GEO-1330 Lecture Notes - Lecture 2: Topsoil, Protozoa, Plastic Mulch
Document Summary
Made by combining nitrogen from the air with hydrogen at high temperature and pressure to make anhydrous ammonia (nh3) The hydrogen source for the process is natural gas, a nonrenewable resource that currently accounts for 80% - 90% of the cost of fertilizer production. Finite resources, expected to hit limits by 2030. Only 20% of fertilizer is taken by plants (the res is pollution) Over 98% of sprayed insecticides and 95% of herbicides reach a destination other than their target species. These chemicals reach other species, air, water, bottom sediments, and food. Fish, birds, amphibians, beneficial soil organisms and insects are killed. Expensive to be certified (typically big farms) Typically used hybrid crops, and some heirloom. A: organic agriculture reduces greenhouse gas emissions primarily because, by definition, it does not use synthetic inputs made from fossil fuels. Organic matter (decomposed plants or animal matter) provides nutrients. A spoonful of healthy soil contains millions of different organisms.
