Riverine Flux of Metals from Historically Mined Orefields in England and Wales     

Mayes  W. M.  Potter  H. A. B.  Jarvis  A. P. 《Water, air, and soil pollution》2013,224(2):1-14

Water, Air, &; Soil Pollution - The flux of metals at the tidal limits of major rivers are an important metric of freshwater contaminant transfer to marine habitats, reported in Northeast...  相似文献   

Air pollution injury of potato in Michigan     

W. J. Hooker  T. C. Yang  H. S. Potter 《American Journal of Potato Research》1973,50(5):151-161

A disorder of Michigan potatoes tentatively called speckle leaf is associated, in part, with air pollution injury. The disease is characterized by reduced yields following early vine maturity, premature vine death, and yellowing of the lower leaves. Necrotic spots developed on the upper surface of leaves, followed by bronzing, and upward leaf rolling. Severely affected leaves became chlorotic and remained attached to the stem. Potato plants were grown in two plastic houses through which was blown either ambient field air or ambient air filtered through activated charcoal. Plants grown in the plastic house receiving ambient air developed symptoms similar to nearby field plants. Plants grew normally in filtered ambient air and remained free of speckle leaf and air pollution injury symptoms. The potato varieties Haig, Norchip, and Superior were most sensitive, Sebago was intermediate, and Kennebec and Katahdin were most tolerant. Tobacco plants in ambient non-filtered air developed symptoms typical of ozone injury. Bean leaves became bronzed with brown necrotic flecks on both surfaces, and severely affected leaves dropped. Neither tobacco nor bean was affected in the filtered air.  相似文献   

Summer cover crop impacts on soil percolation and nitrogen leaching from a winter corn field   总被引：1，自引：0，他引：1  

R. Muñoz-Carpena  A. Ritter  D.D. Bosch  T.L. Potter 《Agricultural Water Management》2008,95(6):633-644

The impacts of a leguminous summer cover crop (sunn hemp; Crotalaria juncea) on nitrogen leaching from a corn (Zea mays L.) field was evaluated by direct measurements of soil water content and nitrogen balance components, complemented by direct and inverse modeling as an exploratory tool to better understand water flow and nitrogen balances in the soil. Water and nitrogen inputs and outputs were measured during winter corn production in an experimental field located in the south Miami-Dade basin in southern Florida (USA). Data from the last two seasons (2001-2002 and 2002-2003) of a 4-year study are presented. The field was divided into six 0.13 ha plots. One-half of the plots were rotated with sunn hemp (CC plots) during the summer while the remaining plots were kept fallow (NC plots). Sweet corn management was uniform on all plots and followed grower recommended practices. A numerical model (WAVE) for describing water and agrochemical movement in the soil was used to simulate water and nitrogen balances in both types of plots during the corn seasons. The hydrodynamic component of WAVE was calibrated with soil water data collected continuously at three depths, which resulted in accurate soil water content predictions (coefficients of efficiency of 0.85 and 0.91 for CC and NC plots, respectively). Measured components of the nitrogen balance (corn yields, estimated nitrogen uptake, and soil organic nitrogen) were used to positively assess the quality of the nitrogen simulation results. Results of the modeled water balance indicate that using sunn hemp as a cover crop improved the soil physical conditions (increase in soil water retention) and subsequently enhanced actual crop evapotranspiration and reduced soil drainage. However, nitrogen simulation results suggest that, although corn nitrogen uptake and yields were slightly higher in the CC plots than in the NC plots, there were net increases of soil N content that resulted in increased N leaching to the shallow aquifer. Therefore, the use of sunn hemp as cover crop should be coupled with reductions in N fertilizer applied to the winter crop to account for the net increase in soil N content.  相似文献   

Strengths and limitations of Bacillus thuringiensis galleriae for managing Japanese beetle (Popillia japonica) adults and grubs with caveats for cross‐order activity to monarch butterfly (Danaus plexippus) larvae     

Carl T Redmond  Lindsey Wallis  Matthew Geis  R Chris Williamson  Daniel A Potter 《Pest management science》2020,76(2):472-479

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Digestion of soybean meal proteinin the equine small and large intestine at various levels of intake     

E.B. Farley MS  G.D. Potter PhD  P.G. Gibbs PhD  J. Schumacher DVM  M. Murray-Gerzik MS 《Journal of Equine Veterinary Science》1995,15(9)

Four mature pony geldings weighing an average of 134 kg and fitted with ileal cannulas were used in a 4×4 Latin square experiment to determine the digestibility of soybean meal (SBM) protein in different segments of the equine digestive tract at various levels of protein intake. A complete basal corn-based diet was supplemented with SBM to formulate four diets with increasing crude protein. The diets, labeled A (basal), B, C and D, contained 4.9%, 9.5%, 14% and 16.5% crude protein (as fed), and provided nitrogen, per feeding, at approximately 44.8, 84.3, 123.9 and 146.3 mg/kg of body weight, respectively. Chromic oxide was fed to measure ileal flow and fecal excretion. Digestion and absorption of nitrogen was determined from changes in nitrogen: chromium ratios, and true digestion of nitrogen was computed by regression analysis. True total tract digestion of nitrogen was 95.7%. True digestibility of nitrogen in the small intestine over the range of linearity was 72.2%, while true digestibility of nitrogen reaching the large intestine was 89.8%. These data indicate that the protein in SBM was almost completely digested in the equine digestive tract. Furthermore, approximately 75% of the digestible protein was digested prececally when nitrogen intake was less than approximately 125 mg/kg of body weight per feeding.  相似文献   

