ISSN:
1573-0867
Keywords:
13C CP/MAS NMR
;
chitosan
;
hexametaphosphate
;
31P MAS NMR
;
pyrophosphate
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract This work was undertaken to characterize a chitosan-polyphosphate complex (CH-PP) and to evaluate its agronomic effectiveness as a source of phosphorus for ryegrass (Lolium perenne) grown on loamy and clayey soils. High resolution solid state31P and13C nuclear magnetic resonance were used to characterize this complex and to monitor the structural changes occurring to it during an 8-week incubation period in a loamy soil. A pot experiment was conducted on the two soils after labelling the available P with32PO4 ions. This experiment allowed for the determination of the agronomic effectiveness of the chitosan-polyphosphate complex compared to polyphosphate and to monocalcium phosphate. Results showed that chitosan immobilized up to 147 mg P kg−1 as pyrophosphate and hexametaphosphate. This reaction did not involve major structural changes in the pyrophosphate or hexametaphosphate groups nor in the chitosan. The chitosan-polyphosphate complex was as efficient as the polyphosphate alone to sustain the P nutrition of ryegrass. The relative agronomic effectiveness of these P sources was slightly lower compared to that of monocalcium phosphate. The high P fertilizing value of the chitosan-polyphosphate complex was attributed to its gradual hydrolysis in the soil. The potential interest of chitosan to remove polyphosphates from waste waters while preserving the high P fertilizing value of polyphosphates was addressed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00748555
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