Day 8 - Home Page
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GEOG 101 Day 8 Housekeeping Items Social Sciences Pizza lunch event on Tuesday the 6th in Building 356 from 12 to 1:30, probably on the main floor atrium. There will also be representatives of agencies serving students on campus. Housekeeping Items Nobody got any of my mass e-mails, so I had IT look into it. (It seems to be fixed now.) All the assignment instructions and deadlines are on the web site, and the deadline for the outlines is October 6th, not the 1st. Were the talks in the Library useful? The deadline for the alternative mid-term assignment remains October 15th. We have a special guest, Melissa Bracken, who will talk on vertical organic gardens, and Daniel from our class will talk about no-till agriculture. He passed on some video resources: -Canadian No-Till farming: https://www.youtube.com/watch?v=I_7d0h2bSoY, and https://www.youtube.com/watch?v=q1aR5OLgcc0 On Quicker and Easier Land Restoration: He says in the Middle East and China’s Loess plateau, it involves Arabian princesses and more. See https://www.youtube.com/watch?v=YBLZmwlPa8A Also awesome Borneo Rainforest recovery involving sugar-palm biofuel production: https://www.youtube.com/watch?v=3vfuCPFb8wk Extra Credit (Voluntary) Homework • • • There are lots of good films on soil and agriculture – Food Matters, Food Inc., The World According to Monsanto, The Future of Food, The Real Dirt on Farmer John, Food Fight, Fresh, King Corn, Super Size Me, The Garden, Forks Over Knives, and Have You Got Milk? If you know of others, let me know. For extra credit: check out any of them and write a one-page, singlespace handwritten response to it, addressing whatever jumps out at you – things you didn’t know, particularly vivid images, ideas for enhancing and conserving soil, or whatever you like, as long as it’s relevant. Try to have it in to me by next Tuesday, October 20th. • Upcoming event: the film “Bikes vs. Cars” on Wednesday, October 7th at 6:30 in Building 250, Room 125, by donation. • Also: Sustainability Fair, October 8th 11:30 to 2 in the Library Quad. Housekeeping Items • Thanks to everyone who responded to my test message. • Bring your LUNCH AND LEARN about research at VIU featuring Michele Patterson, VIU Geography Dept, PhD Geography Candidate, University of Victoria. • WHAT IS A FARMED SALMON? Understanding the social life of a seafood commodity from ocean to table • Over the last few decades the world’s seafood economy has increasingly become both aquaculturebased and globally traded. BC farmed Atlantic salmon is a globally traded, farmed seafood product that is also highly politicized here in British Columbia. This local politicization, however, has seemingly not affected demand or sales in seafood markets outside BC, with farmed salmon being BC’s largest agricultural export, and growing. This presentation will discuss new PhD research in cultural geography that attempts to connect the production to consumption cycle to better understand, among other things, value transformation along the farmed salmon commodity chain. This multisited ethnographic research will capture and characterize the "social life" of farmed salmon using participant observation and informal interviews amongst people who produce, process, transport, prepare, sell and eat farmed Atlantic salmon; in research sites across two BC and two California communities. • Tuesday October 6, noon-1pm • Bldg 305/4th Floor Lounge Upon successfully completing this chapter, you will be able to (we will only hit highlights, and may cover more on agriculture next Tuesday) Delineate the fundamentals of soil science, including soil-forming processes Describe some important properties of soil Characterize the role of soils in biogeochemical cycling State the importance of soils for agriculture and in supporting plant growth Identify the causes and predict the consequences of soil erosion and soil degradation Outline the history and explain the basic principles of soil conservation 7-6 Soil as a System “The nation that destroys its soil destroys itself.” – Franklin D. Roosevelt, Former U.S. President Ganaraska wasteland before World War 2 (northeast of Toronto) Photo courtesy of John Bacher and Ed Borczon Soil as an (eco)system Soil consists of mineral matter, organic matter, air, and water Dead and living microorganisms, and decaying material Bacteria, algae, earthworms, insects, mammals, amphibians, and reptiles It’s like an ecosystem on to itself 7-8 Soil is a complex, dynamic mixture Soil consists of mostly mineral matter with varying proportions of organic matter, the rest is pore space taken up by air, water, and other soil gases Parent material = the base geologic material of soil Determines the starting composition of the soil Organic matter includes living and dead microorganisms