Ch. 12: Food, Soil, and Pest Management
Biodiversity loss
- loss of degradation of grasslands, forests, and wetlands -killing wild predators to protect livestock - fish kills from pesticide runoff
Air fertilizers
-greenhouse gas emission of methane (CH4) by cattle - other air pollutants from fossil fuel use and pesticide sprays
Vitamins and Minerals
1 out of 5 people suffer deficiencies of key nutrients. Lack of: - Vitamin A causes blindness and death in children - Iron causes anemia - Iodine leads to improper function of the thyroid gland (goiter) ...^ we input all of these things (vitamin a, iron, iodine) into our foods so that we don't have nutrition issues
Statistics of scale of organic food in the world:
1% of world cropland is organic 0.6% of US cropland is organic Almost 33% of Australia and New Zealand cropland is organic 6-18% European cropland is organic
Where does the grain production go?
48% eaten by people 35% feeds livestock 17% used to make biofuels (mostly corn)
Industrialized Meat Production and Consumption
50% of meat is grazed and 50% is raised on feedlots and concentrated animal feeding operations World meat production increased by 4x from 1961-2007 and will likely double in the next 40 yrs. With only about 4.5% of the world's population, the US grows and kills nearly 10 billion animals a year as a source of beef, pork, chicken, and other forms of meat.
Eating Lower on the Food Chain
A more sustainable form of meat production and consumption would involve shifting from less grain-efficient forms of animal protein, such as beef, pork, and carnivorous fish produced by aquaculture, to moregrain-efficient forms (such as poultry and plant-eating farmed fish) Animal protein requiring the most grain to feed it: Beef cattle --> Pigs --> Chicken --> Fish (catfish or carp)
Food Quality Protection Act
(1996) Requires the EPA to reduce the allowed levels of pesticide residues by a factor of 10 when there is inadequate info on harmful effects to children
Gully Erosion
(most severe) all rills merge together to create huge gullies
Air pollution
- Agriculture is responsible for 1/4 of the human generated greenhouse gas emissions. (18% of greenhouse gas emissions comes from livestock alone; more than the emissions of cars/planes/trains put together! Reason: because livestock production --> Methane emissions which is more harmful that CO2). - Clearing and burning of crops produces non-greenhouse gas pollutants as well
Biodiversity Impacts:
- Biodiversity is lost during the conversion to agriculture from natural systems (industrial ag generally slows the conversion). - India planted 30,000 varieties of rice and now 70% of production comes from 10 varieties. - Patent laws in the US prevent farmers from saving seeds :(.
Alternatives to Pesticides (6):
- Fool the pest - Provide homes for pest enemies - Genetic resistance - Biological control - Use insect pheromones - Reduce the need for herbicides by rotating crops and use of cover crops or mulches.
Restoring Nutrients = a Way to Increase Soil Fertility (3 ways):
- Organic Fertilizers (animal manure; green manure; compost- made by alternating layers of green and brown waste and stirring) fresh veg. plowed into the soil to increase humus for nxt crop - Inorganic fertilizers are mined - Crop rotation
Ways to produce food more sustainably:
- Reduce soil erosion - Restore soil fertility - Reduce soil salinization and desertification - Practice sustainable aquaculture - Produce meat more efficiently and eat less - Shift to more sustainable production (vs industrial) - Decrease waste in food production
Food Insecurity:
Living with chronic hunger and poor nutrition, which threatens peoples' ability to lives healthy, productive lives
Solutions - More sustainable agriculture:
MORE: high-yield polyculture, organic fertilizers, biological pest control, integrated pest management, efficient irrigation, perennial crops, crop rotation, water-efficient crops, soil conservation, subsidies for sustainable farming. LESS: soil erosion, soil salinization, water pollution, aquifer depletion, overgrazing, overfishing, loss of biodiversity and agrobiodiversity, fossil fuel use, greenhouse gas emissions, subsidies for unsustainable farming.
Who Buys Organic? Why or Why Not?
