Progress 11/18/13 to 09/30/17

Outputs
Target Audience:Urban agriculturists, Urban planners, Biogeochemists, Urban ecologists. Changes/Problems:The only problems we encountered related to backlogs in service labs where we had our samples analyzed. This pushed back our date for project completion. All samples have been analyzed and we are now submitting our final report. What opportunities for training and professional development has the project provided?Throughout the project, grad student Yoshi Harada worked closely with both the professional staff at the Grange and 3 cohorts of summer interns working at the farm. In addition, Whitlow and Harada gave an evening presentation to an NYC stakeholder audience at the Grange about this project. Finally, farm manager and Grange President Benjamin Flanner has giver 3 guest lectures to Whitlow's undergraduate Urban Ecosystems classes explaining the details of optimizing resource use to students with interests in urban farming. How have the results been disseminated to communities of interest?We have one published paper, a second accepted for publication, and 2 other papers to be submitted to peer reviewed journals. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Water retention of soil The current formulation of Rooflite had the lowest moisture retention capacity. Adding biochar, coir and compost increased water retention, indicating that there is room to improve water management by engineering soil properties. Farm hydrology Drainage from the farm was highly variable. During the 2015 growing season, cumulative drainage was nearly twofold precipitation inputs. Nearly all of this loss was due to irrigation. In comparison, in 2016 drainage from the farm was only 96% of precipitation. Over the entire study period, drainage exceeded precipitation by 11%, so the Grange appears to be a net source of water entering the NY sewer system. In order for a rooftop farm to incorporate the ecosystem service retaining precipitation in order to mitigate flooding and reduce combined sewer overflows, soil water storage must be improved and supplemental irrigation must be reduced. Nitrogen Balance N dep in 2014-15 was ca 9 kg ha-1 y-1 compared to 4.81 kg ha-1 y-1 determined by the NADP. This excess is possibly due to a gas fired powered plant within 300 m of the roof. Cumulative N loss to roof drains was 11.4 X the rate of atmospheric deposition. This is likely due to a combination of mineralization of organic nitrogen in the soil mix and irrigation which increased drainage from the farm and hence total loading. The flow-weighted average NO3 concentration was 10.74 mg l-1, which slightly exceeds the NYS water quality standard of 10 mg l-1. Heavy Metals Green roofs are touted as improving air quality by capturing airborne particulates. If these particulates include heavy metals, they could affect the safety of vegetables grown in rooftop farms. Over the course of the study, the maximum concentration of heavy metals in the soil remained below 54% of the NYDEC guidelines. The maximum concentration of lead, an element of primary concern, was 177mg kg-1 soil. In comparison, maximum concentration of lead in/on unwashed samples of leaf lettuce was 0.58 mg kg-1, which exceeds the FDA's allowance of 0.005 mg kg-1 fresh weight. Because Pb has very low solubility at the pH of the farm soil, it is extremely unlikely that the Pb we detected was taken up by the plants and is probably the result of atmospheric deposition. Rinsing the lettuce before consumption would in all likelihood remove Pb from the leaves. Not returning composted above ground portions of crops to the soil is advisable to avoid a cycle of recontamination of metals deposited from the atmosphere.

Publications

• Type: Book Chapters Status: Published Year Published: 2017 Citation: Harada, Y., TH Whitlow, NL Bassuk and Jonathan Russell-Anelli. 2017. pp 275-294. Biogeochemistry of rooftop farm soils. Urban Soils. R. Lal and BA Stewart, eds. CRC Press, Boca Raton.

