“Intercropping: An Approach to Sustainable Agriculture”
Growing a single crop in a field can deplete soil health and compromise agricultural productivity. Intercropping--the practice of growing two or more crops simultaneously on the same plot of land—may be a more sustainable alternative.
Intercropping mixes often include pulse crops which can fix their own nitrogen, a critical nutrient. These crops may reduce fertilizer demand without damaging yields, resulting in economic and environmental benefits. Additionally, intercropping may support a more diverse soil microbial community, a key component of healthy and resilient soils.
As the global population continues increasing, sustainable agricultural practices will be critical to support the rising demand for food, fuel, and fiber. This research assesses measures of soil health such as nutrient status, resource allocation, and microbial diversity in intercropped fields in southern Idaho. The results of this work will help to assess the merit of intercropping as a sustainable production practice.
Torrey Stephenson is a master's student in Environmental Science studying under Dr. Zachary Kayler
“Genotypic and Phenotypic Determinants that Enable Methylorubrum extorquens to Survive Formaldehyde Stress”
A population of genetically identical bacteria growing in the same condition exhibits phenotypic diversity. This allows bacteria to evolve strategies to tolerate stress, such as formaldehyde - a metabolic toxin. Formaldehyde tolerance has been studied in Methylorubrum extorquens, an organism that can grow on methanol, which is oxidized to formaldehyde during its metabolism.
This tolerance ability is heritable. However, a knowledge gap is the genetic basis for tolerance in some but not all members of the same population. Twenty-three genes were implicated in the tolerant population, 22% of which are involved in protein misfolding.
We hypothesize that handling protein misfolding contributes to tolerance and there could be a link between these genes and tolerance. This will be tested via genetic modifications to some of these genes and single-cell analysis. The outcome will expand our knowledge of the behavioral responses of bacteria to environmental stress based on their genetics.
Akorede Seriki is a doctoral student in Biological Sciences under Dr. Christopher J. Marx
“Irrigation of historical drylands: Consequences on soil microbes & antibiotic resistance”
Forty percent of global landmass are drylands, supporting 1.8 billion people in developing countries - partially through irrigated agriculture. While desert farming can be helpful for food security, there are ecological consequences. By irrigating soil once too dry to support crops, the environmental conditions for organisms living within the soil are rapidly changing.
Soil bacteria produce antibiotics as an ecological, competitive strategy. In turn, antibiotic resistance can evolve within the soil community. Inherently, dryland soils have less abundant antibiotic resistance genes (ARGs) than more moist environments. But by manipulating environmental conditions through irrigation, soil community antibiotic interactions may shift. This presents a potential pathway for greater antibiotic resistance exposure to humans because ARGs have been shown to transfer from soil to crop.
This research focuses on the transformation of semi-arid lands into lush, irrigated fields and the effects on soil bacteria, with implications to human health.
Amanda Bauer is a master’s student in Soil and Water Systems under Dr. Michael Strickland
“Evaluation of Variant Calling Programs for Analyzing Diversity Between U.S. Sheep”
Accurately identifying genomic DNA sequence variation is a critical step in discovering causal variants for biological traits and genetic diseases. Several programs can be used to detect variants, but these programs use different quality metrics that may affect call accuracy. Our aim was to compare the performance of two commonly used variant detection programs (GATK HaploptypeCaller and Freebayes) and call variants from fourteen U.S. sheep breeds.
These results showed that Freebayes called an average of 6.11% more SNPs than GATK HaplotypeCaller. From the variants called we clustered the breeds based on genetic similarity which corresponds to different physical characteristics. Furthermore, the variants identified can be used to help determine the genetic cause for the different physical characteristics. This research provides a basis for understanding the genetic diversity within and between breeds and future insight into selection pressures of US breeds.
Morgan Stegemiller is a doctoral student in Animal Physiology studying under Dr. Brenda Murdoch