Final Report for LNE08-277
Our original proposal outlined clear milestones for the first three years of a projected 9 year program. We have now completed the first three years and embarked upon the second with a new award. In the period of the first award, we have completed all of the major tasks proposed. 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.
– Completed 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 5 graduate and 12 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
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.
The following text is modified from the original proposal.
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). The renewal proposal for the second round of funding has recently been submitted
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. Some initial output products can be found at:
A. Ecosystem Concept
The watershed-ecosystem concept was first proposed by Bormann and Likens (1967). At the heart of their approach was the construction of complete input and output water and nutrient budgets using gauged watersheds at the Hubbard Brook Experimental Forest in West Thornton, NH. Initial work was performed on a reference system (watershed 6) for which long-term records have now been developed and reported (Likens and Bormann 1995). This approach has also been valuable in analyzing the impacts of management practices and natural succession (e.g. Bormann and Likens (1994), and the long-term data sets increase in value in time, providing a basis from testing predictive ecosystem-level models (Aber et al. 2002).
PIs on this proposal have significant, long-term experience at Hubbard Brook (e.g. Aber et al. 1979, 2002, McDowell and Likens 1988, Bernhardt et al. 2005), and with other long-term ecosystem experiments related to disturbance, management history, and nutrient and energy balances (Aber et al. 1998; Chestnut et al. 1999, McDowell et al. 1996).
B. Soil and vegetation sampling
Permanent pasture and vegetation sampling points have been established at a set of georeferenced locations as part of a multiscale plot sampling regime in the major vegetation types and management areas on the farm (Stohlgren et al., 1995; Tracy and Sanderson, 2000). Species diversity and coefficient of community (Magurran, 1988) will be determined.
A key aspect of the sampling protocols initiated by our USDA collaborators is the co-location of soil and vegetation sampling sites. This will allow comparisons among vegetation indicators and soil variables, age, and land-use history and current management using the statistical methods of Urban et al. (2002).
The Soil Management Assessment Framework (SMAF) will be used to calculate Soil Quality Index (SQI) values for each indicator (Andrews et al., 2004), and the Pasture Condition Score system developed by the USDA-NRCS will be used to quantify pasture health (Cosgrove et al., 2001; Sanderson et al., 2005).
C. Nutrient and water balances
The watershed-ecosystem approach has been used successfully in regional synthesis efforts describing nitrogen dynamics (Boyer et al. 2002), as well as in more detailed studies of nitrogen and phosphorus budgets in large agricultural watersheds (e.g. Borbor-Cordova et al. 2006). Here we propose to build on this earlier work to develop energy, carbon, and nutrient budgets in a farm ecosystem.
Inputs of nutrients in rainfall will be measured at the nearby AIRMAP site (Talbot et al. 2005) on a storm event basis using an Aerochem Metrics wet deposition collector operated according to protocols similar to those established in the National Atmospheric Deposition program (NADP; e.g. McDowell et al. 1990). Analytes include NH4, NO3, DON, PO4, organic matter (DOC), and major cations and anions (Na, K, Ca, Mg, SO4, and Cl). Major cations and anions are measured by ion chromatography, NH4 and PO4 by automated colorimetric analysis using EPA-approved methods (http://www.epa.gov/waterscience/methods/method/index.html), and organic matter (DOC and DON) by Shimadzu high temperature carbon analyzer with nitrogen module (Merriam et al. 1996). Dry deposition will be estimated using relationships previously established for New England by Ollinger et al. (1993), and will be checked against direct measurements made at the AIRMAP site.
Outputs of nutrients and carbon in surface runoff will be measured as the product of runoff volume and measured nutrient concentration as is typically done in whole-watershed investigations (e.g. Bormann and Likens 1967). Surface water fluxes will be measured with a v-notch weir (Sanders, 1998). Groundwater discharges will be estimated by mapping the water table configuration, measuring hydraulic conductivity via slug-tests, and constructing a simple groundwater model of the site (e.g. Viller et al., 2003). Samples will be taken from wells on a monthly basis, and analyzed using the same methods applied to precipitation Particulate C, N, and P will be measured as well as dissolved materials in stream water. Particulate C and N and P will be measured using a Perkin-Elmer Elemental analyzer with colorimetric analysis of phosphate following digestion (http://www.epa.gov/waterscience/methods/method/index.html). Outputs to the Lamprey River in shallow groundwater will be assessed using hand-augured riparian wells (e.g. McDowell et al. 1992). Hydrologic fluxes from the wells to the river will be estimated using measures of piezometric surface (water table head) and saturated hydraulic conductivity. As with surface runoff, multiplying nutrient concentration by water volume will provide estimates of nutrient mass exported per unit time. Well samples will be taken for nutrients and organic carbon monthly and analyzed with the analytical techniques described above for precipitation.
