Podcast
Questions and Answers
Natural ecosystems receive their soil nitrogen through ______ fixation and atmospheric deposition.
Natural ecosystems receive their soil nitrogen through ______ fixation and atmospheric deposition.
biological
Agricultural ecosystems receive additional nitrogen through ______ addition.
Agricultural ecosystems receive additional nitrogen through ______ addition.
fertilizer
Only a few species of bacteria and cyanobacteria are capable of ______ fixation.
Only a few species of bacteria and cyanobacteria are capable of ______ fixation.
nitrogen
Lightning was the major source of soil nitrogen until recent times when the burning of ______ fuels became a major source of atmospheric deposition.
Lightning was the major source of soil nitrogen until recent times when the burning of ______ fuels became a major source of atmospheric deposition.
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Nitrogen oxides come from a variety of combustion sources that use ______ fuels.
Nitrogen oxides come from a variety of combustion sources that use ______ fuels.
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Crop rotation with legumes such as soybeans or alfalfa is practiced to supplement soil ______.
Crop rotation with legumes such as soybeans or alfalfa is practiced to supplement soil ______.
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______ species of bacteria can convert ammonium (NH4+) into nitrites (NO2-)
______ species of bacteria can convert ammonium (NH4+) into nitrites (NO2-)
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Plants can take in either ammonium (NH4+) or nitrates (NO3-) and make ______ or nucleic acids
Plants can take in either ammonium (NH4+) or nitrates (NO3-) and make ______ or nucleic acids
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Decomposers convert organic nitrogen (CHON) into ______ and ammonium (NH4+)
Decomposers convert organic nitrogen (CHON) into ______ and ammonium (NH4+)
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A broad range of bacterial species can convert nitrites, nitrates and nitrous oxides into molecular ______ (N2)
A broad range of bacterial species can convert nitrites, nitrates and nitrous oxides into molecular ______ (N2)
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Molecular nitrogen in the air can be fixed into ammonia by a few species of ______
Molecular nitrogen in the air can be fixed into ammonia by a few species of ______
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Producers can take up NH4- and to N03- use it to make ______
Producers can take up NH4- and to N03- use it to make ______
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All but a small portion of the earth’s carbon is tied up in ______ rocks; but the portion that circulates is what sustains life.
All but a small portion of the earth’s carbon is tied up in ______ rocks; but the portion that circulates is what sustains life.
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The active pool of carbon is estimated to be around 40,000 ______.
The active pool of carbon is estimated to be around 40,000 ______.
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Of active carbon, 93.2% is found in the ______.
Of active carbon, 93.2% is found in the ______.
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99.4% of exchangeable N is found in the ______.
99.4% of exchangeable N is found in the ______.
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Among the fossil fuel sources, power plants and automobiles are important sources of atmospheric nitrogen ______ in the US.
Among the fossil fuel sources, power plants and automobiles are important sources of atmospheric nitrogen ______ in the US.
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Investigations of native plant and natural ecosystem responses to nitrogen deposition and global warming will be a focus of ______.
Investigations of native plant and natural ecosystem responses to nitrogen deposition and global warming will be a focus of ______.
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