1. Food Chapter 10, Environmental Science J. Stewart-Presenter

2. Food is expensive Modern agriculture hurts the environment So...find new crops or...bugs! Bugs: cheap and easy to get--1500 edible insects, like Mopani Bugs also provide 58-78% protein by weight But, agricultural companies resist change that could hurt profits And...would you eat them? Case Study: Bug cuisine

3. o Food production: 77% croplands, 16% rangelands, 7% fisheries (3/4 of commercial fisheries fished beyond or at biological limit/sustainable yield) o Soil and Fertilizers (erosion faster than formation) o Nutrition and Food (1/6 under- or malnourished, 1/4 overweight) o Pests and Pesticides o Sustainable agriculture Key concepts What is a farm? Is it this? Or this?

4. Agriculture began about 10,000 yrs ago. Now: 77% food from croplands: BIG 3-- corn, rice, wheat=half of all human calories, 16% from rangelands, 7% from fisheries: most important for about 1 billion humans. Food production: Successes Huge advances in technology: production TRIPLED from 1950-85--is it enough?

5. "Agriculture has a greater harmful environmental impact than any human activity!" (p.219) - Pollutes air, water, and affects human health - Leads to soil loss and impacts biogeochemical cycles (CHNOPS) - Reduces biodiversity - 30% of world's cropland degraded--17% seriously Food Production: Issues

6. 80% of present ag. INPUTS: fuel, fertilizer, pesticides 10 units of energy for 1 energy unit of food (p. 211) INCLUDES: Plantation ag. (cash crops like coffee), Feedlots (cows) Agribusiness in USA: -75% of US ag. production is by large companies -0.3% of world's ag. workforce, yet 17% of world's production -Food to table = 17% of US commercial energy -More food since 1950, fewer workers Food production: Industrial/High-input Ag.

7. o Monocultures o 1st Revolution-High short-term yields through fertilizer, pesticide inputs (1950s- 1970s) o Multiple cropping each year o 2nd Revolution- Development of special varieties--since late 1960's (Next: GMO's since late 1990's) o Costs: depends on fertile soil, clean water, 8% of world's oil, and other inputs Food production: Green Revolution

8. 20% is traditional (done by about 40% of world's people). Includes: -subsistence: human labor, animal power -intensive: small farms with increased inputs Methods focus on increased diversity: -interplanting, polyculture, alley cropping (forestry), etc. Food prod: Traditional...These methods have been shown to be more sustainable and produce higher long-term yields than industrial monocultures. 1 unit of energy input for 10 units of food (p. 211)

9. Caused by water and wind and increased with reduced plant cover, overgrazing, vehicle use Topsoil is potentially renewable--on 38% of world's cropland it is not renewed In USA loss 16x > formation, but slowing Soil: Erosion

10. Desertification: drylands lose productivity by 10% or more (only severe cases actually become desert). A problem in 70% of drylands. Salinization: Irrigation (1/5 of cropland, 40% of food) results in concentration of salts through evaporation. Can kill plants. Problem on 1/5 of irrigated cropland. Waterlogging: Over-irrigating raises water table with saline water. Problem on 1/10 of irrigated cropland. Soil: Desertification, Salinization, Waterlogging

11. Soil conservation is key component of sustainable agriculture. How: Conservation tillage: keep soil undisturbed, covered with vegetation Soil: Conservation Windbreaks: reduce wind erosion Terracing, contour farming, strip cropping: control water run off

12. o Fertilizers used to restore lost plant nutrients--esp. N-P-K. o Organic: From plant and animal sources such as manures, compost. Provide nutrients AND structure (humus). o Crop rotation: Added diversity minimizes loss of single nutrient. o Inorganic: Provide nutrients, but NO structure. Runoff is pollutant. Soil and Fertilizers

13. o Enough food is produced :) o Distribution inequal: 1/6 of world underfed :( o Undernutrition=not enough food. Malnourished=not enough nutrients, esp. protein. o Problem: poverty. o Undernutrition problem growing in LDC's. Also lack of micronutrients: vitamin A, iron, and iodine. Nutrition: Problems

14. -Immunizations -Education (esp. women), Family planning -Breast feeding -Vitamins,Nutrients (i.e. A for blindness, iodine for thyroid/metabolism, iron for blood/anemia) -Prevent dehydration -Reduce overnutrition in MDCs: Over 68% of Americans overweight or obese (National Health and Nutrition Examination Survey (NHANES), 2012) Nutrition: Solutions

