Progress report for ONE22-427
Project Information
This project seeks to:
- Monitor and capture heat from the exhaust of active reverse aerated compost piles.
- Demonstrate that this heat will make it more affordable and sustainable to operate a greenhouse in a cold climate.
- Capture carbon dioxide, ammonia, methane and nitrous oxide in a biofilter instead of allowing them to escape into the atmosphere.
- Record and analyze nutrient data to minimize formation and leakage of CH4 and N2O into the environment.
- Understand and document the effects of exhaust nutrients on worms and plants.
- Experiment with different biofilter mediums, plants and lighting arrangements to determine best practice for producing profitable and nutritious crops.
We seek to demonstrate that composting and greenhouse production can be mutually beneficial endeavors, diverting food waste from landfills, increasing nutrient input to farms, decreasing heating costs, and increasing production which will increase profitability and quality of life for farmers. This scalable and replicable project will make entry more affordable for farmers with financial constraints, enabling opportunity for marginalized populations. The facility is scaled small enough, and designed to capture the gases and therefore odors, so it can easily be located within close proximity to waste generators.
Season extension with high tunnels has been encouraged in our area due to the short growing season, but the operation of greenhouses throughout the winter is cost prohibitive due to heat and lighting. Our community agricultural systems have become fragmented and lost value found in natural cycling of nutrients and diversity. This is decreasing profitability for the farmer, resources for local communities and integrity in our environment. Our waste resources are transported to remote landfills while we are experiencing international fertilizer shortages of synthetic fertilizer which is manufactured mostly overseas, using fossil fuels. Synthetic fertilizer is only a short-term solution as it is not retained well by the soil, and at risk of run off and environmental contamination. In the greenhouse industry propane is used to create carbon-dioxide in the greenhouse to increase yield.
New York State is currently beginning mandates for larger Food Waste generators to divert their waste from landfills to composting facilities within a 25-mile radius. Many areas in New York currently do not have a facility at all, allowing Food Waste Generators to receive an exemption and continue to land-fill their food waste. Farmers can diversify by composting at a scale that provides for their needs and gives them a product to sell. Farmers often have land and equipment that is needed in the composting process. In the North Country, during the winter, even the best constructed compost recipes have a very difficult time with uniform heating. Windrow composting does create a quality product, but with more land footprint, fossil fuel use for equipment handling, possible runoff issues and during the turning process carbon dioxide, methane and nitrous oxide are released into the atmosphere. These toxic runoffs and “greenhouse” gasses have value to the farmer.
Most farmers have experienced a bind-up of nitrogen due to excess tree debris or corn sileage in manure spread on fields. This nitrogen is not lost, but the crops in that area will be stunted for the season, as the carbon holds the nitrogen tightly and it takes at least a season, often two or three before the carbon is breaking down and ready to release the nitrogen.
Livestock Farmers have also experienced strong ammonia off-gas from piled manure with insufficient carbon, and vegetable farmers have certainly over fertilized before, where you may have lush foliage, but no fruit on your plants. Nitrogen can be very volatile and have serious effects on your farm, but also in our environment.
Ammonia will damage plant leaf tissue in concentrations as low as 10 ppm and must be scrubbed from the exhaust stream before it enters the greenhouse atmosphere. A number of experimental composting greenhouses have suffered chemical bums of leaves by NH3 that was released directly into the greenhouse atmosphere without being filtered.
The NH3 is transformed to ammonium (NH4+) when it comes in contact with the water vapor in the exhaust stream or condenses in the pipe or soil of the growing bed/filter. Some NH4+ is absorbed by plant root hairs but most of it is mineralized to nitrite (N02-) and then to nitrate (N03-) by bacteria present in the biofilter. The biofilter has a high carbon content, which provides a food source for certain nitrifying bacteria. The warm temperatures and oxygen-rich environment of the biofilter also assist in rapid nitrification ofNH3 to plant-usable N03-
Increasing fertility is easier than decreasing it. Strategies used by farmers to decrease nitrogen include planting hungry crops and introducing carbon, often as old feed, such as sileage, hay. sawdust or other tree debris. We have experienced these problems first hand.
Farmers historically lack the support from people with technical knowledge, labor resources and funds for testing, tracking, recordkeeping, and dissemination of info for use by other farms. This grant will enable that collaboration.