Nutrient content in feed and products(C, N, and P) will be determined directly using methods described for particulate matter in stream runoff Estimates of nitrogen fixation by forest and pastures for New England will be taken from Boyer et al. (2002).
D. Carbon and energy balances
Methods for measuring biomass production in forests and fields are well-established. Diameter distributions and radial increment in forests are used in combination with allometric equations converting diameter into biomass to estimate total tree mass by component, and increment over time (e.g. Pastor et al, 1984a,b, Magill et al. 2004). Methods for pasture biomass sampling are also well-established (e.g. Lauenroth and Sala 1992), and the factors affecting production in managed and natural systems has been discussed in detail (e.g. Frank et al. 1998). Methods for estimating the energy content and carbon equivalents of fuels, and the efficiency of their use, are available at the Department of Energy (DOE) Energy Efficiency and Renewable Energy program (http://www.eere.energy.gov/).
E. Models of Agroecosystems
Several recent efforts have been made to compile energy and nutrient budgets for agricultural ecosystems, and to compare organic and traditional methods. From this extensive literature, only a few studies may be cited here. We have used the outline provided by Van Horn et al. (1996) as a starting point, rather than the more complex realizations found, for example, in Refsgaard et al. (1998). A framework for comparing organic and traditional systems can be drawn from Condron et al. (2000), Haas et al. (2001) and Pimentel et al. (2005). Studies on individual processes and components are available for selected parts of the farm system, notably the handling and impacts of manures (e.g. Van Horn et al., 1994).
Aber, J.D. 1979. Foliage-height profiles and succession in northern hardwood forests. Ecology 60:18-23
Aber, J.D., S.V. Ollinger, C.T. Driscoll, G.E. Likens, R.T. Holmes, R.J. Freuder, and C.L. Goodale 2002. Inorganic N losses from a forested ecosystem in response to physical, chemical, biotic and climatic perturbations. Ecosystems 5:648-658
Aber, J., McDowell, W., Nadelhoffer, K., Magill, A., Bernston, G., Kamakea, M., McNulty, S., Currie, W., L. Rustad, L., Fernandez, I. (1998) Nitrogen saturation in temperate forest ecosystems: Hypotheses revisited. BioScience, 48, 921-934.
Andrews, S.S., D.L. Karlen, and C.A. Cambardella. 2004. The soil management assessment framework: A quantitative soil quality evaluation model. Soil Sci. Soc. Am. J. 68:1945-1962.
Bernhardt, E.S., Likens, G.E., Hall, R.O., Buso, D.C., Fisher, S.G., Burton, T.M., Meyer, J.L., McDowell, W.H., Mayer, M.S., Bowden, W.B., Findlay, S.E.G., Macneale, K.H., Stelzer, R.S., Lowe, W.H. (2005) Can’t See the Forest for the Stream? – In-Stream Processing and Terrestrial Nitrogen Exports. BioScience, 55, 219-230
Bormann, F.H., Likens, G.E. 1967. Nutrient cycling. Science, 155, 424-429.
Bormann, F.H., Likens, G.E. 1994. Pattern and Process in a Forested Ecosystem. Springer-Verlag. NY. 253pp
Boyer, E.W., Goodale, C.L., Jaworski, N.A., Howarth, R.W. (2002) Anthropogenic Nitrogen Sources and Relationships to Riverine Nitrogen Export in the Northeastern USA. Biogeochemistry, 57, 137-169.
Borbor-Cordova, M.J., Boyer, E.W., McDowell, W.H., Hall, C.A. (2006) Nitrogen and Phosphorus Budgets for a Tropical Watershed Impacted by Agricultural Land Use: Guayas, Ecuador. Biogeochemistry, 79, 135-161.
Chestnut, T.J., Zarin, D.J., McDowell, W.H., Keller, M. (1999) A nitrogen budget for late-successional hillslope tabonuco forest, Puerto Rico. Biogeochemistry, 46, 85-108.
