UNH Organic Dairy Farm agroecosystem study

UNH Organic Dairy Farm agroecosystem study

Summary

Our original proposal outlined clear milestones for the first three years of this project. We are now in the middle of the second year, and have made significant progress against all of our goals. For example, at our agroecosystem site – the recently established UNH Organic Dairy Research Farm – we have:

– Produced a first outline of the nitrogen budget and cycle, and identified the major unknowns needing further work.

– Begun detailed studies on these poorly characterized parts of the cycle including:

= Forage production and grazing intensity
= Hydrologic flowpaths and water chemistry

– Characterized energy requirements on the farm and investigated several alternative sources

– Investigated the productivity of woodlands on the Farm and the potential to use this resource for bedding, energy, and soil carbon enhancement

– Leveraged funds from the grant with substantial additional support from the NHAES and the College of Life Sciences and Agriculture

– Through this combined support, involved 4 graduate and 10 undergraduate students in original research projects on the Farm

– Presented the results of our work to a distinguished list of visitors, as well as UNH and pre-college students, and local farmers and community members

Objectives/Performance Targets

Objectives:

The following text is modified from the original proposal, which can be found on the website for the Organic Dairy Research Farm (http://www.colsa.unh.edu/aes/odrf/research/projects/SARE.html)
Dairy dominates animal agriculture in the Northeastern U.S., and is tied to the continuation of important cultural values including the conservation of open land and preservation of historical character. With the establishment of the first commercial-scale Organic Dairy Research Farm (ODRF) in the country, UNH is uniquely positioned to fulfill the traditional land-grant role of supporting a critical agriculture-based community in the state and region.

The purpose of this project is to use the ODRF as a test bed to achieve:
A Closed-System, Energy Independent Organic Dairy Farm for the Northeastern U.S.

We are pursuing a farm-ecosystem level approach to the measurement all of the material and energy flows occurring across the annual production cycle at the ODRF. Natural and human vectors are being compared, including, for example, inputs of nutrients in precipitation, feed and fertilizer, and losses in product shipment, surface water runoff and ground water leaching.

The work currently underway is seen as the first stage in a 9-year project that will use the data acquired in the first 3 years (phase 1) to redesign and implement changes in farm operations to decrease nutrient losses and fossil fuel requirements (phase 2), which will be refined and presented as best management practices (phase 3).

Open communication and transparency have been an integral part of the UNH Organic Dairy Research Farm project from the beginning. UNH has established a set of stakeholder advisory groups which provide direct links and two-way communication between this research enterprise and potential users of the program’s outcomes. Emerging results of the research proposed here will be made available quickly and directly to the dairy industry.

Performance:

As detailed below under Accomplishments and Milestones, we have made substantial progress against all of the goals specified for the first three years of the project.

Accomplishments/Milestones

Our original proposal outlined a project timeline for year 1, and for years 2 and 3, as well as tentative goals for years 4-9. Now in the second half of our second year, we have made good progress against our proposed milestones. These can be summarized using the list from our proposal:

Year 1: Finish outline of energy and nitrogen flows at the Organic Dairy Research Farm.

Basic studies on the energy and nitrogen cycles at the Farm have been completed.

Energy usage is summarized as part of a detailed presentation on the potential for using the forest resource on the farm to meet both the bedding and energy needs of the facility, while also producing compost for application to the fields both to enrich soils and store carbon (powerpoint file can be downloaded from http://www.colsa.unh.edu/aes/odrf/research/results/agroecosystemsresults.html)

A first approximation of the nitrogen cycle has been compiled from measurements made on the Farm, and from invoices and receipts for purchases and sales of feed, bedding, milk and animals. Results from this initial survey are presented in a poster that can also be accessed from
http://www.colsa.unh.edu/aes/odrf/research/results/agroecosystemsresults.html.

Years 2-3:
• Conclude research into those flows which are most significant and least well quantified. These include:

o Water and nutrient flows to the Lamprey River

Measurements of the hydrological balance on the Farm were initiated in year 1 and have continued in Year 2. Increased precision has been achieved with the addition of 2 stream gauges, 5 monitoring wells, and the acquisition and calibration of an in-situ soil moisture probe. Data are acquired at regularly scheduled intervals using both automated and manual methods.

Single well (slug) tests have been conducted on a number of wells to estimate the hydraulic conductivity of the different geologic materials. We have also completed a detailed mapping of the surficial geologic materials present at the farm and, along with information obtained from well drilling, developed a comprehensive conceptual model of groundwater and surface water flows at the site.

