Energy as a potential systems-level indicator of sustainability in organic agriculture: Case study model of a diversified, organic vegetable production system

Ecological Modelling

Volumn 267, Issue , 2013, Pages 102-114

  Schramski, J R ^a   Jacobsen, K L ^b   Smith, T W ^c   Williams, M A ^b   Thompson, T M ^b  

^a University of Georgia   (United States)

^b UNIVERSITY OF KENTUCKY   (United States)

^c UNIVERSITY OF VIRGINIA   (United States)

Author keywords

Agroecology; Energy; Energy return on energy invested; EROI; Organic agriculture; Sustainable agriculture

Indexed keywords

AGRO ECOLOGIES; ENERGY; ENERGY RETURN ON ENERGY INVESTED; EROI; ORGANIC AGRICULTURE; SUSTAINABLE AGRICULTURE;

COMMERCE; ENERGY DISSIPATION; GAGES; PRODUCTION ENGINEERING; RESEARCH; SUSTAINABLE DEVELOPMENT; VEGETABLES;

AGRICULTURE;

AGRICULTURAL ECONOMICS; AGRICULTURAL PRODUCTION; ENERGY DISSIPATION; ENERGY FLOW; ENVIRONMENTAL INDICATOR; MARKETING; ORGANIC FARMING; VEGETABLE;

KENTUCKY; UNITED STATES;

EID: 84883270165     PISSN: 03043800     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.ecolmodel.2013.07.022     Document Type: Article

References (133)

