1. Agriculture
Part 1

2. Human Nutritional Requirements
Healthy diet
Male = 2500 calories
Female = 2000 calories
Balance of nutrition
Protein = 30% of all calories
Carbohydrates = 60% of all calories
Fat = 10% of all calories
Should also include micronutrients (i.e. vitamins, minerals, etc.)

3. Plants and nutrition
About 100 species of 350,000 known plant species are grown for human food
Wheat and rice supply over half of the human intake
Nearly all cultures have some version of the “rice and beans” meal
Rice and beans provide all 8 essential amino acids and together are a “complete” protein source

4. Meat and nutrition
8 species of animals supply over 90% of the worlds needs
20% of the world’s richest countries consume 80% of the world’s meat production
Consequences of increased meat consumption
More greenhouse gasses
Need more resources (growing space, water, etc.)

5. Meat Consequences Benefit Concentrated sources of proteins
It takes 16 lbs. of grain to produce 1 lb. of meat
90% of the grain produce in the US goes to animal feed
Consuming grain directly would provide a 20x increase in the available calories and 8x increase in the amount of protein
Concentrated sources of proteins

6. Malnutrition 11 million children die each year from starvation
850 million people (~13% of the world population are malnourished)
Chronic undernourishment leads to vitamin and mineral deficiencies
Stunted growth
Weakness
Increased susceptibility to illness
Diseases caused by protein deficiency
Marasmus
Kwashiorkor
Victims are less than 80% of their normal weight for their height

7. Types of Agriculture
Subsistence: agriculture is carried out for survival, few to no crops available for sale

8. Types of Agriculture
Agroforestry: system of land use in which harvestable trees or shrubs are grown among or around crops or on pasture land to preserve or enhance the productivity of the land.

9. Types of Agriculture
Monoculture: growing only a single crop species

10. Types of Agriculture High-input agriculture:
includes use of mechanized equipment, chemical fertilizers, and pesticides

11. Types of Agriculture Industrial agriculture or corporate farming:
Characterized by
Mechanization
Monocultures
use of synthetic inputs:
Chemical fertilizers
Pesticides
Emphasis on maximizing productivity and profits

12. Types of Agriculture
Plantation: a commercial tropical agriculture systems devoted to exports
Governments and companies exploit the tropical rainforest for economic gain
Agricultural practices remove natural habitat, disturb the land, and use synthetics

13. Types of Agriculture
Tillage: surface is plowed, breaking up the soil, followed by smoothing of soil and planting
Exposes land to wind and water erosion

14. Types of Agriculture
Low-till, no-till, or conservation-till agriculture: soil is disturbed little or not at all to reduce soil erosion
Lower labor costs
Reduces need for fertilizer
Saves energy

15. Types of Agriculture
Polyculture: uses different crops in the same place to imitate natural diversity
Includes:
Crop rotation
Multicropping
Intercropping
Alley cropping
Requires more manual labor
Avoids some plant diseases

16. Types of Agriculture
Alley Cropping: plant crops in strips with rows of trees or shrubs on each side.
Increases biodiversity
Reduces surface runoff and erosion
Reduces wind erosion
Improves use of nutrients
Modifies microclimate for improved crop production
Improves wildlife habitat

17. Types of Agriculture
Crop rotation: planting a field with different crops form year to year to reduce nutrient depletion
Example: rotation corn or cotton (depletes nitrogen) with soybeans (adds nitrogen to soil)

19. Types of Agriculture
Intercropping: to grow more than one crop in the same field, in alternating rows or sections

20. Types of Agriculture
Interplanting: growing two different crops in an area at the same time
Plants should have similar nutrient and moisture requirements

21. Types of Agriculture
Low input: depends on hand tools and natural fertilizers, lacks large-scale irrigation

22. Types of Agriculture
Organic farming: a form of agriculture that relies on crop rotation, green manure, compost, biological pest control, and mechanical cultivation to maintain soil productivity and control pests
Limits the use of synthetic additives

23. Green Revolution First started in1950 Continues to today
Second started in 1970
Involved:
Planting monoculture
High applications of inorganic fertilizers and pesticides
Widespread use of artificial irrigation systems
Before: Increased crop production was due to increased acreage farmed
After: crop acreage increased 25% but crop yield increased 200%
Continues to today
Involves growing genetically engineered crops
Before: farmers grew locally adapted strains
Now: farmers grow crops engineered to produce more yield
E.g. 50% of wheat in US comes from 9 genotypes

24. Criticisms of the Green Revolution
GR is unsustainable
Increasing food production ≠ increasing food security
Not all famines are caused by decreases in food supply
GR agriculture produces monocultures while traditional includes poly culture
There has been a drop in productivity of intensely farmed land in the past 30 years
Desertification
Land degradation

25. Criticisms of the Green Revolution
Necessary to purchase inputs  rural credit institutions, causing farmers to go into debt and sometimes lose land
GR agriculture increases pesticide use
Salinization, water logging, and lowering water levels in certain areas increased due to increased irrigation
GR reduce agricultural biodiversity – relied on only a few high yield varieties of each crop  susceptibility of food supply to pathogens and permanent loss of many valuable genetic traits