Condron, L.M., K.C. Cameron, U.J. Di,T.J. Clough, F.A. Forbes, R.G. McLaren, and R.G. Silva. 2000. A comparison of soil and environmental quality under organic and conventional farming in New Zealand. New Zealand Journal of Agricultural Research 43:443-466
Cosgrove, D., D.J. Undersander, and J. Cropper. 2001. Guide to pasture condition scoring. USDA NRCS Grazing Lands Technical Institute. ftp://ftp-fc.sc.egov.usda.gov/GLTI/technical/publications/pasture-score-guide.pdf.
Frank, D.A., and S.J. McNaughton. 1998. The ecology of the Earth’s grazing systems. BioScience 48: 513-521
Haas, G., F. Wetterich and U. Kopke. 2001. Comparing intensive, extensified and organic grassland farming in southern Germany by process of life cycle assessment. Agricultural Ecosystems and Environment 83:43-53
Lauenroth, W.K. and O.E. Sala. 1992, Long-term forage production of North American shortgrass steppe. Ecological Applications 2:397-403
Likens, G.E. and F.H. Bormann. 1995. Biogeochemistry of a Forested Ecosystem. Springer-Verlag, NY. 159pp.
Magill, A.H., J.D. Aber, W. Currie, K.J. Nadelhoffer, M.E. Martin, W.H. McDowell, J.M. Melillo and P. Steudler. 2004. Ecosystem Response to 15 years of Chronic Nitrogen Additions at the Harvard Forest LTER, Massachusetts, USA. Forest Ecology and Management 196:7-28
Magguran, A.E. 1988. Ecological diversity and its measurement. Princeton Univ. Press. Princeton, NJ.
McDowell, W.H., Likens, G.E. (1988) Origin, composition, and flux of dissolved organic carbon in the Hubbard Brook valley. Ecological Monographs, 58, 177-195
McDowell, W.H., McSwiney, C.P., Bowden, W.B. (1996) Effects of hurricane disturbance on groundwater chemistry and riparian function in a tropical rain forest. Biotropica, 28, 577-584.
McDowell, W.H., Bowden, W.B., Asbury, C.E. (1992) Riparian nitrogen dynamics in two geomorphologically distinct tropical rain forest watersheds – subsurface solute patterns. Biogeochemistry, 18, 53-75.
McDowell, W.H., Gines-Sanchez, C., Asbury, C.E., Ramos-Perez, C.R. (1990) Influence of seasalt aerosols and long range transport on precipitation chemistry at El Verde, Puerto Rico. Atmospheric Environment, 24A, 2813-2821.
Merriam, J., McDowell, W.H., Currie, W.S. (1996) A high-temperature catalytic oxidation technique for determining total dissolved nitrogen. Soil Science Society of America Journal, 60, 1050-1055.
Ollinger, S.V., Aber, J.D., Lovett, G.M., Millham, S.E., Lathrop, R.G., Ellis, J.M. (1993) A spatial model of atmospheric deposition for the northeastern United States. Ecological Applications, 3, 459-472.
Pastor, J., J.D. Aber, C.A. McClaugherty and J.M. Melillo. 1984. Above ground production and N and P cycling along a nitrogen mineralization gradient on Blackhawk Island, Wisconsin. Ecology 65:256-268
Pastor, J., J.D. Aber and J.M. Melillo. 1984. Biomass prediction using generalized allometric regressions for some northeast tree species. Forested Ecosystems. Forest Ecology and Management 7:265-274
Pimentel, D., P. Hepperly, J. Hanson, D. Douds and R. Seidel. 2005. Environmental, energetic, and economic comparisons of organic and conventional farming systems. BioSceince 55:573-582
Refsgaard, K., N. Halberg and E.S. Kristensen. 1998. Energy utilization in crop and dairy production in organic and conventional livestock production systems. Agricultural Systems 57:599-630
Sanders, L.L., 1998, A Manual of Field Hydrogeology, Prentice Hall
Sanderson, M.A., S.C. Goslee, and J.B. Cropper. 2005. Pasture assessment in the northeast United States. Forage and Grazing Lands. http://www.plantmanagementnetwork.org/fg/. Doi:10.1094/FG-2005-1031-01-RS.
Stohlgren, T.J., M.B. Falkner, and L.D. Schell. 1995. A modified Whittaker plot nested vegetation sampling method. Vegetation 117:113-121.
