Feeding the World

1. Feeding the World CHAPTER 14

2. Human Nutrition • Humans need energy to grow, move, and repair our bodies. • All humans belong to one species – so our dietary requirements are the same. • Nutrients are divided into two groups: • Macronutrients • Micronutrients

3. Nutrients • Macronutrients provide the energy (fuel) our bodies need to function (proteins, carbohydrates and fats) • Micronutrients are small amounts of chemicals needed for our body’s biochemical reactions • kcal kilocalories is how macronutrients are measured • 1 kcal = the amount of energy needed to raise 1 kilogram of water 1 degree Celsius

4. Carbohydrates • Made of carbon (C), hydrogen (H) and oxygen (O) • Ratio of 1C:2H:1O • Ex: glucose (sugar) = C6H12O6 • Basic Building block is sugar or simple carbohydrate • Many sugars put together are called starches or complex carbohydrates • All carbs provide 4 kcal/gram energy

5. Proteins • Made of amino acids • Amino acids have Nitrogen • Proteins are very large molecules • Hair, skin, blood, muscle, nails • All the proteins in your body are made of just 20 amino acids in different combinations • We can make 12 amino acids – the other 8 we get from our food • Protein gives 4 kcal per gram of energy

6. Lipids • Lipids are 3 fatty acids with an alcohol molecule • Lipids make up all cell membranes and lining for all our nerves • Two kinds of lipids: • Solid or hydrogenated at room temperature – butter lard (animal-based fats) • Liquid or dehydrogenated at room temperature – olive oil, canola oil, corn oil (plant-based fats) • Lipids provide 9 kcal of energy per gram

7. Vitamins and Minerals • Vitamins and Minerals are Micronutrients • Important in biochemical reactions that release energy in our bodies • Most micronutrients are found in minimally processed fruits and vegetables

8. Nutritional Deficiency • Average adult requires 2500 kcalories per day • Adults that receive 90% or less of this requirement are undernourished • Adults that receive less than 80% of the 2500 kcal per day are seriously undernourished • Children that receive less than 90% can suffer permanent damage to bones, teeth, brain function

9. World Food Supply • Research and development in agriculture have increased the amount of food produced • Economics is the driving force behind agricultural production • More crops = more money • Green Revolution (1960’s) new strains of wheat and rice • Wheat and rice are the diet basis for most of the world

10. Green REVOLUTION • New strains of wheat and rice were disease resistant and could adapt to many climates • Designed to help feed underfed nations • Used modern machinery to plant and harvest r- giving 4X the crops from the same farmland • PROBLEMS: poorest nations didn’t have money for machines, fuel or fertilizers – so only developed countries used the technology

11. Cash Crops • More wheat and rice mean lower prices • Poor farmers were paid even lower prices for their small harvests • ANSWER: grow more expensive crops that can be exported to richer countries who will pay for them • CASH CROP – crops grown only for sale – not to feed the farmer or the community

12. Aquaculture • Food doesn’t just come from the land – the hydrosphere produces 200 billion tons of biomass each year • Commercial fishing has endangered over 40 of 280 fish species • ANSWER: aquaculture – raising fish and shellfish in salt or freshwater pools or ponds • PROBLEMS: water becomes contaminated with run-off and chemicals used to feed fish

13. Hydroponics • Water isn’t just used for fish – plants can also be grown in water • Hydroponics – plants grown without soil • In the produce section of the supermarket: tomatoes, lettuce, peppers, radishes, cucumbers, herbs and flowers grown without soil in controlled conditions using nutrient solutions and recycled water • Usually pesticide free because grown in controlled conditions indoors

14. Modern Farming Techniques • Huge farm machinery has replaced man and animal labor • Middle of 20th century-began to use machines powered by fossil fuels • Called “Industrialized Agriculture” • Efficient and productive • Require large amount of energy, pesticides, fertilizers. • Often run by corporations (agribuisinesses).

15. Use of pesticides • Increase in resistant insects and other pests. • 1992-California white fly infestation • DDT and decline in bald eagle population • Monoculture • Farms growing only the 1 or 2 crops that bring in the most money. • Crops genetically identical = more vulnerable to disease • Soil depleted of minerals = soil loses ability to produce healthy crop.

16. Quinoa • New grains • Not adapted to local conditions • Looking to use local grains in many areas • Ex: quinoa – grows better than wheat or rice in mountainous areas, high in protein, can be made into flour, cereal, beverages and livestock feed.

17. Sustainable Agriculture • Modern agriculture has resulted in: soil erosion, deforestation, desertification, hunger, war, and environmental damage. • Sustainable agriculture-called regenerative farming; based on crop rotation, reduced soil erosion, pest management, and minimal use of soil additives.

18. Crop Rotation • Crop Rotation- changing the type of crop grown in an area on a regular cycle. • Usually 1 to 6 years per cycle • Prevent soil from becoming depleted of nutrients (nitrogen). • Avoid use of synthetic fertilizers. • Cover Crop- nonfood plants grown between grown seasons on land usually left empty. • Restore nitrogen to the soil and help to reduce erosion

19. Reducing erosion • Erosion- process where soil is lost, transported, and reformed. Caused by wind and flowing water. • When topsoil removed, loss of nutrients= useless for farming. • Can be reduced by irrigation and soil management. • Irrigation-watering of fields; use systems that deliver less water, but directly to the roots reduces erosion. • Tilling-turning the soil so lower layers are brought to the surface. • Destroys weeds and other pests, brings nutrients to the surface, improves drainage, and aerates the soil. • Wastes water, uses energy, can increase erosion.

20. Irrigation

21. Tilling

22. Pest Management • Integrated Pest Management (IPM) • Reduce pesticide use by 90% • Use natural predators to manage pests (ex: wasps, ladybugs, viruses and bacteria, etc)