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United States Department of Agriculture

Agricultural Research Service

Title: What Does P-31 Nmr Tell Us About Phosphorus in Dairy Manures?

item Reeves Iii, James
item Jayasundera, S - EQL, ANRI
item Schmidt, Walter

Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 3, 2002
Publication Date: N/A

Technical Abstract: Solid-state P-31 MAS NMR analysis with high power decoupling and cross-polarization transfer techniques was used to investigate the organic and inorganic forms of phosphorous (P) in intact dairy manure samples collected from diary farms in the Northeastern United States. The total P concentration in the samples varied from 0.06-0.86% of DM. The dry ash content varied from 8-55% of DM. Our results showed that the total P present in dairy manure contained not only inorganic P but also organic P. Phytate P was detected in a significant fraction of the samples analyzed, and was the major component of P in some of the samples. In general, the samples with the lower ash contents showed a high fraction of organic P. This study suggests that dairy manures can contain significant amounts of undigested phytates, which can be detected through solid-state NMR techniques in intact (non-digested) samples. These results show that under some circumstances phytates can represent a significant source of P in dairy manures with the potential to contribute to soil P for crops or to contribute ground water contamination caused by the presence of excess P.

Last Modified: 5/5/2015
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