Nitrogen Management in AgricultureLast Updated on 2010-12-16 00:00:00
Nitrogen fertilization — if one includes CO2 released during the manufacture, distribution, and application of the fertilizer and N2O released during microbial transformation of fertilizer in soils (denitrification)—is responsible for the majority of greenhouse gas emissions from agriculture. Some of the nitrate (NO3-) fertilizer applied to crops leaches from fields and contaminates groundwater; groundwater NO3– concentrations above 4 milligrams of nitrate nitrogen per liter (4 mg NO3– -N L–1) are associated with increased risk of cancer and other human health problems.  Moreover, U.S. maize farmers spend more than $150 per hectare on nitrogen fertilizer each year. Therefore, higher nitrogen-use efficiencies—higher yields per nitrogen fertilizer applied—would not only decrease greenhouse gas emissions but would also decrease crop... More »
Climate Literacy Handbook: Principle 5Last Updated on 2009-07-09 13:35:54
This is a chapter from Climate Literacy Handbook.
Previous: Principle 4 | Table of Contents | Next: Principle 6
Principle 5. Our understanding of the climate system is improved through observations, theoretical studies, and modeling
When it comes to climate, how do scientists know what they know? While studies indicate that actively publishing climate researchers virtually all agree that human activities are altering the climate system, the general public is under the impression that scientists are still debating whether or not humans are through their activities changing climate. Essential Principle 5 concerns key elements of climate studies and the "self-correcting" peer review process.
Concept 5a. The components and processes of Earth’s... More »
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