Agriculture. The farm as an ecosystem

Transcription

1 Agriculture Canada Seeks Redress on Food-Labeling Law The farm as an ecosystem Interplanting in space and time -Recycling of organic matter -Built-in biological control Polycultures Intercropping - Different plants planted together Genetic diversity Alternating strips: alfalfa, corn NE Iowa Agroforestry - crops and trees grown together Shade grown coffee National Sustainable Agriculture Information Service Soil conservation Soil conservation Conservation-tillage farming Crop residues left on the surface Reduced-till farming of wheat in Whitman County, Washington strip (or alley) cropping windbreaks Typical soil horizon contour planting terracing 1

2 Water use efficiency Water use efficiency Build healthy soil (holds more water) Decrease transpiration by weeds Right plant, right place Decrease evaporation from soil Decrease runoff Source: USGS Source: USGS Natural pest management Natural pest management Mechanical Squish, traps, exclusion Physical Humidity, electricity Cultural Crop rotation, time of planting Biological Introduce/attract pests of pests Chemical Use hormones to disrupt life cycles Lure pests with pheromones Biological pest control: wasp parasitizing a gypsy moth Green Revolution: World cultivated acreage: 24% increase World grain yield: 100% increase!! 2% per year Rate of increase leveled off in 1980s Green Revolution Industrialization of food Mexico, 1944 Food supplies versus population growth Norman Borlaug develops high-yield wheat 1000 years: 0.5 to 2 metric tons/ha 40 years: 2 to 6 metric tons/ha "a temporary success in man's war against hunger and deprivation to deal with the Population Monster Dr. Borlaug Nobel Prize winner Father of the Green Revolution 2

3 Green Revolution Green Revolution Mexico (1940s) India (1961) US (1945) Philippines (1960) Columbia (1960s) ! 2.6% / yr 1967 Plant breeding centers adapt technologies for the developing world to fight hunger Green Revolution: Increasing Yields 1. Hybrid crop varieties 2. Synthetic fertilizers 638% increase in use of nitrogen fertilizer 203% increase in use of phosphorous fertilizer 3. Synthetic pesticides 854% increase in pesticide production 4. Irrigation 97% increase in irrigated area Increasing Yields: (1) Hybrid Crops Less sensitive to day length Plants mature early Allows double cropping (rice in summer, wheat in winter) Increase harvest index (rice, wheat) More carbon allocated to grain, less to vegetative parts Hold leaves more vertical (corn) Decreases self shading Allows increased plant density (Percent increases ) Increasing Yields: (2) Synthetic fertilizer Increasing Yields: (2) Synthetic fertilizer Pre-1930s, saltpeter, NaNO 3 (Chile) Demand outweighing supply for fixed nitrogen 1913, German Haber-Bosch process Large scale s Cook nitrogen and hydrogen at 500 C, 200 atm, 1% of the worlds energy Ammonia (NH 3 ) Ammonium nitrate (NH 4 NO 3 ) Nitrogen (1000 nutrient tons) 14, , , , , , ,000.0 Use of Nitrogen Source: USDA Dr. Haber Nobel Prize winner Time (Year) 3

4 Increasing Yields: (3) Synthetic pesticides 1939, DDT (dichloro-diphenyl-trichloroethane) Used widely in WWII to kill mosquitoes Hey! This kills all kinds of bugs! Increasing Yields: (3) Synthetic pesticides 1939, DDT (dichloro-diphenyl-trichloroethane) Used widely in WWII to kill mosquitoes Hey! This kills all kinds of bugs! 1950s Pesticide Era 20,000 pesticides in use today Roundup Machete Lasso Pentagon Prowl Lightning Assert Dr. Muller Nobel Prize winner -Recycling of organic matter -Built-in biological control -Built-in biological control -Built-in biological control pesticides -Built-in biological control pesticides irrigation from ground/surface water 4

5 -Built-in biological control pesticides irrigation from ground/surface water increased mechanization Market Consolidation late 1900s Agribusiness Contract Corporation owns: - Animals/Plants - Processors (366 in the US) - Distribution system Farmer owns: - Land - Buildings - Environmental Liability Sale/processing options: 1. Sold at auction to feedlots 2. Sold live to consumer at least 1/4 carcass 3. Butchered at USDAinspected facility For grocers, restaurants, farmers markets, neighbors! Green Revolution - slowing down? Issues: Genetic uniformity India 75% of rice from 10 varieties originally 30, ! 2.6% / yr ! 0.7 % / yr US 50% of wheat from 9 varieties 71% of corn from 6 varieties 83% milk from Holsteins 99% turkeys - broad-breasted white 90% of varieties grown 100 yrs ago no longer commercially produced Source: OSU Issues: Dust Bowls US Great Plains, 1930 s Soviet Virgin Lands, 1960 s N. China, today Issues: Groundwater overpumping 70% of water use goes to irrigation (US) ~1000 tons of water to produce 1 ton of grain United States TX, OK, KS "30 m N. China plain "3 m / yr Mexico Guanajuanto "2 m / yr Yemen "2 m / yr Pakistan Islamabad "1-2 m / yr Quetta "3.5 m / yr Iran India Chenaran Plain N. Gujarat "2.8 m / "6 m / yr yr Source: Brown 5

6 Issues: Energy use Urban food 48% of people live in urban areas Food travels an average 2400 miles from farm to plate Community Food Security? -Low income food needs -Broad goals - poverty and hunger -Community focus -Self-reliance/empowerment -Local agriculture -Systems-oriented 6