Presentation on theme: "Chp14 Feeding the World During the last 40 years, world food production has increased faster than the rate of population growth."— Presentation transcript:
Chp14 Feeding the World During the last 40 years, world food production has increased faster than the rate of population growth.
Objectives List the major groups of nutrients and the amount of energy provided by each type. Explain the effects of economics on the production of food. Describe how farming techniques have changed during the past 50 years. Describe and explain the basic components of sustainable agriculture.
Chp14.1 Human Nutrition Like all organisms on Earth, humans need energy (E) to carry out their life processes, which include growth, movement, and repair. Humans are omnivores (consume either plants or animals for food).
Chp14.1 Human Nutrition Nutrients: 1) Macronutrients (macro=big)provide the body E. 2) Micronutrients (micro=small)provide the body with small amounts of chemicals needed in biochemical reactions.
Chp14.1 Human Nutrition Macronutrients are measured in units called kilocalories (kcal). 1kcal provides enough E to raise the temperature of 1kg of water 1 degree Celsius. Often referred to as just “Calories.”
Chp14.1 Human Nutrition 3 types of macronutriets: 1. Carbohydrates 2. Proteins 3. Fats
More plant than animal. Fig 14.1 More plant than animal. Fig 14.1
Chp14.1 Human Nutrition 1. Carbohydrates: a compound made up of C, H, and O in approximately a 1:2:1 ratio. 2 main types that humans can use as an E source: Sugars and starches. Provide about 4kcal/gram. Fruits, vegetables, bread, and grains.
Chp14.1 Human Nutrition 2. Protein: a large compound made of amino acids that provides the body with the construction materials for making blood, muscle, and other tissues.
Chp14.1 Human Nutrition Amino acids are small organic (carbon- based) molecules that contain nitrogen (N). Important for the N-cycle (Chp 5). Protein also supply about 4kcal to a person in E.
Chp14.1 Human Nutrition All proteins in the human body are made up of 20 different amino acids. The body can make 12 of them. The remaining 8 must come from foods and are called essential amino acids.
Chp14.1 Human Nutrition Foods that supply the 8 are: Meats, eggs, and dairy. These plants- peanuts, beans, wheat, rice, corn, peas (but must be combined to meet all 8).
Chp14.1 Human Nutrition 3. Fats: Organic compounds (C-based); these are part of a group called lipids. A lipid contains 3 long chains of fatty acids and is a main component of all cell membranes.
Chp14.1 Human Nutrition Solid lipids (at room temperature) are called fats (butter). Liquid lipids are called oils (but referred to as fats nutritionally). Supply 9kcal/gram (twice the amount of proteins and carbohydrates).
Chp14.1 Human Nutrition Fats are saturated (contains the maximum # of H atoms on the fatty acid chain) or unsaturated (has vacancies for H atoms).
Unsaturated fats contain double bonds between the C atoms, reducing the # of places for H to bond. Saturated fats contain only single bonds and have the maximum amount of H atoms. Fig 14.3 Unsaturated fats contain double bonds between the C atoms, reducing the # of places for H to bond. Saturated fats contain only single bonds and have the maximum amount of H atoms. Fig 14.3
Monosaturated fat contains only 1 double C bond.
Polyunsaturated fat contains more than 1 double C bond.
Chp14.1 Human Nutrition Most animal fats are highly saturated, while most plant oils are highly unsaturated. The more saturated the fat the more firm it is at room temperature. Saturated fats contribute to heart disease.
Chp14.1 Human Nutrition Vitamins and Minerals: micronutrients; play key roles in the biochemical reactions that release E. They can all be obtained from plants, especially fruits, vegetables, and breads.
Chp14.1 Human Nutrition Nutritional Deficiency: the average adult needs about 2500kcal/day “Food and Agriculture Organization of the UN (FAO UN)”
Chp14.1 Human Nutrition People who receive less than 90% of their E needs are considered undernourished. Those with under 80% are seriously undernourished. Children suffer the most.
Chp14.1 Human Nutrition In developing nations, 1 out of every 4 children dies of a disease related to poor diet (1 child dies every 2 seconds).