Progress 10/01/15 to 09/30/16

Outputs
Target Audience:The general target audiences include urban farmers and practitioners of sustainable agricultural practices, soil scientists, biogeochemists, urban ecologists, urban planners, and urban hydrologists. The specific target audience where the research is being conducted is the Brooklyn Grange management staff. Changes/Problems:We have encountered delays in the processing of N samples due to personnel changes at our collaborating lab at Boston University. In addition, we detected a potential artifact in the analysis of samples for inorganic elements at the Cornell Nutrient Analysis Laboratory and we are in the process of re-analyzing samples from 2015. We requested an extension on the grant until September, 2017 and should be able to accomplish all of our goals within the timeframe. What opportunities for training and professional development has the project provided?Yoshiki Harada, PhD candidate working with Whitlow on this project, met weekly with the Grange farm management team, farmers and management trainees during the growing season to discuss findings, identify any problems, and revise management practices to alleviate these problems. In addition to these routine meetings, we have engaged in the following: Farm Meeting on Resource Management 01 (September 03, 2016) Farm Meeting on Resource Management 02 (January 13, 2017) Farm Meeting on Soil Design for the New Farm (Sunset Park, NYC) (August 20, 2016) How have the results been disseminated to communities of interest?In addition to on-farm information sharing (Grange practitioners) and the chapter in Advances in Soil Science (the broader scientific audience), we have reached stakeholders through the following events and news media: Cornell Atkinson Center for a Sustainable Future Outreach Event (June 29, 2016) On-farm interview with PeriodiCALS (Cornell University News Media) (February 10, 2017) Presentation at Grey to Green Conference, Toronto, proposal accepted (May 09, 2017) What do you plan to do during the next reporting period to accomplish the goals?We will continue regular interactions with the Grange and stakeholder audiences and will participate in both national and international conferences (see Grey to Green Conference, above). The most significant effort will be devoted to publishing at least 3 papers in peer reviewed journals. These will address a range of topics on the biogeochemistry of rooftop farms and how these influence the larger urban ecosystem.

Impacts
What was accomplished under these goals? 1. Quantify the levels nitrogen, potassium and phosphorous in the artificial rooting medium used at the Grange. a. Quantify the inputs of N and heavy metals to the system from the soil medium and organic fertilizer supplements. b. Quantify the atmospheric deposition of nitrogen and heavy metals to the farm. 2. Quantify the outputs of these elements in leachate from the farm and harvested produce. 3. Quantify the water inputs from precipitation and supplemental irrigation. 4. Model water lost from the farm as evapotranspiration and estimate leachate volume as the difference between water received and ET. 5. Develop approaches to optimize water and nutrient management for a rooftop farm. During FY 2016, we have continued to monitor, sample and analyze water, nutrient and heavy metal inputs and outputs from the Brooklyn Grange Farm located at the Brooklyn Navy Yard. Our analysis of nitrate and ammonia N was delayed due to personnel changes in our partner lab at Boston University, so analysis is ongoing and will be completed by late winter, 2017. We have also developed and tested several alternative soil mixes with the intent of identifying a mix that retains more water and leaches less nitrogen to the municipal storm sewer. One mix looks especially promising and will be used on a new rooftop farm during the 2017 growing season.

Publications

• Type: Book Chapters Status: Accepted Year Published: 2017 Citation: HARADA, Y., Whitlow, T.H., Bassuk, N.L., Russell-Anelli, J. (2017). Biogeochemistry of Rooftop Farm Soils, In Advances in Soil Science, Taylor & Francis, N.Y (accepted)

Progress 10/01/14 to 09/30/15

Outputs
Target Audience:Brooklyn Grange management team: Gwendolyn Schantz, Benjamin Flanner Brooklyn Grange Staff and Interns Brooklyn Grange Customers NYC Dept. of Public Health: Henry Spliethoff The broader urban farming and gardening community Urban Ecologists and Biogeochemists Changes/Problems:We solved the equipment problems from last year and encountered no major problems during this funding cycle. What opportunities for training and professional development has the project provided?We had daily on site contact with Ben Flanner, manager of the Brooklyn Navy Yard farm and appraised him of our findings. We also participated in weekly meetings with the Grange staff. How have the results been disseminated to communities of interest?In addition to the publication in Environmental Pollution, we gave oral presentations at the annual meetings of the Ecological Society of America (Biogeochemistry of the Brooklyn Grange, An Urban Rooftop Farm) and the American Geophysical Union (Dispersion and Deposition of Fine Particulates and Heavy metals in the Urban Atmosphere). We also held a roundtable discussion among the collaborators on the Cornell campus in November, 2015. What do you plan to do during the next reporting period to accomplish the goals?Characterize soil media for upcoming season's field trials. Conduct greenhouse experiment to determine water retention characteristics for 4 alternative growing media. Continue to monitor precipitation, weather and irrigation. Maintain equipment as needed. Swap resin columns and soil bags every 6 weeks. Sample and characterize soil medium, fertilizer supplements, and selected vegetable crops (a leafy vegetable, a fruit and a root). Swap resin columns and soil bags every 6 weeks. Analyze for N and heavy metals. Conduct lab experiments to determine N mineralization rates. Present at the national meeting of the Ecological Society of America. Prepare manuscripts for publication.

