Conservation management practices reduce non-point source pollution from grazed pastures.

Producers in Northwest Arkansas and globally need alternative management practices to ensure long-term sustainable and economical use of poultry litter, which is an abundant source of valuable carbon (C), nitrogen (N) and phosphorus (P). Project objectives were to measure the efficacy of conservation management practices (i.e., pasture aeration and subsurface litter incorporation) to reduce nutrient runoff compared to poultry litter surface applications from small watersheds under rainfed and grazed conditions. Watersheds (0.23 ha each) were assigned a treatment [pasture aeration, subsurface litter incorporation, or surface application of litter (positive control)] on a Leadvale (fine-silty, siliceous, thermic Typic Fragiudult) silt loam. Poultry litter was applied annually to each watershed from 2007-2012. Over the 4-yr study period, runoff loads of NO3-N, total nitrogen (TN), soluble reactive phosphorus (SRP), and total phosphorus (TP) varied per conservation practice (P ≤ 0.05). Specifically, average annual loads of NO3-N, TN, SRP, and TP loads were reduced 49, 42, 28, and 35% following pasture aeration and by 78, 72, 55, and 59% from subsurface applying poultry litter, relative to surface applications, respectively. Greatest annual N loads and runoff corresponded with surface poultry litter applications, followed by pasture aeration, with subsurface incorporation of poultry litter resulting in lowest (P ≤ 0.05) TN and NO3-N loads. Overall, subsurface incorporation of poultry litter and pasture aeration are two promising conservation practices for reducing non-point source pollution in watersheds with nutrient imbalances. Further work needs to be done on factors influencing the efficacy of these conservation practices under rainfed conditions, as well as the economic feasibility of these conservation agricultural practices.

A 16-Year-Old Boy With Cough and Fever in the Era of COVID-19.

A 16-year-old white boy with a history of chronic lung disease of prematurity, cough-variant asthma, and incidental lung nodules presented to the emergency center in spring 2020 with acute onset dry cough, shortness of breath, and fever. An initial history, gathered from his mother because of the patient's respiratory distress, revealed no recent travel. However, his mother is a health care worker at a hospital, and sick contacts included ongoing contact with a friend with cold-like symptoms. He had a variety of animals at home, including a dog, cats, fish, rodents, and reptiles. He had a history of vaping tobacco products >6 months ago. Fever and respiratory symptoms were associated with fatigue, chest tightness, abdominal pain, and myalgias. On examination, he was ill appearing and had tachycardia, tachypnea, borderline hypoxia with an oxygen saturation of 91% on room air, diminished breath sounds at the lung bases, and unremarkable abdominal examination results. A chest radiograph was consistent with the lung examination, revealing bilateral lower lobe hazy infiltrates. He showed initial improvement for 48 hours with antibiotics, intravenous fluid resuscitation, oxygen via nasal cannula, albuterol, and prednisone. Subsequently, he worsened with persistent high fever, increasing respiratory distress with pulmonary findings, and severe persistent epigastric pain, which added a layer of diagnostic complexity. As this patient's clinical course evolved and further history became available, pulmonary medicine and infectious diseases services were consulted to guide diagnostic evaluation and treatment of this patient early in the era of coronavirus disease 2019.

Long-term effects of grazing management and buffer strips on phosphorus runoff from pastures fertilized with poultry litter.

Phosphorus (P) runoff from pastures can cause accelerated eutrophication of surface waters. However, few long-term studies have been conducted on the effects of best management practices, such as rotational grazing and/or buffer strips on P losses from pastures. The objective of this study was to evaluate the long-term effects of grazing management and buffer strips on P runoff from pastures receiving annual (5.6 Mg ha-1 ) poultry litter applications. A 14-yr study was conducted on 15 small watersheds (0.14 ha) with five treatments: hayed (H), continuously grazed (CG), rotationally grazed (R), rotationally grazed with an unfertilized buffer strip (RB), and rotationally grazed with an unfertilized fenced riparian buffer (RBR). Runoff samples were collected using automatic samplers during runoff events. Average annual runoff volumes from H (40 mm yr-1 ) and RBR (48 mm yr-1 ) were lower than CG and RB, which were both 65 mm yr-1 , and from R (67 mm yr-1 ). Rotational grazing alone did not reduce P loads compared with continuous grazing (1.88 and 1.71 kg P ha-1 for R and CG, respectively). However, compared with CG, total P losses from RB pastures were reduced 36% with unfertilized buffer strips (1.21 kg P ha-1 ), 60% in RBR watersheds with unfertilized fenced riparian buffer strips (0.74 kg P ha-1 ), and 49% by converting pastures to hayfields (0.97 kg P ha-1 ). Hence, the use of unfertilized buffer strips, unfertilized fenced riparian buffer strips, or converting pastures to hayfields are effective best management practices for reducing P runoff in U.S. pasture systems.

