Sustainable Agriculture Agriculture is the single most harmful

Sustainable Agriculture

Agriculture is the “single most harmful human action that has taken place. ”

OAgriculture destroys more of the Earth’s natural ecosystems and its species than any other human activity. Agriculture is the #1 reason for habitat destruction

Environmental Impact of Agriculture

Biodiversity Loss Soil Water Air Pollution Human Health Nitrates in drinking water Loss and degradation of grasslands, forests, and wetlands Erosion Water waste Loss of fertility Aquifer depletion Greenhouse gas emissions from fossil fuel use Salinization Increased runoff and flooding from cleared land Pesticide residues Other air pollutants in drinking water, from fossil fuel use food, and air Fish kills from pesticide runoff Desertification Waterlogging Killing wild predators to protect livestock Loss of genetic diversity of wild crop strains replaced by monoculture strains Sediment pollution from erosion Fish kills from pesticide runoff Greenhouse gas emissions of nitrous oxide from use of inorganic fertilizers Surface and groundwater pollution from pesticides and fertilizers Belching of the greenhouse gas Overfertilization of methane by cattle lakes and rivers from runoff of fertilizers, livestock wastes, and Pollution from food processing wastes pesticide sprays Contamination of drinking and swimming water with disease organisms from livestock wastes Bacterial contamination of meat Fig. 13 -18, p. 285

Arable land=farmable land

Soil O Erosion= Movement of topsoil by wind or water O Erosion is NOT a good thing! O Nutrients are found in the topsoil O Takes 1 year to produce 1 mm of topsoil O More soil is lost each year to erosion than is formed!

Crops are traditionally raised by two types of agriculture: Industrialized agriculture & Subsistence agriculture

Industrialized Agriculture O Also known as high-input agriculture O Goal: increase crop’s yield by increasing amount of food produced per land area O Practiced on 25% of all cropland, mostly in developed countries O Produces about 80% of the world’s food O Focuses on monoculture O Uses heavy equipment along with large amounts of fossil fuels, water, inorganic fertilizer & pesticide

Industrialized Agriculture O In TROPICAL developing countries the type of industrialized agriculture is plantation agriculture O Grow cash crops: like palm oil, coconut oil, bananas, soybeans, coffee, sugarcane etc. O Most of it is exported to developed countries

Environmental Impact Stripping land; organisms displaced (habitat destruction) Use of commercial seeds, fertilizers, herbicides, and pesticides are expensive & constitute a large portion of the farm’s operating costs Chemical fertilizers, herbicides & pesticides leach into soil & groundwater. Rains wash them (“run-off”) into nearby streams & rivers (nitrogen & phosphate-rich fertilizers cause eutrophication) Monoculture. Single crops deplete soil of nutrients. Nutrients then have to be replaced artificially. Land has to sit bare for return of nutrients After harvesting, bare field is susceptible to soil erosion by wind and rain

Chemical (Inorganic) Fertilizer Pro’s O Composition known O Readily available (buy @ store); easily applied O Rapidly increase soil fertility (fast acting) Con’s O Leach away into groundwater and enter surface runoff (N &P: eutrophication) O Cannot increase water -holding capacity of soil O Releases greenhouse gas, N 2 O O Reduces oxygen content in soil

Industrialized Agriculture O New form: Growing crops indoors! O A sustainable solution O Not as dependent on climate & can take up less land O Large arrays of greenhouses used to grow crops indoors O Good for arid areas like Spain, where they are water-short O Vertical Farming O Urban areas

Subsistence Farming O Also known as Traditional Farming O 39% of the people in developing countries practice this type of farming O Practiced on 75% of all cropland in developing countries O Produces 20% of the world’s food O Uses sunlight, animals, and human labor to produce food for a farm family’s survival; little is left over to sale O Focus on polyculture

Subsistence Farming O Slash and burn agriculture O Involves burning and clearing small plots in TROPICAL RAINFORESTS O Grow a variety of crops for few years until the soil is depleted of nutrients & then shifting to other plots to begin the process again O Abandoned slash-and-burn fields have to be left alone for 20 -30 years before the soil becomes fertile again to support crop growth

Sustainable Farming Low-till or no-till farming or contour farming to decrease wind & water erosion Polyculture/Crop rotation. Plot is never bare. Different crops have different harvest time. This decreases erosion Use organic fertilizers Minimize pesticide use by using Integrated Pest Management strategies Minimize use of fossil fuels by selling to local markets, using local materials, etc. (produce less greenhouse gases) Reduces dependence on irrigated water

OSustainable agriculture does not yield as many crops as conventional OProducts from sustainable agriculture tend to be more expensive than conventional agriculture and look less uniform (not as pretty)

10_SBS 02 -02. JPG

Tillage= Soil is turned over prior to planting seeds (increases erosion) No tillage= leaving the root residues from prior crops in the soil (holds soil in place, reducing erosion)

Organic Fertilizer Pro’s O Can be made up of manure, crop reside, bone meal, compost (reusing instead of throwing away in landfill) O Increases waterholding capacity of soil Con’s O Composition varies- exact composition unknown O Slow-acting but long -lasting

Including legumes in crop rotation O Using legumes in rotation increases nitrogen in soil O Bacteria in roots of legumes fix atmospheric N 2 into nitrate so don’t need to use as much fertilizer

Sustainable Agriculture methods Crop rotation, contour plowing, strip cropping/polyculture, terracing, shelterbelts, allycropping, cover crops

Contour Plowing

Strip Cropping

Terracing

Terracing Rice Fields; China

Shelterbelts

Allycropping/Agroforestry

Fig. 13 -35, p. 303

9 is the first number in the code Organic agriculture Means they are free of: Synthetic pesticides, synthetic inorganic fertilizers & genetically engineered plants or animals

Organic agriculture O Organically grown means…Animals are grown on 100% organically grown feed without the use of antibiotics or growth hormones O 100% organic means…the produce is produced only by organic methods & contains all organic ingredients O Products labeled as organic …must contain at least 95% organic ingredients O Those labeled made with organic ingredients…must contain at least 70% organic ingredients O Those labeled natural…carry no requirement for organic content

Which produce should you spend $ on to buy organic? O Apples O Celery O Strawberries O Leafy greens O Peppers O Nectarines & O Blueberries Peaches O Potatoes O Cherry tomatoes O Cucumbers O Grapes O Snap peas Why? They were found to have the most residue of pesticides (some up to 50 different kinds) on them Always remember to wash your produce All you need to do is thoroughly rinse them off with water (no need to buy “produce wash”)

Organic Clothes? ? O Gap, Levi’s, & Patagonia are increasing their use of organic cotton

INDUSTRIALIZED AGRICULTURE ORGANIC AGRICULTURE Uses synthetic inorganic fertilizer and sewage sludge to supply plant nutrients Emphasizes prevention of soil erosion & uses organic fertilizers such as animal manure & compost, but no sewage sludge Makes use of synthetic chemical fertilizers Uses conventional & genetically modified seeds Employs crop rotation & biological pest control Uses no genetically modified seeds Depends on nonrenewable fossil fuels Produces significant air & water pollution and greenhouse gases Is globally export-oriented Uses antibiotics and growth hormones to produce meat & meat products Reduces fossil fuel use & increases use of renewable energy Produces less air & water pollution & greenhouse gases Is regionally & locally oriented Uses no antibiotics or growth hormones to produce meat & meat products

Can organic agriculture produce as much food as traditional industrialized means?