Thesis--University of Wisconsin--Madison. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 152-165).

The subject of soil absorption is an old one, dating back to before 1850. The nature of soil absorption has been, and still is, a puzzle, in spite of the vast amount of work that has been done in the last few years. Two theories have been held as the cause of the absorption. The first is that the absorption is chemical, the compounds being changed into insoluble ones by double decomposition. The second is that the salts or radicals are physically held, that is, adsorbed by the soil particles. These theories have been held separately and combined.

No description available.

Food insecurity and nutrition are two of the biggest challenges facing our society. Urban agriculture can help address these challenges, though lack of awareness about opportunities for engagement and degraded soils are two barriers that could prevent people from realizing the benefits that these operations can provide. Soils in urban areas are often highly degraded due to development activities and lack the structure and microbial life needed to sustain healthy, productive plants. Many lifelong habits such as healthy eating and engagement in community gardening are best established during young adulthood. Graduate school is a particularly unique time period, as many students are living on their own for the first time with modest incomes and some have young families that are particularly vulnerable to food insecurity. Consequently, the first objective of this project was to identify which barriers, if any, Purdue graduate students face when purchasing and consuming fresh produce and participating in local urban agriculture initiatives as Purdue’s campus and much of the surrounding area are characterized as food deserts by the USDA. We also sought to determine how the COVID-19 pandemic influenced food access and motivations for healthy eating and community garden engagement. To answer these questions, we distributed a voluntary 33 question online Qualtrics® survey to all Purdue graduate students via mass email blast. Results indicate that many Purdue graduate students face individual and structural barriers to accessing fresh fruits and vegetables. International respondents, in particular, were particularly vulnerable to structural barriers. Not having access to a personal vehicle appears to be the primary predictor of who was most vulnerable, especially during the pandemic. Results also indicate that students are interested in participating in local urban agriculture initiatives, but most are unaware of their existence. Students indicated that e-mails were the best method for increasing awareness and engagement. The second objective of this study was to determine whether leaf mold compost could improve the health and productivity of degraded urban soils. In addition, we aimed to determine whether the leaf compost could better support a beneficial microbial inoculant to further enhance crop productivity, as well as the extent to which plant genotype moderates these beneficial plant-soil-microbial relationships. To answer these questions, leaf compost was obtained from a local grower and applied to experimental plots at the Purdue University Farm. Two tomato varieties, Wisconsin 55 and Corbarino, were inoculated with Trichoderma harzianum T-22 or a sterile water control, and transplanted into the field trials. 15 Survival following transplanting, vigor, disease ratings and the yield and quality of tomato fruit were quantified over the course of two growing seasons. Results indicated that several measures of soil health were significantly increased in compost-amended soils and the health and productivity of tomato plants greatly improved. The microbial inoculant dramatically reduced transplant stress, especially in Wisconsin 55. Other more subtle differences among the tomato varieties indicated that urban agriculture systems could be improved through varietal selection. These studies highlight the fact that graduate students are not immune to food insecurity and proper nutrition and they are interested in connecting with urban agriculture initiatives to address these challenges. Pairing of the two groups could prove to be a successful mutualistic symbiosis as graduate students provide the enthusiasm and manpower that urban gardens need while urban gardens offer access to low-cost fresh produce that many graduate students desire. Leaf mold compost can aid in these initiatives by providing a cost-effective approach to improve the health and productivity of urban soils and crops, while at the same time providing further benefits such as reduced accumulation of valuable carbon sources in municipal landfills. Results like these provide stark evidence that agriculture, particularly urban agriculture, can continue to improve access to nutritious foods through green initiatives and innovations.