Challenges in Food Production: Soil Erosion, Food Insecurity, and Sustainable Agriculture

1. The sector of the economy that seems likely to unravel first is food. Eroding soils, deteriorating rangelands, collapsing fisheries, falling water tables, and rising temperatures are converging to make it difficult to expand food production fast enough to keep up with the demand. LESTER R. BROWN

2. Soil (12) Why is soil so important? It’s simple food. Feeding a growing human population: Many of the poor suffer health problems from chronic lack of food and poor nutrition, while many people in developed countries have health problems from eating too much food. A proper diet requires around a balanced 2000 calories a day. Proteins (30%), carbohydrates(60%) fats(10%). • In terms of famine and malnutrition, about 11 million children die from starvation each year (15 people per minute) : • People are considered _____________ with fewer than 2000 calories per day. • 850 million people are considered _____________ (_______________________________). Chronic undernourishment results in mental retardation, stunted growth, susceptibility to disease, lower life expectancy and weakness. • _________________: 1 billion people have health problems because of this. Lowers life expectancy, greater susceptibility to disease and illness and lower life quality.

3. Hunger Although there is enough food produced in the world many people go hungry. ____________ is the ability to meet the needs of the present human population without compromising the ability of future generations to meet their needs. Food insecurity (1 in 6 people: Sound Familiar?) living with chronic hunger and poor nutrition. The root of which is poverty. Food security means that every person gets enough nutritious food to live an active and healthy life. The greatest obstacles to providing enough food for everyone are: ________________ Political upheaval , corruption, war which interfere with food distribution and transportation systems. Stored food spoils and many people _________________. The harmful environmental effects of food production. Rapid population growth ______________________________________________ _______________________(land we can easily grow food on).

4. Food Production Food production ____________________ ___________________________________________________________________. • _____________________________. (Grains are small, hard, dry seeds. Corn is considered a grain when harvested late) They supply 77% of the world’s food and use 11% of the land. • ____________________________________________which supply 16% of the world’s food and use 26% of the land. About 69% of the grain grown in the United States is used to feed animals. • ______________________________supply about 7% of the world’s food.

5. Feeding a Growing Population Only about 14 of the 50,000 known plant species are commercially grown for human consumption and amount to 90% of the world’s food calories. 1. Of the 14 ____________________ supply about 50% the human caloric intake. They also supply the world with 42% of their protein. Because of poverty, many people cannot afford meat and must get their protein from grains 2. Many people suffer from vitamin A deficiency. ________________was genetically engineered to contain _________________. 3. The controversy over using corn as ________because it is driving up the price leading to more hunger. (high fructose corn syrup is the most common ingredient in modern food)

6. Growing Crops There are three basic ways that agriculture is accomplished: 1. _____________________________________(Mostly done in developed countries) 2. _____________________________________(Mostly done in developing countries) 3. _____________________________________(Mostly done in developing countries) Industrialized agriculture (__________________________________________) uses: 1. Heavy equipment that burn ___________________ 2. Large financial investments (become corporate- Monsanto) 3. Large _____________________ 4. Large use of ___________________(monocultures deplete soil nutrients) 5. Large use of ___________________ Why grow crops this way? To produce high yield monocultures. Yield-The amount of food produced per unit of land.

7. Traditional Subsistence Agriculture Traditional agriculture (low input) is practiced by 2.7 billion people in developing countries. It involves mainly human labor and draft animals to grow enough food for the family with a little left over to sell or store. Main agricultural practice is polyculture: growing many different crops on the same plot of land. Benefits of polyculture involve: Slower depletion of soil nutrients Reduces chance of losing most or all of the year’s food supply to pests, bad weather etc. Many environmentalist consider traditional agriculture to be _______________ _____________________________________________________________________ _____________________________________________________________________

8. Slash and Burn Agriculture Slash and burn agriculture is used to quickly clear land for plantation farming (cash crops), raising livestock and. Plantation agriculture: is industrialized agriculture used in tropical developing countries to grow cash crops. (bananas, coffee, soybeans, sugar cane and palm oil). It brings money to countries that need it but leads to : Issues with slash and burn agriculture: • Burning the biomass ________________________________________________________ and become part of the soil again. • Larger inputs of _________________________due to very low nutrients in rainforest soil • Heavy ________________________________________. • loss of biodiversity as rainforests are destroyed • Soils are depleted quickly and more forest is needed every 4 years to continue Decomposition enriches the soil (like making it new) by breaking down dead organisms and returning some of their nutrients to the soil. But, in the tropical rainforests, all of the nutrients are in the trees and when cut down and burned the soil cannot get the nutrients back.