We are working with several variables, that if we manage them correctly, we should be able to find the correct balance to harness all the inputs for the best financial and environmental benefit. These variables include:
- Compost recipes and external temperature control will affect gaseous content in the harnessed condensate.
- The amount of aeration will affect how quickly and at what temperature the composting process happens, affecting the microbes, types and amounts of gas formed.
- The design of condensate movement from the pile to the biofilter will affect the amount of vapor and nutrients that reach the biofilter.
- The composition of the biofilter will affect how well it holds the nutrients and how quickly it becomes saturated.
- The variety of plants will affect what nutrients are removed and how quickly, and are an integral part of the biofilter itself.
- Sufficient lighting will affect the ability of the plants to uptake the nutrients and turn them into profit for the farmer.
Composters who process manures and highly nitrogenous feedstocks will benefit from the deployment of effective N capture systems. NH4 is commonly the greatest form of N losses from almost all aerobic manure management systems. Deployment of composting practices that conserve the N value via NH4 volatilization and mitigate GHG releases of CH4 and N2O achieve significant environmental and agronomic goals.
Working in a low income, limited food access area, we are going to demonstrate how pairing a properly constructed and managed composting facility with greenhouse production will not only reduce the costs, but provide increased yield, and additional income stream. This will improve the profitability and sustainability of local farms while conserving soil and protecting water quality. It should also lead to enhancement of employment in farm communities and improvement of quality of life for farmers, their employees and the community.
Cooperators
- - Technical Advisor
- - Technical Advisor
- - Producer
Research
Farm partner, Cherie Whitten, seeks to record and analyze data to minimize formation and leakage of CH4 and N2O into the environment and to understand how to manage exhaust through a biofilter to positively affect nutrient availability and temperature for the worms and plants.
The biofilter consists of a 30" deep bed of material layered in the bottom of the greenhouse which includes the root zone and the plants growing therein. The bottom layer of wood chips creates an aeration plenum, so the nutrients in the compost exhaust move evenly into the upper layers.
We endeavor to match the compost aeration and resulting moisture, gaseous N and CO2 to the needs of plants and worms, and to maintain a healthy enclosed workspace. Excessive accumulation of nutrients in growing matrices would be detrimental to crop health and yield, and the air quality within the greenhouse must be safe for occupants.
High-yield greenhouse crops will be selected in our trial to optimize removal of nutrients from the biofilter. A combination of supplemental lighting will be provided to ensure vigorous crop production and efficient nutrient uptake throughout the winter.
These trials will be conducted in plots of varying biofilter media. This media will include zeolite, aragonite, biochar, clay, rock phosphate, bone char and sawdust. We endeavor to find the most advantageous mix of media and understand how to adjust it as needed.
Representative sampling and analyses of feedstocks will establish baseline nutrient mass balances to be composted. Aeration regimes and temperature data will be tracked in the composting batches. A control and monitoring package to measure temperature, air flow rate and oxygen content of the compost exhaust will be assembled by Agrilab Technologies, programmed, and tested for this project. Exhaust gases, biofiltration growing media, plants, and population and nutrient accumulation of Eiseniia foetida will be sampled and analyzed to determine the efficacy and key performance factors within the integrated biofiltration system.
Nitrogen dynamics are highly variable in active compost, soils, exhaust ductwork, and biofiltration media. As feedstock N decomposes, NH4 and N2O will be generated in varying concentrations based on feedstock composition and compost management. The air handling system, heat exchanger, and condensate removal ductwork will remove some of the NH4 and entrain it as NH3. When ammonia in the exhaust touches the soil, it converts to ammonium, a form of nitrate that bonds to the soil so plants can use it. When too much ammonia enters the soil, or the biofilter becomes saturated, ammonia odors can enter the greenhouse, which can become toxic for the plants. Therefore this approach to biofiltration in greenhouses needs to be done carefully. The biofilter will capture most or all of the remaining NH4, and mineralize it into plant available N. The high carbon content of the biofilter soil should buffer the heavy loading rates of NH3 by providing colloidal surface area and increasing the cation exchange capacity. The worms will digest carbonaceous material and the other amendments and nutrients incorporated into the biofilter. In this way, some of the N will be converted into worm biomass within the biofilter.
Nitrification and denitrification processes within the biofilter media will be tracked via representative sampling and analyses in the varying treatments. Greenhouse atmosphere will be monitored for CO2, temperature and N2O to optimize plant growth and control ventilation to ensure workplace health and safety. Due to the worms sensitivity to high levels of nutrient build up sampling the movement and health of the worms will help us determine media saturation as well.
