UNH Organic Dairy Farm Agroecosystem Study, Phase II; A closed system, energy independent organic dairy farm for Northeastern U.S.

Final Report for LNE11-313

Project Type: Research and Education
Funds awarded in 2011: $392,658.00
Projected End Date: 12/31/2014
Region: Northeast
State: New Hampshire
Project Leader:
Dr. John Aber
University of New Hampshire
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Project Information

Summary:

Our original proposal outlined clear milestones for the first six years of a projected 9 year program. We have now completed the first two rounds of funded research and have embarked upon the third and final round. In the period of the first award, we completed all of the major tasks proposed. In brief, we:
• Produced a first outline of the nitrogen budget and cycle
• Completed detailed studies on forage production, grazing intensity and hydrology
• Characterized energy requirements on the farm and investigated several alternative sources
• Investigated the productivity of woodlands and their energy potential
• Developed a plan for closing the energy and carbon cycles by using woodland production for bedding and composting manure and bedding in an aerobic, heat-capture facility

With the second round of funding, we used the baseline data collected in round one to develop and test three major technologies for reducing energy demand and closing the carbon and nitrogen cycle. These included:
• Use of a commercial wood shaving machine to turn low-quality wood into bedding
• Development and testing of a unique, custom-built Static Pile Aerobic (SPA) composting facility with an innovative energy capture technology.
• Analysis of the potential for geothermal technologies for cooling milk prior to storage.

To provide context for the wood shaving study, we:
• Completed a survey of bedding usage among New England dairy farmers

Over the full six-year period, we have:
• Leveraged funds from the grant with substantial additional support from the NHAES and the College of Life Sciences and Agriculture as well as a major contribution from an anonymous donor for the construction of the composting facility
• Through this combined support, involved 6 graduate and 16 undergraduate students in original research projects on the Farm
• Presented the results of our work to a distinguished list of visitors, as well as to UNH and pre-college students, and local farmers and community members through on-site visits, presentations at meetings, and an active website

Introduction:

The goals of this research project are expressed in the title of the original proposal:
A Closed-System, Energy Independent Organic Dairy Farm for the Northeastern U.S.
We are using the unique characteristics of the Burley-Demeritt Agroecology Research Station, which includes the first commercial-scale Organic Dairy Research Farm at a land-grant institution, to advance the goal of developing a sustainable farm production system that comes as close as possible to achieving a closed nutrient cycle and complete energy independence.

The project advances the science of agroecosystem research by bringing well-developed concepts derived from the study of native ecosystems to bear on this 300-acre (~120 ha) managed systems. A primary goal of the work is to test the long-term sustainability (economic, environmental and cultural) of this integrated agroecosystem through the development, implementation and evaluation of innovative management practices and systems designed to reduce energy demand and to close nutrient cycles.

In the first three years of funding we established baseline characteristics of nitrogen and energy usage and flows on the farm. With this background, we proposed in the second round just completed, to develop and test three innovative technologies to internalize nitrogen and energy flows, reduce costs, and enhance financial and environmental sustainability. We also proposed to continue to monitor water quality and groundwater hydrology.

Performance Target:

Specific objectives for the second round of funding included:

A. Test a new machine for producing bedding from low-quality pine and hemlock logs
B. Develop productivity and cost data for producing bedding by this method.
C. Assist in a survey on bedding needs and practices among New England dairy farmers
D. Help with fund-raising for, and design of, a unique static-pile, aerobic composting system with energy recovery designed to support research on this emerging technology
E. Test the energy production and capture of the composting facility using several different mixtures of materials and under different conditions
F. Optimize the operation of the composting facility, including modification of air handling and data gathering capabilities
G. Assist in the design of workflow on the farm to make best use of the composting facility and to minimize labor requirements for manure management
H. Assess the potential for using geothermal cooling (flow-through heat exchanger) for reducing milk temperature prior to storage

Cooperators

Click linked name(s) to expand
  • Dr. Matt Davis
  • Dr. Bill McDowell

Research

Materials and methods:

A. Test a new machine for producing bedding from low-quality pine and hemlock logs

With support from the NHAES, UNH purchased a Tremzac 248T model wood shaving machine capable of producing all the bedding material used campus-wide (see image). Two deliveries totaling ~100 cords of Eastern White Pine and Hemlock harvested from the woodlands at the ODRF has been processed.