as well as decaying plant and animal material Water – is not pure, contains dissolved minerals and organics and is important for support of plant growth Air – soil air is not the same as air we breathe Soil can have an influence on a region’s ecosystem 7-9 Soil formation is slow and complex Soil formation begins when parent material is exposed to the effects of the atmosphere, hydrosphere, and biosphere Parent material can be lava, volcanic ash, rock, dunes or most commonly, bedrock - the continuous mass of solid rock comprising the Earth’s crust Weathering = the physical, chemical, or biological processes that break down rocks to form soil Physical (mechanical) = wind and rain, no chemical changes in the parent material Chemical = substances chemically interact with parent material Biological = organisms break down parent material 7-10 Soil formation is slow and complex (cont’d) 7-11 Soil formation is slow and complex (cont’d) Biological activity includes deposition, decomposition, and accumulation of organic matter Humus = a dark, spongy, crumbly mass of material formed by partial decomposition Erosion = the dislodging and movement of soil by wind or water Occurs when vegetation is absent When deposited elsewhere referred to as sediment We destroy soil much faster than it re-creates itself 7-12 weighing the issues Earth’s Soil Resources It can take anywhere from 500 to 100 years to produce 1 cm of natural topsoil, depending on local conditions. Much of Canada’s land area was scraped free of soil during the last glaciation by the passage of huge ice masses, which retreated about 10,000 years ago. Today much of interior and northern Canada still lacks soil. Given this very long renewal time, is soil truly a renewable resource? How should the very long renewal time influence soil management? 7-13 A soil profile consists of layers known as horizons Horizon = each layer of soil Soil profile = the cross-section of soil as a whole Topsoil = inorganic and organic material most nutritive for plants Leaching = dissolved particles move down through horizons Litter = surface deposits of leaves, branches, mosses, animal waste 7-14 A soil profile consists of layers known as horizons (cont’d) O Horizon – peat deposits A Horizon – topsoil B Horizon = subsoil, hardpan C Horizon = broken parent material R Horizon = unaltered parent material W Horizon = distinct layer of water in some soils Permafrost = some arctic soils contain a perennially frozen layer (which is beginning to melt in some cases) 7-15 Soils vary in colour, texture, structure, and pH Soils are classified into 10 orders based largely on the processes thought to form them Soils classified into various categories using properties such as: Color Texture Structure pH Near Nanaimo, the soils tend to be HumoFerric Podzols and Distric Brunisols 7-16 Soils vary in colour, texture, structure, and pH (cont’d) Soil color = indicates its composition and fertility Black or dark brown = rich in organic matter Pale gray or white = indicates leaching 7-17 Soils vary in colour, texture, structure, and pH (cont’d) • Soil texture = the size of particles - Clay (smallest), silt, sand (largest) • Loam = soil with an even mixture of the three - Influences how easy it is to cultivate and let air and water travel through the soil • Silty soils with medium-size pores, or loamy soils with mixtures of pore sizes are best for plant growth and crop agriculture 7-18 Soils vary in colour, texture, structure, and pH (cont’d) Soil structure (“tilth”= a measure of soil’s “clumpiness” Large clumps can discourage plant roots Repeated tilling compacts soil Plowpan = a hard layer resulting from repeated plowing that resists water infiltration and root penetration Soil pH = influences a soil’s ability to support plant growth Soils that are too acidic or basic can kill plants 7-19 Biogeochemical Cycling in Soil 7-20 Soil is an important terrestrial reservoir for carbon Soil plays a crucial role in the global carbon cycle Soil represents the largest terrestrial reservoir for carbon Main carbon fluxes in which soil is involved are driven by photosynthesis and the production of organic matter, followed by respiration and decay or organic matter Decay of soil organic matter produces soil gas that contains carbon Carbon dioxide Methane 7-21 See http://eusoils.jrc.ec. europa.eu/projects/ SOCO/FactSheets/ ENFactSheet03.pdf Soil Degradation: A Global Concern 7-23 Soil degradation: A global concern 7-24 Soil degradation: A global concern Soil degradation results from deforestation, agriculture and overgrazing Over the past 50 years, soil degradation has reduced global grain production by 13% 7-25 Regional differences affect soil productivity Rainforests have high primary productivity, but the nutrients are in plants, not the soil. If the forests are removed, the soils dry