1. Alcorn J.A. Embodied Energy Coefficients of Building Materials 1996, Centre for Building Performance Research, Victoria University of Wellington, Victoria.
2. Allison I., Bindoff N.L., Bindoff R.A., Bindschadler R.A., Cox P.M., de Noblet N., England M.H., Francis J.E., Gruber N., Haywood A.M., Karoly D.J., Kaser G., Le Quéré C., Lenton T.M., Mann M.E., McNeil B.I., Pitman A.J., Rahmstorf S., Rignot E., Schellnhuber H.J., Schneider S.H., Sherwood S.C., Somerville R.C.J., Steffen K., Steig E.J., Visbeck M., Weaver A.J. The Copenhagen Diagnosis, 2009: Updating the World on the Latest Climate Science 2009, 60. The University of New South Wales Climate Change Research Centre (CCRC), Sydney, Australia.
3. Alluvione F., Moretti B., Sacco D., Grignani C. EUE (energy use efficiency) of cropping systems for a sustainable agriculture. Energy 2011, 36(7):4468-4481.
4. Anundskas A. Technical improvements in mineral nitrogen fertilizer production. Harvesting Energy with Fertilizers 2000, European Fertilizer Manufacturers Association, Brussels, Belgium.
5. Appelbaum, B., 2000. Water and Sustainability (volume 4): U.S. Electricity Consumption for Water Supply and Treatment-the Next Half Century. March 1, 2002. Electric Power Research Institute. Available from: 〈〉. (accessed July 22, 2012). http://epri.com/.
6. ASAE Standards Agricultural Machinery Management 2002, ASAE, St. Joseph, Michigan, EP496.2. 49th ed.
7. Bailey A.P., Basford W.D., Penlington N., Park J.R., Keatinge J.D.H., Tehman T., Tranter R.B., Yates C.M. A comparison of energy use in conventional and integrated arable farming systems in the United Kingdom. Agriculture, Ecosystems and Environment 2003, 97:241-253.
8. Baird, G., Chan, S.A., 1983. Energy Cost of Houses and Light Construction Buildings. New Zealand Energy Research and Development Committee. NZERDC Report No. 76. Auckland.
9. Berry R.S., Fels M.F. The Production and Consumption of Automobiles: An Energy Analysis 1973, 56. University of Chicago, Chicago, Ill.
10. Berry R.S., Makino H. Energy thrift in packaging and marketing. Technology Review 1974, 76(4):32-43.
11. Bhat, M.G., English, B.C., Turhollow, A.F., Nyangito, H.O., 1994. Energy in Synthetic Fertilizers and Pesticides: Revisited. Research Report No. ORNL/Sub/90-99732/2. Oak Ridge National Laboratory, U.S. Dept. Energy, Oak Ridge, TN.
12. Biosystems, LLC., January, 2009. Biosystems Services and Products. Blacksburg, VA. Available from: 〈〉. (accessed July 20, 2012). http://www.biosystemsllc.com/.
13. Black J.N. Energy relations in crop production: a preliminary survey. Annals of Applied Biology 1971, 67:272-278.
14. Brantly J.E. History of Oil Well Drilling 1971, Gulf Publishing, Houston.
15. Brinton W.F. What's your compost energy index?. Biocycle 2008, 49(2):45.
16. Button, S., Sell, B., 2008. Appendix C: Natural Gas: Potential, EROI and Social and Environmental Impacts. The Oil Drum. Available from: 〈〉. (accessed on July 21, 2012). http://www.theoildrum.com/node/3810.
17. Cao S., Xie G., Zhen L. Total embodied energy requirements and its decomposition in China's agricultural sector. Ecological Economics 2010, 69(7):1396-1404.
18. Cleveland C.J. The direct and indirect use of fossil fuels and electricity in USA agriculture, 1910-1990. Agriculture, Ecosystems and Environment 1995, 55:111-121.
19. Cleveland C.J. Resource degradation, technical change, and the productivity of energy use in U.S. agriculture. Ecological Economics 1995, 13:185-201.
20. Cox G.W., Atkins M.D. Agricultural Ecology 1979, San Francisco, Freeman.
21. Crop pest, 2010. Crop Pest Weed, and Disease Management Practice Standard. Code of Federal Regulations Title 7. Pt. 205.206.
22. Dalgaard T., Halberg N., Porter J.R. A model for fossil energy use in Danish agriculture used to compare organic and conventional farming. Agriculture, Ecosystems and Environment 2001, 87:51-65.
23. Deleage J.P., Julien J.M., Sauget-Naudin N., Souchon C. Eco-energetics analysis of an agricultural system: the French case in 1970. Agro-Ecosystems 1979, 5:345-365.
24. Dovring F. Energy use in United States agriculture: a critique of recent research. Energy in Agriculture 1985, 4:79-86.
25. Duhon D. One Circle 1985, Ecology Action, Willits, CA.
26. 2 emissions from farm field operations using a regional level crop and land use database for Canada. Energy 2010, 35:2261-2269.
