Phosphorus Speciation in Manure‐Amended Alkaline Soils

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 (31)P 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.

Spectroscopic quantification of soil phosphorus forms by 31p-nmr after nine years of organic or mineral fertilization

“…They reported P accumulation mainly in inorganic forms, and monoester Po was accumulated only in soil treated with pig slurry. Similar results were found by Hansen et al (2004) in a soil that had been treated with cattle manure application over 10 years. The accumulation of monoester Po in soil occurs because the most animals are unable to digest phytic acid (inositol hexaphosphate), which accumulates in manures and, consequently, in soils treated with this waste.…”

“…Likewise, some kinds of monoester Po, especially inositol hexaphosphate (myo and scyllo), are also accumulated in soils because of their high residual charge, promoting stabilization of the soil mineral components (Anderson et al, 1974). The P forms detected by 31 P-NMR in this work were similar of those described by Koopmans et al (2003), Hansen et al (2004), He et al (2008) and Dou et al (2009) in soils treated with long-term fertilization or animal manure applications.…”

“…When added to soil, manure enhances P levels, both in organic and inorganic forms, although the increase in inorganic forms is always higher (Koopmans et al, 2003;Hansen et al, 2004). The reason is mainly that most P in manure is in inorganic forms (Koopmans et al, 2003;McDowell & Stewart, 2005), which in cattle manure represents about 70 % of total P (Cassol et al, 2001).…”

Phosphorus Distribution in Soils from Australian Dairy and Beef Rearing Pastoral Systems

“…Pasture soils tend to contain a higher proportion of organic P than cultivated soils [9]. Some of the "available" organic P forms play important role in biological cycling of P in soils, however the dynamics of organic P are not completely understood and require further investigation [10,11].…”

Phosphorus transformation in poultry litter and litter-treated Oxisol of Brazil assessed by 31P-NMR and wet chemical fractionation

“…The identification of P compounds was based on the chemical shift of phosphoric acid (85 % v/v). The general classes of P compounds and the respective chemical shifts were: phosphonates 19 ppm, inorganic orthophosphate 6.1 ppm (PO 4 3-), orthophosphate monoesters 3-6 ppm, orthophosphate diester 0.5-2 ppm; pyrophosphate 4 ppm and inorganic polyphosphates 20 ppm (Turner et al, 2003;Chen et al, 2004;Hansen et al, 2004;Leytem et al, 2008). The relative contribution of each class of P compounds was obtained by dividing the integrated spectral area for each band by the total integrated area.…”