Correction to: Are soils beneath coniferous tree stands more acidic than soils beneath deciduous tree stands?

Fig. 1. was amended to reduce the size of the map and improve formatting of the manuscript. The authors claim this amendment does not affect the information being conveyed.

Are soils beneath coniferous tree stands more acidic than soils beneath deciduous tree stands?

In 2008, the Mulberry River, a National Wild and Scenic River, was listed as impaired due to low pH (below pH 6.0). Over the last 50 years, the volume of conifers in the Ozark region has increased 115% since 1978 which may result in the acidification of nearby aquatic ecosystems. The objective of this study was to determine if differences exist in soil and litter chemical properties between deciduous and coniferous tree stands. Aboveground litter (n = 200) and soil (n = 400) at 0- to 5- and 5- to 15-cm depths were collected at paired deciduous and coniferous stands at 10 locations within the Mulberry River watershed and analyzed for a suite of chemical parameters. There were no differences (P > 0.05) in several measures of soil acidity between deciduous and coniferous stands. Litter collected from the coniferous stands was more acidic than deciduous litter (4.4 vs 4.7; P < 0.05). Cation exchange capacity, exchangeable Ca and Mg, and water-soluble P and Mg contents differed (P < 0.05) by stand and depth. Cation exchange capacity and exchangeable Ca and Mg were greatest in the 0- to 5-cm depth interval of the coniferous stands. Water-soluble P and Mg contents were greatest within the 0- to 5-cm depth interval which did not differ (P > 0.05) between stand but were greater than the 5- to 15-cm depth interval. Although limited to the top 15-cm of soil, the similarity in soil acidity between stands suggests that conifer growth may not be a substantial source of acidity to the Mulberry River.

Phosphorus Leaching from Soil Cores from a Twenty-Year Study Evaluating Alum Treatment of Poultry Litter.

Adding alum to poultry litter is a best management practice used to stabilize P in less soluble forms, reducing nonpoint-source P runoff. However, little research has been conducted on how alum additions to litter affect subsequent leaching of P from soil. The objective of this study was to evaluate the effects of alum-treated versus untreated poultry litter on P leaching from soil cores receiving long-term poultry litter applications. Two intact soil cores were taken from each of 52 plots in a long-term study with 13 treatments: a control, four rates each of untreated and alum-treated litter (2.24, 4.49, 6.72, and 8.96 Mg ha), and four rates of ammonium nitrate (65, 130, 195, and 260 kg N ha). One core from each plot received the same fertilizer as for the previous 20 yr, whereas the other was unfertilized in the study year, resulting in a total of 25 treatments. Cores were exposed to natural rainfall, and P leaching was measured for 1 yr. The average soluble reactive P concentrations in the leachate varied from 0.16 to 0.44 mg P L in fertilized alum-treated cores, whereas leachate from cores fertilized with untreated litter ranged from 0.40 to 2.64 mg P L. At the highest litter rate (8.96 Mg ha), alum reduced total dissolved P and total P concentrations in leachate by 83 and 80%, respectively, compared with untreated litter. These results indicate that alum additions to poultry litter significantly reduced soluble and total P fractions in leachate.

Morbidity and mortality of coagulase-negative staphylococcal sepsis in very-low-birth-weight infants.

BACKGROUND: Coagulase-negative staphylococci (CoNS) are the most common cause of late-onset sepsis in the neonatal intensive care unit (NICU) and usually require vancomycin treatment. Our objective was to determine whether CoNS are associated with neonatal morbidity and mortality. METHODS: This was a retrospective cohort study of very-low-birth-weight (VLBW, ≤ 1500 g) infants from 1989 to 2015. Exclusion criteria were major congenital anomaly or death within 72 h. CoNS was considered a pathogen if recovered from ≥ 2 cultures, or 1 culture if treated for ≥ 5 days and signs of sepsis were present. Logistic regression was used to examine factors associated with morbidity and mortality. RESULTS: Of 2242 VLBW infants, 285 (12.7%) had late-onset sepsis. CoNS (125, 44%), Staphylococcus aureus (52, 18%), and Escherichia coli (36, 13%) were the most commonly recovered organisms. In multivariate analysis, CoNS sepsis was not associated with mortality [OR 0.6 (95% CI 0.2-2.6)), but sepsis with other organisms was [OR 4.5 (95% CI 2.6-8.0)]. CoNS sepsis was associated with longer hospitalization but not risk for bronchopulmonary dysplasia, intraventricular hemorrhage, or retinopathy of prematurity. CONCLUSION: CoNS sepsis was not associated with mortality or morbidities other than length of stay. These findings support vancomycin-reduction strategies in the NICU.