You Don’t Have To Go Home But You Carrot Stay Here: Root-Knot Nematode Biological Control in Carrots

Root-knot nematodes cause tens of billions of dollars in damages annually in agricultural production. The enormous economic losses brought about by nematodes, combined with the downsides to current methods for handling them, have led to an increased focus in understanding natural plant defense mechanisms and finding alternative methods to lessen the damage done by root-knot nematodes. Endophyte biocontrol agents such as Trichoderma harzianum have shown promise in reducing nematode damage. Recent studies have demonstrated that soil management practices and plant genotype can influence endophyte community structure, but it is unclear whether such differences influence susceptibility to nematode damage. This study seeks to better understand these dynamics by quantifying how differences in endophyte community structure influence nematode (Meloidgyne incognita) infection and plant performance in three carrot varieties that are susceptible, moderately resistant, or highly resistant to nematodes. The treatments are 1) unamended control, 2) Trichoderma harzianum, 3) endophytes from an organically farmed field, and 4) endophytes from a conventionally farmed field. Preliminary results indicate that carrot genotype significantly impacts carrot biomass, and carrots grown in the presence of endophytes from organically farmed soils have greater biomass than carrots grown in the other treatments. Analysis of endophyte community structure and nematode infection are ongoing

Characterization of Microbial Populations in Landfill Leachate

In the United States, municipal solid waste (MSW) landfills remain a potential mining source of recoverable materials, including but not limited to critical, precious, and rare earth metals found in electronic waste. This is possible due to collectible leachate that filters through MSW landfills, carrying metals, nutrients of value, and microbes—some of which may hold key metal bioleaching properties—within. The purpose of this study is to begin analyzing leachate from MSW landfills in the American Midwest to understand the composition of microbial communities within these landfills. Landfill leachate samples sourced in northern Indiana, representing the landfill process during unique times of operation, were used in this study. Culture-independent studies, utilizing both DNA extraction and PCR for communities of archaea, bacteria, and fungi, were performed on leachate samples. Current results indicate that in 6 of 11 samples, both bacterial and archaeal DNA were likely present, while 1 additional sample yielded only amplified archaeal DNA, and 1 more yielded only amplified bacterial DNA. This implies the presence of both archaea and bacteria which may hold metal bioleaching capabilities. Follow-up research will involve analyzing other Midwestern leachate samples, identifying landfill microbes with metal bioleaching properties, and developing a way to integrate these microbes with membrane filtration and other physico-chemical processes to improve recovery of important metals from leachate

Analysis of Integrated Farming Systems in Eastern Nebraska

Agroecosystems in the U.S. are beset with social, ecological and environmental problems as large industrial farming methods are edging out small family-sized farms and replacing ecological services provided by biodiversity with synthetic inputs and practices. While many of the benefits of smaller diversified or integrated farming systems are well known, farm producers need a concrete model that shows how integration is possible and with what crops. The objective of this study was to investigate some of these supplemental farm activities, and identify and evaluate whether they were compatible given the time and resource constraints of a typical eastern Nebraska farm. These activities included stalk grazing, cabbage, and herbaceous floral perennial production. Detailed enterprise budgets of the alternative cropping systems were entered into a linear programming model to determine the optimal acreage allocation given the various alternatives to maximize net returns. The compatible operations increased producer profitability while theoretically making use of synergistic relationships to decrease reliance and application of off-farm inputs, thus improving \u27sustainability\u27. Advisors: James Brandle and Chuck Franci

Abstract

The members of the Committee appointed to examine the dissertation of LORI A. HOAGLAND find it satisfactory and recommend that it be accepted

Does the Corn/Soybean Farmer Have Time for Alternative Crops? [ABSTRACT]

Diversification of traditional row-crop farming in the Corn Belt is seen as advantageous in providing a wider economic base, decreasing economic risk associated with the link between commodity grain and cattle, increasing net farm income, and increasing biodiversity in the region. As farm size has increased to provide sufficient farm income, farm operations during the critical planting and harvesting windows are seen as limits to additional on-farm enterprises