B. Develop productivity and cost data for producing bedding by this method.

Careful records were kept of the time, effort and cost of producing bedding with the Tremzac machine, including down-time, and costs for maintenance and repair.

C. Assist in a survey on bedding needs and practices among New England dairy farmers

A detailed survey of bedding sources, uses and outcomes, with additional information on farm characteristics, herd size, milk production and somatic cell count was developed and mailed to 600 organic and conventional dairy farms throughout New England. A total of 128 responses were received – a 21% return rate.

D. Help with fund-raising for, and design of, a unique static-pile, aerobic composting system with energy recovery designed to support research on this emerging technology

Worked closely with personnel from the UNH foundation, the NHAES and the UNH facilities group to achieve a completed and functioning facility

E. Test the energy production and capture of the composting facility using several different mixtures of materials and under different conditions

F. Optimize the operation of the composting facility, including modification of air handling and data gathering capabilities

Since operations began in June of 2013, we have loaded 26 bays, processing approximately 1,200 wet tons or 2,000 cubic yards of material. BTU generation and capture has been measured under a wide range of material and climate conditions. BTU capture is measured by replacing the water in the hot water storage tank with groundwater (~55F) and then measuring temperature change continuously during facility operation.

Initial results demonstrated that air movement was too slow and residence time in the pipes between the composting floor and the heat exchanger was too long, resulting in excess condensation in the pipe system and less than optimal energy capture. Therefore, a complete rebuild of the air-handling system in the mechanical room of the facility was designed and completed. Pipes were narrowed from 10” to 8” or less where possible. Pipe lengths were reduced by dropping the manifold from over 8’ in height to the height of the heat exchanger.

G. Assist in the design of workflow on the farm to make best use of the composting facility and to minimize labor requirements for manure management

Composting has been integrated into the regular flow of work on the farm. All stockpiles of manure have been processed and we are on a regular schedule to load one bay every 4-6 weeks. All manure and bedding produced on the farm are now composted in the facility before spreading on the fields at the farm.

H. Assess the potential for using geothermal cooling (flow-through heat exchanger) for reducing milk temperature prior to storage

Data were collected on rate of milk production during milking, temperature of milk produced and the potential yield of water from an open-loop geothermal system and used to assess the practicality of using a flow-through heat exchanger to reduced milk temperature and hence the cost of electric cooling of milk in the storage tank.

Tremzac Shaving machine used to test viability of local bedding production
Tremzac Shaving machine used to test viability of local bedding production
Research results and discussion:

A. Test a new machine for producing bedding from low-quality pine and hemlock logs
B. Develop productivity and cost data for producing bedding by this method.

Data were collected on the time, effort and cost of producing bedding using the Tremzac shaving machine. Initial economic analyses suggest that the highest economic value to farmers as woodlot owners of low-quality softwoods, as well as some higher-quality materials, is as bedding, rather than pulp, chips or perhaps even sawn timber. However, initial trials with the machine have highlighted issues that reduce the realized value to levels well below projected. Data collected during the processing of logs to bedding are being used to refine the initial economic model in order to produce realistic estimates of costs and revenues. (http://www.aberlab.net/wp-content/uploads/2013/08/Production-Costs-of-Wood-Shavings-for-Animal-Bedding-Stump-to-Shed.pdf).

C. Assist in a survey on bedding needs and practices among New England dairy farmers

Initial results suggest a very wide range of bedding materials and processes in use. No immediate relationship between bedding type and milk quality is apparent. Data on average farm characteristics suggest that the Burley-Demeritt Farm (the Organic Dairy Research Farm) is very similar to the modal dairy farm in the region responding to this survey in terms of acreage, herd size and amount of woodland potentially available for the production of bedding. This survey has yielded a large number of practitioners who are interested in the bedding work and willing to participate in the process.

