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Garden Plot (garden + plot)
Selected AbstractsToxicity of nitrogenous fertilizers to eggs of snapping turtles (Chelydra serpentina) in field and laboratory exposuresENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2007Shane Raymond de Solla Abstract Many reptiles oviposit in soil of agricultural landscapes. We evaluated the toxicity of two commonly used nitrogenous fertilizers, urea and ammonium nitrate, on the survivorship of exposed snapping turtle (Chelydra serpentina) eggs. Eggs were incubated in a community garden plot in which urea was applied to the soil at realistic rates of up to 200 kg/ha in 2004, and ammonium nitrate was applied at rates of up to 2,000 kg/ha in 2005. Otherwise, the eggs were unmanipulated and were subject to ambient temperature and weather conditions. Eggs were also exposed in the laboratory in covered bins so as to minimize loss of nitrogenous compounds through volatilization or leaching from the soil. Neither urea nor ammonium nitrate had any impact on hatching success or development when exposed in the garden plot, despite overt toxicity of ammonium nitrate to endogenous plants. Both laboratory exposures resulted in reduced hatching success, lower body mass at hatching, and reduced posthatching survival compared to controls. The lack of toxicity of these fertilizers in the field was probably due to leaching in the soil and through atmospheric loss. In general, we conclude that nitrogenous fertilizers probably have little direct impacts on turtle eggs deposited in agricultural landscapes. [source] Soil survival of Escherichia coli O157:H7 acquired by a child from garden soil recently fertilized with cattle manureJOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2006A. Mukherjee Abstract Aims:, This investigation was conducted to determine the survival of a naturally occurring Escherichia coli O157:H7 in garden soil linked to a sporadic case of E. coli O157 infection in Minnesota. Methods and Results:, The presence and viability of E. coli O157:H7 was monitored in manure-contaminated garden soil for several weeks. Bacterial isolates were characterized using PCR and pulsed-field gel electrophoresis (PFGE). Isolates obtained from the patient and the garden plots during this investigation had indistinguishable PFGE patterns and had the same virulence factors (stx1, stx2, eaeA, ehxA). The E. coli O157:H7 levels obtained from the garden plots declined gradually for a period of 2 months, and on day 69 only one garden plot of four had detectable levels of pathogen. All plots were negative on day 92. The rate of decline in the soil samples stored at 4°C was faster compared with soil samples that remained in ambient conditions, and in refrigerated storage E. coli O157:H7 could not be detected after 10 days. Conclusions:,E. coli O157:H7 strains can survive on manure-amended soil for more than 2 months, and this survival could be reduced by low temperature. Significance and Impact of the Study:, This is one of the few reports that have investigated the survival of a proven virulent strain in naturally contaminated soil samples. This case stresses the importance of avoiding the use of raw cattle manure to amend soil for cultivation of foods, including soils in residential garden plots. [source] | ||||||||||