P-FLUX: A phosphorus budget dataset spanning diverse agricultural production systems in the United States and Canada.

Quantifying spatial and temporal fluxes of phosphorus (P) within and among agricultural production systems is critical for sustaining agricultural production while minimizing environmental impacts. To better understand P fluxes in agricultural landscapes, P-FLUX, a detailed and harmonized dataset of P inputs, outputs, and budgets, as well as estimated uncertainties for each P flux and budget, was developed. Data were collected from 24 research sites and 61 production systems through the Long-term Agroecosystem Research (LTAR) network and partner organizations spanning 22 U.S. states and 2 Canadian provinces. The objectives of this paper are to (a) present and provide a description of the P-FLUX dataset, (b) provide summary analyses of the agricultural production systems included in the dataset and the variability in P inputs and outputs across systems, and (c) provide details for accessing the dataset, dataset limitations, and an example of future use. P-FLUX includes information on select site characteristics (area, soil series), crop rotation, P inputs (P application rate, source, timing, placement, P in irrigation water, atmospheric deposition), P outputs (crop removal, hydrologic losses), P budgets (agronomic budget, overall budget), uncertainties associated with each flux and budget, and data sources. Phosphorus fluxes and budgets vary across agricultural production systems and are useful resources to improve P use efficiency and develop management strategies to mitigate environmental impacts of agricultural systems. P-FLUX is available for download through the USDA Ag Data Commons (https://doi.org/10.15482/USDA.ADC/1523365).

Effect of inorganic or organic selenium supplementation on reproductive performance and tissue trace mineral concentrations in gravid first-parity gilts, fetuses, and nursing piglets.

The objective of this experiment was to evaluate 2 supplemental forms of Se on reproductive performance and tissue trace mineral concentration in fetus and first-parity gilts during pregnancy and their progeny. Crossbred gilts (n=100) were selected at 183±2.7 d and 137±10 kg BW and fed a common diet. After 1 mo, 8 gilts were sacrificed to establish baseline liver Se concentration and the remaining 92 gilts allotted to receive Se (0.3 mg/kg diet) as inorganic Se (Na2SeO3) or a Se supplement that contains organoselenium compounds (Sel-Plex; Alltech Inc., Nicholasville, KY). At 267±5.7 d (171±11 kg), gilts were estrus-synchronized and bred. Gilts were then slaughtered at defined time points throughout gestation (d 0, 43, 58, 73, 91, 101, or 108 of gestation; n=6 to 12 gilts/time point). A week before the expected farrowing day, 10 pregnant gilts (5 from each treatment) were moved to farrowing crates and monitored. Two pigs from each litter were randomly selected and euthanized at d 0 (within 2 h after birth; nursing deprived), 7, 14, and 21 from each litter. During the gestation phase, maternal liver, and fetal body and liver were collected for determination of trace mineral concentration by inductively coupled plasma mass spectrometry. Total number of fetus, crown-rump length, and corpora lutea of gilts were recorded as well. During the lactation phase, pigs (without liver and gastrointestinal tract) and associated liver were analyzed for Se concentration. The results demonstrated that the source of Se generally did not affect the maternal reproductive traits and fetal characteristics. Also, the source of Se supplemented to the maternal diet did not, in general, affect Cu, Fe, Mn, or Zn concentrations in the tissues evaluated other than the observation of a greater maternal liver Mn content (P<0.01) in gilts fed Sel-Plex and a greater amount of Fe accumulated in the entire litter (P<0.01) in gilts fed Sel-Plex. However, with regard to Se concentrations, Se in fetal body, fetal liver, and maternal liver were greater (P<0.01) when Sel-Plex was fed. Postnatal pigs from gilts fed Sel-Plex had greater (P<0.05) Se retention in body and liver with similar growth performance during the 21-d period. The results demonstrate Se form differences wherein Sel-Plex is associated with greater Se accumulation in both maternal and fetal tissues.

Coal fly ash basins as an attractive nuisance to birds: parental provisioning exposes nestlings to harmful trace elements.

Birds attracted to nest around coal ash settling basins may expose their young to contaminants by provisioning them with contaminated food. Diet and tissues of Common Grackle (Quiscalus quiscala) nestlings were analyzed for trace elements to determine if nestlings were accumulating elements via dietary exposure and if feather growth limits elemental accumulation in other tissues. Arsenic, cadmium, and selenium concentrations in ash basin diets were 5× higher than reference diets. Arsenic, cadmium, and selenium concentrations were elevated in feather, liver, and carcass, but only liver Se concentrations approached levels of concern. Approximately 15% of the total body burden of Se, As, and Cd was sequestered in feathers of older (>5 days) nestlings, whereas only 1% of the total body burden of Sr was sequestered in feathers. Feather concentrations of only three elements (As, Se, and Sr) were correlated with liver concentrations, indicating their value as non-lethal indicators of exposure.