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Publications: (Details Below)
Jeremy C. Hansen, Barbara J. Cade-Menun, and Daniel G. Strawn (2004)
"Phosphorus Speciation in Manure-Amended Alkaline Soils"
J. Environmental Quality, 33 1521-1527.
(Details Below)
Benjamin L. Turner, Barbara J. Cade-Menun, and Dale T. Westermann (2003)
"Organic Phosphorus Composition and Potential Bioavailability in Semi-Arid Arable Soils of the Western United States"
Soil Sci. Soc. Am. J., 67 1168-1179.
(Details Below)
Toor, GS; Condron, LM; Di, HJ; Cameron, KC; Cade-Menun, BJ (2003)
"Characterization of organic phosphorus in leachate from a grassland soil"
SOIL BIOLOGY & BIOCHEMISTRY, 35 1317-1323.
(Details Below)
Paytan, A; Cade-Menun, BJ; McLaughlin, K; Faul, KL (2003)
"Selective phosphorus regeneration of sinking marine particles: evidence from P-31-NMR"
MARINE CHEMISTRY, 82 55-70.
Details: Phosphorus Speciation in Manure-Amended Alkaline Soils Jeremy C. Hansen, Barbara J. Cade-Menun, and Daniel G. Strawn (2004) J. Environmental Quality, 33 1521-1527. 
Abstract: ABSTRACT Two common manure storage practices are stockpiles and lagoons. The manure from stockpiles is applied to soils in solid form, while lagoon manure is applied as a liquid. Soil amendment with manure in any form introduces a significant amount of phosphorus (P) that exists in both organic and inorganic forms. However, little is known about P speciation in manure stored under different conditions, or the subsequent forms when applied to soils. We used solution 31P nuclear magnetic resonance (NMR) spectroscopy and conventional P fractionation and speciation methods to investigate P forms in dairy manure and liquid lagoon manure, and to study how long-term amendment with these manures influenced surface and subsurface soil P speciation. Our results show that the P forms in solid and lagoon manure are similar. About 30% of the total P was organic, mostly as orthophosphate monoesters. On a dry weight basis, total P was much higher in the solid manure. In the manure-amended soils the total P concentrations of the surface soils were similar, regardless of manure type. Total P in the subsurface soil was greater in the lagoon-manure- amended soil than the solid-manure-amended subsurface soil. However, the fraction of organic P was greater in the subsurface of the solid-manure-amended soil. The NMR results indicate that the majority of organic P in the soils is phytic acid, which is enriched in the surface soils compared with the subsurface soils. These results provide insight into P speciation and dynamics in manure-amended soils that will further increase our understanding on how best to manage manure disposal on soils.
Organic Phosphorus Composition and Potential Bioavailability in Semi-Arid Arable Soils of the Western United States Benjamin L. Turner, Barbara J. Cade-Menun, and Dale T. Westermann (2003) Soil Sci. Soc. Am. J., 67 1168-1179.
Abstract: The organic P composition of semi-arid arable soils is largely unknown, but such information is fundamental to understanding P dynamics in irrigated agriculture. We used solution 31P nuclear magnetic resonance (NMR) spectroscopy and phosphatase hydrolysis to characterize organic P in semi-arid arable soils from the western USA (organic C 2.0-30.7 g C kg-1 soil, clay 2-48%, pH 5.2-8.2, CaCO31-480 g kg-1 soil). Total P concentrations ranged from 220 to 1210 mg P kg-1 soil, of which between 12 and 45% was extracted with NaOH-EDTA. Inorganic orthophosphate was the dominant P compound, but concentrations determined by solution 31P NMR spectroscopy were consistently greater than those determined by molybdate colorimetry. Concentrations of organic P were relatively small, and were dominated by orthophosphate monoesters (11-130 mg P kg-1 soil), with smaller concentrations of orthophosphate diesters (0-7 mg P kg-1 soil). Pyrophosphate was present in almost all soils at concentrations up to 14 mg P kg-1 soil. Bicarbonate-extractable organic P ranged from 1.7 to 22.8 mg P kg-1 soil, of which between 37 and 87% was hydrolyzed by phosphatase enzymes, suggesting its bioavailability. Soil organic P concentrations were positively correlated with mean annual precipitation, organic C, clay, and oxalate-extractable metals (Al, Fe, Mn), and negatively correlated with mean annual temperature and soil pH. However, CaCO3 concentrations were not significantly correlated with any soil property. These results indicate that equilibrium levels of organic P in semi-arid arable soils are controlled by a balance between the physical protection offered by the soil matrix and the suitability of the environment for biological productivity.