Our observations to date suggest that the farm shows a rapid response to individual precipitation events as water infiltrates through a relatively thin and permeable unsaturated zone and flows towards the lower elevations where it discharges through seeps and springs into a set of small streams discharging into the Lamprey River. Evapotranspiration is significant and diurnal fluctuations in both groundwater levels and streamflow are observed. These fluctuations will be used to help constrain estimates of evapotranspiration which, in turn, will help constrain our estimates of discharge from the farm. Groundwater withdrawals at the farm occur through a deep bedrock well and do not appear to significantly impact the natural shallow groundwater system through with the majority of the flows occur.

We are now in the process of synthesizing the geologic, topographic, and hydrologic information into a three-dimensional groundwater model using MODFLOW 2005. We are utilizing the Unsaturated Zone Flow package which is enabling us to 1) simulate flow and storage in the unsaturated zone, and 2) account for surface water discharges that occur when the water table reaches the ground surface. At present the modeling effort is focused on the summer-fall season.

The hydrologic budget is being combined with monthly sampling of groundwater wells and surface runoff in order to quantify nutrient exports. Results of the groundwater sampling show that levels of nitrate-nitrogen (NO3) are elevated in some wells downgradient of the agricultural operation, and can routinely exceed 10 mg/L NO3-N. Despite these high nitrate concentrations in groundwater, the surface creek draining the sites has moderate levels of NO3-N, typically below 1 mg/L. In the adjacent Lamprey River, there is no evidence to date of an impact of the ORDF on river water quality. Based on our chemical data and likely flow paths, it appears that passage of groundwater through a naturally vegetated wetland prior to entering the creek may play an important role in minimizing the impact of this contaminated groundwater on total N export from the site.

In Year 3, we will continue to monitor water levels, streamflow, and soil moisture, and will focus additional efforts on the wetland that appears to play a major biogeochemical role. Our modeling efforts will also be extended to include winter and spring data. Measured and modeled flow rates will be combined with water quality data to estimate mass fluxes. We will also begin the process of including solute transport processes into the modeling effort.

o Rate and composition of manure production as well as current storage practices and effects on decay and energy and nutrient balances

Manure production has been estimated as part of the nitrogen cycling work, based primarily on literature values. More precise estimates will be available from the pasture production and grazing work described below, and from volumetric estimates of material removed from barns.

In addition, we have begun examining alternative methods for manure management to produce energy while reducing greenhouse gas emissions and nutrient leaching to ground and surface waters. An undergraduate honors thesis is being completed that has measured the interactions among manure pile age and degree of aeration, and both pile temperature and CO2, CH4, O2 and H2S concentrations and emissions. Measurements have been made in large production piles at a major commercial farm operation, in operational piles at the ODRF, and in smaller experimental piles. Highly predictive relationships among the concentrations of these four gases are emerging which should quantify the benefit of either passive or active aeration for reducing greenhouse gas impacts of manure storage and composting. This thesis will be finished in the spring of 2010 and results will be posted to the ODRF/SARE website (http://www.colsa.unh.edu/aes/odrf/research/projects/SARE.html). A poster will also be presented at the UNH Undergraduate Research Conference.

As described below (Impacts and Contributions), the research around manure handling and composting has affected the design of a recently completed new barn at the Farm, as well as current planning for a new manure storage facility that will be designed to produce energy while minimizing nutrient leaching and trace gas emissions.

o Productivity of pasture and woodland systems

Productivity of the woodlands included in the ODRF site has been measured and is results have been posted to sites webpage. It is estimated that the nearly 200 acres of woodlands on tarm can produce enough wood on a sustainable basis to meet total farm demand for both bedding and energy. (http://www.colsa.unh.edu/aes/odrf/research/results/agroecosystemsresults.html)

In compiling the initial nitrogen cycle data reported above, it became apparent that better estimates of pasture productivity, grazing, and in-field manure production are essential. We are currently working with a Masters student on a detailed study of each of these parameters. The work so far has included a comparison of 4 different methods for rapid and accurate estimation of pasture biomass. Using the selected method, sequential measures of biomass before and after grazing, and during the regrowth period between grazing events, has been shown to yield consistent and very interesting information on the factors affecting grazing intensity and pasture production between grazing events. The use of intensive rotational grazing as the management scheme on the Farm has been crucial to the development of these estimates. A second season of field work on this topic is planned for 2010, and a thesis will be presented, and submitted for publication, in 2011. Results will be posted to the webpage as they are finalized.

• Investigate alternative methods for increased efficiency of resource use, generation of energy and minimization of nutrient loss.

A number of other alternatives for energy production on the farm have been identified. Exploration of the potential for wind, solar, increased efficiency, geothermal and other approaches have made perfect student project topics. Of these, two were shown to have significant potential.

The first is geothermal. Initial contacts have been made with a geothermal energy company and preliminary designs produced for general heating and cooling of milk tanks using this resource (http://www.colsa.unh.edu/aes/odrf/research/results/agroecosystemsresults.html).