27. EIA, 2007. International Energy Outlook. U.S. Department of Energy, Energy Information Administration, Washington, DC. Available from: 〈〉 (accessed April 4, 2012). http://tonto.eia.doe.gov/ftproot/forecasting/0484(2007).pdf.
28. EIA, 2012a. Electric Power Monthly, June. Department of Energy, Energy Information Administration. Available from: 〈〉 (accessed July 20, 2012). http://www.eia.gov/electricity/monthly/pdf/epm.pdf.
29. EIA, 2012b. Annual Energy Outlook 2012, June. Department of Energy, energy Information Administration. Available from: 〈〉 (accessed July 23, 2012). http://www.eia.gov/forecasts/aeo/chapter_executive_summary.cfm.
30. Engström R., Wadeskog A., Finnveden G. Environmental assessment of Swedish agriculture. Ecological Economics 2007, 60:550-563.
31. Evans, H.R., 2003. What are biopesticides. In: Roettger, U., Muschler, R. (Eds.) International Symposium on Biopesticides for Developing Countries, October, 2003, Costa Rica, Catie, Turrialba, pp. 28-30.
32. Fadare D.A., Bamiro O.A., Oni A.O. Energy and cost analysis of organic fertilizer production in Nigeria. Energy 2010, 35:332-340.
33. FAO/WHO/UNU, 2001. Human Energy Requirements. Report of a Joint FAO/WHO/UNU. FAO Food and Nutrition Technical Report Series, Rome.
34. Fluck R.C. Energy sequestered in repairs and maintenance of agricultural machinery. Transactions of the American society of agricultural engineers (ASAE) 1985, 28:738-744.
35. Energy in Farm Production 1992, 6. Elsevier, Amsterdam.
36. Fluck R.C., Baird C.D. Agricultural Energetics 1980, The AVI Publishing Company, Westport, CT.
37. Forbes R.J. Power to 1850. A History of Technology 1958, 4:148-167. Clarendon Press, Oxford, London.
38. Gagnon N., Hall C.A.S., Brinker L. A preliminary investigation of energy return on energy investment for global oil and gas production. Energies 2009, 2:490-503.
39. Gately M. The EROI of U.S. offshore energy extraction: a net energy analysis of the Gulf of Mexico. Ecological Economics 2007, 63:355-364.
40. Giampietro M., Pimentel D. Assessment of the energetics of human labor. Agriculture, Ecosystems and Environment 1990, 32:257-272.
41. Gliessman S.R. Agroecology; Ecological Processes in Sustainable Agriculture 2007, Ann Arbor Press, Chelsea, MI.
42. Gomiero T., Paoletti M.G. Organic and sustainable agriculture and energy conservation. Biofuels, Solar and Wind as Renewable Energy Systems 2008, Springer, New York, Heidelberg. D. Pimentel (Ed.).
43. Green M. Energy in pesticide manufacture, distribution, and use. Energy in Plant Nutrition and Pest Control 1987, 165-196. Elsevier, New York. Z.R. Helsel (Ed.).
44. Grisso, R.D., Kocher, M.F., Vaughan, D.H., 2004. Predicting Tractor Fuel Consumption, Biological Systems Engineering: Papers and Publications. Paper 164. Nebraska Tractor Test Laboratory (NTTL).
45. Gupta A.K., Hall C.A.S. A review of the past and current state of EROI data. Sustainability 2011, 3(10):1796-1809.
46. Gussow J.D. Chicken Little, Tomato Sauce & Agriculture: Who Will Produce Tomorrow's Food? 1991, Toes Books and the Bootstrap Press, New York.
47. Guzmán G.I., Alonso A.M. A comparison of energy use in conventional and organic olive oil production in Spain. Agricultural Systems 2008, 98(3):167-176.
48. Haas G., Wetterich F., Kopke U. Comparing intensive, extensified and organic grassland farming in southern Germany by process of life cycle assessment. Agriculture, Ecosystems and Environment 2001, 83:43-53.
49. Hagens, N., 2008. An Update on the Energy Return on Canadian Natural Gas. The Oil Drum. Available from: 〈〉. (accessed July 21, 2012). http://www.theoildrum.com/node/4376.
50. Hammond G.P., Jones C.I. Embodied energy and carbon in construction materials'. Energy 2008, 161(2):87-98.
51. Harris J.R. The rise of coal technology. Scientific American 1974, 233(2):92-97.
52. Hayes E.T. Energy implications of materials processing. Science 1976, 191:661-665.
53. Heichel G.H. Assessing the fossil energy costs of propagating agricultural crops. Handbook of Energy Utilization in Agriculture 1980, CRC Press, Boca Raton, FL. D. Pimentel (Ed.).
54. Helsel Z.R. Energy and alternatives for fertilizer and pesticide use. Energy in Farm Production 1992, 6:177-201. Elsevier, New York.
55. Helsel Z.R. Energy in pesticide production and use. Encyclopedia of Pest Management 2007, 2. Taylor & Francis, NY.
