Term
about 75-80% of N in soil is found in... |
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Definition
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Term
2 common valence states for soil N |
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Definition
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Term
behavior of ammonia (NH3) in solution |
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Definition
strong base that's hydrolyzed to produce hydroxide and the the ammonium ion |
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Term
what happens to ammonium (NH4+) in aerated systems? |
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Definition
gets oxidized to nitrate (NO3-), which is a microbially mediated process |
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Term
how NH4+ and NO3- are relatively conservative in soils |
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Definition
-they don't form mineral precipitates -they don't participate in aqueous complexation rxns |
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Term
where ammonium fixation can occur |
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Definition
in soils containing vermiculite |
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Term
valence state of P in soils |
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Definition
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Term
amount of P in soil that's organic P |
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Definition
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Term
the basic inorganic P species |
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Definition
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Term
when orthophosphate (PO43-) occurs as H2PO4- |
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Definition
when the soil solution pH is < 7.2 |
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Term
how orthophosphate (PO4-3) is affected by pH |
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Definition
releases protons as the pH increases |
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Term
the orthophosphate (PO4-3) species that form stable aqueous complexes with numerous mono- and divalent metal cations |
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Definition
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Term
the phosphate species that can become strongly, if not irreversibly, adsorbed by Al and Fe oxyhydroxides and clay minerals and how this happens |
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Definition
-H2PO4-
-HPO42-
-this happens via ligand exchange mechanisms |
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Term
the commonly occurring oxidation states of As and Sb |
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Definition
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Term
why As and Sb may be able to isomorphically substitute in primary and secondary minerals |
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Definition
similarities in ionic radii |
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Term
how AsIII exists in soil solution |
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Definition
as arsenite, a hydroxyanion (As(OH)3) |
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Term
where the AsV oxidation state is stable |
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Definition
in oxic and suboxic environments |
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Term
when neither AsIII nor SbIII are stable |
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Definition
when in the presence of FeIII or MnIV oxyhydroxides
thus, they are readily oxidized |
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Term
will As or Sb form stable secondary minerals in soil? |
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Definition
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Term
why As and Sb won't form stable secondary minerals in soil |
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Definition
because of their innately low soil concentrations |
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Term
the primary retention mechanism for As and Sb |
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Definition
adsorption by Fe oxyhydroxides |
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