Nutrient Recycling in Urban Agriculture
The project has three primary objectives with performance targets connected to each.
1. COMPOST HEAT SYSTEMS- Begin compost heating projects at three sites- Re-Vision House in Dorchester MA, Solidarity Farm Project in Orange MA, and the New Entry Farm Project in Lowell.
2. AQUAPONIC SYSTEMS- Linked aquaculture and plant production will be operational at Re-Vision House and two women in the Internship program will be trained in aquaculture system design and management, as well as performance data collection and analysis.
3. EDUCATION AND OUTREACH- contact other organizations, farms and school groups to provide wider access to our projects and research information, while identifying additional sites for compost and aquaculture projects.
1. COMPOST HEAT- Work is underway at these three sites to create and operate compost-heating systems for greenhouse production although each is at a different stage of the process due to specific conditions and challenges encountered. An additional site, VanGaurden Farm in Dover, MA will also be operational by spring. The early onset and severe cold of this winter has delayed the full implementation of new compost heating systems at Re-Vision, VanGuarden and Seeds of Solidarity Farm, but projects should be on track by the early spring at these three Massachusetts farm sites. The experience of the past fall 2002/ winter 2003 highlights some of the limitations of the approach on farms that are dependant on off-farm sources of equipment and materials for their compost production. At Re-Vision House, upgrades to the greenhouse and the linked composting system have been designed and partially constructed. These improvements have been to the greenhouse shell, the composting pad, and internal aerated growing beds that filter the exhaust from the composting system. Redesign of the external composting pad and heat recovery system have been completed. Last season’s compost has been moved to a nearby urban garden managed by Re-Vision House that needed intensive supplement of nutrient and organic matter to be productive in the coming growing season. The acquisition of more than 200 cubic yards of fresh leaves and manure from the Boston Parks Department and formation of these materials into a heating windrow is underway as I write this report and will be completed by February 1, 2003. At Seeds of Solidarity Farm work has been on-going since April 2002 to develop a compost greenhouse. Design of the greenhouse heating system has been completed and a new 30’ x 96’ steel framed gothic poly greenhouse has been erected on a newly leveled pad. They have installed in-soil growing beds that are to be compost heated. The greenhouse will be in part heated using a blend of imported manures and wood chips in an exterior composting windrow. Progress on construction of the composting pad was suspended by early and heavy snowfall and unseasonably cold weather. An existing 27 x 48’ greenhouse with an internal composting chamber is being upgraded and the farm plans to use it during seedling season. Modifications to the compost bin and closure system will result in greater thermal efficiency, easier loading and better composting. The compost materials include fresh manure and commercial food waste from local businesses. At The VanGuarden Farm, compost heat will be used primarily for production of spring vegetable seedlings and salad greens, and to produce a weed-free high-nutrient compost in a controlled setting in time for the growing season. Grower Chris Yoder will be using a small PTO manure spreader and 24 hp tractor to form compost windrows, top dressed with finished compost and soil blend to prevent plant-damaging loss of ammonia into the greenhouse atmosphere. Feedstock materials for the compost will include horse manure with softwood shavings for bedding and fresh poultry (caged layer) manure. At the New Entry Farm Program we are in the planning stage of a hydronic compost heat system (it would use heated water rather than air) for greenhouse production. Bruce Fulford has been working with farm manager Amy Carrington to design this system. The farm is making improvements to their 80’ hoop-house and should be ready to start working on the compost system this spring. They have plenty of materials on site- soft-wood chips and animal manure which could be utilized for their compost-heat system.
2. AQUAPONIC SYSTEMS- As we complete the first 10 months of this project, we are behind where we projected we would be at this point. This is because we have had a number of set-backs to the aquaculture program at Re-Vision House in the past six months, including fish loss, system problems, staff changes and difficulties with technical assistance. Yet, as I write this in late January, things are moving forward again and we are very optimistic about meeting production goals and getting back on track with educational efforts. All of the difficulties we have had have been great learning experiences for staff and interns and we have incorporated these lessons into improved systems and program structure. The Internship program has been on-going through the SARE project period, so women in the program have been taking care of 1,000 fish, working on the systems, collecting water quality and production data and analyzing that information. What our team has learned is that there are many variables that affect an aquaculture ecosystem and it is difficult to achieve the proper balance for healthy water and fish. We lost more fish than we produced in 2002, although plant production was stable, and we lost our aquaculture manager in September, a key person in the aquaculture program at Re-Vision House. It took us until December to get things moving forward, with the hiring of Adam Hoelper as the new Aquaculture Manager at Re-Vision House, the re-design/re-building of our systems and the implementation of a collaboration with Keith Wilda, Aquaculture Specialist with UMASS Extension. Since December, we have installed two new integrated systems for rearing fish from hatchlings to 3-4 inches in size. These tanks would each hold a cohort of 500-700 fish. Each system utilizes biological filtration and each incorporates a different hydroponic system for basil production. These systems have been designed and built by Keith and Adam to replace the previous systems that were extremely problematic- (they were tall barrels connected to gravel beds where basil was growing) These systems had inadequate filtration, poor water flow, poor fish growth, etc. The construction is now 90% complete and we plan to have plants and fish growing by early February. The next step is to make improvements to the large grow-out tank on the first-floor greenhouse so that we will be ready to move fish down there in a few months and incorporate a third type of hydroponic production. Although we will not be able to harvest fish before April, we plan to harvest 1,000 pounds, or more, of fish per year beginning in the fall of 2003. Beyond production, we currently have three interns, Margaret Bulport, Rosetta Hainsworth and Shahonda Levon, working with the aquaculture program. All of them have been in the program since the fall and they have been active in all aspects of the project- from feeding fish and trouble-shooting to tearing apart and rebuilding the systems to water quality monitoring and fish weighing. Once the new systems are operational, these interns will be able to track levels of ammonia and its breakdown products at different points in the water flow cycle, along with other indicators to evaluate nutrient recycling and filtration systems and compare plant growth in different hydroponic systems.
3. EDUCATION & OUTREACH- Our project team has been engaged in a variety of outreach activities. To date, outreach has concentrated more on the compost component of this project because our aquaculture project has focused on building a successful production system and program at Re-Vision House before we expand those efforts out into the community. Re-Vision House has established relationships with other organizations and educational programs in our area and the aquaculture project is planning to create links to existing and potential school-based aquaculture programs, as well as to other local fish production initiatives, such as the one at The Center for Family, Work and Community, based in Lowell, that works with the Asian immigrant community. Once our systems are operating successfully, we plan to bring groups through for tours and other on-site programs. Bruce Fulford, of City, Soil & Greenhouse has been doing outreach about compost-heating to both farmers and other potential project participants, as well as the general public. Slide presentations were made at Massachusetts NOFA conference in Belchertown on August 11, 2002, at the BioCycle Composting & Organics Recycling Conference in Portland ME on August 19, 2002, and at the winter MA-NOFA conference in Barre MA January 25, 2003. He has also made visits to a number of farms with an interest in using compost-heat. We are working on a SARE Project link to the Re-Vision Farm website, where we can post data, observations, information and results from each site and communicate with classes, programs and individuals who are interested in this work.
Impacts and Contributions/Outcomes
It is too soon to report on any specific results. By summer we will have sufficient data on the aquaculture system at Re-Vision House and compost-heat systems at Re-Vision, VanGaurden and Seeds of Solidarity farm to evaluate their effectiveness for nutrient recycling and production. At that point we will also have some educational collaborations to document.
City Soil & Greenhouse Co.
285 Cornell Street
Boston, MA 02131
Office Phone: 6174698164
Re-Vision House Inc.
38 Fabyan Street
Dorchester, MA 02124
Office Phone: 5082078345
Western MA Center for Sustainable Aquaculture