56. Hirsch, R.L., Bezdek, R., Wendling, R., 2005. Peaking of World Oil Production: Impacts, Mitigation, & Risk Management. Task no. 21006W. U.S. Department of Energy National Energy Technology Laboratory and Energy and Environmental Solutions, LLC.
57. Hoeppner J.W., Entz M.H., McConkey B.G., Zentner R.P., Nagy C.N. Energy use and efficiency in two Canadian organic and conventional crop production systems. Renewable Agriculture and Food Systems 2006, 21(1):60-67.
58. Hynes R.K., Boyetchko S.M. Research initiatives in the art and science of biopesticide formulations. Soil Biology & Biochemistry 2006, 38:845-849.
59. Jones M.R. Analysis of the use of energy in agriculture-approaches and problems. Agricultural Systems 1989, 29:339-355.
60. Kaltsas A.M., Mamolos A.P., Tsatsarelis C.A., Nanos G.D., Kalburtji K.L. Energy budget in organic and conventional olive groves. Agriculture, Ecosystems and Environment 2007, 122:243-251.
61. Nachwachsende energietrager-grundlagen, verfahren, okologische bilanzierung 1997, Vieweg-Verlag, Braunschweig/Wiesbaden, Germany. M. Kaltschmitt, G.A. Reinhardt (Eds.).
62. Karlen D.L., Duffy M.D., Colvin T.S. Nutrient, labor, energy, and economic evaluations of two farming systems in Iowa. Journal of Production Agriculture 1995, 8. 540-346.
63. 2 and climate. Global Biogeochemical Cycles 2008, 22:GB3012.
64. Lawson B., Rudder D. Building Materials, Energy and the Environment: Towards Ecologically Sustainable Development 1996, 135. Royal Australian Institute of Architects, Barton.
65. Leach G., Slesser M. Energy Equivalents of Network Inputs to Food Producing Processes 1973, 38. University of Strathclyde, Glasgow.
66. Lynch D.H., MacRae R., Martin R.C. The carbon and global warming potential impacts of organic farming: does it have a significant role in an energy constrained world?. Sustainability 2011, 3:322-362.
67. MacDougall, N.A, 2005. The Certified Organic Seed Market: Implications of Delayed Development. In: A Report Prepared for the California Institute for the Study of Specialty Crops, CISSC.
68. Mäder P., Flieβbach A., Dubois D., Gunst L., Fried P., Niggli U. Soil fertility and biodiversity in organic farming. Science 2002, 296:1694-1697.
69. McArdle W.D. Exercise Physiology 1986, Lea & Febigier, Philadelphia, PA. second ed.
70. Meinshausen, M., 2007. Climate Change and Human Development-Risk and Vulnerability in a Warming World, Human Development Report 2007/2008. Palgrave Macmillan, New York.
71. Meitner L., Frisch O.R. Disintegration of uranium by neutrons: a new type of nuclear reaction. Nature 1939, 143:239-240.
72. Millennium ecosystem assessment Ecosystems and Human Well-Being: General Synthesis 2005, Island Press, Washington, DC, US.
73. Moore S.R. Energy efficiency in small-scale biointensive organic onion production in Pennsylvania, USA. Renewable Agriculture and Food Systems 2010, 25(3):181-188.
74. Murphy D.J., Hall C.A.S. Year in review EROI or energy return on (energy) invested. Annals of the New York Academy of Sciences 2010, 1185:102-118.
75. Murphy D.J., Hall C.A.S., Dale M., Cleveland C. Order from chaos: a preliminary protocol for determining the EROI of fuels. Sustainability 2011, 3(10):1888-1907.
76. Nagy, C.N., 1999. Energy Coefficients for Agriculture Inputs in Western Canada. Report by the Canadian Agricultural Energy End-Use Data Analysis Centre. Centre for Studies in Agriculture, Law and the Environment. University of Saskatchewan, Saskatoon, Canada.
77. Needham J. The Department of Iron and Steel Industry in China 1964, W. Heffer, Cambridge.
78. Nef U. The Rise of the British Coal Industry 1932, Routledge, London.
79. Newell G.R., Jaffe J.A., Stavins N.R. The effects of economic and policy incentives on carbon mitigation technologies. Energy Economics 2006, 28:563-578.
80. Nguyen M.L., Haynes R.J. Energy and labour efficiency for three pairs of conventional and alternative mixed cropping (pasture-arable) farms in Canterbury (New Zealand). Agriculture, Ecosystems and Environment 1995, 52:163-172.
81. NPC (National Petroleum Council), 2007. Electric Generation Efficiency. NPC Global Oil & Gas Study, Topic Paper no. 4.
82. Ozkan B., Akcaoz H. Energy input-output analysis in Turkish agriculture. Renewable Energy 2004, 29(1):39-51.
