Energetics of Biointensive Vegetable Production

1. Energetics of Biointensive Vegetable Production Sara Hendershot Agroecology Internship Penn State University August 11, 2003

2. A Quote... “And energy is superhuman in the sense that humans cannot create it. They can only refine or convert it. And they are bound to it by one of the paradoxes of religion. They cannot have it except by losing it; they cannot use it except by destroying it…Perhaps from an “objective” point of view it is incorrect to say that we can destroy energy. We can only change it. Or we can destroy it also by wasting it – that is, by changing it into a form in which we cannot use it again.” ~ Wendell Berry, “The Use of Energy,” The Unsettling of America, 1977

3. Energy Flow Chart Steve Moore, Harmony Essentials, July 2003

4. Energy Quantified • Human Labor • Embodied Energy of Tools Not quantified • Pest Control • Compost (manure, leaves) • Irrigation • Transportation

5. Materials and Methods • All data is presented based on 100 square feet beds (20’ X 5’) • Study focuses on 4 crops: Onions, lettuce, broccoli, and carrots • Time in labor was recorded per crop over past 10 weeks • Tool usage was also logged for each crop

6. Calorie Calculations Calories = Labor time x Activity Factor x weight Very light – standing activities…seeding, “pricking out”, etc. Light– transplanting, harvesting, etc. Moderate – weeding, U-barring, etc. Heavy – double digging, strenuous lifting, etc. ** Duhan, David. One Circle, 1985

7. Lettuce Activities: Seeding, “pricking out”, bed preparation, transplanting, weeding, & harvesting LABOR INPUT OUTPUT

8. Broccoli Activities: Seeding in flats, “pricking out”, bed preparation, transplanting, weeding, & harvesting LABOR INPUT OUTPUT

9. Onions Activities: seeding,bed preparation, transplanting, weeding, & harvesting LABOR INPUT OUTPUT

10. Carrots Activities:Bed preparation, seeding, weeding, & harvesting LABOR INPUT OUTPUT

11. The Tools

12. Embodied Energy of Steel in Tools *

13. Embodied Energy of Wood in Tools *

14. Total Embodied Energy of Tools Per Year in Calories

15. Embodied Energy of Tools per Crop Bed Calculation: Sum energy of tools x bed crop = Energy of tools 52 weeks weeks needed for crop / yr Energy of tools / 313 beds = Energy of tools per crop bed

16. Results

17. Results

18. Which means... • Leaf/Fruit crops yielded an average of 12x more energy than was invested • Root crops yielded an average of 92xmore energy than was invested ! !

19. For Future Research... • investigate energetics of compost, irrigation, pest control, and transportation • accurate comparison of conventional and mechanized organic farming to biointensive practices • effects of labor requirements based on farm size

20. References: Duhon, David. “Solving the Diet” One Circle, Ecology Action, Willets, CA 1985, pp25-26. Jeavons, John. “Master Charts”, How to Grow More Vegetables. Ten Speed Press, Berkeley CA, 2002, pp 88-92. Miller, G. Tyler. Living in our Environment, 8th Ed. Wadsworth Publishing, Belmont CA, 1994, p 365. Moore, Steve. Personal Correspondence, June-August 2003.* Pimentel, David, “Energy Inputs in Production Agriculture” in Fluck, Richard D., Ed, Energy in Farm Production, Elsevier Press, New York 1992,p 24. Pimentel, David. Personal Correspondence via email, July-August 2003