The significance of small vs large intestinal digestion of cereal grain and oilseed protein in the equine     

P.G. Gibbs PhD  G.D. Potter PhD  G.T. Schelling PhD  J.L. Kreider PhD  C.L. Boyd DVM   《Journal of Equine Veterinary Science》1996,16(2):60-65

Mature ponies fitted with permanent ileal cannulas were used in two 3×3 Latin square experiments to quantify prececal, postileal and total tract digestion of N. In trial 1, corn, oats and sorghum were each fed with coastal Bermuda grass hay in 75:25 ratios. Apparent prececal digestibilities were similar (P>.05) and averaged 46.6%. By-difference procedures were employed to calculate digestibility of the cereal grain N only and apparent prececal N digestibility averaged 57.1%. In trial 2, a basal corn and hay diet was supplemented with cottonseed meal and soybean meal. Apparent total tract N digestibilities were similar (P>.05) across treatments, and prececal digestibility averaged 45.6%. By-difference calculations were used to determine digestibility of SBM and CSM N alone. Apparent prececal digestibility of SBM was 52.5% and was lower (P<.05) than 81.2% for CSM. It is possible that inadequate or excessive heat treatment of SBM affected enzymatic digestion. True digestibility of total rations fed in trial 2 was estimated by linear regression of nitrogen digested on nitrogen intake or N presented to the large intestine. True N digestibility of diets containing SBM and CSM was 54.7% and 69.4%, respectively.  相似文献   

Ecology and management of earthworm casting on sports turf     

Paige E Boyle  Michael D Richardson  Mary C Savin  Douglas E Karcher  Daniel A Potter 《Pest management science》2019,75(8):2071-2078

Earthworm activity is beneficial in most natural and agricultural systems, but excessive earthworm casting is a problem on sports fields worldwide. Expulsion of soil‐rich earthworm fecal matter, or casts, as mounds of soil on the turf canopy can muddy the surface, reduce photosynthesis, and lead to thinning, weed invasion and surface softening. Casts affect ball roll on sports fields, cause fouling of maintenance equipment, and dull mower blades. Build‐up of cast material on reel mower units can affect height and quality of cut. Casting activity is dependent on environmental conditions such as soil texture, temperature, moisture, pH, and organic matter. Response to environmental conditions varies by species. Management options are limited, because no pesticides are specifically labeled for earthworm control at this time, and cultural control methods such as soil modification, turfgrass clipping removal, and sand topdressing have limited and inconsistent efficacy. Products containing plant‐derived saponins and irritants show promise for earthworm management. Pest management practices to mitigate excessive earthworm casting will likely need to be species‐specific, but limited knowledge of earthworm identification by end‐users further inhibits the efficacy of control measures. © 2019 Society of Chemical Industry  相似文献   

Blood buffering in sedentary miniature horses after administration of sodium bicarbonate in single doses of varying amounts     

C.D. Corn BS  G.D. Potter PhD  T.W. Odom PhD  O.C. Jenkins PhD 《Journal of Equine Veterinary Science》1993,13(10)

Blood acid-base and electrolyte status was studied in four sedentary Miniature Horses treated with 200, 300, 400 and 500 mg of sodium bicarbonate (NaHCO₃) per kg of body weight (BW). Arterial blood was collected before treatment with NaHC0₃ and each hour for 5 h after treatment. All treatments resulted in an increase in blood pH, bicarbonate (HCO₃⁻) concentration and base excess (BE) by 1 h post-dosage, which continued through the 5th hour (P < .05). Treatment with 200 mg NaHC0₃/kg BW resulted in less elevated blood HCO₃⁻ concentrations (P < .03) and BE values (P < .01) when compared to the other treatments. Following dosing with NaHCO₃, plasma Na⁺ concentrations increased among all treatments but declined to initial values by 3 h post-treatment. The 200 mg NaHCO₃/kg BW dosage resulted in the smallest increases in plasma Na⁺ concentrations (P < .03). Both plasma K⁺ and Ca⁺⁺ concentrations were lower (P < .05) among all treatment groups 1 h post-dosage but returned to initial values by 5 h and 3 h posttreatment, respectively, with no differences (P >.05) among treatments. All NaHCO₃ dosages increased blood buffering capacity as indicated by increased blood pH, HCO₃⁻ concentration and BE. Maximum blood pH, HCO⁻₃ concentration and BE was reached using a dosage of 300 mg NaHCO₃/kg BW. Also, all treatments altered the plasma electrolyte concentrations.  相似文献   

Inflammation and mediators of lung injury     

R W Leid  K A Potter 《Veterinary Clinics of North America: Food Animal Practice》1985,1(2):377-400

This article covers the major pathways involved in acute inflammation in mammals with a particular emphasis on their relevance to the bovine species. It focuses on the potential and proven contributions of these systems to pulmonary defense mechanisms and lung pathology. The article also points out what is known and where gaps in our information exist as well as promising areas for research in the coming years.  相似文献   

Renal vascular hamartomas in a captive coyote     

B R LeaMaster  K A Potter  J S Green  R A Woodruff 《Journal of the American Veterinary Medical Association》1984,185(11):1392-1393

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