83. Pelletier N., Arsenault N., Tyedmers P. Scenario modeling potential eco-efficiency gains from a transition to organic agriculture: life cycle perspectives on Canadian canola, corn, soy, and wheat production. Environmental Management 2008, 42(6):989-1001.
84. Pelletier N., Audsley E., Brodt S., Garnett T., Henriksson P., Kendall A., Kramer K.J., Murphy D., Nemecek T., Troell M. Energy intensity of agriculture and food systems. Annual Review of Environment and Resources 2011, 36:223-246.
85. Handbook of Energy Utilization in Agriculture 1980, 475. CRC Press, Boca Raton, FL. D. Pimentel (Ed.).
86. Pimentel D. Energy flow in agroecosystems. Agricultural Ecosystems: Unifying Concepts 1984, 121-132. Wiley, New York, NY. R. Lowrance, B.R. Stinner, G.J. House (Eds.).
87. Pimentel D. Impacts of Organic Farming on the Efficiency of Energy use in Agriculture: An Organic Center State of Science Review. The Organic Center 2006, Cornell University, Ithaca, NY.
88. Pimentel D., Berardi G., Fast S. Energy efficiency of farming systems: organic and conventional agriculture. Agriculture, Ecosystems & Environment 1983, 9(4):359-372.
89. Pimentel D., Hepperly P., Hanson J., Douds D., Seidel R. Environmental, energetic, and economic comparisons of organic and conventional farming systems. Bioscience 2005, 55(7):573-592.
90. Pimentel D., Hurd L.E., Bellotti A.C., Forster M.J., Oka I.N., Sholes O.D., Whitman R.J. Food production and energy crisis. Science 1973, 182:443-449.
91. Pimentel D., Pimentel M. Food, Energy, and Society 2008, CRC Press, Boca Raton, FL, USA. third ed.
92. Piringer G., Steinberg L.J. Reevaluation of energy use in wheat production in the United States. Journal of Industrial Ecology 2006, 10(1-2):149-167.
93. Pfeiffer D.A. Eating Fossil Fuels: Oil, Food and the Coming Crisis in Agriculture 2006, New Society Publishers, Gabriola Island, BC, Canada.
94. Rasheed, S.T., 1997. Net-Energy Life-Cycle Analysis of a Natural Gas Combined-Cycle Power Ensemble. Graduate Thesis. Master of Science Mechanical Engineering. University of Oklahoma.
95. Rogers D., Alum M. Comparing Irrigation Energy Cost. Kansas State Research and Extension Service MF-2360 2007, Kansas State University, Manhattan, KS.
96. Sartori L., Basso B., Bertocco M., Oliviero G. Energy use and economic evaluation of a three year crop rotation for conservation and organic farming in NE Italy. Biosystems Engineering 2005, 91(2):245-256.
97. Schahczenski J.J. Energetics and traditional agricultural systems: a review. Agricultural Systems 1984, 14:31-43.
98. Schnepf, R., 2004. Energy use in Agriculture: Background and Issues. Congressional Research Service, Library of Congress. CRS Report for Congress no. RL32677.
99. Schramski J.R., Rutz Z.J., Gattie D.K., Li K. Trophically balanced sustainable agriculture. Ecological Economics 2011, 72:88-96.
100. SFNB (Subcommittee of the Food and Nutrition Board), 1989. Recommended Dietary Allowances. 10th ed. Commission on Life Sciences, National Research Council, National Academy of Science, National Academy Press, Washington, DC.
101. Shapouri, H., Duffield, J.A., Wang, M., 2002. The Energy Balance of Corn Ethanol: An Update. U.S. Department of Agriculture, Office of the Chief Economist. Office of Energy Policy and New Uses. Agricultural Economic Report No. 813.
102. Sloggett, G., 1979. Energy Use and U.S. Agriculture: Irrigation Pumping 1974-1977. Agriculture Economic Report No. 436. USDA, Washington, DC.
103. Sloggett G. Estimating energy use in world irrigation. Energy in Farm Production 1992, 203-218. Elsevier, Amsterdam. R.C. Fluck (Ed.).
104. Smil V. Energy in Nature and Society: General Energetics of Complex Systems 2008, MIT Press, Cambridge, MA.
105. Smil V., Nachman P., Long T.V.I.I. Energy Analysis and Agriculture: An Application to Corn Production 1983, 191. Westview, Boulder, CO.
106. Smil V., Nachman P., Long I.I.T.V. Technological changes and the energy cost of U.S. grain corn. Energy in Agriculture 1983, 2:177-192.
107. Solomon S., Plattner G.K., Knutti R., Friedlingstein P. Irreversible climate change due to carbon dioxide emissions. Proceedings of the National Academy of Sciences 2009, Available from:. Accessed on July 20, 2012. http://www.pnas.org/content/early/2009/01/28/0812721106.