D. Help with fund-raising for, and design of, a unique static-pile, aerobic composting system with energy recovery designed to support research on this emerging technology
With support from an anonymous donor, UNH, COLSA and the NHAES, a $550,000 research composting facility was constructed at the ODRF (see first attached figure). Details of construction and initial operation are presented in a publication recently released through UNH Cooperative Extension (http://www.aberlab.net/wp-content/uploads/2013/08/Smith-and-Aber-2014-Heat-Recovery-from-Compost.pdf)

F. Test the energy production and capture of the composting facility using several different mixtures of materials and under different conditions
E. Optimize the operation of the composting facility, including modification of air handling and data gathering capabilities

The facility was completed in the June of 2013. The redesign and rebuild were completed in the summer of 2015. Temperatures achieved during composting have ranged from 110F to 150F depending on age and nature of material.

Temperatures achieved during composting have ranged from 110F to 170F depending on age and nature of material. We have now begun to measure BTU generation and capture by the system as a function of age of material and temperature of water in the storage tank.

Efficiency of capture is closely related to tank temperature (see second attached figure), indicating that placing a higher load on the hot water storage (e.g. heating a greenhouse or drying shavings) would increase the efficiency of the overall system.

G. Assist in the design of workflow on the farm to make best use of the composting facility and to minimize labor requirements for manure management

Composting has been integrated into the regular flow of work on the farm. All stockpiles of manure have been processed and we are on a regular schedule to load one bay every 4-6 weeks. All manure and bedding produced on the farm are now composted in the facility before spreading on the fields at the farm.

H. Assess the potential for using geothermal cooling (flow-through heat exchanger) for reducing milk temperature prior to storage

Initial calculations of installation and operation costs of the geothermal system, and of the rate and temperature of milk production suggested that this approach was not feasible.

Static Pile Aerobic Composting facility with Heat Capture as constructed at the Burley-Demeritt Farm at UNH
Static Pile Aerobic Composting facility with Heat Capture as constructed at the Burley-Demeritt Farm at UNH

BTU extraction from heated air stream from the UNH composting facility as a function of temperature of water in the buld storage tank. BTU extraction from heated air stream from the UNH composting facility as a function of temperature of water in the buld storage tank.

Participation Summary

Education

Educational approach:

A fully functional website presenting all of the results and accomplishments to date has been developed and can be viewed at www.aberlab.net. This is the most complete and rapid way to communicate results. Recent outreach activities highlighted on the website include:

Heat Recovery from Compost: A Step-by-Step Guide on Building an Aerobic Static Pile Heat Recovery Compost Facility – A major, detailed description of the specifications and construction process for the static-pile aerobic composting facility has been completed: http://www.aberlab.net/wp-content/uploads/2013/08/Smith-and-Aber-2014-Heat-Recovery-from-Compost.pdf.
Publication may occur through NH Cooperative Extension but we are also talking with BioCycle about a possible outlet.

Smith, M. and J.D. Aber. 2013. Heat Recovery from Compost. BioCycle 55:27-29
A summary description of the composting system in the trade journal BioCycle, published in February. http://www.biocycle.net/2014/02/21/heat-recovery-from-compost/

A presentation on the bedding/composting system at the NHAES Farm and Forest Expo in February 2014

Technical advice has been provided to the following companies and organizations:
Earthbank Resource Systems Ltd., Vancouver British Columbia July 2014
Moor Farm/Stewardship & Sustainability, Durham, NH May 2014
Seacoast Energy Alternatives, Dover, NH March 2014
Hall and Moskow Real Estate , Neburyport, MA February 2014
The Peters Company, Lee, NH February 2014
Aquaponics & Compost Heat Recovery Venture, Manchester, NH February 2014
Payeur Farm Composting, Parsonsfield, ME September 2013
Fox Composting, Dover, NH January 2013

A major event sponsored by the College of Life Sciences and Agriculture and the NHAES marking the dedication of the composting facility for an innovator in sustainable agricultural technologies.