Middle-aged white women with kids. People often make the switch to buying organic when they have kids. WHY: healthier, concern for the environment, superior taste, food safety (lack of confidence in the conventional food industry) WHY NOT: expensive, physically unattractive, sometimes inaccessible, skepticism of certification and organic labels
salinization of the soil
a soil degradation process in which repeated applications of irrigation water in dry climates lead to the gradual accumulation of salts in the upper soil layers. - stunts crop growth, lowers crop yields, and can eventually kill plants and ruin the land. photo: cracked land (like in HOLES): Because of high evaporation, poor drainage, and severe salinization, white alkaline salts have displaced crops that once grew on this heavily irrigated land in Colorado. -reduce irrigation - flush with tons of water -occurs in Asia, China, India, Egypt, Iraq, pakistan, Western US is affected
Soil Erosion Act
established Soil conservation service which taught farmers good farming practice to avoid another event like this
FIFRA
federal insecticide, Fungicide, and Rodenticide Act (1972) regulates the selling, manufacturing and use of pesticides
Soil Erosion & the Leading cause of topsoil erosion:
the movement of soil components, especially surface litter and topsoil, from one place to another by the actions of wind and water. in nature, the roots of plants help to anchor the topsoil and prevent erosion. leading cause of topsoil erosion: flowing water from rainfall, leading to GULLIES. In 2008, the Chinese government estimated that one-third of China's land suffers from serious topsoil erosion. *what's the problem?
Soil Permeability
the rate at which water moves through a type of soil Downward movement of soil is called infiltration
pesticide treadmill
treatment becomes less effective over time, so apply more, and spend more money
Contour Planting
used on terrains w/ a slope plant rows across the slope rather than up and down (right angles)
Marasmus
waste away diet low in calories and protein mostly infants of malnourished mothers look very old
Rill Erosion
water gathers together in little streams/channels or Rills (more common)
Hypoxia
lack of oxygen
Agribusiness
small group of multinational corporations control the growing, processing, and distribution of food in the US
Loam
soil with equal amounts of sand, silt, clay, and humus
Terracing
steep sides mountainous areas no erosion making a series of steps
Kwashiorkor
displaced child severe protein deficiency Infants 1-3 happens when mothers stop breast feeding too soon because another was born. Diet- sweet potatoes or grains no proteins but enough calories. Swollen stomach, red hair, mental
Plantation Ag (industrial)
Specific type of Industrial Agriculture focused on growing cash crops (e.g. bananas, ethanol, sugar, coffee, and palm oil). Primarily occurs in tropical developing countries
Irrigation
Supplying water to crops by artificial means
Traditional Subsistence Agriculture
Traditional subsistence agriculture supplements energy from the sun with the labor of humans and draft animals to produce enough crops for a farm family's survival, with little left over to sell or store as a reserve for hard times. In traditional intensive agriculture, farmers increase their inputs of human and draft-animal labor, animal manure for fertilizer, and water to obtain higher crop yields. If the weather cooperates, they produce enough food to feed their families and to sell some for income.
Slash and Burn (traditional agriculture)
Type of subsistence agriculture involving burning and clearing small plots in tropical forests, growing a variety of crops for a few years until the soil is depleted of nutrients, and then shifting to other plots to begin the process again. Need to remain fallow (unplanted) for 10-30 yrs Can be more productive than high-input monocultures
Results of Food Insecurity:
Undernutrition (hunger) - not getting enough calories Malnutrition - deficiencies of protein or other key nutrients Famine - severe shortage of food in an area accompanied with mass starvation
Industrialized (High-Input) Agriculture
Uses heavy equipment and large amounts of financial capital, fossil fuels, water, commercial inorganic fertilizers, and pesticides to produce single crops, or monocultures. The major goal of industrialized agriculture is to steadily increase each crop's yield—the amount of food produced per unit of land. Industrialized agriculture is practiced on 1/4 of all cropland, mostly in more-developed countries, and now produces about 80% of the world's food.
Integrated Pest Management
Utilizing a combination of tools designed to work with each crop and pest
waterlogging
Water accumulates underground and gradually raises the water table, esp. when farmers apply large amounts of irrigation water in an effort to leach salts deeper into the soil. - deprives plants of the oxygen they need to survive. - (without adequate drainage) lowers the productivity of crop plants and kills them after prolonged exposure. At least 1/10 of the world's irrigated land suffers from this, and the problem is getting worse.
Croplands: the 3 important grains they provide (on which 2/3 of the world pop. survives)
Wheat, rice and corn provide 48% of the world's calories 2/3 of the world population survives on these 3 grains What impact does this have on sustainability of our crop systems?
GM Foods
Adv. -more resistant to insects, disease, frost, and drought -can grow in slightly salty soils, need less water Disadv. - Irreversible and unpredictable genetic and ecological effects - Harmful toxins in food from possible plant cell mutations
US Industrial Food Production
Agriculture is bigger than auto, steel and housing industries combined! US grows 17% of the world's crops with 0.3% of the world's farm labor We spend less than 10% of our income on food while people in developing countries spend between 40-70% of their income.