Characterization of organic phosphorus in leachate from a grassland soil Toor, GS; Condron, LM; Di, HJ; Cameron, KC; Cade-Menun, BJ (2003) SOIL BIOLOGY & BIOCHEMISTRY, 35 1317-1323.
Abstract: The degree of eutrophication in fresh water ecosystems may be influenced by the forms of phosphorus (P) leached from agricultural systems. Physico-chemical fractionation of P in leachate from a grassland soil carried out over a two year period indicated that the majority of the P loss from the Lismore soil occurred in unreactive particulate (55-76%) P forms. 31P nuclear magnetic resonance analysis of a selected leachate sample indicated that unreactive P was mainly comprised of monoester and diester forms of organic P. The presence of phosphomonoesterase (20-200 microg p nitrophenol l-1 h-1) and phosphodiesterase (68 microg bis-p nitrophenol l-1 h-1) activity in leachate resulted in hydrolysis of 10-21% of total unreactive P (TUP), indicating that some of the monoesters and diesters can be eventually hydrolyzed into inorganic P forms during P transport. Enzyme hydrolysis showed that 23% of the TUP was present as labile monoester P (LMP), followed by 20% as inositol hexakisphosphate (IHP) and 14% as diesters (phospholipids and nucleic acids). The findings of this study suggest that LMP, IHP and diesters are an important component of organic P leaching from the grassland soil.
Selective phosphorus regeneration of sinking marine particles: evidence from P-31-NMR Paytan, A; Cade-Menun, BJ; McLaughlin, K; Faul, KL (2003) MARINE CHEMISTRY, 82 55-70.
Abstract: Phosphorus (P) regeneration and transformation in the oceanic water column and in marine sediments depends on the chemical nature of the sinking particulate P pool. For the first time, we have characterized the molecular composition of this pool, in various oceanic settings and water depths, using 31P nuclear magnetic resonance (NMR) spectroscopy. Both inorganic P (orthophosphate, pyrophosphate, and polyphosphate) and organic P compounds (orthophosphate monoesters, orthophosphate diesters, and phosphonates) were identified. The inorganic P is present predominantly as orthophosphate with small amounts ( < 10%) of pyro- and polyphosphates. These inorganic compounds may be at least partially of biological origin. The relatively high abundance of inorganic P suggests that considerable transformation from the organic to the inorganic pool occurs in the water column. Some of this inorganic P may be present in association with mineral phases (apatite, clays, and oxyhydroxides) and thus may not be bioavailable. The distribution of organic P compounds in the sinking particulate matter pool is generally similar in composition to phytoplankton and significantly different than in the dissolved organic matter (DOM) pool. Results indicate that in most oceanic regions the majority of P regeneration occurs at very shallow depths. However, in the Ross Sea, a significant fraction of organic P is exported to depth below the euphotic zone. Hydrolysis of P compounds continues throughout the water column as indicated by a decrease in total particulate P with depth and a relative decrease in the organic P fraction at some sites. Orthophosphate monoesters dominate the organic P pool at all locations, followed by orthophosphate diesters. Phosphonates are present in a few samples but never contribute more than 6% of total extractable P compared to 25% abundance in the dissolved organic P (DOP) pool. This work shows that considerable spatial and temporal variability in the molecular composition of sinking particulate P exists. A more systematic study is needed to assess the different environmental parameters that affect the composition of particulate P and result in this variability.
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