Soil Health Indicators and Sustainable Practices on Indy Urban Farms: An Investigation of Ecosystem Functionality

Urban agriculture is capable of restoring ecosystem services like food production, recreation, and clean soil and water to cities. Urban farms in particular can help relieve pressure for areas with limited food access, also known as food desserts. This is especially important to the community of Indianapolis because the city is tied for the most food desert areas within a U.S. metropolitan area. To help a community, an urban farm must have healthy, nutrient rich soils. Nitrogen is the most limiting nutrient for plants when it comes to growth and development. Plants cannot produce nitrogen; they acquire the mineral by external inputs (mulch, manure, fertilizer etc.) or internal N-fixing bacteria. If biological nitrogen fixation increases, the immediate and long-term nitrogen supply would increase, leading to an increase in ecological sustainability. In addition to nitrogen, carbon is another mineral that can tell researchers a lot about the health of a soil system. Organic carbon is a major factor for plants, it promotes the structure, of soil, and it also acts as a pH buffer. The goal of this project is to test if common urban farming management processes are increasing the health of the ecosystem at the level of the soil. To analyze this, we looked at multiple different health indicators including: organic matter composition, percentage of carbon and nitrogen, carbon nitrogen ratio, soil pH, and bulk density of the soil samples collected. It is hypothesized that soil samples retrieved from actively farmed land will have increased health indicators. If this is true, farmed samples will be more similar to naturally established ecosystems than controlled, unfarmed samples with regard to the indicators tested. The soils used were collected from multiple sites around the city. Because of this, the data collected can be analyzed in a larger context with the goal of helping farms across Indianapolis restore fundamental ecosystem functions and improve overall sustainability