15. Human population expected to reach 9 billion by 2050 3rd Revolution: Genetic Engineering? Over 2/3 of US supermarket food contains GE crops. Benefits: Short-term reduction in pesticide, herbicide use, no loss in nutrition. Drawbacks: Superbugs, superweeds, persistent toxins in food, allergies, corporate ownership of seeds, minimal or no long term yield increases, no long-term reduction in inputs, few long-term studies. Food: Increasing Plant Production

16. Use more water? Water expensive and aquifers (underground water) are being depleted. Use more land? Very little new land left that is viable for growing crops. What can be done? See the green on upcoming slides. Food: Increasing Plant Production

17. Meat production is intensive: -Half of world's cropland and water useage, -20x more manure than humans, -22% or more (Sci. Amer., 2009) of greenhouse gases (CH 4, CO 2 ), overgrazing, endanger wild species. Food: Meat

18. 43% of beef from feedlots with as many as 100,000 cattle! Over 50% of pork, about 75% of poultry is non-pasture, “factory” farmed. Shift from beef, pork--> to fish, poultry (more grain-efficient) OR grass-fed, free-range cattle. Food: Meat

19. Fisheries: Aquatic species suitable for commercial harvest Food: Fish About 3/4 of 200 the most valuable fisheries overfished or at limit. Often subsidized by governments.

20. Careful management would allow 125 of 128 depleted fisheries to recover. Management: -Quotas -Limit boats -No fish during spawning -Restrict use of long lines, drift nets, other harmful methods -Create reserves -Consumer awareness  Food: Fishing Management

21. Aquaculture Food: Fish Farming, Ranching PROS Highly efficient High yield in small volume of water Increased yields through cross- breeding and genetic engineering Can reduce over- harvesting Little use of fuel High profits CONS: Large inputs of land, feed, And water needed Produces large and concentrated outputs of waste Destroys mangrove forests Increased grain production needed to feed some species Fish can be killed by pesticide runoff from nearby cropland Dense populations vulnerable to disease Farming=Controlled environment Ranching=Captive with some release (ie salmon)

22. Pests and Food Pests damage crops and reduce yield: weeds, herbivorous insects, fungus, microbes. In balanced ecosystems, pests are not usually a major problem. Ecosystem service: Natural enemies (i.e. ladybugs, spiders eat herbivorous insects). In agricultural systems (low diversity), up to 55% of crops can be lost to pests.

23. Pesticides Insecticides (pesticides) kill animal pests, Herbicides kill plant pests--usually toxic chemicals. But they also... -Accelerate genetic resistance -Kill natural pest enemies -Do NOT reach target pests 98% of time! -Harm wildlife -Threaten human health: cancer, death In 1942, we lost 7% of crops to insect pests. Now we use 33x more pesticides, yet we lose 13%! So why use them? -Can help eradicate disease and save lives -Can increase food supply and profits when used correctly -Work well in short term -New pesticides safer and needed in smaller amounts Rachel Carson’s Silent Spring (1962) raised awareness about DDT and pesticides in general.

24. Pesticides: Solutions Laws: 57 pesticides banned by the EPA 1972-2004. Poorly enforced. Different outside US. 1996 Food Quality Protection Act. Genetic Engineering?: See previous slides Biological controls: Introduce natural enemies Natural chemicals: Pheromones and hormones can change pest behavior. Physical controls: Water spray or vacuuming. Integrated Pest Management (IPM): 1) Allow for some crop loss, 2) Learn: Biological, physical controls first. 3) Small amount of carefully applied pesticides How? Educate, change farming subsidies practices, tax pesticides to fund IPM

25. Mentioned previously: Traditional methods, Soil conservation Reduce resource input, work with nature (BioSPoRN) Sustainable Agriculture MORE: organic fertilizers pest control efficient irrigation perennial crops crop rotation soil conservation subsidies LESS: soil erosion soil salinization overgrazing overfishing food waste population growth poverty ALSO... Reduce poverty Slow population growth

26. Miller, Environmental Science, (2006) Fiala, Nathan, How Meat Contributes to Global Warming, Scientific American, http://www.scientificamerican.com/articl e.cfm?id=the-greenhouse-hamburger (2009) http://www.scientificamerican.com/articl e.cfm?id=the-greenhouse-hamburger National Health and Nutrition Examination Survey (NHANES) (2012) Carson, Rachel, Silent Spring (1962) Bibliography THE END