The second is wood energy. Analyses have compared the use of wood directly in a conventional thermal system, or in a cogeneration plant that yields for heat and electricity. Cogeneration plants are not yet available at the size needed for the Farm, but investigations into that possibility will continue. The use of wood for bedding, energy and as a soil amendment has been discussed above and is summarized in
http://www.colsa.unh.edu/aes/odrf/research/results/agroecosystemsresults.html.

• Analyze economic impact of alternative systems
o Reduction in energy costs
o Increase in sales of products (e.g. organic compost and milk products)

These two topics will be addressed in the third year of the project, once the information on the full set of energy alternatives, and the potential for direct marketing an on-farm processing have been fully explored.

Impacts and Contributions/Outcomes

Impacts of the work reported here include

1. Changes in direction for support for research, facilities design and construction, and Farm operations by the New Hampshire Agricultural Experiment Station (NHAES)

2. Visits to the Farm by stakeholders both individually and as part of organized outreach functions

3. Students trained and traditional scientific presentations

1. The NHAES is providing considerable funding to leverage this project. In round numbers, these include:

• $28,000 annually to support the 12-month cost for a graduate student
• $11,000 to cover tuition for another graduate student whose stipend is paid by SARE

• $7,000 for half-time support for a third graduate student to compile historical cropping and related information

• $5,000 to undertake water quality monitoring in the adjacent Lamprey River

• $21,000 of Dr. McDowell’s salary for work on this project

• $200,000 per year (ne of milk revenues), to cover the operations of the farm, which are managed in close cooperation with the SARE project in terms of goals and objectives.

In addition, the new direction in experimental management for the Farm established as part of the SARE project has resulted in significant changes in facilities design.

• The newly (2009) constructed barn which houses stock in the winter was constructed as a bedded pack facility, and with nutrient retention features in cooperation with the composting and nutrient management goals of the SARE project.

• Plans for a manure handling facility are going forward with the goal of incorporating information gained from the composting research objective of this project.

2. A full-time on-site manager with considerable farm operations experience and a background in cooperative extension work supports the outreach components of the project. The list of recent visitors to the Farm include:

• Approximately 40 Agricultural Attaches arrange by Deputy Secretary of Agriculture Dr. Kathleen Merrigan

• Top management personnel from Stonyfield Farms, Horizon Organic Dairy, Aurora Organic Dairy and Organic Valley, attended also by Lorraine Merrill, State Commissioner of Agriculture.(http://www.colsa.unh.edu/aes/odrf/news/fallgathering09.html)

• UNH Alumni Association (Site visit for annual meeting)

• Students in UNH classes, including:
o Dairy Management I and II
o “The Real Dirt”
o Introduction to Horticulture
o Forages
o Ecogastronomy
• Students from pre K-12 schools, including
o Oyster River Preschool/Parents
o Phillips Exeter Academy
o Dairy Travel Course

• As well as local farmers, visiting Faculty, and community members

3. The combination of SARE and NHAES funding described above has supported a number of undergraduate and graduate students who have made significant contributions to the project, and represent a first generation of new professional trained at UNH in the agroecosystem area. These students include:

Masters Degree Level

Jennifer Campbell – Earth Science – Defining the hydrologic fluxes and stores at the ODRF – Degree expected in May of 2010.

Catherine Dunlap – Natural Resources and the Environment – Examining the fate of nitrate additions to the surface stream draining the Dairy to determine rates of nitrate uptake – Degree expected in May of 2010

Michelle Galvin – Natural Resources and the Environment – Measuring the effects of floodplain processes on losses of nitrogen, carbon, and other elements from stream that drains the dairy site – Degree Expected in May of 2010

Ashley Green – Natural Resources and the Environment – Investigating optimal methods for measuring pasture productivity and grazing intensity under intensive rotational management – Degree expected in December of 2010.

It is anticipated that each thesis will result in a published paper.

Undergraduate Level

Gabriel Perkins – Environmental Sciences – Completing an honors thesis on the nitrogen cycle at the ODRF

Amy Lamb – Environmental Sciences – Completing an honors thesis examining the effects of experimental modifications of material quality and degree of aeration on heat generation and trace gas production during composting of manures

Cathleen Turner – Environmental Sciences – Conducted regular measurements of soil moisture, assisted with analyses and calibration of soil moisture probe, and installation of stream flow monitoring equipment.

In addition, the following undergraduates have been engaged in research projects relating to history of land use on the farm and potential alternative sources of energy:

Jacqueline Amante, class of 2012
Makenzie Benander, class of 2012
Helen Clark, class of 2010
Brian Godbois, class of 2010
Paul Pellissier, class of 2012
Isabella Oleksy, class of 2012
Bryan Vangel, class of 2012

Undergraduates of presented their finding at the UNH Undergraduate Research Conference, and some of their posters can be found on the ODRF webpage.

Collaborators: