Organic Agriculture

Michael Bomford, PhD

Organic Agriculture

Michael Bomford

Kentucky State University

Food production

• Past 40 years:– Doubling of grain yield

– 700% increase in fertilizer use

– 70% increase in irrigated cropland

• Now – ~40% of land surface

1960 1970 1980 1990 20000

2

4

6

8

10

12

14

Mean yield of 23 main food crops(million kCal/ha)

Developed worldDeveloping world

Adapted from Green et al. 2005. Farming and the fate of wild nature. Science 307: 550-555.

Agricultural land use

Adapted from Green et al. 2005. Farming and the fate of wild nature. Science 307: 550-555.

1960 1970 1980 1990 2000

5

10

15

20

25

% of usable land

Cropland

1960 1970 1980 1990 2000

25

30

35

40

45

% of usable land

Pasture

Developed worldDeveloping world

WorldWatch, 2000

Agriculture threatens bird species

225 951039 687

0

10

20

30

40

50

60

70

Threatened Near Threatened

Percentage of

threats

attributable to

agriculture

Developed world

Developing world

Adapted from Green et al. 2005. Science 307: 550-555.Data from World Bird Database, BirdLife International.

N and P fertilizer use

0

10

20

30

40

50

60

70

1950 1960 1970 1980 1990 2000 2010

N fertilizer

use (Million metric tonnes)

Developed world

Developing world

0

5

10

15

20

25

30

1950 1960 1970 1980 1990 2000 2010

P2O5 fertilizer use (Million metric

tonnes)

Developed world

Developing world

International Fertilizer Industry Association. 2006. http://www.fertilizer.org/ifa/statistics.asp

Nitrogen groundwater contamination

USGS. 2001. http://water.usgs.gov/nawqa/wcp/wcpfig1.html

High vulnerability:

• Shallow groundwater• Well-drained soils

• Little forest

Water pollution

0

5

10

15

20

25

30

35

1910 1930 1950 1970 1990

Farmers (millions)

Farm fuel use (petajoules)

Changing Face of US Agriculture

Animal

Production

8%

Irrigation

13%

Transportation

16%

Machinery

Operation

19%

Fertilizer

Manufacturing

31%

Misc.

3%

Pesticide

Production

5%

Crop Drying

5%

Agricultural Energy use

Household storage

and preparation,

2.3 calories

Farming,

1.6 calories

Transport,

1.0 calorie

Processing,

1.2 calories Packaging,

0.5 calories

Food retail,

0.3 calories

Commercial food

service,

0.5 calories

Energy inputs per food calorie

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 reductionistagricultural 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

Howard on Western

agriculture- 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)

Lady Eve Balfour

(1899-1990)

Soil Association (2003) / Mary Erstman

• 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.”

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 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.”

Organic Production Standards

USDA

ORGANIC

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, separatecontainers, equipment cleaning etc.

• $10,000 fine for misuse of word

• 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.

– (Organic Trade Association’s 2004 Manufacturer Survey) 0

5

10

15

20

25

1991

1994

1997

2000

2003

2006

2008

Billions

of dollars

US Organic Farms, 2006

Clear Boundaries & Buffers

Organic

Buffer

Conventional

Conventional

Soil Fertility: Cover Cropping

• Rye/vetch mix adds ~135 lb N/ac

• Slow release

• Organic matter

• Erosion control

WVU organic research project

4

4.5

5

5.5

6

6.5

7

1998 2000 2002 2004 2006

Soil

organic

matter

(%)

Winter rye & vetchcover crop

Cover crop +compost @10t/ac

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:

NaturalEnemies

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, quickknock-down

• chemistry inspiredsynthetic 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