Alternative methods for terminating green manures in organic grain systems

Legume green manures (GM) are a vital source of nitrogen (N) for many organic grain systems. A common practice among organic growers is to undersow clover into a small grain, harvest the grain crop and terminate the clover stand in late fall by moldboard plowing in preparation for a cash crop the following spring. While fall plowing offers excellent clover kill, growers increasingly seek an alternative termination method that reduces tillage intensity and bare winter soil. This study, performed at two sites in Maine, evaluates three clover termination methods for kill efficacy, winter soil cover, spring soil conditions and N uptake and grain yield and protein of a subsequent test crop of hard red spring wheat (Triticum aestivum L., var. Glenn). Red clover (Trifolium pratense L.) was intercropped with spring barley (Hordeum vulgare L.) and terminated in late fall by moldboard plowing (PL), skim plowing (SK) or undercutting (UC). A control treatment received no clover and was fall plowed. An additional treatment, winterkilled field peas (WK), was evaluated at one site. SK, UC and WK increased soil cover relative to PL, though UC resulted in low clover kill efficacy in a wet spring and is in need of improved design. Grain yield was higher following red clover compared to the no-clover control at one site, but was unaffected by termination method. At one site, grain crude protein was higher following PL than the other treatments, indicating the possibility for more favorable timing of N availability associated with PL.

1209. The Evolving Nature of Syndromic Surveillance During the COVID-19 Pandemic in Massachusetts

Background We developed a syndromic algorithm for COVID-19 like illness (CLI) to provide supplementary surveillance data on COVID-19 activity. Methods The CLI algorithm was developed using the Electronic Medical Record Support for Public Health platform (esphealth.org) and data from five clinical practice groups in Massachusetts that collectively care for 25% of the state’s population. Signs and symptoms of CLI were identified using ICD-10 diagnosis codes and measured temperature. The algorithm originally included three categories: Category 1 required codes for coronavirus infection and lower respiratory tract infections (LRTI); Category 2 required an LRTI-related diagnosis and fever; Category 3 required an upper or lower RTI and fever. The three categories mirrored statewide laboratory-confirmed case trends during spring and summer 2020 but did not detect the increase in late fall. We hypothesized this was due to the requirements for fever and LRTI. Therefore, we added three new categories defined by milder symptoms without fever: Category 4 requires LRTI-related diagnoses only; Category 5 requires upper or lower RTI or olfactory/taste disorders; and Category 6 requires at least one sign of CLI not identified by another category. Results The six-category algorithm detected the initial surge in April 2020, the summer lull, and the second surge in late fall (see figure). Category 1 cases were not identified until mid-March, which coincides with the first laboratory-confirmed cases in Massachusetts. Categories 2 and 3, which required fever, were prominent during the initial surge but declined over time. Category 5, the broadest category, declined during February and March 2020, likely capturing the end of the influenza season, and successfully detected the spring surge and fall resurgence. Weekly number of COVID-19 like illnesses by category, February 2, 2020 through May 8, 2021 Conclusion A syndromic definition that included mild upper RTI and olfactory/taste disorders, with or without fever or LRTI, mirrored changes in laboratory-confirmed COVID-19 cases better than definitions that required fever and LRTI. This suggests a shift in medically attended care and/or coding practices during initial vs subsequent surges of COVID-19, and the importance of using a broad definition of CLI for ongoing surveillance. Disclosures Michael Klompas, MD, MPH, UpToDate (Other Financial or Material Support, Chapter Author)

Comparison of Length-at-Date Criteria and Genetic Run Assignments for Juvenile Chinook Salmon Caught at Sacramento and Chipps Island in the Sacramento–San Joaquin Delta of California

