ISSN:
1432-0789
Keywords:
Key words Phosphorus
;
Specifically sorbed
;
Soils
;
Transformation
;
Microorganism
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Geosciences
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract Crop production on red soils in China is largely limited by the low availability of phosphorus, which is frequently attributed to the adsorption of phosphate by variable-charge minerals including Fe and Al oxides and kaolinite. Isotopic tracing analysis and soil incubation were carried out to investigate the desorption and microbial transformation of applied specifically sorbed P in two pH-contrasting light-textured soils. A rapid release of P from the added mineral-P surface complex in the two tested soils was observed. Most of the released P was recovered in a 0.5MNaHCO3 extract and in soil microbial biomass. Microbial biomass-32P was detected at early stages of incubation and reached up to 10–30% of the added 32P. Approximately 50–70% of the added complex 32P, varying between minerals and soils, was extractable in the 0.5MNaHCO3 at 75 days after incubation for the acid soil but up to 120 days for the neutral soil. Microbial biomass-P plus 0.5MNaHCO3-extractable 32P accounted for more than 60–80% of total added complex-32P, implying high desorption and transformation of the specifically sorbed P in the two soils. There was more inorganic 32P than organic 32P in the NaHCO3 extract, suggesting that chemical release of specifically sorbed P was dominant. Ligand exchange and chemical desorption due to a change in environmental conditions such as pH and ionic strength are likely the major mechanisms responsible for the chemical release of specifically sorbed 32P in the tested soils.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s003740050300
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