Urban Agriculture Act of 2018 This bill establishes an Office of Urban Agriculture and Innovative Production within the Department of Agriculture (USDA) to encourage and promote urban, indoor, and other emerging agricultural practices. The bill also makes farmers developing innovative agricultural production practices and using traditional practices in innovative areas such as urban areas eligible for various USDA loan and grant programs. USDA must work with producers to mitigate the presence of contaminants in soil by taking several specified actions, such as establishing a coordinated soil testing protocol, coordinating and conducting research, and providing soil assessment and remediation technical assistance. The bill establishes various USDA pilot projects, including programs to: establish urban and suburban county committees, increase municipal compost and food waste reduction activities; and strengthen marketplace links between healthy food consumption, good environmental practices, and direct public health outcomes.