out and cannot readily be regenerated. Swidden agriculture = cultivation of a plot for a few years and then letting it regrow into forest • Temperate grasslands have lower rainfall and less nutrient leaching 7-26 Erosion can degrade ecosystems and agriculture Deposition = the arrival of eroded material at its new location Flowing water deposits sediment in river valleys and deltas Floodplains (e.g. Fraser Delta) are excellent for farming Erosion occurs faster than new soil is formed Erosion increases through: overcultivating fields, overgrazing rangelands, and clearing forested areas A possible solution is “no-till agriculture,” which Daniel will tell us about briefly (check out also the videos) 7-27 Soil erodes by several mechanisms Wind (aeolian) erosion Water erosion (splash, sheet, rill, gully) Rill erosion moves the most topsoil, followed by sheet and splash erosion Gully erosion 7-28 Soil erosion is widespread Humans are the primary cause of erosion 19 billion hectares of croplands worldwide suffer from erosion Kazakhstan lost tens of millions of hectares to wind erosion Soil degradation over the next 40 years in Africa could reduce crop yields by half The on-farm cost of agricultural land degradation in Canada is $670 million per year 7-29 Desertification reduces productivity of arid lands Desertification A loss of more than 10% productivity from erosion, soil compaction, forest removal, overgrazing, salinization, climate change, depletion of water sources A type of land degradation Affects 1/3 of the planet’s land area Most prone areas are arid and semiarid lands (e.g. Sahel) Climate change could result in displacement of 50 million people in 10 years 7-30 The Dust Bowl was a monumental event in North America (cont’d) Native prairie grasses originally held erosion-prone soils in place 1879-1929: Widespread cultivation of wheat, and grazing of many thousands of cattle Great Depression brought a cycle of poverty and overly intensive agricultural practices Dust storms (black blizzards) travelled up to 2000 km Lung irritation, dust pneumonia, grasshopper infestations 7-31 The Dust Bowl was a monumental event in North America (cont’d) 7-32 Protecting Soils 7-33 Erosion-control practices protect and restore plant cover Crop rotation Contour farming Intercropping and agroforestry Terracing Shelterbelts Reduced tillage 7-34 Crop rotation Intercropping Crop Rotation = alternating • Intercropping = planting the crops grown field from one different types of crops in season or year to the next Cover crops protect soil alternating bands or other spatially mixed arrangements to increase ground cover 7-35 Contour Farming Terracing • Contour Farming = plowing furrows sideways across a hillside, perpendicular to its slope, to prevent rills and gullies Terracing = level platforms are cut into steep hillsides, forming a “staircase” to contain water 7-36 Shelterbelts Shelterbelts or Windbreaks = rows of tall, perennial plants are planted along the edges of fields to slow the wind Alley cropping = shelterbelts + intercropping Reduced tillage • Reduced Tillage = furrows are cut in the soil, a seed is dropped in and the furrow is closed 7-37 Irrigation can cause long-term soil problems Irrigation = Artificially providing water to support agriculture Waterlogging = over-irrigated soils which suffocates roots Salinization = the buildup of salts in surface soil layers Salinization inhibits production of 20% of all irrigated cropland, costing more than $11 billion/year 7-38 Irrigation can cause long-term soil problems (cont’d) Remedies for correcting salinization once it has occurred: Choose crops appropriate for the area Irrigate with low-salt water Irrigate efficiently Drip irrigation targets water directly to plants 7-39 Other chemicals also contribute to soil contamination Fertilizer = substances that contain essential nutrients but over-application can damage soils Inorganic fertilizers = mined or synthetically manufactured mineral supplements Organic fertilizers = the remains or wastes of organisms Manure, crop residues, fresh vegetation Compost = produced when decomposers break down organic matter Manure can be a source of water contamination 7-40 Other chemicals also contribute to soil contamination (cont’d) Nitrogen and phosphorous runoff from farms and other sources can lead to algal blooms Nitrates can leach through soil and contaminate groundwater Pesticides are another source of soil contamination Industrial activity contaminates soil through inappropriate disposal of wastes and improper storage 7-41 Grazing practices can contribute to soil degradation Overgrazing is largely responsible for the permanent drying out of parts of the Mediterranean – e.g. Greece and Syria 7-42 Conclusion The preservation of arable soil is crucial for the maintenance of global food security Programs in