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12 Cards in this Set
- Front
- Back
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In what form do plants take up most of the nitrogen they need from the soil? |
Nitrate ions (NO3-) |
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how are these ions absorbed? |
active transport through root hairs |
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how can level of soil nitrate be further increased? |
by the addition of fertilizers |
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what are the 4 main stages of the nitrogen cycle? what do they all involve? |
-ammonification -nitrification -nitrogen fixation -denitrification all involve saprobiotic microorganisms |
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what is ammonification? |
the production of ammonia from organic ammonium containing compounds. |
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how are saprobiotic organisms involved in ammonification? |
they feed on organic ammonium containg compounds and releases ammonia which then forms ammonium ions in the soil. |
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what is nitrification? |
it is an oxidisation reaction where ammonium ions are converted to nitrate ions by nitrifying bacteria. |
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what two stages does nitrification occur in? |
1- oxidation of ammonium ions to nitrite ions(NO-2) 2-oxidation of nitrite ions to nitrate ions(NO-3) |
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Why do nitrifying bacteria need lots of air spaces? |
because they require oxygen to carry out these conversions. |
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how can farmers increase productivity? |
by keeping soil structure light and aerated by ploughing with good drainage to prevent saturation. |
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What is nitrogen fixation? |
A process where nitrogen gas is converted into nitrogen containing compounds . |
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when is nitrogen fixation carried out? |
industrially and when light passes through atmosphere. |
