POL469H1 Lecture Notes - Nutrient Pollution, Food Security, Smog
Document Summary
Idsb02 readings nutrient imbalances in agricultural development. Nitrogen and phosphorous are necessary for high crop yields but downwind and downstream losses of them diminish environmental quality and human well being. Agricultural nutrient imbalances differ with economic development: ex. Sub-saharan africa inputs are inadequate to maintain soil fertility. National and regional policies contribute to patterns of nutrient use and consequences in these situations. Solutions to these nutrient challenges (excess/limiting) can be informed from analyses of trajectories of change within and across agricultural systems. Harvesting crops removes nitrogen and phosphorous & other nutrients. China: agricultural production increased dramatically since 1975. Policy driven increases in fertilizer use contributed to rising crop yields as they strived for food security. The fertilizer additions far exceeded the amounts used in europe and usa -> lots lost to the environment degrading the air and water quality. N&p fertilizers in the us contributed to rising crop yields since the 1940s.
