Plant Sciences Commons^™

Detecting Shifts In Soil Microbial Community Structure And Function Post Landspread Of Manure Or Biosolids Containing Antimicrobial Chemicals, Kelly Lehnert, Sharon A. Clay, Susan Gibson, Volker Brozel

Agronomy, Horticulture and Plant Science Faculty Publications

Soil microbial diversity and community interaction play an indispensable role in 2,4-dichorophenoxyacetic acid (2,4-D) herbicide degradation. The addition of manure or municipal waste biosolids through landspreading may alter soil community structure and function if these materials contain antimicrobial chemicals like chlortetracycline (CTC), administered in livestock feed to promote animal growth and health or tetracycline (TET) utilized in human health. In this study, soil applied with manure collected from pigs fed standard CTC levels was compared to soil containing manure from control pigs fed no CTC, and a comparison of soil applied with biosolids containing TET or without TET to distinguish …

The Potential Role Of Probiotics In Reducing Poverty-Associated Infections In Developing Countries, Kingsley C. Anukam

Kingsley C Anukam

Probiotics are defined by the Food and Agricultural Organization/ World Health Organization as “live microorganisms which when administered in adequate amounts confer a health benefit on the host” [1]. The potential benefits of their use have not been adequately investigated, especially in the developing world. Japan introduced Yakult, a probiotic fermented food drink in 1935, and in the Northern hemisphere, research and use of probiotics has gained an unprecedented momentum in the last decade [2]. Use of probiotics is not uncommon in Europe [3], but in many developing countries use of probiotics in its present definition is a foreign concept. …

The Effect Of Residue C:N Ratio On The Turnover Of N And C In Various Soil Organic Matter Fractions, Ana B. Wingeyer

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Identifying soil organic matter (SOM) fractions that contribute to soil indigenous nitrogen (N) supply and understanding their turnover under different management constitute necessary tools toward an efficient N use. The objectives of this study were: i) trace the endpoint of carbon (C) flux from residue inputs into SOM; and ii) asses the role of the light fraction (LF), mobile humic acid (MHA) fraction and calcium humate (CaHA) fraction as N sources for heterotrophic decomposition of fresh plant residues with contrasting C:N ratio. A long-term aerobic soil incubation was carried out on ¹⁵N-labeled soil samples from Lincoln and Mead, NE. …

Soil Microbial Community Response To Hexavalent Chromium In Planted And Unplanted Soil, Ioannis Ipsilantis, Mark S. Coyne

Plant and Soil Sciences Faculty Publications

Theories suggest that rapid microbial growth rates lead to quicker development of metal resistance. We tested these theories by adding hexavalent chromium [Cr(VI)] to soil, sowing Indian mustard (Brassica juncea), and comparing rhizosphere and bulk soil microbial community responses. Four weeks after the initial Cr(VI) application we measured Cr concentration, microbial biomass by fumigation extraction and soil extract ATP, tolerance to Cr and growth rates with tritiated thymidine incorporation, and performed community substrate use analysis with BIOLOG GN plates. Exchangeable Cr(VI) levels were very low, and therefore we assumed the Cr(VI) impact was transient. Microbial biomass was reduced …

Downy Mildew In Vineyards, Diana Fisher, Andrew Taylor, Colin Gordon, Peter Magarey

Bulletins 4000 -

Downy mildew, caused by Plasmopara viticola, is a major fungal disease of grapevines that originates from North America. This disease was first detected in a commercial Western Australian vineyard in October 1998 and has since been found in most grape growing areas within the State. It is found in all other grape growing areas of Australia.

Plasmopara viticola is specific to grapevines (e.g. Vitis vinifera), although not all Vitis spp. are susceptible. The American rootstock species and hybrids are less susceptible or are resistant (refer to ‘Varietal susceptibility’). Other species of downy mildew, such as those found on …

In The Heat Of The Law, It's Not Just Steam: Geothermal Resources And The Impact On Thermophile Biodiversity, Donald J. Kochan, Tiffany Grant

Donald J. Kochan

Significant research has been conducted into the utilization of geothermal resources as a ‘green’ energy source. However, minimal research has been conducted into geothermal resource utilization and depletion impacts on thermophile biodiversity. Thermophiles are organisms which have adapted over millions of year to extreme temperature and chemical compositions and exist in hot springs and other geothermal resources. Their ability to withstand high temperatures makes them invaluable to scientific and medical research. Current federal and California case law classify geothermal resources as a mineral, not a water resource. Acquisition of rights to develop a geothermal resource owned or reserved by the …