Bruce Fulford will review data regularly and will be contacted when there are outliers. Biofilter media manipulation will produce the mineralization of plant available N.
We will record the following data:
- Compost quantity and recipe
- Heat provided by the compost
- Ammonia in the compost exhaust
- Soil nitrogen at various points in the biofilter
- Moisture at various points in the biofilter
- Carbon dioxide at various points above the biofilter
- Location and condition of the worms
- Health of the plants
- Yield of vegetables from various plots
- BRIX levels of vegetables and plants
With this information we will:
- Analyze increases or decreases in production quantity and quality in correlation to nutrient and temperature factors.
- Analyze the cost savings in heating a greenhouse, as well as the reduction in carbon footprint.
- Estimate the amount of greenhouse gases that were sequestered during this project.
- Demonstrate improved productivity and reduction of costs.
- Produce reports that will enable other farmers to duplicate this process, or scale it up.
Progress to date:
Report 1: Jan, 2023 - Since launching the project in August, 2022, ANCA purchased a biogas monitoring system from Agriblab in Vermont on behalf of partner farmer Cherie Whitten from Whitten Family Farm for $5,000. Cherie has just completed construction of the building that will be housing the composting process – a 30x40 timber frame structure (covered by a different grant). The structure is immediately adjacent to a greenhouse that will be the location of this experiment. Cherie has been collecting food waste from regional entities for three months and will be composting these materials with wood chip mix in early February. Gases from the aerated static pile (ASP) system will be bio filtered and funneled into the adjacent greenhouse this spring and summer. She will be starting plants in the greenhouse in February. It will be these plants that will be monitored to determine the quality of the exhaust gas entering the greenhouse. Cherie’s next purchase will be for a lighting system to go in the greenhouse.
Report 2: March, 2024 -
Project update:
The Whitten Family Farm (WFF) compost barn has (5) covered shed bays for reverse aerated compost located on the north side of the barn. Each bay is 12’ wide and 16’ deep with a 12” channel in the center of the bay with 4” Perforated HDPE pipe which contains air that is drawn down through the piles and through a manifold, heat exchanger and blower. The warm and moist air contains nutrients from the compost. Some of the moisture is shed from the air as it cools, at specific points, including when leaving the channels under the bay and entering the insulated building as well as at the heat exchanger. Condensate traps collect the moisture that is released at these points.
The air still retains heat after the heat exchanger and is then exhausted into a biofilter that is inside the south side of the insulated building. The south side of the building has polycarbonate on an angled wall and on the roof, creating passive solar heat gain in this greenhouse area.
On February 10, 2023 we received a control and monitoring package assembled by Agrilab Technologies, programmed, and tested for this project. It measures temperature, aeration regimes, air flow rate and oxygen content of the compost exhaust.
We installed the exhaust system, biofilter and Agrilab Tech system during March. This was completed on March 27th and we began composting on March 28th. We used all sources available for compost inputs and were only running at 18% capacity. We tracked the feedstocks we composted for further analysis. At this point the biofilter consisted of 4” perforated HDPE pipe running in two continuous loops on either side of the center, covered in 24” of wood chips layered in the bottom of the greenhouse creating an aeration plenum. This was designed so the heat, moisture and nutrients in the compost exhaust should move evenly throughout the biofilter and then dissipate evenly into the upper layers. The heat from the compost that was exhausted into this biofilter was sufficient to quickly warm the building in early April, which was still very cold from the unheated winter. By the end of April we were experiencing temperatures and moisture in the building which were too high and required us to ventilate, and divert the exhaust from the biofilter into an exterior bay of compost and woodchips. This still captured the nutrients, but in another compost and woodchip pile as opposed to the biofilter we were looking to test from. Because the compost pile will work as usual and be cycled from the bay, we took turns exhausting into several piles, and the tracking of nutrient build up is not possible. Because our compost inputs in large part come from several local colleges, in May, capacity decreased to 10% and between lack of food waste inputs and needing to ventilate, we discontinued the experiment until September.
September food waste collection produced food waste at 20% of capacity. These trials are being conducted in plots of varying biofilter media, as the biofilter was now amended with an additional 3” of woodchips, sawdust, Aragonite, Zeolite, Soft Rock Phosphate, BioChar and Bone Char in five differing plots per the attached sketch.
