To address this, we present an updated derivation for electrical crosstalk in higher-bandwidth DfMUX systems and identify two previously uncharacterized contributions to readout noise, which become dominant at high bias frequency. The updated crosstalk and noise models successfully describe the measured crosstalk and readout noise performance of SPT-3G. These results also suggest specific changes to warm electronics component values, wire-harness properties, and SQUID parameters, to improve the readout system for future experiments using DfMUX, such as the LiteBIRD space telescope

CMB-S4

We describe the stage 4 cosmic microwave background ground-based experiment CMB-S4

CMB-S4: Forecasting Constraints on Primordial Gravitational Waves

Abstract: CMB-S4—the next-generation ground-based cosmic microwave background (CMB) experiment—is set to significantly advance the sensitivity of CMB measurements and enhance our understanding of the origin and evolution of the universe. Among the science cases pursued with CMB-S4, the quest for detecting primordial gravitational waves is a central driver of the experimental design. This work details the development of a forecasting framework that includes a power-spectrum-based semianalytic projection tool, targeted explicitly toward optimizing constraints on the tensor-to-scalar ratio, r, in the presence of Galactic foregrounds and gravitational lensing of the CMB. This framework is unique in its direct use of information from the achieved performance of current Stage 2–3 CMB experiments to robustly forecast the science reach of upcoming CMB-polarization endeavors. The methodology allows for rapid iteration over experimental configurations and offers a flexible way to optimize the design of future experiments, given a desired scientific goal. To form a closed-loop process, we couple this semianalytic tool with map-based validation studies, which allow for the injection of additional complexity and verification of our forecasts with several independent analysis methods. We document multiple rounds of forecasts for CMB-S4 using this process and the resulting establishment of the current reference design of the primordial gravitational-wave component of the Stage-4 experiment, optimized to achieve our science goals of detecting primordial gravitational waves for r > 0.003 at greater than 5σ, or in the absence of a detection, of reaching an upper limit of r < 0.001 at 95% CL

Active Learning Methods and Strategies to Improve Student Conceptual Understanding: Some Considerations from Physics Education Research

Active learning methods and strategies are credited to be important means for development of student cognitive skills This paper describes some forms of active learning common in Physics Education and briefly introduces some of the pedagogical and psychological theories at the basis of active learning. Then, some evidence for active learning effectiveness in developing student critical cognitive skills and improving their conceptual understanding are examined. An example study regarding the effectiveness of an Inquiry-Based learning approach in helping students to build mechanisms of functioning and explicative models, and to identify common aspects in apparently different phenomena, is briefly discussed

A Measurement of the Cosmic Microwave Background Lensing Potential and Power Spectrum from 500 deg2 of SPTpol Temperature and Polarization Data

We present a measurement of the cosmic microwave background lensing potential using 500 deg2 of 150 GHz data from the SPTpol receiver on the South Pole Telescope. The lensing potential is reconstructed with signal-to-noise per mode greater than unity at lensing multipoles L lesssim 250, using a quadratic estimator on a combination of cosmic microwave background temperature and polarization maps. We report measurements of the lensing potential power spectrum in the multipole range of 100 < L < 2000 from sets of temperature-only (T), polarization-only (POL), and minimum-variance (MV) estimators. We measure the lensing amplitude by taking the ratio of the measured spectrum to the expected spectrum from the best-fit Λ cold dark matter model to the Planck 2015 TT + low P + lensing data set. For the minimum-variance estimator, we find ${A}_{\mathrm{MV}}=0.944\pm 0.058(\mathrm{Stat}.)\pm 0.025\ (\mathrm{Sys}.);$ restricting to only polarization data, we find ${A}_{\mathrm{POL}}=0.906\pm 0.090\ (\mathrm{Stat}.)\pm 0.040\ (\mathrm{Sys}.)$. Considering statistical uncertainties alone, this is the most precise polarization-only lensing amplitude constraint to date (10.1σ) and is more precise than our temperature-only constraint. We perform null tests and consistency checks and find no evidence for significant contamination