No abstract

Urban agriculture is a global and growing pursuit that can contribute to economic development, job creation, food security and community building. It can, however, be limited by competition for space with other forms of urban development, a lack of formalized land use rights and health hazards related to food contamination. The use of green roof technology in urban agriculture has the potential to alleviate some of these problems, without adversely affecting the benefits provided by urban agriculture. It would not only enable the use of land for development and agriculture, but may also facilitate the formation of formal space and water use agreements, and enable redistribution of ground-level resources among urban farmers. This could decrease the use of contaminated land and water at ground level and alleviate health concerns. Before green roof technology can be incorporated into urban agriculture on a larger scale, installation costs must be reduced, roof weight limitations should be assessed, and appropriate management practices should be developed which will ensure that the benefits of green roofs, such as energy savings and storm water management, are still provided to urban communities.

No abstract

Rooftop vegetable gardening is a production system in urban agriculture based on green roof technology. To broaden the scope of this practice, the use of relatively shallow substrate depths must be explored, since most existing flat roofs are unable to support much added weight. Three growing systems-a green roof, raised green roof platforms, and in-ground-were evaluated for vegetable and herb production over three growing seasons (2009)(2010)(2011). Tomatoes ( Solanum lycopersicum), green beans ( Phaseolus vulgaris), cucumbers ( Cucumis sativus), peppers ( Capsicum annuum), basil ( Ocimum basilicum), and chives ( Allium schoenoprasum) were studied because of their common use in home gardens. All plants, except pepper, survived and produced biomass in all growing systems and yielded crops large enough for analysis in 2009 and 2010. Overall, yields and basil biomass were higher and of better quality in-ground during 2009, the only year irrigation was applied, and similar on the roof and platforms. Variability in success was partially due to annual weather variation with the greatest impact on cucumber. Yields of chive, a perennial crop, were not affected by growing system after the first year. 465 Downloaded by [University of Colorado at Boulder Libraries] at 03:55 03 January 2015 466 L. J. Whittinghill et al.Results suggest that, with proper management, vegetable and herb production in an extensive green roof system is possible and productive.

A number of benefits have been attributed to green roofs including food production. However, little research has been done to quantify the effects of rooftop farming practices on green roof benefits. The impact of rooftop farming on stormwater runoff is especially important, considering the different nutrient management practices on ornamental and agricultural green roofs. In order to advance knowledge on this potential impact, runoff water quality from a fullscale rooftop farm in Long Island City, Queens, New York, was monitored and compared to runoff water quality from a suite of extensive, sedum green roofs, also located in New York City. Samples of runoff water and rain were collected and analyzed for pH, electrical conductivity,

No abstract

As urban populations increase, there is growing interest in developing innovative technologies, sustainable urban farming practices, policy measures, and other strategies to address key barriers in urban agriculture that impede improved food security and sustained urban livelihoods. We surveyed forty urban farmers and gardeners (growers) in Louisville, Kentucky, for base-level information to assess their agricultural practices and the various factors or key barriers that could influence such practices. Secondary objectives were identifying areas where practices could be improved, and identifying opportunities for research, outreach, and incentives for urban growers to transition to more sustainable and higher-yielding practices. The majority of these urban growers were white females, were more diverse than Kentucky farmers, and attained a higher degree of education than Kentucky residents as a whole. Most were engaged in urban agriculture for non-commercial reasons, and 11% were full-time urban growers operating farms for profit. Smaller farms were less likely to be operated for profit or have farm certifications than medium-sized or larger farms (Chi-squared = 14.459, p = 0.042). We found no significant differences among farm sizes in terms of whether growers rented or owned the land they were on (Chi-squared = 9.094, p = 0.168). The most common sustainable practices recorded were composting (60%), crop rotation (54%), polyculture (54%), organic farming (49%), and low or no-till (46%). The least common practices were alley cropping (5%), plasticulture (3%), and hydroponics (3%). Small farms were less likely to use crop rotation than medium-sized or large farms (Chi-squared = 13.548, p = 0.003), and farms responding to the survey in the latter part of the data collection were less likely to use compost than expected based on responses from the early part of data collection (Chi-shared = 5.972, p = 0.014). Challenges faced by these growers included limited space, accessibility to farm certification, presence of pests and diseases, and lack of record keeping and soil testing for fertility and contamination. Our study documents the need for more farm certification, education, outreach, training, research, investment, innovative ideas and solutions, collaboration among stakeholders, and better access to land through favorable urban policies and local support.

No abstract