Organic Agriculture Organic Agriculture Michael Bomford, PhD Kentucky State University
Past 40 years: Doubling of grain yield 700% increase in fertilizer use 70% increase in irrigated cropland Now ~40% of land surface Food production Mean yield of 23 main food crops (million kcal/ha) 14 12 10 8 6 4 2 Developed world Developing world 0 1960 1970 1980 1990 2000 Adapted from Green et al. 2005. Farming and the fate of wild nature. Science 307: 550-555.
Agricultural land use 25 Cropland Developed world Developing world 45 Pasture % of usable land 20 15 10 % of usable land 40 35 30 5 1960 1970 1980 1990 2000 25 1960 1970 1980 1990 2000 Adapted from Green et al. 2005. Farming and the fate of wild nature. Science 307: 550-555.
WorldWatch, 2000
Agriculture threatens bird species 70 60 Developed world Developing world Percentage of threats attributable to agriculture 50 40 30 20 10 0 225 1039 95 687 Threatened Near Threatened Adapted from Green et al. 2005. Science 307: 550-555. Data from World Bird Database, BirdLife International.
N and P fertilizer use 70 60 Developed world Developing world 30 25 Developed world Developing world 50 N fertilizer 40 use (Million metric tonnes) 30 20 P 2 O 5 fertilizer use (Million metric tonnes) 20 15 10 10 5 0 1950 1960 1970 1980 1990 2000 2010 0 1950 1960 1970 1980 1990 2000 2010 International Fertilizer Industry Association. 2006. http://www.fertilizer.org/ifa/statistics.asp
Nitrogen groundwater contamination High vulnerability: Shallow groundwater Well-drained soils Little forest USGS. 2001. http://water.usgs.gov/nawqa/wcp/wcpfig1.html
Water pollution
Changing Face of US Agriculture 35 30 Farmers (millions) 25 20 15 10 Farm fuel use (petajoules) 5 0 1910 1930 1950 1970 1990
Agricultural Energy use Animal Production 8% Irrigation 13% Crop Drying 5% Pesticide Production 5% Misc. 3% Transportation 16% Machinery Operation 19% Fertilizer Manufacturing 31%
Energy inputs per food calorie Farming, 1.6 calories Household storage and preparation, 2.3 calories Transport, 1.0 calorie Food retail, 0.3 calories Processing, 1.2 calories Packaging, 0.5 calories Commercial food service, 0.5 calories M.C Heller and G.A. Keoleian (2000). Life Cycle-Based Sustainability Indicators for Assessment of the U.S. Food System. University of Michigan
Albert Howard (1873-1947) British agricultural scientist. 25 years in India. Critical of reductionist agricultural science and specialization Blamed fall of past civilizations on unsustainable agriculture Wrote An Agricultural Testament (1940)
Howard on Chinese agriculture The small-holdings of China, for example, are still maintaining a steady output and there is no loss of fertility after forty centuries of management.
Howard on Eastern agriculture Small farms Mix of people, plants and animals; wastes recycled as nutrients Human and animal labor, not machines Food crops, not cash crops (subsistence) Nitrogen fixed by legumes Reduced cultivation Composting Mimic natural ecosystems
- Large, growing farms - Monocultures - Mechanization - Synthetic fertilizer dominates - Increasing crop disease - More processed and preserved foods - Success judged by profit - Too much food (low prices force farmers off land and into cities) Howard on Western agriculture
Lady Eve Balfour (1899-1990) Among first women to graduate from University of Reading (agriculture) 1939 began long term experiment comparing conventional and organic production 1943 wrote The Living Soil 1946 founded the Soil Association Healthy soil, healthy plants, healthy people. Soil Association (2003) / Mary Erstman
J.I. Rodale Bought farm in PA to test Howard s ideas Popularized term organic, through his Organic Gardening and Farming magazine Relationship with science Presented reader testimonials as research ( science for the people by the people ) Solid long-term research trials continue
Lady Eve Balfour (1899-1990) Jerome Irving Rodale (1898-1971)
Organic Production Standards Organic agriculture is a production system that is managed in accordance with the Act and regulations in this part to respond to site-specific conditions by integrating cultural, biological, and mechanical practices that foster cycling of resources, promote ecological balance, and conserve biodiversity. USDA ORGANIC
Organic Production Standards Land is certified by gov t-approved agencies Farmer develops and follows organic farm plan Synthetic substances prohibited Includes synthetic organics Natural substance allowed Includes natural inorganics Maintain or increase soil organic matter content Separation from conventional products In time 3 year transition period In space buffer zones, barriers, separate containers, equipment cleaning etc. $10,000 fine for misuse of word USDA ORGANIC
U.S. organic food sales have grown between 17 and 21% each year since 1997 (total U.S. food sales over this time have grown in the range of 2-4% a year) Organic food sales represent approximately 2% of U.S. food sales. Billions of dollars 25 20 15 10 (Organic Trade Association s 2004 Manufacturer Survey) 0 5 1991 1994 1997 2000 2003 2006 2008
US Organic Farms, 2006
Clear Boundaries & Buffers Conventional Organic Buffer Conventional
Soil Fertility: Cover Cropping Soil organic matter (%) 7 6.5 6 5.5 5 4.5 WVU organic research project Winter rye & vetch cover crop Cover crop + compost @10t/ac Rye/vetch mix adds ~135 lb N/ac Slow release Organic matter Erosion control 4 1998 2000 2002 2004 2006
Soil Fertility: Animal Waste
Soil Fertility: Animal Waste Raw manure pre-harvest interval: > 90 days if edible portion does not contact soil > 120 days if edible portion contacts soil
Soil Fertility: Compost No pre-harvest interval Strict requirements for manure-based compost 131-170 F for 15 days in windrows C/N = 25-40
Pest Management: Solarization and Biofumigation
Pest management: Resistant varieties
Pest Management: Natural Enemies
Pest Management: Farmscaping
Pest Management: Botanicals Chemicals derived from plants Rotenone rat poison, very toxic to fish, linked to Parkinson s allowed under NOP; temporary ban in Europe Pyrethrum neurotoxin, quick knock-down chemistry inspired synthetic pyrethroids Neem inhibits moulting
Pest Management: Microbials Bacteria e.g. Bacillus thuringiensis Fungi e.g. Coniothyrium minitans Nematodes e.g. Steinernema
Pest Management: Oils & Soaps Oils Petroleum / vegetable based kill through suffocation most widely used insecticide, by weight Soaps kill through desiccation (penetrate protective waxy covering) mainly kill soft-bodied insect No resistance observed to these modes of action