108. Sonesson, U., 1996. Modelling of the Compost and Transport Process in the Orware Simulation Model. Institutionen för Iantbruksteknik, Swedish University of Agriculture Sciences, Department of Agricultural Engineering. Rapport 214, Uppsala 1996, ISSN 0283-0086; ISRN SLU-LT-R--214-SE.
109. Spath P.L., Mann M.K., Kerr D.R. Life Cycle Assessment of Coal-Fired Power Production 1999, National Renewable Energy Laboratory, U.S. Department of Energy, Golden, CO, NREL/TP-570-25119.
110. Spath P.L., Mann M.K. Life Cycle Assessment of a Natural Gas Combined-Cycle Power Generation System 2000, National Renewable Energy Laboratory, U.S. Department of Energy, Golden, CO, NREL/TP-570-27715.
111. Stanhill G. Energy and agriculture: a national case study. Agro-Ecosystems 1974, 1:205-217.
112. Stout B.A. Energy Use and Management in Agriculture 1984, Breton Publishers, N. Scituate, MA.
113. Tainter J. The Collapse of Complex Societies 1990, Cambridge University Press, Cambridge.
114. Tharion W.J., Lieberma H.R., Montain S.J., Young A.J., Baker-Fulco C.J., DeLany J.P., Hoyt R.W. Energy requirements of military personnel. Appetite 2005, 64:47-65.
115. Treloar G.J. Extracting embodied energy paths from input-output tables: towards an input-output-based hybrid energy analysis method. Economic Systems Research 1997, 94(4):375-391.
116. Treloar G.J., Love P.E.D., Crawford R.H. Hybrid life-cycle inventory for road construction and use. Journal of Construction Engineering and Management 2004, 130(1):43-49.
117. University of Kentucky Sustainable Agriculture Program April 2012. Community Supported Agriculture Project. Lexington, Kentucky. Available from: 〈〉 (accessed July 20, 2012). http://www2.ca.uky.edu/sustainableag/csa.
118. USCB, 2008. World Population Clock, August 2008. U.S. Census Bureau, Washington, DC. Available from: 〈〉 (accessed May 4, 2010). http://www.prb.org/Articles/2008/worldpopulationclock2008.aspx.
119. USDA, Agricultural Research Service 2011. USDA National Nutrient Database for Standard Reference, Release 24. Nutrient Data Laboratory Home Page, 〈〉. http://www.ars.usda.gov/nutrientdata.
120. USDA Alternative Farming Systems Information Center 2012, Available from: 〈〉, (accessed on July 20, 2012). http://afsic.nal.usda.gov/organic-production.
121. van Haaren R., Themelis N.J., Barlaz M. LCA comparison of windrow composting of yard wastes with use as alternative daily cover (ADC). Waste Management 2010, 30:2649-2656.
122. van Winkle T.L., Edeleanu J., Prosser E.A., Walker C.A. Cotton vs. polyester. American Scientist 1978, 66:280-290.
123. Vitousek P.M., Ehrlich P.R., Ehrlich A.H., Matson P.A. Human appropriation of the products of photosynthesis. Bioscience 1986, 36:368-373.
124. Vitousek P.M., Mooney J.L., Melillo J.M. Human domination of earth's ecosystems. Science 1997, 277:494-499.
125. Wackernagel M., Schulz N.B., Deumling D., Linares A.C., Jenkins M., Kapos V., Monfreda C., Loh J., Myers N., Norgaard R., Randers J. Tracking the ecological overshoot of the human economy. Proceedings of the National Academy of Sciences 2002, 99(14):9266-9271.
126. Walker, K., 2007/2008. United Nations Development Programme. Human Development Report 2007/2008. Fighting Climate Change: Human Solidarity in a Divided World. Palgrave Macmillan, New York.
127. Whiffen H.H. Energy Use in Irrigation, Energy Efficiency and Environmental News. Florida Energy Extension Service 1991, 1-6. University of Florida, Gainesville, FL.
128. Whitacre P.T., Fagen A.P., Husbands J.L., Sharples F.E. Implementing the New Biology: Decadal Challenges Linking Food, Energy, and the Environment, National Research Council of the National Academies 2010, The National Academies Press, Washington, DC.
129. WHO, 1985. Energy and Protein Requirements: Report of a Joint FAO/WHO/UNU Expert Consultation. WHO Technical Report Series No. 724. Geneva.
130. Worldwatch Vital Signs, 2010. The World Watch Institute, Washington, DC.
131. Zhengfang, L., 1994. Energetic and ecological analysis of farming systems in Jiangsu Province, China. In: Presented at the 10th International Conference of the International Federation of Organic Agriculture Movements (IFOAM). 9-16 December 1994, Lincoln University, Lincoln, New Zealand.
132. Ziesemer J. Energy Use in Organic Food Systems 2007, UN-Food and Agriculture Organization, Rome.
133. Zucchetto J., Bickle G. Energy and nutrient analyses of a dairy farm in central Pennsylvania. Energy in Agriculture 1984, 3:29-47.