1. © 2011, 2007, 2002, 1988 Pearson Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 Practical Horticulture 5 th edition By Margaret J. McMahon, Anton M. Kofranek and Vincent E. Rubatsky tab Chapter 3 - Growing Plants for Human UseNutrition Plants are the only terrestrial organisms that convert inorganic carbon, oxygen, hydrogen, nitrogen, and sulfur to organic forms, via photosynthesis. –They are called autotrophs (meaning “self-feeder”). Humans, and just about everything else that live on land are heterotrophs (or “other feeders”). –Because they feed off autotrophs or other heterotrophs.

2. © 2011, 2007, 2002, 1988 Pearson Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 Practical Horticulture 5 th edition By Margaret J. McMahon, Anton M. Kofranek and Vincent E. Rubatsky tab Chapter 3 - Growing Plants for Human UseNutrition Only a small percentage of all the plant species in existence feed the world’s people: –Cereal crops—wheat, maize (corn), rice, barley, oats, sorghum, rye, millet. Over half the world’s food supply come from these crops. –Roots & tubers—potatoes, sweet potatoes, cassavas. –Oil crops—soybeans, corn, peanuts, palm, coconuts, sunflowers, olive, safflower. –Sugar—sugar cane & sugar beets. –Fruit crops—bananas, oranges, apples, pears, etc. –Vegetable crops—tomatoes, lettuce, carrots, melons, asparagus, etc.

3. © 2011, 2007, 2002, 1988 Pearson Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 Practical Horticulture 5 th edition By Margaret J. McMahon, Anton M. Kofranek and Vincent E. Rubatsky tab Chapter 3 - Growing Plants for Human UseNutrition Common crops ranked in relation to the calories and proteins produced per unit of land area. Not all of the total production of food materials is available for human consumption. Much is lost during harvesting, transportation, and marketing. Some of the production is saved to be used as seed for future plantings.

4. © 2011, 2007, 2002, 1988 Pearson Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 Practical Horticulture 5 th edition By Margaret J. McMahon, Anton M. Kofranek and Vincent E. Rubatsky tab Chapter 3 - Growing Plants for Human Use Twenty-four to thirty-six slices of bread is one way to get our daily energy requirement. Lipids provide energy in more condensed form. Nutrition Adults need 2000 to 3000 kcal of energy per day, depending on their size and level of activity. This energy can be provided by carbohydrates, typically found in plant foods.

5. © 2011, 2007, 2002, 1988 Pearson Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 Practical Horticulture 5 th edition By Margaret J. McMahon, Anton M. Kofranek and Vincent E. Rubatsky tab Chapter 3 - Growing Plants for Human UseNutrition Animal fats tend to be saturated fats, which lack double bonds in their fatty acids. Plant energy carbohydrate sources are healthy as they are associated with indigestible fiber, which protects from colon disorders. –Purified carbohydrates such as refined sugar or starch are not as beneficial, and carry their own health risks.

6. © 2011, 2007, 2002, 1988 Pearson Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 Practical Horticulture 5 th edition By Margaret J. McMahon, Anton M. Kofranek and Vincent E. Rubatsky tab Chapter 3 - Growing Plants for Human UseNutrition An adult needs about 70 grams of protein in a day. Plant foods, especially cereal grains and pulses (peas & beans), often provide enough protein along with the energy they supply.

7. © 2011, 2007, 2002, 1988 Pearson Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 Practical Horticulture 5 th edition By Margaret J. McMahon, Anton M. Kofranek and Vincent E. Rubatsky tab Chapter 3 - Growing Plants for Human UseNutrition A plant diet may not satisfy protein requirements, as it may be deficient in one or more amino acids. Deficiencies of individual plant foods can be remedied to a large extent by combining them. A balance can also be achieved on a plant diet with a small amount of meat or other animal food. –Plant proteins often have a low proportion of essential amino acids –An exception is quinoa (Chenopodium quinoa). –Animals generally provide better-quality protein. Eggs are generally regarded as providing perfect protein.

8. © 2011, 2007, 2002, 1988 Pearson Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 Practical Horticulture 5 th edition By Margaret J. McMahon, Anton M. Kofranek and Vincent E. Rubatsky tab Chapter 3 - Growing Plants for Human UseNutrition Carbohydrates, lipids (fats), and proteins are the bulk constituents of our diet. –We also need small amounts organic molecules—vitamins. Most can be obtained from fruits, vegetables, or grains.

9. © 2011, 2007, 2002, 1988 Pearson Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 Practical Horticulture 5 th edition By Margaret J. McMahon, Anton M. Kofranek and Vincent E. Rubatsky tab Chapter 3 - Growing Plants for Human UseNutrition Vitamin C is found only in fresh fruits and vegetables. Vitamin A is derived from carotene, found in green, yellow, orange, or red fruits, vegetables, and grains. Vitamin B 12 is not provided by plants. –Cyanocobalamin is manufactured by bacteria, especially in ruminant organisms, is available in meat & dairy foods. We require six major inorganic nutrients—calcium, phosphorus, magnesium, sodium, potassium, chloride—and seven micronutrients. –All can be obtained from plant foods, although often more abundant in animal foods.

10. © 2011, 2007, 2002, 1988 Pearson Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 Practical Horticulture 5 th edition By Margaret J. McMahon, Anton M. Kofranek and Vincent E. Rubatsky tab Chapter 3 - Growing Plants for Human UseNutrition Worldwide there are about 0.25 hectares (0.6 acres) of cropland for each person. –With realistic inputs/yields, this is about enough to provide everyone with a vegetarian diet. In addition to land required to grow crops, we should count area needed to provide inputs of energy and chemicals, and absorb the wastes generated.

11. © 2011, 2007, 2002, 1988 Pearson Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 Practical Horticulture 5 th edition By Margaret J. McMahon, Anton M. Kofranek and Vincent E. Rubatsky tab Chapter 3 - Growing Plants for Human UseNutrition Crop production has become concentrated and specialized in regions & countries around the world. –California and Florida produce more than 60% of U.S. grown fruits and vegetables. Crops can move thousands of miles from producer to consumer.

12. © 2011, 2007, 2002, 1988 Pearson Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 Practical Horticulture 5 th edition By Margaret J. McMahon, Anton M. Kofranek and Vincent E. Rubatsky tab Chapter 3 - Growing Plants for Human UseNutrition Some argue—from an ecological perspective—that we should consume local produce. –However, energy costs of transport are much lower than for out-of-season production in a greenhouse. Nutrient flow from food transport presents problems. –The nutrients in the produce are removed from the area where the crop was grown.

13. © 2011, 2007, 2002, 1988 Pearson Education, Inc. Pearson Prentice Hall - Upper Saddle River, NJ 07458 Practical Horticulture 5 th edition By Margaret J. McMahon, Anton M. Kofranek and Vincent E. Rubatsky tab Chapter 3 - Growing Plants for Human UseNutrition In moist, temperate parts of the world, it is easy to forget how much water is needed to produce crops. –It can take a ton of water to produce a kilogram of grain. In dry areas, a large land surface may be needed to collect water to be used for irrigation to grow crops. –Water needs in arid locations cause political problems.