2017 ASHS Annual Conference

One of the most widely promoted benefits of green roofs is storm water management. This includes reduction in storm water runoff and reduction in peak flow rate, but also improvements in runoff water quality. There is however some disagreement about weather ornamental green roofs are a source or sink of nutrients. Agricultural green roofs have been less widely studied, but research has shown that they can be a source of many macro and micro nutrients. The status of a roof as a source or sink depends on many factors including nutrient management practices. In some cases, nutrient management practices don’t match up with plant needs, resulting in leaching of the excess nutrients provided. This is a known issue in traditional agriculture and horticulture but has not been studied in other urban agricultural settings.