Talbot, R., H. Mao, and B. Sive (2005), Diurnal characteristics of surface-level O3 and other important trace gases in New England, J. Geophysical Research, 110, D09307, doi:10.1029/2004JD005449.
Tracy, B.F. and M.A. Sanderson 2000. Patterns of plant species richness in pasture lands of the Northeast United States. Plant Ecology 149:169-180.
Urban, D., S. Goslee, K. Pierce, and T. Lookingbill. 2002. Extending community ecology to landscapes. Ecoscience 9:200-212.
Van Horn, H.H., G.L. Newton and W.E. Kunkle. 1996. Ruminant nutrition from an environmental perspective: Factors affecting whole-farm nutrient balance. Journal of Animal Science 74:3082-3102
Van Horn, H.H., A.C. Wilkie, W.J. Powers and R.A. Nordstedt. 1994. Journal of Dairy Science 77:2008-2030
Vellidis, G., R. Lowrance, P. Gay, and R.K. Hubbard, 2003, Nutrient transport in a restored riparian wetland, Journal of Environmental Quality, 32: 711-726.
Our original proposal outlined a project timeline for the first three years, as well as tentative goals for years 4-9. Using the outline from the original proposal, we can document the following accomplishments:
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 on website). 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 on the website given above.
• 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 gages, 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 which the majority of the flows occur.
We have recently completed the synthesis of the geologic, topographic, and hydrologic information into a three-dimensional groundwater model using MODFLOW 2005 for a summer-fall season. 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. A detailed water budget analysis suggests that the 84 acre watershed inclusive of the farm buildings and the majority of the main pasture (Field 2) is dominated by precipitation, evapotranspiration, and discharge into the wetland and small stream. Groundwater seepage rates out of the watershed appear to be small. The stream gauging instrumentation installed initially was destroyed during the two large floods in spring of 2010. We have upgraded the monitoring and are now positioned to obtain streamflows for the upcoming winter and spring.
The hydrologic flows are 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 (NO3) are elevated in some wells down gradient 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. We have also sampled above and below the farm in the adjacent Lamprey River, and find no evidence of an impact of the ODRF 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.
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 role in reducing the impacts of dairy farm operations on water quality. 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 has been completed that has measured the interactions among degree of aeration, and both pile temperature and CO2, CH4, O2 and H2S concentrations. 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. A poster summarizing some of the key results from this research is available at the website given at the top of this section. This poster was presented at the 2010 Undergraduate Research Conference. Of interest to the energy analyses described in Part II, the fans for this system were powered by a solar collector/battery energy source.
As described below (Impacts and Contributions), the research around manure handling and composting has affected the design of a newly constructed 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 results have been posted to the projects webpage. It is estimated that the nearly 160 acres of woodlands on the farm can produce enough wood on a sustainable basis to meet total farm demand for both bedding and energy. This work was carried out with the help of a number of undergraduates who were introduced to field research through this project. A powerpoint file summarizing the results is available at our results website given above. It is not unusual for operating farms in New England to have similar forest resources. The historical pattern of land clearance until the mid-nineteenth century, followed by land abandonment and forest regrowth over the last 150 years has resulted in a mix of open and forested land in most areas in which agriculture is still active.
Alternative ways for utilizing the energy resource represented by this forest resource are presented in the next section.
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. A key finding has been that pastures were overgrazed in the summer of 2009 (reduced to too little plant mass following grazing) and this has been used to redefine paddock size in 2010.
• Investigate alternative methods for increased efficiency of resource use, generation of energy and minimization of nutrient loss.
A number of 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 (see results website). Milk cooling seems to be the best first avenue for exploration, as described in the section on proposed work below.
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 both 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 a presentation on the website.
We have tested two different methods for producing shavings suitable for bedding either from wood chips, or directly from whole logs. In the following section on proposed work we outline steps to be taken to test this method for producing bedding, and the applicability of an integrated wood-bedding-compost system for producing both energy and soil amendments.
• 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 and on-farm processing have been fully explored.
Close cooperation between this research project and the operation of the organic dairy, along with significant contributions by a major organic processor (Stonyfield Farms) have resulted in significant changes in farm infrastructure and overall farm management practices. These changes provide excellent opportunities for documenting the effects of alternative management methods on energy and nutrient cycles.
