Life Sciences Commons^™

Soil And Compost Tea: A New Restoration Technique?, Carol E. Day

Master's Theses and Doctoral Dissertations

Historically, prairie restorations have lacked the plant diversity seen in remnant prairies. Most restoration practices focus on reestablishing the plant community but overlook the soil microbial community even though microbes are critical to habitat functioning. Developing techniques that increase soil microbes in prairie restorations is critical to ensuring diverse restored habitats. We compared how microbial communities differed between remnant and restored prairie sites. We also investigated if soil and compost teas could be used to reintroduce microbes to restored prairie soil and if the teas affected native plant establishment. We found significant differences in the levels of bacterial taxa between …

Vermicompost Versus Traditional Compost Amendments Leads To Different Soil Health Outcomes In A Mediterranean Vineyard, Elizabeth L. Luck

Master of Science in Environmental Sciences and Management Projects

Compost application has become a common practice in vineyard management to increase soil and crop health, however, the environmental externalities such as greenhouse gas emissions (GHG) from cropping systems that utilize organic fertilizers, such as compost, is uncertain. Vermicompost, which is compost created through the digestion of organic matter by earthworms, and its related ‘extract’ are commonly thought to provide more benefits for soil and crop health compared to standard compost. However, organic fertilizers such as vermicompost, vermicompost extract, and compost have not been compared in their effects on soil health in Mediterranean vineyards. In this two-year study, I assessed …

Organic Amendments Alter Soil Hydrology And Belowground Microbiome Of Tomato (Solanum Lycopersicum), Taylor Readyhough

Graduate College Dissertations and Theses

Manure-derived organic amendments are a cost-effective tool that provide many potential benefits to plant and soil health. For example, amendment applications may increase soil fertility, improve soil structure, stimulate microbial activity, and suppress plant pathogens. Yet, responses to these applications may have unintended consequences. Inherent variability in the physical, chemical, and biological characteristics of these materials can result in inconsistent outcomes observed after their application. These differences are manifested in plant growth, soil physiochemical properties, and soil microbial community composition. Popular manure-derived organic amendments include dairy manure compost and poultry manure pellets. Dairy manure is an abundant resource on many …

Effectiveness Of Windrow Composting Methodology In Killing A Thermo-Tolerant Species Of Salmonella During Mortality Composting, Spencer Gabriel Myers

Master's Theses

In a large agricultural operation, such as the one at Cal Poly San Luis Obispo, disposal of deceased animals is an immense issue. The cost of transporting and rendering every dead animal is inhibitory to the general function of the agricultural operations and their thin budget. Therefore, we propose that composting mortalities could be an economical alternative. Composting is a recognized method for taking animal waste products along with carbon waste and turning it into a pathogen-free, nutrient-rich topsoil. Carcass composting is in fact performed in other countries and states to varying degrees of success. However, the California EPA limits …

Agriculture In The Classroom Farm Day Lesson Plan, Tessa Nicole Thompson

Agricultural Education and Communication

Nontraditional educational programs have been proclaimed desirable by many teachers, and proven effective through data collection and feedback (Coombs and Ahmed, 1974). Of the more popular unconventional educational programs, outside learning activities are commonly implemented as they are not only advantageous to students, but to teachers as well (Cengelci, 2013; Knoblock, 2008). Though nontraditional, much thought must be put into creating lesson plans for these educational programs.

El Dorado County’s Agriculture in the Classroom program utilizes nontraditional outdoor learning activities to conduct “Farm Day.” This lesson plan, created for Farm Day, is to teach third graders the importance of composting …

Compost Land Management And Soil Carbon Sequestration, Kylene A. Hohman

Senior Honors Projects, 2010-2019

Extensive fossil fuel burning has released carbon dioxide into the atmosphere. Under proper ecological conditions plants convert atmospheric carbon dioxide into stable soil organic matter, a natural and efficient means of mitigating climate change. In the symbiotic relationship between mycorrhizae and plants, mycorrhizae provide plants with essential nutrients in exchange for carbon sugars leaked from the plants. Mycorrhizae convert carbon sugars to an exudate called glomalin, a protein that assists in developing soil aggregates composed of sand, silt, and clay. These aggregates, called humus, store carbon for hundreds of years under healthy ecological conditions. Compost prompts soil microbes to aerobically …

Ecological Dynamics In Compost-Amended Soils And The Resulting Effects On Escherichia Coli Survival, Anya Cutler

Graduate College Dissertations and Theses

Escherichia coli (E. coli) are common and typically innocuous copiotrophic bacteria found in the mammalian gut microbiome. However, over the past 30 years, pathogenic E. coli have been responsible for several outbreaks of foodborne illness linked to contaminated produce. The introduction of Escherichia coli to an agricultural soil, via contaminated water, compost, or raw manure, exposes the bacterium to a medley of ecological forces not found in a mammalian gut environment. This study assesses a variety of abiotic and biotic soil factors that influence the ability of an "invasive" copiotrophic coliform bacterium to survive in compost-amended agricultural soil. The study …

Biological Indicators Of Compost-Mediated Disease Suppression Against The Soilborne Plant Pathogen Rhizoctonia Solani, Lynn Fang

Graduate College Dissertations and Theses

Compost can suppress soilborne plant pathogens that cause significant damage on globally important food crops. However, reports of plant pathogen suppression are inconsistent likely because there are no established standards for feedstock material, application rate, and maturity age upon application. Excellent results can be achieved in greenhouse trials, but field applications are much less reliable. Disease suppression occurs through the activity of biocontrol organisms (direct antagonism), and general microbial competition. Biocontrol species are hypothesized to colonize the pile during the curing phase, but single species may not be as important as microbial consortia. Substrate composition during maturation may give rise …

An Evaluation Of Vermicompost As A Fast-Acting Nitrogen Amendment To Mitigate Nitrogen Deficiencies In Organic Vegetable Production, Peter Dalton Austin

Graduate College Dissertations and Theses

For sustained production, organic agriculture depends on plant needs being synchronized with the release of nutrients from organic amendments during decomposition within the soil. Because decomposition is strongly dependent on soil moisture and temperature, nutrient needs may not always be met as planned or synchronous with plant need. Unlike conventional agriculture, fast acting amendments are not readily available. Much of the evidence that vermicompost benefits crop production comes from studies on seed germination and production of starts in greenhouses. Yet, there is a dearth of information derived from field studies. Soil, soil and water nitrogen, plant development, and marketable yield …