Agriculture

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

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 Second started in 1970 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 • 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%

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 • 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 • 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

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. 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 Soil management

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. 2000 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 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 Pros and Cons of pesticide use

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