Dust Bowl:
Americans learned a harsh environmental lesson in the 1930s, when much of the topsoil in several dry and windy midwestern states was lost because of a combination of poor cultivation practices and prolonged drought. This threatened to turn much of the U.S. Great Plains into a vast desert.
Soil
Erosion Desertification
Circle of Poison
Every 5 yrs. the EPA requires the removal and replacement of pesticides. We cannot sell or use that chemical in the US. We can still manufacture it
Food Security:
Every person in a given area has daily access to enough nutritious food to have an active and healthy life (Goal of UN)
Oceanic Fisheries and Aquaculture (one place our food comes from: _%):
Fisheries: a concentration of an aquatic species suitable for harvest Aquaculture: raises fish in ponds or cages
Eating Less Meat
If everyone in the world today had the average US meat-based diet, the world's current annual grain harvest could feed only about 2.5 billion people - a little over 1/3 of the current world population.
State of Soil Erosion in USA:
In the United States, a third of the country's original topsoil is gone and much of the rest is degraded. We're losing topsoil & adding pollutants to the water
Types of Croplands:
Industrial: fossil fuels and machinery. monocultures. 1/4 of croplands. 80% of world's food crops Subsistence: human labor and draft animals. primarily polycultures. 3/4 of the cultivated land. 20% of the world's food crops by 2.7 billion people.
Decrease Waste
Industrialized agriculture uses about 17% of all commercial energy used in the United States, and food travels an average 2,400 kilometers (1,300 miles) from farm to plate. The resulting pollution degrades the air and water and contributes to global warming. food production: crops -> livestock -> food processing -> food distribution and preparation
Industrialized Agriculture vs. Organic Agriculture
Industrialized agriculture: uses synthetic, inorganic fertilizers and sewage sludge to supply plant nutrients. Makes use of synthetic chemical pesticides. Uses conventional and genetically modified seeds. Depends on nonrenewable fossil fuels (mostly oil and natural gas). Produces significant air and water pollution and greenhouse gases. Is globally export-oriented. Uses antibiotics and growth hormones to produce meat and meat products. Organic agriculture: (labor intensive) Emphasizes prevention of soil erosions and the use of organic fertilizers such as animal manure(transportation cost => pollution) and compost, but no sewage sludge to help replace lost plant nutrients. Employs crop rotation and biological pest control. Uses no genetically modified seeds. Reduces fossil fuel use and increases use of renewable energy such as solar and wind power for generating electricity. Produces less air and water pollution and greenhouse gases. Is regionally and locally oriented. Uses no antibiotics or growth hormones to produce meat and meat products.
Soil Conservation (a way to decrease soil erosion)
Involves multiple methods to increase soil fertility and decrease erosion: (a) Terracing (b) Contour planting and strip cropping (c) Alley cropping (d) Windbreaks (slow down the wind so that it isn't interacting with the soil at a high velocity)
Anemia
Iron poor blood
Excessive Irrigation
Irrigation accounts for 70% of human water use. 45% of the world's food is produced with irrigation. EFFECTS OF EXCESSIVE IRRIGATION: - Salinization occurs when irrigation water repeatedly evaporates leaving a layer of salts on the topsoil. You end up with cracked/crusty layer of salt above the soil (like in HOLES!) - (Occasional): Waterlogging (occurs when irrigation raises the water table). Waterlogged soils lack oxygen necessary for plant survival.
Windbreaks of Shelterbreaks
Plains states- planting trees or large shrubs around your field to block your wind flow
Strip Cropping
Planting different type of crops in the same field. Use a plant that uses a lot of nitrogen and plants that produce nitrogen (legumes- peanuts, alfalfa, clover, rye) plant corn and then peanuts next to it
What Causes Food Insecurity (5):
Poverty Political upheaval, war, and corruption Bad weather Environmental impacts of food production Biofuel production
Rangelands, Pastures, Feedlots
Produce 16% of the world's food on 29% of the land area
Macronutrients & their Food Sources & functions
Proteins: food source = Animals and some plants. Function: help to build and repair body tissues. Carbohydrates: food source = wheat, corn, and rice. function: Provide short-term energy Lipids (oils and fats): food source = Animal fats, nuts, oils. Function: help to build membrane tissues and create hormones
Sheet Erosion
as water goes through it takes a thin layer of soil/sediments
Overnutrition
When food energy intake is greater than energy use and causes excess body fat Health outcomes are similar to those of undernutrition (lower life expectancy, greater susceptibility to disease and illness, lower productivity and life quality)
Water
-Increased runoff, sediment, pollution, and flooding from cleared land - pollution from pesticides and fertilizers
Pests:
Anything that interferes with human welfare
What are the environmental impacts of industrial food production?