There are four distinct runs of Chinook Salmon (Oncorhynchus tshawytscha) in the Central Valley, named after their primary adult return times: fall, late-fall, winter, and spring run. Estimating the run-specific composition of juveniles entering and leaving the Sacramento–San Joaquin Delta is crucial for assessing population status and processes that affect juvenile survival through the Delta. Historically, the run of juvenile Chinook Salmon captured in the field has been determined using a length-at-date criteria (LDC); however, LDC run assignments may be inaccurate if there is high overlap in the run-specific timing and size of juveniles entering and leaving the Delta. In this study, we use genetic run assignments to assess the accuracy of LDC at two trawl locations in the Sacramento River (Delta entry) and at Chipps Island (Delta exit). Fin tissues were collected from approximately 7,500 juvenile Chinook Salmon captured in trawl samples between 2007 and 2011. Tissues were analyzed using 21 microsatellites to determine genetic run assignments for individuals, which we compared with LDC run assignments. Across years, there was extensive overlap among the distributions of run-specific fork lengths of genetically identified juveniles, indicating that run compositions based on LDC assignments would tend to underestimate fall-run and especially late-fall-run compositions at both trawl locations, and greatly overestimate spring-run compositions (both locations) and winter-run compositions (Chipps Island). We therefore strongly support ongoing efforts to include tissue sampling and genetic run identification of juvenile Chinook Salmon at key monitoring locations in the Sacramento–San Joaquin River system.

Nitrous oxide emissions with enhanced efficiency and conventional urea fertilizers in winter wheat

Optimizing nitrogen fertilizer management can reduce nitrous oxide (N2O) emissions. This study tested if split applying enhanced efficiency fertilizers (EEFs) resulted in lower N2O emissions than applying equivalent rates of urea at planting. In semiarid southern Alberta, field trials were conducted during three years (planting to harvest) in rainfed winter wheat crops. Annual fertilizer rates ranged from 146 to 176 kg N ha−1. Fertilizer types were urea, and three EEFs (polymer-coated urea, urea with urease and nitrification inhibitors, and urea with a nitrification inhibitor). Each fertilizer type was applied three ways: 100% banded at planting, split applied 30% banded at planting and 70% broadcast in late fall, and split applied 30% banded at planting and 70% broadcast at Feekes growth stage 4 (GS4, post-tiller formation, wheat entering the greening up phase in the early spring). Nitrous oxide was measured using static chambers between sub-weekly and monthly from planting to harvest. Over three years, cumulative N2O emissions ranged from 0.16 to 1.32 kg N ha−1. This was equivalent to emissions factors between 0.009 and 0.688%. Cumulative N2O emissions and emissions factors did not differ between fertilizer types, but they were lower when fertilizer was split applied at GS4 compared to in late fall (P ≤ 0.10). Our study suggests that EEFs do not reduce N2O emissions from rainfed winter wheat crops, but a well-timed split application with a majority of fertilizer applied after winter can minimize N2O emissions.

Russian thistle (Salsola tragus L.) control with soil-active herbicides in no-till fallow

The benefits of no-till fallow, which include reduced soil erosion, improved soil health, and increased stored soil water, are in jeopardy because of the widespread development of glyphosate resistance in Russian thistle. The objective of this research was to evaluate the efficacy of soil-active, residual herbicides for Russian thistle control in no-till fallow. The combinations of sulfentrazone + carfentrazone and flumioxazin + pyroxasulfone, and metribuzin alone were each applied in late fall, late winter, and split-applied in late fall and late winter at three sites: Adams, OR, in 2017–2018; Lind, WA, in 2018–2019; and Ralston, WA, in 2019–2020. All treatments provided good to excellent control of the initial flush of Russian thistle when assessed in mid-May, except the late-fall application of metribuzin at all three sites, and the late-fall application of sulfentrazone + carfentrazone at Adams. Cumulative Russian thistle densities, evaluated monthly throughout the fallow season, were lowest for the sulfentrazone + carfentrazone treatments, except for the late-fall application at Adams. However, flumioxazin + pyroxasulfone and metribuzin provided greater control of tumble mustard and prickly lettuce than did sulfentrazone + carfentazone. Sulfentrazone + carfentrazone, flumioxazin + pyroxasulfone, and metribuzin can all be used for Russian thistle control in fallow. To reduce the risk for crop injury to subsequently planted winter wheat, a late-fall application of sulfentrazone + carfentrazone may be the preferred treatment in low-rainfall regions where winter wheat–fallow is commonly practiced. A late-winter application may be preferred in higher rainfall regions where a 3-year rotation (e.g., winter wheat–spring wheat–fallow) is common. Flumioxazin + pyroxasulfone should be considered if other broadleaf weeds, such as tumble mustard or prickly lettuce, are of concern. The use of these soil-applied herbicides will reduce the need for the frequent application of glyphosate for Russian thistle control in no-till fallow.

