Soil and Agriculture: Fertility, Texture, Erosion, and Pest Management - Prof. George Byrn, Study notes of Health sciences

Download Soil and Agriculture: Fertility, Texture, Erosion, and Pest Management - Prof. George Byrn and more Study notes Health sciences in PDF only on Docsity! 1. Be able to describe the things that make soil fertile- 1. A root environment with oxygen, proper PH, and low salt 2. Mineral nutrients: phosphate, potassium, and others 3. water holding capacity: low permeability is better. 2. Explain how soil texture affects water holding capacity- Salinization- too much salt in the soil (high evaporation, poor drainage/heavy irrigation); Waterlogging- excessive irrigation/poor drainage 3. The best type of soil for growing crops is a combination of what three things and what is the combination called? Silt, Sand, Clay = LOAM 4. What are the root causes of erosion and what are the immediate causes? Root – Over Cultivation, overgrazing, deforestation immediate causes- water and wind 5. How do you prevent erosion? crop rotations, no-till or low-till agriculture, use organic fertilizer, terrace and contour planting (follows lay of land), wind breaks and strip cropping( grow trees around crop for wind protection) 6. What are salinization and water-logging? Salinization- too much salt in the soil (high evaporation, poor drainage/heavy irrigation); Waterlogging- excessive irrigation/poor drainage 7. What are the goals of sustainable agriculture? Minimize oil erosion, salinization, and waterlogging; grow more perennial crops; reduce water waste in irrigation; reduce use and waste of fossil fuels; increase use of biological pest control and integrated pest management; shift to full cost pricing that includes the harmful environmental impacts of agriculture in food prices (tax); reduce poverty; slow population growth 8. What are the benefits of organic verse inorganic fertilizer? 9. What is Blue Baby Syndrome? Methemoglobinemia- nitrate gets into baby’s blood, causing them to turn blue 10. What is the difference between subsistence and industrialized agriculture? Subsistence - farmers of the developing world that use traditional agricultural methods for raising plants, animals, and food; requires either large amounts of land or large amounts of human/animal labor. Industrialized- More money, less labor; shift from animal labor to machines; irrigation; increasing use of fertilizers and pesticides; new crop varieties. 11. Describe the world-wide total and per capita production of food over time. Significant increases in productivity until early 1980s; may be due to limit in how much fertilizer you can apply, farmland is shrinking, population growth is increasing. 12. Describe the environmental costs of agriculture- fossil fuel, soil erosion, resistant pest varieties, groundwater depletion, water pollution 13. Explain The Green Revolution- Development of high yielding foods; these have increased crop yields 14. What is the People-Food Predicament? 15. Be able to correctly identify nutritional deficiency diseases in terms of their causes  Kwashiorkor- protein deficiency, exp. People in Africa  Marasmus- depletion of calories and protein; thin children, skin hangs, eyes are large & bright  Xerophthalmia- blindness; vitamin A deficiency; associated with protein shortages  Anemia- iron deficiency, seen in everyone; lack of energy and low levels of productive activity  Goiter- iodine deficiency; affects over 20 million worldwide; swollen growth of thyroid gland 16. Discuss the prospects for reducing world hunger- reduce post harvest lost, eat lower on the food web, improve yields per acre; expanding amount of land under cultivation and increasing world fish catch do not work. 17. Describe the steps in promoting sustainability in agriculture (8 were listed in class) 18. What is a pest, and what is a pesticide? Pest- any organism which adversely affects human interests (animal, plant, etc.) pesticide- substance or mixture of substances used to kill a pest (insecticides, herbicides, rodentcides) 19. List problems caused by pests 1. Resource competition- loss in farm production, property damage, weeds take 30-35 percent of harvest each year 2.Sources of discomfort- lice, fleas, mites, spiders, bedbugs 3.Vectors of disease- mosquitos, flies and roaches, body lice, fleas, ticks (lime disease) 20. Be able to explain the major differences between the classes of insecticides. Natural organic- chemical extracted from plants; chlorinated hydrocarbons (DDT)- stored in fat; organophosphates (OP)- nerve toxins; carbamates- similar to OP but less toxic; microbial agents and biological controls- living organisms or toxins that kill pests 21. List environmental & human health impacts of pesticide use- developing resistance, killing of beneficial species either directly or by food web interruption, environmental contamination 22. Be able to explain the pesticide treadmill- ongoing event (pest problems)- the development of resistance means that pesticides will never destroy pests completely & means that larger amounts or more potent pesticides must be used to kill the pests. 23. Be able to explain the concept of Integrated Pest Management (IPM) - aims to minimize the use of synthetic organic pesticides without jeopardizing the environment. Goal is to just manage the pests, not get rid of them and hurt the environment (combines two or more methods) 24. Be able to list and explain alternatives to chemical pest control- natural enemies; pathogens and parasites (kills only insects, not humans); sex attractants; sterile male technique; development of resistance host plant; crop rotation; sanitation 25. What is Bacillus thurengensis (BT)? Pathogens and parasites (kills insects – doesn’t harm humans)