Biodiversity Loss: loss and degradation of grasslands, forests, and wetlands in cultivated areas; fish kills from pesticide runoff; killing wild predators to protect livestock; loss of genetic diversity of wild crop strains replaced by monoculture strains. Soil: erosion; loss of fertility; salinization; desertification; waterlogging; desertification; increased acidity. Water: water waste; aquifer depletion; increased runoff, sediment pollution, and flooding from cleared land; pollution from pesticides and fertilizers; algal blooms and fish kills in lakes and rivers caused by runoff of fertilizers and agricultural wastes. Air Pollution: emissions of greenhouse gas CO2 from fossil fuel use; emissions of greenhouse gas N2O from use of inorganic fertilizers; emissions of greenhouse gas methane (CH4) by cattle (mostly belching); other air pollutants from fossil fuel use and pesticide sprays. Human Health: nitrates in drinking water (blue baby); pesticide residues in drinking water, food, and air; contamination of drinking and swimming water from livestock wastes; bacterial contamination of meat. More than 20% of the world's cropland (65% in Africa) has been degraded to some degree by soil erosion, salt buildup, and chemical pollution
Pesticides:
Chemicals used to kill or control pests. 2 different types of pesticides: - 1st generation: developed from plants - 2nd generation: produced in a lab (DDT)
Pesticides have NOT reduced crop loss
Crop loss doubled from 1942->1997. Environmental, health and social costs are $5-10 in damages (recovery efforts for large birds; restitution for ppl who get cancer from the pesticides) for every dollar spent on pesticides! Alternatives could reduce pesticide use by 40%.
Where does food come from?
Croplands: produce 77% of the world's food (mostly grain) using 11% of the land Rangelands, Pastures, Feedlots: produce 16% of the world's food on 29% of the land area Oceanic Fisheries and Aquaculture: produce 7% of the world's food
How did grain production increase 88% since 1950?
From using high-input industrialized agriculture to increase crop yields in a process called the Green Revolution: 3 STEPS involved in a GREEN REVOL.: 1) Breeding and GMOs 2) Increase yields with fertilizer, pesticides and water 3) Increase the number of crops grown on a plot per year through multiple cropping. Betw. 1950-70, this high-input approach dramatically increased crop yields in most of the world's more-developed countries, esp. the USA, in what was called the first green revolution. a second green revolution has been taking place since 1967: Fast-growing dwarf varieties of rice and wheat, specially bred for tropical and subtropical climates, have been introduced into middle-income, less-developed countries such as India, China, and Brazil. Producing more food on less land has helped to protect some bio- diversity by preserving large areas of forests, grasslands, wetlands, and easily eroded mountain terrain that might otherwise be used for farming.
Hydroponics & its advantages
Growing plants in nutrient-rich water solution instead of soil. Usually inside of a greenhouse. Advantages over conventional outdoor growing systems: Indoors, Year round, Urban, Recycling of water and nutrients, No need for pesticides. • Crops can be grown indoors under controlled conditions almost anywhere. • Yields and availability are increased because crops are grown year round, regardless of weather conditions. • In dense urban areas, crops can be grown on rooftops, underground with artificial lighting (as is now done in Tokyo), and on floating barges, thus requiring much less land. • Fertilizer and water use are reduced through the recycling of nutrient and water solutions. There is no runoff of excess fertilizer into streams or other waterways. • In the controlled greenhouse environment, there is little or no need for pesticides. There is no soil erosion or buildup of excess mineral salts (common problems on heavily irrigated cropland) .
Polyculture
Growing several crops on the same plot simultaneously (method used by traditional farmers). This crop diversity reduces the chance of losing most or all of the year's food supply to pests, bad weather, and other misfortunes.
Soil Erosion
Movement of soil components from one place to another via wind or water. *What's the problem? Losing the soil. Leads to water pollution downstream. Solution: Having a layer of insulation above the soil would DECREASE the erosion. * 38% of croplands are losing soil faster than can be replenished
Is there not enough food? Is this the reason for food insecurity?
NO! We're just eating too much food: 1 billion people have health problems because they are not getting enough to eat and 1.2 billion have health problems from eating too much. ...the problem is not that there isn't enough food... it's simply that it is not evenly distributed!!!