Additional Project Outcomes
Impacts of Results/Outcomes
1. Visits to the Farm by stakeholders both individually and as part of organized outreach functions
2. Changes in direction for support for research, facilities design and construction, and Farm operations by the New Hampshire Agricultural Experiment Station (NHAES)
3. Students trained and traditional scientific presentations
Transparent and open communication has been a goal of this project, and of the Organic Dairy Research Farm since its inception. Diverse groups of stakeholders have visited the farm over the last 2 years, and each group learns about the SARE Agroecosystem study underway here. The College of Life Sciences and Agriculture at UNH, as well as the NH Agricultural Experiment Station (NHAES) have been generous with matching support, and have used the goals and early results of this project to design facilities and alter management processes. That support has also multiplied the number of students engaged in the project to date. The outcome of faculty and graduate student research has been captured in a number of masters theses, and is being prepared for publication.
1. 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.
• 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 Water – How Much is Enough?
o Principles of Hydrology
• Students from pre K-12 schools, including
o Oyster River Preschool/Parents
o Phillips Exeter Academy
o Dairy Travel Course
• About 50 people from UNH and surrounding communities, including NH Secretary of Agriculture Lorraine Merrill, who attended the first Burley Demeritt/Organic Diary Field Day in August 2010
• A number of local farmers, visiting Faculty, and community members who are always welcome at the Farm.
2. Contributions from NHAES and Impacts of this Research on Operations
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 (net 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. This includes 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.
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 in cooperation with the composting and nutrient management goals of the SARE project. It also includes runoff reduction and sediment retention that should reduce N inputs to groundwater.
• Plans for a manure handling facility are going forward with the goal of incorporating information gained from the composting research objective of this project.
NHAES is also supporting a number of related studies focusing on animal nutrition and health, including:
• Tom Foxall, Pete Erickson, Nancy Whitehouse and Colleen Chapman (graduate student) will be starting a study titled “Markers of Health Status in Pasture-Fed vs. Total Mixed Ration-Fed Dairy Cows.”
• André Brito and Lindsay Chase (undergraduate-Animal Science Pre-Vet, Senior Honor’s Thesis) will be conducting a study titled “Effect of Kelp on Growth of Dairy Calves” to start shortly.
• In addition, Professor Brito has, with initial support from NHAES, submitted two grant proposals: 1) To Organic Farming Research Foundation (OFRF), titled “Molasses as an Alternative Energy Feed Source for Organic Dairies”;, and 2) “Can sunset pasture allocation and low concentrate supplementation optimize milk production?”
3. Graduate and Undergraduate Student Support
The combination of SARE funding and the collaborative support from the NHAES 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.
The following Masters students have completed or are nearing completion of their thesis work (with thesis titles and date of completion):
• Jennifer Campbell (SARE) – Earth Science – Spatial and temporal groundwater recharge patterns in a temperate climate: An investigation at the Burley Demeritt Farm, Lee, New Hampshire – May 2010.
• Catherine Dunlap (SARE/NHAES) – Natural Resources and the Environment – Seasonal nitrate dynamics in an agriculturally influenced New Hampshire headwater stream – May 2010
• Michelle Galvin (SARE) – Natural Resources and the Environment – Hydrologic and nutrient dynamics in an agriculturally influenced New England floodplain – May 2010
• Ashley Green (NHAES/SARE) – Natural Resources and the Environment – Investigating optimal methods for measuring pasture productivity and grazing intensity under intensive rotational management – Degree expected December 2010.
It is anticipated that each thesis will result in a published paper.
In addition Dr. Davis will be presenting a paper at this year’s meeting of the American Geophysical Union (AGU) on “Hydrological and biogeochemical investigation of an agricultural watershed, southeast New Hampshire, USA” authored by JM Davis, WH McDowell, JE Campbell, and AN Hristov.
The SARE project has provided an excellent platform for a number of significant undergraduate research projects. Two undergraduate honors theses were completed in May 2010:
• Gabriel Perkins – Environmental Sciences – Assessing Avenues for Sustainability: Evaluating Nitrogen Flows at UNH’s Organic Dairy Research Farm
• Amy Lamb – Environmental Sciences – Composting and Sustainability: Trace Gas Yields and Energy Production with Different Materials and Methods
In addition, the following undergraduates have been engaged in research projects relating to history of land use on the farm, potential alternative sources of energy, and measurement of groundwater dynamics:
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
Cathleen Turner, class of 2013
Bryan Vangel, class of 2012
All of these undergraduates have presented their finding at the UNH Undergraduate Research Conference, and some of their posters can be found on the ODRF webpage.