1 child dies every 2 seconds as a result of poor nutrition. Fig 14.4 1 child dies every 2 seconds as a result of poor nutrition. Fig 14.4
Chp14.1 Human Nutrition Malnutrition: the lack of a specific type of nutrient in the diet. This can also result from the inability to absorb or use a particular nutrient. Vitamin deficiencies like Scurvy (lack of C), beri beri (B 1 Thiamine), and rickets (D).
Chp14.1 Human Nutrition Kwashiorkor is a deficiency disease caused by too little protein.
Goiter is the swelling of the thyroid gland as a result of a lack of iodine. Fig 14.5 Goiter is the swelling of the thyroid gland as a result of a lack of iodine. Fig 14.5
Chp14.2 World Food Supply If more food is produced than is consumed, why starvation? Food is traded as a commodity whose price is driven by economic factors.
Chp14.2 World Food Supply The Green Revolution: began in the mid-1960’s with the development of new strains of wheat and rice, the two main foods of the world. Huge in India. Increase in foods should drive the price down.
When regular wheat is given extra water and fertilizers, it grows too tall, falls over, and cannot be harvested. Fig 14.6 When regular wheat is given extra water and fertilizers, it grows too tall, falls over, and cannot be harvested. Fig 14.6
Chp14.2 World Food Supply Cash Crops: a crop grown for the purpose of sale (tobacco). Many developing nation farmers have chosen to grow crops that can be exported to other nations for higher prices.
Chp14.2 World Food Supply In much of the world, 85% of the farmland is owned by less than 5% of the people. Concentrated wealth as a result (by weapons, etc.).
Chp14.2 World Food Supply Food from Water: Fish and other sea animals provide much of the animal protein consumed by people around the world and 40% of the animal protein supply in developing nations.
Chp14.2 World Food Supply The FAO estimates that the world can provide about 100 million metric tons of food/year w/o damaging the marine biome. Commercial harvest of fish reached 100 million metric tons in 1989.
Chp14.2 World Food Supply An alternative to open ocean fishing for food is to raise fish in confined pools. Aquaculture: commercial production of fish and other marine animals in a controlled, maintained environment.
Chp14.3 Modern Farming Techniques Widespread use of pesticides has altered ecosystems in many harmful ways. This has also led to resistant insects. In 1992 many California crops were destroyed by white flies due to resistance.
Chp14.3 Modern Farming Techniques Monoculture: growing one or two corps that command the highest price at the time. This depletes the soil, raises vulnerability of disease for genetically identical crops
Chp14.3 Modern Farming Techniques Exploration of new (old) grains like quinoa of the Inca (S. America). Very high in protein, good balance of amino acids, and grows well in mountainous areas. Possible for S.E. Asia, Africa, and Himalayas.
Chp14.4 Sustainable Agriculture Modern agriculture is driven by economics and by international trade. This has pushed soil erosion, deforestation, desertification, hunger, war, and environmental damage on a global scale.
Chp14.4 Sustainable Agriculture As the population increases (Chp13) the pressure to produce more food will increase.
Chp14.4 Sustainable Agriculture Sustainable agriculture (regenerative farming): based on crop rotation, reduced soil erosion, pest management, and a minimal use of soil additives.
Chp14.4 Sustainable Agriculture Crop Rotation: changing the type of crop grown in an area on a regular cycle; usually every 1 to 6 years. This helps prevent mineral and N depletion (which has to be added when depleted).
Chp14.4 Sustainable Agriculture Can use N-fixing crops to serve as a “cover crop” (nonfood plants that are grown between growing seasons); restore N to the soil and reduce erosion.
Chp14.4 Sustainable Agriculture Reducing Erosion: process by which soil is lost, transported, and reformed. Since the 1800’s heavy tilling has been part of traditional agriculture. This turns the soil to bring better layers to the top. Reduced tilling is key.
Chp14.4 Sustainable Agriculture Pest Management: Integrated pest management (IPM) can reduce the use of pesticides by 90%. Relies on natural predators of pests (wasps, ladybug beetles, viruses, bacteria, Praying Mantis’, etc.).
Integrated Pest Management (IPM) systems use natural predators. Fig 14.10 Integrated Pest Management (IPM) systems use natural predators. Fig 14.10
Chp14.4 Sustainable Agriculture In 1986, the President of Indonesia banned 56 of the 57 insecticides commonly used and launched a program to educate farmers. This was due to the “brown planthopper” which developed a resistance to insecticides and destroyed the rice harvest.