Transcript CH 13
Food Resources G. Tyler Miller’s Living in the Environment 13th Edition Chapter 13 Dr. Richard Clements Chattanooga State Technical Community College Key Concepts Methods of producing food Increasing food production Environmental effects of food production Increasing sustainability How Is Food Produced? Sources of food Primary plants: wheat, corn, and rice Primary animals: beef, pork, and chicken Major Types of Agriculture Traditional subsistence Traditional intensive Plantation Industrialized (high-input) See Fig. 13-3 p. 280 World Food Production Industrialized agriculture Plantation agriculture Shifting cultivation Nomadic herding Intensive traditional agriculture Fig. 13-2 p. 279 No agriculture Producing Food by GreenRevolution Techniques High-input monoculture Selectively bred or genetically-engineered crops High inputs of fertilizer Extensive use of pesticides High inputs of water Increased intensity and frequency of cropping Green Revolutions Fig. 13-6 p. 282 First green revolution Second green revolution (developed countries) (developing countries) Major International agricultural research centers and seed banks Producing Food by Traditional Techniques Intercropping Polyvarietal cultivation Agroforestry (alley cropping) Polyculture –like a home garden Food Production Rapidly increasing Prices decreasing Shortages in developing countries Approaching limits on meat production Nutrition Undernutrition Malnutrition Overnutrition Refer to Fig. 13-11 p. 286 Refer to Solutions p. 289 Environmental Effects of Food Production Biodiversity loss Soil Air pollution Water Human health See Fig. 13-13 p. 288 Increasing World Crop Production Crossbreeding and artificial selection Genetic engineering (gene splicing) Genetically modified organisms (GMOs) Continued Green Revolution techniques Introducing new foods Working more land See Fig. 13-16 p. 291 Producing More Meat Rangeland Pasture Efficiency Kilograms of grain needed per kilogram of body weight Beef cattle 7 Pigs Chicken Fish (catfish or carp) 4 2.2 2 Adaptations of rangeland plants Fig. 13-25 p. 298 Range condition and management Environmental consequences (Connections p. 299) CAFO’s (confined animal feeding operations) Farm Water Use •Drip • Center Pivot •Sprinkler Catching and Raising More Fish Fisheries Fishing methods (See Fig. 13-30 p. 303) Sustainable yield Overfishing Commercial extinction Aquiculture Fish farming and ranching Aquaculture •Farms (marine cages) –raise and cultivate fish and harvest when reach desired age or size. •Ranch –raise juveniles, then release to grow to adulthood in wild waters, then recapture when return to spawn (ex: salmon) *farm raised vs wild caught. (uncommon) Government Agricultural Policy Artificially low prices Subsidies Elimination of price controls Food aid Solutions: Sustainable Agriculture Low-input agriculture Organic farming See Fig. 13-36 p. 308 More benefits to the poor Increasing funding for research in sustainable techniques Solutions: Soil Conservation Conventional-tillage All topsoil is turned under and exposed to erosion and the elements. Conservation tillage Minimum or no-till –either loosely break the surface or use special planting equipment to put seeds into earth without exposing topsoil. Refer to Fig. 10-26 p. 224 Solutions Cont.d •Cropping methods •Strip •Contour •Terrace •Windbreaks •Land Classification Soil Restoration Organic fertilizer Animal manure Green manure Compost Crop rotation Commercial inorganic fertilizer Soil Conservation • 1985 Farm Act – strategy to reduce soil erosion in the US • Reduce erosion & restore fertile land – – – – – – – Conservation tilling – disturb soil as little as possible Terracing – reduce erosion on slopes Contour farming – plant along contours of gentle slopes Strip cropping – planting alternate strips of crops Alley cropping – planting between shrubs and trees Wind breaks – planting a row of trees or shrubs on perimeters Gully reclamation – fast growing vines and shrubs