Impacts
What was accomplished under these goals? During the 2015 growing season we designed, fabricated and installed a V notch weir in a downspout receiving runoff from the roof in order to directly measure the volume of water leaching from the Farm. We continued to collect and analyze nutrient and water fluxes from the farm. We estimate that atmospheric inputs of N are ca 6.4 kg/ha/yr and that more than 500 kg/ha/yr of N leaches from the Farm, far exceeding typical leachate losses from in ground cropping systems. Based on our estimates, the Farm modified its irrigation schedule to apply smaller, more frequent irrigation in order to reduce leaching. We also determined that the artificial growing medium used on the roof drains very rapidly, indicating that there is an opportunity to develop a medium with greater moisture holding capacity that would reduce the leaching rate. We have initiated greenhouse experiments to test alternative mixes this winter so that test plots can be installed for the 2016 growing season.

Publications

• Type: Journal Articles Status: Published Year Published: 2015 Citation: Tong, Z., T. H. Whitlow, A. Landers, B. Flanner. 2015. A case study of air quality above an urban roof top vegetable farm. Environmental Pollution o3/2015; 201:141-149. DOI:10.1016/j.envpol.2015.02.026.

Progress 11/18/13 to 09/30/14

Outputs
Target Audience: Brooklyn Grange management team: Gwendolyn Schantz, Benjamin Flanner Brooklyn Grange Customers NYC Dept. of Public Health: Henry Spliethoff The broader urban farming and gardening community Urban Ecologists Changes/Problems: We had problems with wireless data transmission from sensor units to the server. Volunteer help at the farm moved equipment without our permission or prior knowledge. We have been able to deal with these problems as they occurred but it requires a nearly constant presence on the site during the growing season. What opportunities for training and professional development has the project provided? Provided technical assistance and advice for rationalizing water and nutrient application. During the growing season, we had daily on site contact with Ben Flanner, manager of the Brooklyn Navy Yard farm and apprised him of our findings. Presented early findings at a conference on the Cornell Biogeopchemistry IGERT at the Cary Institute How have the results been disseminated to communities of interest? Reported water use rates to the Grange staff on a daily basis and helped develop management strategies for next growing season. We also provided technical reports and feedback on issues as they emerged, including an assessment of the health risk posed by atmospheric deposition of heavy metals. Presented early findings at a conference on the Cornell Biogeopchemistry IGERT at the Cary Institute for Ecosystem Studies in Millbrook, NY. What do you plan to do during the next reporting period to accomplish the goals? Characterize soil media for upcoming season. Conduct greenhouse experiment to determine water retention characteristics for 4 alternative growing media. Continue to monitor precipitation, weather and irrigation. Maintain equipment as needed. Swap resin columns and soil bags every 6 weeks. Sample and characterize soil medium, fertilizer supplements, and selected vegetable crops (a leafy vegetable, a fruit and a root). Swap resin columns and soil bags every 6 weeks. Analyze for N and heavy metals. Conduct lab experiments to determine N mineralization rates. Present at the national meeting of the Ecological Society of America.

Impacts
What was accomplished under these goals? Acquired and tested equipment, assembled ion exchange columns and bags, fabricated bulk collectors. Installed meters and met station at the Brooklyn Navy Yard farm. Monitored irrigation, precipitation, and ET. Sampled and characterized soil medium, fertilizer supplements, and harvested vegetables as needed. Analyzed for N and heavy metals. Characterized end of season soil. Analyzed samples and meteorological data. Reported findings to Grange, develop management strategies for next growing season.

Publications