26. Genetic Engineering and Crop Production
EVERYTHING YOU EAT IS A GMO
Selective breeding which lead to domesticated species is a form of genetic engineering
Genetic engineering = moving genes from one species to another or designing gene sequences with desirable characteristics.
Transgenic = an organism with the genes of another species in it (usually one not closely related)

27. Genetic engineering and crop production
Transgenic genes
Pest, drought, mold, and saline resistance
Higher protein yields
Higher vitamin content
~75% of all crops grown derive from modern genetically engineered or transgenic crop species

28. Genetic engineering and crop production
Others:
Sweet potatoes resistant to a virus
Rice with increased iron and vitamins
Plants able to withstand weather extremes
Golden Rice – has genes from daffodil and a bacterium
Supplies vitamin A to populations suffering from deficiency
In 2006, 10 million farmers in 22 countries planted 252 million acres of transgenic crops
Most transgenic crops are herbicide and pesticide resistant
Soybeans
Corn
Cotton
Canola
alfalfa

31. Assignment
What type(s) of agriculture are we using in the ECA garden?

32. Irrigation ¾ of the fresh water on earth is used for agriculture
World wide 40% of crops come from 16% of irrigated farmland
Inefficiencies:
Seepage
Leakage
evaporation
Up to 70% of water is lost
Drip irrigation – reduces water usage and waste but more expensive to install

33. Sustainable agriculture
Main goals:
Environmental health
Economic profitability
Social and economic equity
Four parts:
Efficient use of inputs
Selection of site, species, and variety
Soil management
Species diversity

34. Efficient use of inputs
Maximize reliance on natural, renewable farm inputs
Goal: develop efficient biological systems that do not require high levels of inputs
Use least toxic and least energy intensive options
Use preventative strategies before chemical inputs
E.g. Integrated pest management

35. Selection of site, species, and variety
Understanding location to select appropriate plants for the site
Soil type and depth
Previous crop history
Climate
topography
Pest resistant crops (when possible)

36. Soil management
Proper soil water and nutrient management help prevent crop stress
Soil is viewed as a fragile living media that must be protected to increase
aggregate stability
soil tilth
diversity of microbial life
Methods to protect soil:
Cover crops
Compost
Manures
Reducing tillage
Maintaining soil cover with plants
Mulch

37. Species diversity Farmers grow a lot of crops to
Limit economic risk
Increase health of soil and environment
Optimum diversity reached by integrating crops and livestock in the same farm
Grow crops on level ground and pasture or forage crops on steeper slopes
Reduces soil erosion
Manure is a fertilizer
Feeding and production is more flexible in animal production systems
Animals can eat “failed” crops

38. Types of Pesticides Biological – living organisms to control pests
Bt, ladybugs, parasitic wasps, etc.
Carbmates – affect the nervous system of pests
Can be used in lower doses that chlorinated hydrocarbons (100 grams vs grams)
More water stable  can contaminate water sources

39. Types of Pesticides
Chlorinated hydrocarbons and other persistent organic pollutants (POPs)
Example: DDT
Synthetic organic compounds that do not break down easily in the environment
Capable of bioaccumulation
Affect the nervous system
Low water solubility, high lipid solubility, semi-volatility, high molecular mass
Volatize in hot regions, accumulate in cold regions
Fumigates
Used to sterilize the soil and prevent pest infestation
Grain storage

40. Types of Pesticides Inorganic
Broad based toxin
Accumulate in the environment
Examples: arsenic, copper, lead, mercury
Organic and natural - natural toxins derived from plants
Examples: tobacco or chrysanthemum
Organophosphates
Extremely toxic but degrade quickly
Used to control mosquitoes

41. Pros and Cons of pesticide use
Kill unwanted pests that carry disease
More food means food is less expensive
Newer pesticides are safer and more specific
Reduces labor costs
Agriculture is more profitable
Cons
Accumulate in food chain
Pests develop resistance and create a pesticide treadmill
$5 - $10 in environmental damage done for every $1 of pesticide used
Pesticide runoff effects aquatic systems through biomagnifications
Inefficiency only 5% of pesticide reaches the pest
Threatens endangered species, pollinators, and human health

42. Integrated Pest Management
Does not eradicate pests but controls their numbers
Methods:
Polyculture
Intercropping
Planting pest-repellent crops
Using mulch to control weeds
Using natural methods to control pests (Bt)
Natural insect predators
Rotating crops to interrupt insect life cycles
Releasing sterilized insects
Developing genetically modified crops that are insect resistant
Constructing mechanical controls (insect barriers, traps, etc.)

43. Relevant Laws
Federal Insecticide, Fungicide and Rodenticide Control Act (FIFRA)(1947)
Regulate manufacture and use of pesticides
Pesticides must be registered and approved
Label must contain direction for use and disposal
Federal Environmental Pesticide Control Act (1972)
Requires registration of all pesticides in U.S. commerce
Food Quality and Protection Act (FQPA) (1996)
Emphasizes protection of infants and children in reference to pesticide residue in food