Canada and worldwide have been successful in reducing topsoil erosion However, soil is still being degraded at a rate that threatens the sustainability of the resource The role of soil as a reservoir in biogeochemical cycling is also of increasing interest to scientists 7-43 Agriculture Learning Outcomes: At the end of this class, you should be able to: Outline the historical development of agriculture and the transition to industrialized agriculture Identify the causes of soil erosion and soil degradation, and explain the basic principles of soil conservation Explain the challenge of feeding a growing human population Evaluate sustainable agriculture Describe the science behind genetically modified food and evaluate controversies over genetically modified food 3-45 Why Should You Care About Food Resources Three major reasons •Food •1 required for healthy & productive life billion people do not get enough food •Food production has large environmental impact - 38% of world’s ice free land in agriculture - 70% of freshwater used for agriculture - 60% of water pollution - 25% of human greenhouse gases Most of Canada's wasted food dumped from homes $27B worth of food wasted across the country every year, research group says See the documentary, “Just Eat It” by the same folks who made “The Clean Bin Project.” The people who made it tried to live off ‘waste food’ for six months in Vancouver. 3-47 7 ways to reduce household food waste 1. Take stock before you shop 2. Plan your meals 3. Be smart about expiration dates 4. Don't assume you need to buy in bulk 5. Learn the art of pre-portioning 6. Use more of your fruits and veggies 7. Think twice before tossing overripe fruits and veggies http://www.cbc.ca/news/canada/story/2012/10/01/f-food-waste-reduction-tips.html 3-49 Percent of land use for growing crops 3-50 Food Choices • There are fewer than two dozen species of major food sources. They all share three characteristics: 1. High yield - High production per unit area of land. Essential to subsistence farmers dependant on small parcels of land 2. High food value - Staple foods have high total calories and essential nutrients: carbohydrates, proteins, fats and vitamins Most subsistence farmers plant a grain or tuber crop for caloric intake and then vegetables and fruit for additional nutrients 3. Storageability - Most foods are harvested at a certain time of year and must last until the next harvest Food Choices • Top five global crops: 1. 2. 3. 4. 5. Potato Cassava (Manioc) Wheat Rice Corn (Maize) Food Choices Efficiency 90% of human food comes from plants Developing World are more efficient than developed world because they rely on the lowest trophic level in the energy pyramid Consumption of animal products is growing FIGURE 8.15 8-54 Our food choices are also energy choices 8FIGURE 8.17 55 90% of energy is lost every time energy moves from one trophic level to the next The lower on the food chain from which we take our food sources, the more people the Earth can support Environmental ramifications of eating meat Land and water are needed to raise food for livestock Producing eggs and chicken meat requires the least space and water; beef requires the most FIGURE 8.18 When we choose what to eat, we also choose how we use resources 8-56 The Evolution of Agriculture Agriculture led to: stable food source urban centres specialization of labour social hierarchies Systems of Agricultural Production • • Subsistence Agriculture: basic needs are met with a small surplus for trade or store most widespread agricultural system in the world Three Subsistence Agricultural Methods: 1. Intensive Subsistence Farming: supports dense populations as it produces relatively high yields per unit of land 2. Shifting cultivation: supports small populations, requires large areas 3. Nomadic herding: supports very small populations, based on seasonal migration Systems of Agricultural Production Industrial Revolution Mechanization led enabled farmers to specialize and mass produce to commercial agricultural systems that dominated regions Systems of Agricultural Production Wheat Dairy General Range Cotton Systems of Agricultural Production Industrial Agriculture: emphasizes specialized production of crops and livestock to sell can produce enough food to feed many other people Production efficiency is achieved in two ways: 1. improved inputs such as seeds, irrigation, fertilizers and pesticides promote higher yield 2. It was two German scientists – Fritz Haber and Carl Bosch – who figured out how to ‘fix’ nitrogen. Haber went on to develop poison gas for use in combat in World War I, and his research indirectly contributed to the development of Xylon-B, the gas which was the main means of eliminating the Jews during World War II 3. specialized machinery speeds up production and requires fewer people, uses