9. The Birth of Industrialized (modern) Agriculture The Green Revolution (High impact Agriculture) Green revolution is a popular term for the technologically advanced agricultural practices that increased crop yield after WWII. It involved: • The first _______________________________________________(Rice, wheat and corn). These are new strains of crops not found in nature (GMO). • Large use of _________________________(Chemical pellets of phosphorus, nitrogen and potassium). • ________________________________________________________________________. • Intensive __________________________________(many used to save troops in WWII). • Multiple cropping is growing more than one kind of crop in the same area per year.

10. Genetically Modified Organisms • Instead of using genetic modification we can increase genetic resistance to pest and disease by _________________________________________ found in nature. This ________________has been used for centuries to develop genetically improved varieties of crops without any genetic modification. • It is a slow process but, crosses with older strains can improve the health of the crops. Genetic Engineering (faster): isolation of a gene from one source (plant, bacteria, animal) for a desired trait (insect resistance), make copies of gene, then place those genes in another organism. Producing a GMF or GMO. EXAMPLE: Tomatoes Ethylene production (gas produced which makes them ripen quickly) grocers spray fruit with ethylene to start ripening process STRATEGY: isolate gene responsible for ethylene GE tomato (Endless Summer) does not ripen until it gets to the store: longer shelf-life

11. Trade-Offs Genetically Modified Crops and Foods Projected Advantages Projected Disadvantages _________________ Irreversible and unpredictable genetic and ecological effects ________________ Harmful toxins in food from possible plant cell mutations More resistant to insects, disease, frost, and drought ____________________ Grow faster __________________ Can grow in slightly salty soils Increased development of pesticide-resistant insects and plant diseases Less spoilage Better flavor Can create herbicide-resistant weeds __________________ Tolerate higher levels of herbicides Can harm beneficial insects _______________ _______________________

12. Producing More Meat About half of the world’s meat is produced by livestock grazing on grass in unfenced rangelands and fenced in pastures. The other half is produced under factory-like conditions (feedlots), densely packed livestock are fed grain or fish meal. Eating more chicken and fish and less beef and pork reduces harmful environmental impacts of meat production and _______________ _________________________________________________________. Eating lower on the food chain (plant products/ vegetarians) frees up even more food resources. Main issue of raising free range cattle is the ________________________________. Increases chance of _________________________________________________ Trampling of native species opens niches for _____________________________. __________________________________________________________________.

13. Trade-Offs Animal Feedlots Advantages Disadvantages _____________________ Need large inputs of grain, fish meal, water, and fossil fuels Higher profits Concentrate animal wastes that can pollute water Less land use ______________________ Reduced soil erosion _________________________________________________________________________________________________. Help protect biodiversity

14. Trade-Offs Aquaculture Aquaculture Because there is a _______ ______________________________________________________________(raising fish in cages) is the world’s fastest growing type of food production. Advantages Disadvantages High efficiency Needs large inputs of land, feed, and water High yield in small volume of water Large waste output destroy quality of water, mangrove forests and estuaries Can reduce overharvesting of conventional fisheries Uses grain to feed some species Low fuel use High profits Dense populations vulnerable to disease and parasites (loss of genetic diversity) Profits not tied to price of oil Labeled in the stores as farmed raised verses wild caught.

15. Solutions More Sustainable Aquaculture • _____________________________________________________________________ • Improve management of aquaculture wastes • Reduce escape of aquaculture species into the wild they can ____________________ ___________________________________ • Restrict location of fish farms to reduce loss of mangrove forests and estuaries • Farm some aquaculture species in deeply submerged cages to protect them from wave action and predators and allow dilution of wastes into the ocean • Certify sustainable forms of aquaculture

16. Food Production: Environmental Impacts ____________________________________________________________________________________________________________________________________________________________ Industrialized agriculture uses about __________________________in the U.S. and food travels an average 2,400 kilometers from farm to plate.

