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Every science requires a special language because every science has its own ideas.
~Étienne Bonnot de Condillac (1715-1780)

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Term Definition
natural chemical

copper fungicidea chemical compound or substance produced by a living organism found in nature that usually has a pharmacological or biological activity. A natural product can be considered as such even if it is prepared by chemical synthesis (although not under USDA organic guidelines). Natural pesticides are not universally better for us or for the environment (e.g. the copper-based fungicides used in organic agriculture are actually 10 times as toxic as modern synthetic fungicides). A focus on natural or synthetic is not optimal for safety or sustainability; it would be better to evaluate compounds individually for risk.

natural fertilizers

until the early 20th century all fertilizers were effectively natural. Potassium and phosphorus are mined from mineral deposits called potash and rock phosphorus, respectively. Nitrogen comes from mostly animal-associated materials (manures and guano, blood meal, bone meal, fish meal, feathers, etc). For most crops, manure must be composted before being applied as a fertilizer to prevent the spread of human pathogens (like E. coli or salmonella). Approximately 5% of all US crops are fertilized with manure and manure-related materials like compost. See also nitrogen fertilizer.

natural selection

the differential reproduction of organisms with certain traits attributed to improved survival or reproductive ability (fitness).


Sustainablog: no-till soybeans following wheatsowing a crop with minimal soil disturbance. No-till (encompassing direct drilling, narrow point seeding, and disc seeding practices) improves physical, chemical, and biological soil fertility, reduces erodibility, and increases carbon sequestration, leading to more sustainable farm management.

nonpoint source pollution

contamination from diffuse sources arising from every day activities, e.g. storm water runoff from roads, parking lots, suburban areas, and farms (in contrast to point sources, which include factories and sewage treatment plants). Most of the pollution on farms is nonpoint sourced. Pollution is carried primarily by rainfall and irrigation water, running off into surface water or leaching into ground water.

nitrogen use efficiency

A measure of crop production per unit of nitrogen fertilizer input. Currently, more than two thirds of fertilizer nitrogen is lost, released into the environment as soluble nitrates in groundwater discharge and as gaseous compounds, including the toxic gas nitrous oxide. Moreover, high nitrogen stimulates microbes to break down organic carbon at an accelerated rate, thus depleting soil humus and degrading overall soil fertility.

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