fossil fuels Fertilizers boost yields but can be overapplied • Fertilizer = substances that contain essential nutrients • Inorganic fertilizers = mined or synthetically manufactured mineral supplements • Organic fertilizers = the remains or wastes of organisms - manure, crop residues, fresh vegetation - Compost = produced when decomposers break down organic matter Fertilizers boost yields but can be overapplied “Dead zone” at the mouth of the Mississippi (http://serc.carleton.edu/microbelife/topics/deadzone/ index.html) We are producing more food per person FIGURE 8.1 Food security = the guarantee of an adequate, reliable, and available food supply to all people at all times 8-65 We face both too little and too much food • Undernourishment = people receive less than 90% of their daily caloric needs Mainly • in developing countries Malnutrition = a shortage of nutrients the body needs The diet lacks adequate vitamins and minerals Affects • some people who rely overly on “fast” and processed food Overnutrition = receiving too many calories each day In Canada, 48% of adults exceed their healthy weight and ~25% are obese Between 1981 and 2009, measured obesity doubled Obesity in Canada: A joint report from the Public Health Agency of Canada and the Canadian Institute for Health Information (2011). See also Stuffed and Starved: The Hidden Battle for the World’s Food System by Raj Patel. 8-66 New Horizons in World Agriculture The Green Revolution: the use of new technology, crop varieties and farming practices introduced to developing countries the Green Revolution led to a tripling of grain yields between 1950 and 1990 From 1900 to 2000, humans expanded the world’s total cultivated area by 33% and energy inputs increased by 80 times: Synthetic fertilizers Chemical pesticides Irrigation Heavy equipment New Horizons in World Agriculture Shortcomings of the Green Revolution limited participation by small, subsistence farmers increased mechanization and farm size increased commercialization loss of genetic diversity (monocultures) reduction soil in soil fertility and increased erosion potential damage and water resource depletion from increased irrigation many regions initially bypassed by the Green Revolution Pests and pollinators Pest = any organism that damages valuable crops Weed = any plant that competes with crops FIGURE 8.4 Armyworms easily defoliate monocultures 8-69 Many thousands of chemical pesticides have been developed Pesticides = poisons that target pest organisms Insecticides = target insects Herbicides = target plants (e.g weeds) Fungicides = target fungi 91% of pesticide sales are for agricultural purposes 85% of pesticides sold in Canada are herbicides 8-70 Pests evolve resistance to pesticides Resistance is passed through their genes to insect offspring Pesticides stop being effective Evolutionary arms race: chemists increase chemical toxicity to compete with resistant pests 8-71 Biological control pits one organism against another Biological control (Biocontrol) = uses a pest’s natural predators to control the pest FIGURE 8.6 8-72 Biocontrol agents themselves may become pests No one can predict the effects of an introduced species The agent may have “non-target” effects on the environment and surrounding economies Removing a biocontrol agent is harder than halting pesticide use Due to potential problems, proposed biocontrol use must be carefully planned and regulated 8-73 Integrated Pest Management (IPM) combines biocontrol and chemical methods IPM uses multiple techniques to suppress pests Biocontrol Chemicals, when necessary Population monitoring Habitat alteration Crop rotation and transgenic crops Alternative tillage methods Mechanical pest removal 8-74 We depend on insects to pollinate crops Pollination = male plant sex cells fertilize female sex cells Value of insect pollination services in Canada is $1.2 billion • Animals pollinate 75% of the world’s staple crops and 90% of all non-food flowering plants. FIGURE 8.8 8-75 Flowers are evolutionary adaptations to attract pollinators Conservation of pollinators is vital Beekeepers are hired regularly to bring honeybee colonies to crops for pollination • To conserve bees: Reduce or eliminate pesticide use • http://www.cbc.ca/news/canada/huge-honey-bee-losses-across-canada-dash-hopes-of-upturn1.1699198 http://www.cbc.ca/news/canada/pesticide-linked-to-bee-deaths-to-get-tighter-regulation1.1829858 8-76 Crossbreeding and Genetic Engineering Early efforts at crop improvement - Crossbreeding, or artificial selection - Many current crops produced this way - Requires long periods of time Genetic engineering - Adding, removing or changing DNA directly - produces genetically modified organisms (GMOs) - Similar to crossbreeding, but can use new genes - Much faster than crossbreeding - Can yield improvements quickly, but