SENSATIONAL UNKNOWN FACTS FROM GEORGIAN DIPLOMACY OF 90-IES OF XVIII CENTURY

The Italian translation of Erekle the Second’s letter maintained in the archive of Vienna which was published in 1979 by Professor Ilia Tabaghua, reveals a sensational secret. In this letter we found a unique delf unveiling the fact that after the Krtsanisi tragedy suffered in 1795 Erekle the Second addressed Europe.In the course of studies and analyses we came across several delfs in one document that had been considered to be one letter, namely, in the Italian translation of a letter by Erekle the Second; chronologically these delfs turned out to be significantly distant from one other. Further studies conducted on these delfs brought us to the conclusion that in 1795, after the Krtsanisi tragedy, Erekle the Second’s ambassadors arrived to Vienna and handed the letter to the Emperor of Austria.In the Italian translation of a document by Erekle the Second that had been considered by scientists to be one single letter and which is dated with 1782, the fragment saying that “in these days the king’s residence in the East was totally destroyed” caused the first suspicion. We want to especially underline the circumstance that there is no evidence of destruction of any city or a town what could be considered to be the eastern residence of the king, found in the 80-s of the XVIII century. Therefore, there is only one way left – we should accept it that Erekle the Second is speaking about the fact of Agha Mohammad Khan destroying Tbilisi in 1795 – the tragedy that took place 13 years later. It is another fact that in 1782 Erekle the Second had no means to write about the events that would have taken place in 1795.And thus, we have come to the conclusion that the Italian translation of the letter by Erekle the Second prepared by the chancellery of the Emperor of Austria based upon the letter sent by Erekle, is not a single letter but a compilation of at least two letters written by him. We should give due significance to the fact that the mentioned Italian translation does not contain any specific personalized addressee but is addressed to the Emperor of Austria, not revealing to which of the Emperors it addresses namely. The translation does not contain any concrete date either. The article provides review of the purposes and goals that the ambassadorial mission of late fall of 1795 sent by the king Erekle to the Emperor of Austria as well as other delfs of the above mentioned letter that cause suspicion and that unambiguously confirm it that certain fragments of the letter are written in 1795 which on its part implies confirmation of the fact that in the late fall of the year 1795 there had place a diplomatic communication between the Austrian Empire and the Kingdom of Kartli and Kakheti.This latter fact abolishes the view that had been established in historiography up today that Erekle the Second unconventionally turned to Russia after Agha Mohammad Khan brought Tbilisi to earth in 1795.

175 Effect of age at calving on greenhouse gas emissions from simulated beef farms grazing four stockpiled forage species in late fall/early winter

The impact of age at first calving (2 versus 3 yrs) and type of forage species grazed in late fall/early winter on lifetime greenhouse gas (GHG) emissions from a cow-calf herd over an 8 or 9 yr period was examined. Farm simulations, based in Manitoba, Canada, were assessed using the Holos model to determine whole-farm GHG emissions for each scenario. The baseline herd consisted of 170 cows, 6 bulls, and their progeny which were sold at weaning, apart from herd replacements. Each simulation began with 207 newborn, female calves, with GHG emissions measured annually. From October to December, 1 of 4 stockpiled forages/forage mixtures were grazed: i) standing corn (COR), ii) tall fescue/meadow bromegrass (TFM), iii) orchardgrass/alfalfa (OGA), and iv) tall fescue/alfalfa/cicer milkvetch (TAC). All other feeding phase diets did not differ across all scenarios. Herd GHG emissions (Mg CO2e) were lower with heifers calving at 2 yrs (3,938 ± 71 Mg CO2e) versus 3 yrs (4,634 ± 72 Mg CO2e). Enteric methane (CH4) was the largest source of GHG emissions accounting for 66% of the total in both the 2- and 3-yr scenarios. Average enteric CH4 values were 3,820±61, 4,251 ± 68, 4,887±79, and 4,220 ± 68 Mg CO2e for simulations grazing COR, TFM, OGA, and TAC, respectively and were inversely related to total digestible nutrient (TDN) content of the forage mixtures with 72, 54, 45 and 55% TDN. Emissions were highest from OGA, the lowest quality forage, in both calving scenarios. Nitrous oxide emissions from livestock manure were the second highest contributing source, representing 15% of total emissions. Reducing age at first calving (2 versus 3 yrs) and providing higher energy forage in late fall/early winter reduced cow-calf GHG emissions. The adoption of management strategies such as reducing age at first calving and improving forage quality for extended grazing may reduce emissions from the cow-calf sector.

