Comparison of phosphorus forms in wet and dried animal manures by solution phosphorus-31 nuclear magnetic resonance spectroscopy and enzymatic hydrolysis.
Both enzymatic hydrolysis and solution (31)P nuclear magnetic resonance (NMR) spectroscopy have been used to characterize P compounds in animal manures. In this study, we comparatively investigated P forms in 0.25 M NaOH/0.05 M EDTA extracts of dairy and poultry manures by the two methods. For the dairy manure, enzymatic hydrolysis revealed that the majority of extracted P was inorganic P (56%), with 10% phytate-like P, 9% simple monoester P, 6% polynucleotide-like P, and 18% non-hydrolyzable P. Similar results were obtained by NMR spectroscopy, which showed that inorganic P was the major P fraction (64-73%), followed by 6% phytic acid, 14 to 22% other monoesters, and 7% phosphodiesters. In the poultry manure, enzymatic hydrolysis showed that inorganic P was the largest fraction (71%), followed by 15% phytate-like P and 1% other monoesters, and 3% polynucleotide-like P. NMR spectroscopy revealed that orthophosphate was 51 to 63% of extracted P, phytic acid 24 to 33%, other phosphomonoesters 6 to 12%, and phospholipids and DNA 2% each. Drying process increased orthophosphate (8.4% of total P) in dairy manure, but decreased orthophosphate (13.3% of total P) in poultry manure, suggesting that drying treatment caused the hydrolysis of some organic P to orthophosphate in dairy manure, but less recovery of orthophosphate in poultry manure. Comparison of these data indicates that the distribution patterns of major P forms in animal manure determined by the two methods were similar. Researchers can utilize the method that best fits their specific research goals or use both methods to obtain a full spectrum of manure P characterization.
He
Zhongqi
Z
USDA-ARS, New England Plant, Soil, and Water Lab., Orono, ME 04469, USA. Zhongqi.He@ars.usda.gov
Cade-Menun
Barbara J
BJ
Toor
Gurpal S
GS
Fortuna
Ann-Marie
AM
Honeycutt
C Wayne
CW
Sims
J Thomas
JT
D000818:Animals; D002417:Cattle; D002645:Chickens; D003890:Desiccation; D004492:Edetic Acid; D006851:Hydrochloric Acid; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D008372:Manure / Q000032:analysis*; D010744:Phosphoric Monoester Hydrolases; D010758:Phosphorus / Q000032:analysis*; D010759:Phosphorus Isotopes / Q000032:analysis
D008372:Manure; D010759:Phosphorus Isotopes; D010758:Phosphorus; D004492:Edetic Acid; D010744:Phosphoric Monoester Hydrolases; D006851:Hydrochloric Acid