controversial 8-77 Genetic engineering is like, and unlike, traditional agricultural breeding Scientific techniques to develop more productive crops and livestock has been around for more than a century Similar: Both alter gene pools for preferred characteristics Both apply to plants and animals Different: Traditional Selective In breeding uses genes from the same species breeding deals with whole organisms, not just genes traditional breeding, genes come together on their own 8-78 weighing the issues GM foods and you Do you think you have ever eaten a food product that contained genetically modified organisms? • As much as 70% of the food products on shelves in North American grocery stores contain at least some GM ingredients. • Check your kitchen cupboards for any foods that contain products or ingredients made from corn, soy, or canola. • For a pro-GM perspective, see http://www.geneticliteracyproject.org/2014/10/28/not-all-science-iscreated-equal-the-genetically-engineered-crops-story/. 8-79 Biotechnology is transforming the products around us FIGURE 8.12 2006: Globally, GM foods grew on 106 million hectares of farmland, producing $6.15 8-80 billion worth of crops Concerns with transgenic crops Biotechnology herbicide resistant crops (e.g. “Round-up Ready Canola”) will encourage the use of herbicides (kills non-target species and pollutes soil/water) crops might transfer their herbicide tolerance to closely related weeds (super weeds) built-in pesticides will promote rapid evolution of resistant pests (super pests) may permanently alter wild and domesticated plants and reduce diversity genetically engineered seeds add to production costs only a small group of N.A. and European companies will control most of the worlds certified seed supply health concerns have led to a debate about labelling Precautionary principle Supporters make the following points: GM crops pose no ill health effects They benefit the environment by using less herbicides Herbicide-resistant crops encourage no-till farming GM crops reduce carbon emissions by needing fewer fuel-burning tractors and sequestering carbon in the soil by no-till farming Critics argue that we should adopt the precautionary principle = don’t do any new action until its impacts are fully understood http://www.cbc.ca/news/technology/gmo-debate-shows-big-opinion-gapbetween-scientists-public-over-safety-1.3011371 and 14-year-old debating Kevin O’Leary: https://www.youtube.com/watch?v=TX_-Zoom9Uc 8-82 Debate over GM foods involves more than science Ethical issues play a large role People don’t like “tinkering” with “natural” foods With increasing use, people are forced to use GM products, or go to special effort to avoid them Multinational corporations threaten the small farmer Research is funded by corporations that will profit if GM foods are approved for use Crops that benefit small, poor farmers are not widely commercialized Fears that companies like Monsanto will gain control of 8-83 world’s food Sustainable Agriculture Sustainable agriculture = does not deplete soil, pollute water, or decrease genetic diversity Low-input agriculture = uses smaller amounts of pesticide, fertilizers, growth hormones, water, and fossil fuel energy than industrial agriculture Organic agriculture = Uses no synthetic fertilizers, insecticides, fungicides, or herbicides Relies on biological approaches (composting and biocontrol) 2009: Organic Products Regulations Multi-ingredient products must be 95% organic Organic certification logo 8-84 The benefits of organic farming For farmers: Lower input costs, enhanced income from higher-value products, reduced chemical costs and pollution Obstacles include the risks and costs of switching to new farming methods and less market infrastructure For consumers: Concern A about pesticide’s health risks desire to improve environmental quality Obstacles include the added expense and less aesthetically appealing appearance of the product 8-85 Locally supported agriculture is growing The average food product sold in North America travels at least 2300 km between the farm and the shelf, and is often chemically treated to preserve freshness and colour. Farmers and consumers are supporting local agriculture Fresh, local produce in season Community-supported agriculture = consumers pay farmers in advance for a share of their yield Consumers get fresh food Farmers get a guaranteed income Community gardens = areas where residents can grow their own food -increasingly popular in cities 8-86 Summary Intensive commercial agriculture has substantial negative environmental impacts If our planet will be able to support 9 billion humans, we must shift to sustainable agriculture Biological Organic pest control agriculture Pollinator protection Preservation Careful, of native crop diversity responsible genetic modification of food 8-87
