Term
| oxidation state of B in soil |
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Definition
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Term
| the orincipal soil solution species of B |
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Definition
| charge neutral boric acid (B(OH)3) |
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Term
| what boric acid does in strongly alkaline solutions |
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Definition
| hydrolyzes to make borate
B(OH)3 + H2O --> B(OH)4- + H+ |
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Term
| in soil solutions, does boric acid form soluble complexes with metal cations? |
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Definition
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Term
| why does boric acid not form soluble complexes with metal cations? |
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Definition
| because of its charge beutrality |
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Term
| aqueous concentrations of B are controlled by... |
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Definition
-adsorption to Fe and Al hydroxides
-clay minerals
-calcite
-soil organic matter |
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Term
| how B adsorption responds to pH |
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Definition
| B adsorption increases with increasing pH |
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Term
| types of minerals in the soil Al is found in |
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Definition
| primary and secondary aluminosilicates as well as in the hydroxide and gibbsite |
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Term
| oxidation state of Al in soil |
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Definition
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Term
| how Al exists in soil solution |
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Definition
| either as free Al3+ or as a hydrolysis product (Al bound to 1 or more OH's), depending on the pH |
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Term
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Definition
| because it may exist as cationic or anionic species, depending on pH |
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Term
| some things Al+ can form soluble aqueous complexes with |
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Definition
| -OH-
-F-
-SO4-2
-H4SiO4
-organic substances containing carboxylate and phenolic functional groups |
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Term
| this controls the concentration of Al in soils |
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Definition
| the precipitation-dissolution of poor to well crystallized Al oxyhydroxides |
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Term
| pH at which Al is not very detectable in soil solution |
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Definition
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Term
| the total acidity of a soil |
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Definition
| the concentration of exchangeable Al |
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Term
| in addition to participating in cation exchange, Al oxyhydroxides participate in... |
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Definition
-ligand-exchange rxns
-proton-exchange rxns |
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