6.3 Non-Sustainable Agriculture
Industrialized Agriculture
Tech Advances
synthetic pesticides - chemicals manufactured to kill or control populations of organisms that interfere with crop production
synthetic fertilizers - manufactured chemicals that contain nutrients like nitrogen, phosphorus, potassium, calcium, etc
irrigation - methods by which water is supplied to crops by artificial means
steadily increase each crop's yield- the amount of food produced per unit of land
impacts in environment
uses large amounts of fossil fuels
requires lots of capital
uses large amount of water
Soil Degradation and Erosion
soil erosion - the movement of soil components, especially surface litter and topsoil from one place to another by actions of wind and water
problems
release of carbon stored in the soil to into the atmosphere as CO2 which contributes to atmospheric warming and climate change
water pollution in surface waters where eroded topsoil ends up as sediment and cause eutrophication by overloading the water with plant nutrients
loss of soil fertility through depletion of plant nutrients in topsoil
Traditional Agriculture
slash and burn: a type of agriculture that involves burning and clearing small plots in tropical forests, and moving to another plot once the old one becomes infertile.
polyculture: various crops mature at different times, providing food year-round and keeps the topsoil covered to reduce erosion from wind and water.
Two Forms of Agriculture
traditional subsistence agriculture - combines energy from the sun with the labor of humans and 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
traditional intensive agriculture where farmers try to obtain higher crop yields by increasing their inputs of human and draft animal labor
Pesticides
some pesticides harm wildlife, kill natural predators and parasites that help control other pest populations, dangerous to human health, they don't stay effective for long use
pests interfere with human welfare by competing for food, invading homes or gardens, destroying building materials, spreading disease, and invading ecosystems
pesticide Pros: save human lives from insect-borne diseases, increase food supplies, fast-acting, can be stored and shipped easily
Water Pollution
eroded topsoil flows as sediments into streams, lakes ad wetlands where it can smother fish and shellfish and clog irrigation ditches and boat channels
High input, high yield
Eutrophication: excess nutrients cause algal blooms, which take all the oxygen from the water and effectively kill all the organisms living in it.