17. Soil Degradation: Erosion Erosion is the movement of soil components, especially surface litter and topsoil, from one place to another and is a serious issue facing modern farming. No soil = no crops. Erosion _____________________________________________________________________________. Erosion is caused by: ____________________________________ ___________________ ___________________ Wind erosion causes: Suspension(SPM): airborne soil. Soil can travel hundreds of miles in the right conditions. • Water erosion cause: • ______________: small layer of soil is removed from entire area Because the topsoil disappears evenly, sheet erosion may not be noticeable until too much damage has been done. • ________________: water converges into small streams and takes with it large amounts of soil

18. Human Impact on Erosion ________________________ ________________________ ________________________ ________________________ ________________________ ________________________ Soil is eroding faster than it is forming on more than one-third of the world’s cropland.

19. Desertification: Degrading Dry lands Desertification is a type of land degradation in which a relatively dry land region becomes increasingly arid typically losing its bodies of water as well as vegetation and wildlife. _____________________________________________________________________.

20. Irrigation techniques: Brings water to agricultural crops uses about 70% of the world’s freshwater supplies. _____________________ ____________________________________________________________________________________________________________________________________. Drip irrigation (efficiency 90–95%) Water usually pumped from underground and sprayed from mobile boom with sprinklers. Requires machinery. Gravity flow Above- or below-ground pipes or tubes deliver water to individual plant roots. The most effective way to conserve water. Water usually comes from an aqueduct system or a nearby river. Cheap and easy. Gravity flow was invented to simulate natural flood plains. Before irrigation many civilization developed near flood plains. The __________________________________________________ _______________________________________.

21. Repeated Irrigation has Consequences Excessive salts in soil may decrease productivity by: 1. _________________________________________________. 2. _________________________________________________. 3. _________________________________________________. 4. _________________________________________________.

22. Solutions Soil Salinization Prevention Cleanup Reduce irrigation or use _____________ to use less water and lower influx of salt. Flush soil (expensive and wastes water) Stop growing crops for _________until the salt has been flushed away Irrigate with water that has a low salt content Switch to salt-tolerant crops (such as barley, cotton, sugarbeet) Install underground drainage systems that will prevent water from pooling and evaporating (expensive)

23. Further Impacts of Agriculture 1. Habitat destruction: to build farms and feedlots reduces biodiversity. Herbivores that feed on crops and carnivores that feed on livestock may be displaced or killed (Yellowstone/Wolves) 2. Water pollution: ______________________from erosion, ________________________from fertilizer runoff (excess phosphates and nitrates causing blooms) and ___________________________. 3. _______________: Monocultures deplete soil of vital nutrients and must be replaced artificially 4. _________________: Pumping out groundwater faster than it can recharge. Added to this, the loss of recharge areas from urbanization (concrete). Replacing Nutrients • Fertilizers can help restore soil nutrients in turn restoring soil fertility. • Organic fertilizers: from plant and animal (_______________________) materials. _______ ___________________________________________________________________________ • B. Commercial inorganic fertilizers: Active ingredients contain nitrogen, phosphorous, and potassium and other trace nutrients. (small white pellets of concentrated nutrients)

24. Reducing Soil Degradation and Water Loss Keep soils __________________________. In undisturbed ecosystems, the roots of plants help anchor the soil, and usually soil is not lost faster then it forms. Reduce deforestation, overgrazing and keep farmlands planted. Producing food more sustainably through soil and water conservation: 1. Building shelterbelts or windbreaks: can reduce wind erosion. Long rows of trees are planted to partially block the wind. They can also help retain soil moisture, supply some wood for fuel, and provide habitats for birds.

25. 2. ________or contour planting: converting steeply sloped land into a series of broad nearly level terraces. 4. _______________: involves planting rows of crops with alternating strips of a cover crop that completely covers the soil. (corn or cotton with legumes, rye or alfalfa) 5. _____________or agroforestry: trees planted in strips; crops grown between trees 6. ____________: Eliminate the use of machines to till or turn over the soil. This greatly reduces the amount of ___________________________________________.