Dedication of the UNH Names Innovative Composting Facility after Sustainable Agriculture Pioneer – Technology Advanced by Josh Nelson Used at NHAES/UNH COLSA Organic Dairy Research Farm
http://colsa.unh.edu/aes/article/unh-names-innovative-composting-facility-after-sustainable-agriculture-pioneer

About 40 attendees
Story picked up and published in the following (40+) regional and national outlets:

NH/New England
Fosters (NH) New Hampshire Public Radio (NH)
New England Cable News (Boston) WHDH (Boston)
Caledonian Record (VT) WCAX (VT)
St. Albans Messenger (VT) Brattleboro Reformer (VT)
Portland Press Herald (ME) Stamford Advocate (CT)
Connecticut Post (CT) Greenwich Time (CT)
News Times (CT)

National
The News & Observer (NC) Heraldonline.com (PA)
Tampa Tribune (FL) The Sun News (SC)
Miami Herald (FL) Belleville News Democrat (IL)
The News Tribune (WA) Lake Wylie Pilot (SC)
SF Chronicle (CA) Seattle Post Intelligencer (WA)
The Island Packet (SC) The Sacramento Bee (CA)
Bradenton Herald (FL) Merced Sun-Star (CA)
The Fresno Bee (CA) The Olympian (WA)
The Macon Telegraph (GA) Tri-City Herald (WA)
The State (SC) Daily Journal (IL)
Pendleton Times-Post (IN) Daily Reporter (MI)
The Register-Guard (OR) Washington Times (MD)
Kansas City Star (MO) The Republic (National news aggregator)
NewsDaily (National news aggregator)

Niche Media Outlets
Biocycle.net Green Building Elements
Weekly Market Bulletin (NH Department of Agriculture)

At the outset of this project in 2007, we proposed that the first three years would involve measurement of processes on the farm, that the second (now completed) would concentrate on development and testing of innovative technologies and approaches, and that the third three-year term would emphasize economic analyses, development of tools and reports, and increased publication and outreach. The third round has now been funded and the proposal includes a long list of promised products.

No milestones

Additional Project Outcomes

Project outcomes:

Impacts of Results/Outcomes

The major results from this round of funding have the potential for major impacts in the forestry, dairy and waste management areas. In forestry, the development of techniques for converting low quality softwoods into valuable bedding offers the opportunity to create a new revenue stream for woodlot owners. For dairy farmers, our survey showed that most have significant woodlot acreage which can be used either as a revenue source by selling shavings for bedding, or to costs for bedding use on the farm. The composting results open a wide range of options for processing organic wastes on dairy or other farms (the UNH facility can be scaled-down considerably to reduce initial investment while maintaining throughput), and may also provide opportunities for new ways to process organic wastes from other sources (e.g. restaurants, food processing) as states and towns increase restrictions on sanding these wastes to landfills.

Economic Analysis

See discussion of analysis of shaving operation above. In the third round of funding we will conduct a full environmental and economic analysis of different combinations of management approaches.

Farmer Adoption

While interest in both the shaving machine and composting process has been very high, results are not yet formalized sufficiently to encourage farmer adoption. In the third round of work now funded, we will concentrate on communication, support and helping with adoption. Results from the survey of dairy farmers suggests high interest in the potential for alternative bedding practices.

Assessment of Project Approach and Areas of Further Study:

Areas needing additional study

As our tests of new approaches has prceeded and matured, additional work in the third round of funding can concentrate on specific experiements with regards to the composting process and continued measurement of nitrogen and energy dynamics using established protocols. New work will be focused on synthesizing results to date, running additional specific experiments on composting, and adding new measurements proposed for the third round on the characteristics of the exhaust air from the facility in terms of driving year-round greenhouse production (described in proposal).

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.