This phase 1 work obtained many of the basic data needed to put changes in process into practice (e.g. bedding/compost/energy). In the second round, we are beginning with a full-cycle economic analysis of this particular process, and will also be adding life cycle analyses of water use and nutrient flows.
As with the economic analysis, we have, in the first three years, collected the basic data about processes on the Farm for use in alteration of management practices, which will be tested in the second round currently underway. As indicated under Impacts, a large number of producers and managers have visited the farm and seen the research projects.
Areas needing additional study
Areas requiring further research are described in detail in the proposal for the second phase of the research. These can be summarized briefly here:
1. Hydrology and Water Quality
a. Continued groundwater hydrology
The hydrologic monitoring goals for Phase II include:
• Year 4: Continue monitoring of main watershed. Extend hydrologic monitoring to adjacent watershed (establish stream gauging station, install additional wells). Initiate routine monitoring of soil moisture.
• Year 5: Continue monitoring of both watersheds. Begin utilizing multi-year observations and natural inter-annual variability to better understand relationships between farm management practices and hydrologic fluxes.
• Year 6: Summarize how different management practices affect hydrologic fluxes. Use improved understanding to develop appropriate strategies for dealing with drought.
b. Continued water quality monitoring
The goals of the water quality monitoring during the second phase of this project are to: 1) document the effectiveness of changing farm management practices (including the new barn and feeding station now in place and proposed changes in manure processing described below) on nutrient losses from the site; and 2) quantify the role of the wetland in reducing off-site nutrient losses.
c. Calculating the water footprint of the Farm
During Phase II, we will quantify the water footprint of milk production at the UNH Organic Research Dairy Farm by
• Metering the (blue) water used in stock tanks and washdowns.
• Computing the (green) water taken up by evapotranspiration in the growing of forage and the production of pelletized feed and bedding.
• Quantifying the amount of (gray) water that leaves the site impaired. Preliminary results suggest that this component is small.
2. Closing the Nitrogen Cycle
a. Measurement of gaseous N exchanges
In this phase of our project, we will quantify the inputs of N to the pastures using the acetylene reduction method for measuring N fixation. We will also quantify denitrification rates by measuring field fluxes of N2O using the static chamber approach, and the acetylene block method to measure the molar ratio of N2O to N2.
b. Updating data on the nitrogen cycle
A first assessment of the current nitrogen cycle on the farm has been produced (see Part I above). In addition to the new work proposed on gaseous exchanges, we will continue to measure and monitor nitrogen inputs and output in products purchased and sold, and N dynamics associated with water balances.
c. Minimizing nitrogen input
Primary sources of N inputs to the farm are in feeding supplements and grains imported from organic sources outside of the UNH farm system, and in hay harvested from other UNH sites. We will examine ways to minimize grain imports by maximizing feeding of forage. Bedding is an import expense to the farm but, given the very low nitrogen concentration in the wood fibers used, represents a relatively small nitrogen input to the system. Still, the proposed integrated wood shavings/bedding/energy/compost system described in the next section would also reduce N inputs to the farm somewhat.
3. Moving Toward Energy Independence
a. Finalizing the current energy budget and energy system analysis
With a thorough understanding of the current use of energy on the farm, we will support a Ph.D. student who will formalize initial analyses of alternative energy systems for the farm, and develop and test solutions. While we are not sure of the outcomes from this analysis before it is complete, the next two sections cover two of the most likely initial energy system modifications.
b. Geothermal application for milk cooling
During Phase II, we will develop a geothermal well on site and, using the specifications of different possible components of the three approaches. We will also examine the possibility for using an earth-energy heat pump to air condition the room in which the milk tank sits in order to improve the efficiency of the mechanical cooling provided to the tank. Because these applications will be used exclusively to reject heat into the ground, we will also monitor to subsurface temperatures and explore the possibility of circulating cold surface water into the well during the winter so that heat does not build up over time
c. Integrated wood shavings/bedding/energy/compost system
Integrated systems approaches to internalizing energy, carbon and nitrogen cycles will succeed where one resource can be used several times to meet different needs. In our Organic Dairy Agroecosystem context, the best candidate for reducing our energy and carbon footprints is a multi-step process that uses the abundant wood resource on the farm to meet energy, bedding and soil amendment requirements. We will pursue the integrated system outlined in our renewal proposal.