By early October the compost pile size and recipe was sufficient enough to begin emitting enough heat to keep the building warm with October temperatures. We had varying results with pile temp throughout the winter as shown in the following chart:
We were able to heat well until December 3rd. At this point we were losing some ground. Beginning December 6th we had colder temperatures and were bringing trailers filled with 10-15 frozen totes of food waste into the building by opening an overhead door. We now realized that without sufficient compostables volume the temperatures in the building would dip very close to freezing (see attached air temp report). On December 10th we built compost batch 12, with a higher carbon percentage, lacking sufficient greens. This pile failed to heat properly, and we began installation of a basic 40 gallon 4500 watt electric water heater. We ran this heater from Dec 26th through January 24th, using an estimated 1489 kWh of electricity to boost temps in this 2800 sq ft area during this time.
We were very diligent in trying to increase food waste and compostable products to increase the volume in the compost bays. Because the capacity was less than anticipated, the nutrients and moisture in the biofilter were not close to saturation levels in the biofilter.
We believe that we have demonstrated that composting and greenhouse production can be mutually beneficial endeavors, diverting food waste from landfills and decreasing heating costs. The minimal boost that the greenhouse needed at only 20% of capacity, shows that heating costs can be substantially reduced. The resulting compost provides increased nutrient input to farms, which increases production and therefore will increase profitability and quality of life for farmers.
Further analysis of nutrients was expected to be done as follows:
- Capture carbon dioxide, ammonia, methane and nitrous oxide in a biofilter instead of allowing them to escape into the atmosphere.
- Record and analyze nutrient data to minimize formation and leakage of CH4 and N2O into the environment.
- Understand and document the effects of exhaust nutrients on worms and plants.
- Experiment with different biofilter mediums, plants and lighting arrangements to determine best practice for producing profitable and nutritious crops.
At this point, the nutrient level is low enough that we are not seeing any escape or build up. This shows that we are capturing these nutrients and they are not escaping into the atmosphere. However, we can’t quantify their value at this lower-than-expected level. In order to analyze this, we need a longer time-frame of an additional winter and we need to increase our volume of compost.
We sought to not just to minimize formation and leakage of CH4 and N2O into the environment but also to understand how to manage exhaust through a biofilter to positively affect nutrient availability and temperature for the worms and plants. This we haven’t been successful doing during this period of time.
This was what we hoped to track with a higher volume of composting:
Excessive accumulation of nutrients in growing matrices would be detrimental to crop health and yield, and the air quality within the greenhouse must be safe for occupants. Due to projected likely high levels of nutrients, High-yield greenhouse crops were to be used in our trial to optimize removal of nutrients from the biofilter. Exhaust gasses, biofiltration growing media, plants, and population and nutrient accumulation of Eiseniia foetida are to be sampled and analyzed to determine the efficacy and key performance factors within the integrated biofiltration system, because nitrogen dynamics are highly variable in active compost, soils, exhaust ductwork, and biofiltration media.
When too much ammonia enters the soil, or the biofilter becomes saturated, ammonia odors can enter the greenhouse, which can become toxic for the plants. This has not occurred, but is unlikely at the low levels we have. The biofilter should capture most or all of the remaining NH4, and mineralize it into plant available N. The high carbon content of the biofilter soil should buffer the heavy loading rates of NH3 (BUT- we don’t have heavy loading rates) by providing colloidal surface area and increasing the cation exchange capacity. The worms will digest carbonaceous material and the other amendments and nutrients incorporated into the biofilter. In this way, some of the N will be converted into worm biomass within the biofilter. Nitrification and denitrification processes within the biofilter media were planned to be tracked via representative sampling and analyses in the varying treatments, but with the low levels this testing will not show much deviation from the compost and amendments in the biofilter. Greenhouse atmosphere will be monitored for CO2 and N2O (but levels are too low to do this) to optimize plant growth and control ventilation to ensure workplace health and safety. Due to the worms’ sensitivity to high levels of nutrient build up (which there isn’t) sampling the movement and health of the worms will help us determine media saturation as well. Bruce Fulford will review data regularly and will be contacted when there are outliers. Biofilter media manipulation will produce the mineralization of plant available N.
We will record the following data:
- Compost quantity and recipe -DONE
- Heat provided by the compost-DONE
- Ammonia in the compost exhaust -not yet
- Soil nitrogen at various points in the biofilter -we can test, but levels are not high- results won’t mean much yet
- Moisture at various points in the biofilter - needing to water about 25%
- Carbon dioxide at various points above the biofilter -not yet
- Location and condition of the worms -noted, no specific trend
- Health of the plants -noted, no important observations with lower nutrient level
- Yield of vegetables from various plots -not yet
- BRIX levels of vegetables and plants -not yet
With this information we will:
-
- Analyze increases or decreases in production quantity and quality in correlation to nutrient and temperature factors. -not possible with low levels
- Analyze the cost savings in heating a greenhouse, as well as the reduction in carbon footprint -yes, we can complete this for the past winter.
- Estimate the amount of greenhouse gases that were sequestered during this project-we can estimate what was sequestered.
- Demonstrate improved productivity and reduction of costs. -we can prove reduced heating costs
- Produce reports that will enable other farmers to duplicate this process, or scale it up.
Thoughts regarding possible extension:
Our current end date is July 31, 2024. That will give us one winter of results on temperatures, during a mild winter. We initially wanted to report on two winters. Our options are to only report on this winter, or to extend the deadline through at least 3/15/25. At the current volume of composting, I do not anticipate getting near nutrient saturation levels in the biofilter, even with an additional winter. We are trying hard to increase the volume we are composting. I have begun discussions with a neighboring horse farmer and we could try to find a local dairy that we can get feedstock from to increase our volume. There are sufficient funds remaining in the grant to cover through April 30th 2025, which would be an ideal 9 month extended end date for recording data.
Education & Outreach Activities and Participation Summary
Participation Summary:
CfG consultants/staff will leverage our vast partner network including over 200 stakeholders, Cornell Cooperative Extensions, the ANCA local food program, Adirondack Harvest, the ten local universities (including a strong relationship with Clarkson University), BOCES, and Hub on the Hill to share the results directly, while asking partners to share results with their respective stakeholder groups.
We are working in partnership with the NYS Department of Environmental Conservation (DEC) to focus and increase farmer engagement through workshops, case studies, eblasts, toolkit development and 1:1 assistance and will incorporate information learned from this project into those efforts.
To achieve our outreach goals, we will:
- Disseminate the results to the above groups with a focus on replicability and feasibility through the same processes that we have used to share results from other projects: a graphically designed case study overviewing the project, challenges, results and resources.
- Engage others early on so they can follow the project as it progresses, post progress and results on our facebook page and website, send targeted eblasts through the above list and announce completion through a press release.
- Share the results with the dozens of members of the NYS Organics Council - of whom we are a member - through Biocycle Magazine, and through the Composting Operators course offered by James McSweeney and attended by our staff.
- Contextualize the results into a bigger picture which would highlight the importance and relevance of the work in light of a current fertilizer crisis, global climate change, soil depletion, and adverse impacts of storm water runoff.
- Support others who seek to apply the technology or expand upon it through direct support and identification of implementation funding.
Progress to date: Jan, 2023
In light of COVID and a new return to in person events, it is difficult to identify specific events that will be targeted, however we are planning a farmer workshop this May and plan to host several others throughout the year - again in coordination with the NYS DEC. We have applied for a grant that would target farmers as recipients of our aforementioned support, and would incorporate practices as informed by this project in our toolkit and decision tree.
Interest in this project is already growing as the number of composting entities in the area expands rapidly, each interested in maximizing the beneficial impacts of the composting process. Composters who process nitrogenous feedstocks will benefit from the deployment of effective N capture systems. We have included only a portion of the hours that we will actually spend on outreach on this project. Much of this will become synergistic with the many programs and funding opportunities which are already the focus of our work.
Progress to date: March, 2024
ANCA’s CfG consultants have been in close contract with the Whittens throughout project implementation. They co-hosted a workshop last year inviting regional farmers and compost operators to tour their ASP system and to answer questions. It was attended by several local farmers and regional composters. With their system now fully operational, several outreach and educational events will be presented throughout the next several months including a second workshop/open house this April, inclusion in a presentation by CfG at the NYS Organics Summit, through a recently awarded Lake Champlain Basin Program grant (also targeting farmers) and through a current partnership with the Compost Association of Vermont (CAV). (CAV and and CfG are supporting the Whittens in a separate but related USDA grant targeting farmers in NY and New England to improve their food composting practices. This project has been shared with them in the hopes that they can share with their farmer network. The final project case study and results will be available to this group as well upon completion of the project.