Greenhouses (industrial agriculture method)
Newer form of industrialized agriculture using large arrays of greenhouses to raise crops indoors. - In sunny areas, greenhouses can be used to grow crops year round and in some areas such as Iceland and parts of the western United States they are heated with geothermal energy. - In water-short, arid areas, farmers can save water by using greenhouses, because they can deliver water more efficiently to greenhouse crops than they can to outdoor crops. - Because the water can be purified and recycled, water use and water pollution are reduced sharply in such systems It costs more to raise crops in greenhouses than it does to raise crops using conventional industrialized agriculture, BUT the costs of using greenhouses are coming down as the costs of conventional industrialized agriculture are rising because of its harmful environmental effects and because of higher fossil fuel prices.
Conservation Tillage (a way to decrease soil erosion)
No-till / Minimum-Tillage Farming (decreases soil erosion, increases yield, increases carbon storage, decreases water use, decreases tractor fuel, requires more herbicides). 41% of US cropland used conservation tillage in 2007 :-)
HORIZONS OF Soil: O Horizon (leaf litter) A Horizon (topsoil) B Horizon (subsoil) C Horizon (parent material/bedrock)
O-A: Nutrient uptake happens here; where vegetation is getting most of its nutrients and most of its water. Earthworms chew up the O Horizon and transfer it over to the A Horizon. *Problem: loss of O&A Horizons :(.
Case Study: Organic Agriculture is on the Rise
Organic = a sustainable type of agriculture in which crops are grown without the use of synthetic pesticides, synthetic inorganic fertilizers, or genetically engineered seeds, and animals are grown without the use of antibiotics or synthetic growth hormones
Root cause of the Food Security Issue:
POVERTY
Tradeoffs of GMOs:
PROS: Need less fertilizer, Need less water, More resistant to insects/disease/frost/drought, Grow faster, May need less pesticides or tolerate higher levels of herbicides, May reduce energy needs. CONS: Unpredictable genetic&ecological effects, Harmful toxins and new allergens in food, No increase in yields, More pesticide-resistant insects and herbicide-resistant weeds, Could disrupt seed market, Lower genetic diversity.
Tradeoffs of Aquaculture:
PROS: high efficiency, high yield, reduced over-harvesting of fisheries, low fuel use, high profits CONS: large inputs of land, feed, and water; large waste output; loss of mangrove forests and estuaries; some species fed with grain, fish meal, or fish oil; dense populations vulnerable to disease & parasites
Tradeoffs of Animal Feedlots:
PROS: increased meat production, higher profits, less land use, reduced overgrazing, reduced soil erosion, protection of biodiversity, less soil erosion CONS: large inputs of grain, fish meal, water, and fossil fuels; greenhouse gas (CO2 and CH4) emissions; concentration of animal wastes that can pollute water; use of antibiotics can increase genetic resistance to microbes in humans
Tradeoffs of Conventional Chemical Pesticides
PROS: save lives, increase food supplies, profitable, work fast, safe if used properly. CONS: promote genetic resistance, kill natural pest enemies, pollute the environment, can harm wildlife and people, are expensive for farmers.
desertification
occurs when the productive potential of topsoil falls by 10% or more because of a combination of prolonged drought and human activities such as overgrazing and deforestation that reduce or degrade topsoil. Desertification can be moderate (a 10-25% drop in productivity) , severe (a 25-50% drop), or very severe (a drop of more than 50% , usually resulting in huge gullies and sand dunes). Only in extreme cases does desertification lead to what we call desert. But severe desertification can expand existing desert areas or create new desert. HUMAN USE OF THE LAND, ESP. FOR AGRICULTURAL PURPOSES, HAS ACCELERATED DESERTIFICATION in some parts of the world mostly due to deforestation, overplowing, and overgrazing. Severe desertification: Sand dunes threaten to take over an oasis in the Sahel region of West Africa. Such severe desertification is the result of prolonged drought from natural climate change and destruction of natural vegetation as a result of human activities such as farming and overgrazing.
Desertification
occurs when topsoil productivity decreases by 10% or more. Not completely our fault; This is a natural change = combination of drought + our disruption of the soil. occurs only in arid or semi-arid areas Greatest in Australia
Human Health
pesticide residues in drinking, water, food, and air Bacterial contamination of meat
Alley Cropping/ Agroforestry
planting crops and trees together, usually fruit trees, tree roots help keep the soil in place (windblock)