26. NATURAL CAPITAL DEGRADATION Food Production Biodiversity Loss Soil Water Air Pollution Human Health Loss and degradation of grasslands, forests, and wetlands Erosion Water waste Greenhouse gas emissions (CO2) from fossil fuel use Nitrates in drinking water (blue baby) Aquifer depletion Loss of fertility Increased runoff, sediment pollution, and flooding from cleared land Greenhouse gas emissions (N2O) from use of inorganic fertilizers Pesticide residues in drinking water, food, and air Salinization Fish kills from pesticide runoff Waterlogging Contamination of drinking and swimming water from livestock wastes Pollution from pesticides and fertilizers Greenhouse gas emissions of methane (CH4) by cattle (mostly belching) Desertification Killing wild predators to protect livestock Algal blooms and fish kills in lakes and rivers caused by runoff of fertilizers and agricultural wastes Loss of genetic diversity of wild crop strains replaced by monoculture strains Bacterial contamination of meat Other air pollutants from fossil fuel use and pesticide sprays

27. Importance of Soil Soil is ___________________as it is slowly renewed by the breakdown of parent material (rock) from biological processes and weathering. 1. Organisms, mainly microorganisms, inhabit the soil and depend on it for ________________________. Typical composition of Soil 2. Plants anchor themselves into the soil, and get their nutrients and water. 3. ____________________as it travels through it. 4. Undisturbed soils, or soils that have developed over a long time are arranged in a series of horizontal layers called soil horizons

28. O HORIZON (________________________________ ___________________________________) Leaves and partially decomposed organic debris waiting for decomposition to turn them into soil. Thick in ___________________________very thin in _________________________ Soil Horizons Plant roots A HORIZON (____________________) Organic matter decomposed plants and animals (___________, living organisms, inorganic minerals Begins to lose nutrients due to plants using them and to deeper layers by leaching referred to as eluviation. ________________________________ Leeched out B HORIZON (subsoil) light-yellowish in color because it accumulates iron, clay, aluminum and organic compounds, a process referred to as Illuviation. Deposited in C HORIZON (weathered parent material) Partially broken-down inorganic materials like rocks (broken bedrock). R HORIZON (bedrock-parent material)

29. Layers in Mature Soils Infiltration: the downward movement of water through soil. ________: dissolving of minerals and organic matter in upper layers carrying them to lower layers. The smaller the particles are the more leaching will occur. _____________________________________ __________________________________________. E HORIZON (zone of leaching) Zone where minerals have been leached (E for eluviation) These are present only in older, well-developed soils, and generally occur ______________________ ___________________________________________

30. Soil Components ____________________________

31. Soil Properties Continued ___________: The rate at which water and air moves from upper to lower soil layers. Water and oxygen cannot be used by plants if it cannot infiltrate the soil. __________: This affects the soil’s ability to absorb and hold water. If soil cannot retain water within reach of plant roots, crops will need frequent rains or irrigation. ________: The ability of oxygen to infiltrate the soil. Oxygen in needed by plant roots. Soil organisms need it for respiration.

32. Using a Textural Triangle The three sides of the textural triangle represent increasing or decreasing percentages of sand, silt and clay particles. Assume that you have a soil that is 30 percent clay, 20 percent silt and 50 percent sand. Clay: Move along the left side of the triangle until you reach 30 percent clay. Then draw a line at 30 percent clay that is parallel to the bottom of the triangle. Silt: Move along the right side of the triangle until you reach 20 percent silt. Now draw a line at 20 percent silt that is parallel to the left side of the triangle. Sand: Move along the bottom of the triangle until you reach 50 percent sand. Draw a line at 50 percent sand that is parallel to the right side of the triangle. The point at which these three lines intersect will define the soil’s texture.

33. Reducing the Amount of Land Needed for Agriculture Increase crop yield by: A. Develop crops through GM techniques that can be grow closer together, are more resistant to pests and weather extremes. B. Institution of crop rotation to improve soil fertility. C. Use of polycultivation allowing multiple crops to be grown on the same plot of land during different seasons. D. Use of more effective pesticides and fertilizers. 2. Decreasing the demand for agricultural land by: A. Eating lower on the food chain (vegetarians) reduces the amount of land needed to raise livestock. B. Switching from cotton to hemp for textiles would provide more material per acre. C. Switching to aquaculture D. Preventing food spoilage and wastage.

34. Case Studies and Legislation The Dust Bowl, of the 1930’s in Oklahoma, Texas, Kansas, was a period of severe dust storms that greatly damaged the ecology and agriculture of the US and Canadian prairies severe drought, plowing and uncovered land caused the phenomenon. These choking billows of dust – named "black blizzards" or "black rollers" – traveled cross country, reaching as far as such East Coast cities as New York City and Washington, D.C. The Dust Bowl led to the Soil Conservation(Erosion) Act of 1935 in an attempt to address farm erosion problems.