Editorial Note

To support our authors, reviewers and editors during the COVID-19 pandemic, the Spectrum Editorial Board has relaxed its timelines for the publication of this most recent issue (Issue 5). We are working with our authors on their Issue 5 submissions, and will publish continuously into Issue 5 over the remainder of Summer 2020. Please check back often for new articles, which will be added to Issue 5 as they are finalized. At this time, Issue 6 (Fall 2020) submissions are in the review process, and we anticipate publication in late fall, as we transition to a new editorial team. If you are an undergraduate or graduate student interested in joining the Spectrum editorial team for 2020-2021, we encourage you to submit your application here, by July 31, 2020. Peer Reviewer applications are accepted year-round - see the “Become a Reviewer” page for more information. We thank our authors, reviewers, and readers for their patience and continued support, and we hope you enjoy the latest issue! The Spectrum Editorial Board

Status of an Anomalous Population of Northern Long-Eared Bats in Coastal North Carolina

Although previously well-documented in the mountains of the Blue Ridge Ecoregion of western North Carolina, the northern long-eared bat Myotis septentrionalis was only recently discovered in coastal North Carolina in 2007. After being listed as a federally threatened species in April 2015, a five-year effort of mist net surveys and tracking was initiated to better understand the species’ distribution and behavior in eastern North Carolina. Since 2015, 163 healthy northern long-eared bats have been captured, and the documented range of the species has expanded from 4 coastal counties to 19. Captures occurred in all months of the year and mostly occurred in or adjacent to wetland forests. Captures were limited to the Middle Atlantic Coastal Plain Ecoregion of the state, and the maximum distance from the Atlantic Ocean or associated sounds was <87 km. Northern long-eared bats have not been documented in the Southeastern Plains or Piedmont Ecoregions of North Carolina. The lack of captures in the middle portion of the state suggests geographically disjunct populations of the species in North Carolina. During late fall–winter netting and tracking, northern long-eared bats were observed to be active throughout most of the winter and roosted in trees. Across three late fall–winter seasons from 2015–2018, 43 northern long-eared bats were tracked to 165 winter roost trees. Most (94.6%) winter roost trees occurred in wetland forest. Winter roost trees varied greatly in species, diameter-at-breast-height, status (dead or live), and type of roost (cavity, crack, crevice, or exfoliating bark). The species’ lack of long-term hibernation in coastal North Carolina documents a vastly different survival strategy as opposed to the well-documented hibernation strategy the species is known to use in the rest of its range. This portion of the state is nearly devoid of caves or mines suitable for hibernacula, but also experiences milder winters with low-level insect activity. During spring 2019, 21 reproductive females were captured in the northernmost portion of the coastal plain of North Carolina and tracked to 64 maternity roost trees. Pregnant females began to be captured on April 25, and juveniles began to be captured on June 16. This indicates that pups are likely born in late May in the northern portion of the coastal plain of North Carolina, but birth likely occurs earlier in the southern portion of the coastal plain of the state. Most (92.2%) maternity roost trees occurred in wetland forest. Maternity roost trees varied greatly in species, diameter-at-breast-height, status, and type of roost. Swab samples collected during late fall–winter from 198 bats from species susceptible to white-nose syndrome provided no evidence of Pseudogymnoascus destructans. Since northern long-eared bats in coastal North Carolina are active most of the winter and not dependent upon caves or mines for hibernation, they are likely not susceptible to white-nose syndrome. With the species in sharp decline elsewhere due to white-nose syndrome, this coastal North Carolina population and a recently discovered coastal South Carolina population may serve as a refugium for the species.