scholarly journals Reviews and syntheses: Ironing out wrinkles in the soil phosphorus cycling paradigm

2020 ◽  
Vol 17 (21) ◽  
pp. 5309-5333
Author(s):  
Curt A. McConnell ◽  
Jason P. Kaye ◽  
Armen R. Kemanian
Keyword(s):  
Soil Phosphorus ◽  
Phosphorus Cycling ◽  
Organic P ◽  
New Techniques ◽  
Inorganic P ◽  
Soil P ◽  
Plant System ◽  
P Sorption ◽  
Biogeochemical Models ◽  
Critical Challenge

Abstract. Soil phosphorus (P) management remains a critical challenge for agriculture worldwide, and yet we are still unable to predict soil P dynamics as confidently as that of carbon (C) or nitrogen (N). This is due to both the complexity of inorganic P (Pi) and organic P (Po) cycling and the methodological constraints that have limited our ability to trace P dynamics in the soil–plant system. In this review, we describe the challenges for building parsimonious, accurate, and useful biogeochemical models that represent P dynamics and explore the potential of new techniques to usher P biogeochemistry research and modeling forward. We conclude that research efforts should focus on the following: (1) updating the McGill and Cole (1981) model of Po mineralization by clarifying the role and prevalence of biochemical and biological Po mineralization, which we suggest are not mutually exclusive and may co-occur along a continuum of Po substrate stoichiometry; (2) further understanding the dynamics of phytate, a six C compound that can regulate the poorly understood stoichiometry of soil P; (3) exploring the effects of C and Po saturation on P sorption and Po mineralization; and (4) resolving discrepancies between hypotheses about P cycling and the methods used to test these hypotheses.

scholarly journals Reviews and Syntheses: Ironing Out Wrinkles in the Soil Phosphorus Cycling Paradigm

2020 ◽  
Author(s):  
Curt A. McConnell ◽  
Jason P. Kaye ◽  
Armen R. Kemanian
Keyword(s):  
Soil Phosphorus ◽  
Phosphorus Cycling ◽  
Organic P ◽  
New Techniques ◽  
Inorganic P ◽  
Soil P ◽  
Plant System ◽  
P Sorption ◽  
P Cycling ◽  
Critical Challenge

Abstract. Soil phosphorus (P) management remains a critical challenge for agriculture worldwide, and yet we are still unable to predict soil P dynamics as confidently as that of carbon (C) or nitrogen (N). This is due to both the complexity of inorganic P (Pi) and organic P (Po) cycling and the methodological constraints that have limited our ability to trace P dynamics in the soil-plant system. In this review we describe the challenges to building parsimonious, accurate, and useful P models and to explore the potential of some new techniques to advance modeling efforts. To advance our understanding and modeling of P biogeochemistry, research efforts should focus on the following: 1) update the McGill and Cole (1981) model of Po mineralization by clarifying the role and prevalence of “biochemical” and “biological” Po mineralization which we hypothesize are not mutually exclusive and may co-occur along a continuum of Po substrate stoichiometry; 2) further understand the dynamics of phytate, a 6-C compound that can regulate the poorly understood stoichiometry of soil P; 3) explore the effects of C and Po saturation on P sorption and Po mineralization; and 4) resolve discrepancies between hypotheses about P cycling and the methods used to test these hypotheses.

Phosphorus cycling in wheat-pasture rotations. III. Organic phosphorus turnover and phosphorus cycling

Soil Research ◽  
1988 ◽  
Vol 26 (2) ◽  
pp. 343 ◽  
Author(s):  
MJ Mclaughlin ◽  
AM Alston ◽  
JK Martin
Keyword(s):  
Organic Phosphorus ◽  
Soil Surface ◽  
P Uptake ◽  
Phosphorus Cycling ◽  
Plant Residue ◽  
Organic P ◽  
Inorganic P ◽  
Soil P ◽  
Wheat Pasture ◽  
P Cycle

The incorporation of 32P and 33P from 33P-labelled fertilizer and 33P-labelled pasture residues into organic and inorganic fractions of soil P was studied in a solonized brown soil (Calcixerollic xerochrept) cropped to wheat (Triticum aestivum). Most of the plant residue 33P was present as inorganic P at the time it was added to the soil, but only 7 days later almost 40% had been incorporated into organic P fractions of the soil. As the fertilizer was banded near the soil surface at sowing, little of the 32P from the 32P-labelled fertilizer was incorporated into organic forms, even after 95 days. From a knowledge of the P uptake by the plants and microorganisms, an integrated P cycle for this soil under wheat-pasture rotations was developed. We propose that fertilization of the pasture phase of the rotation stimulates the build-up of residual inorganic and organic P, while fertilization of the wheat phase predominantly stimulates the accumulation of inorganic forms of P in the soil.

scholarly journals Implications of long-term superphosphate applications on the accumulation and plant availability of soil phosphorus under irrigated pastures

1990 ◽  
pp. 191-193
Author(s):  
L.M. Condron ◽  
K.M. Goh
Keyword(s):  
Dynamic Balance ◽  
Soil Phosphorus ◽  
Organic P ◽  
P Fractionation ◽  
Inorganic P ◽  
Soil P ◽  
Grazed Pasture ◽  
P Addition ◽  
Apparent Stability

Changes in soil phosphorus (P) associated with the establishment and maintenance of improved ryegrass-clover pasture under different superphosphate fertiliser treatments were examined over a 20-year period (1957-77). Results showed that soil organic P increased with increasing applications of P fertiliser. This represents a dynamic balance between rates of organic P addition and breakdown in the soil. This balance is reached slowly and may be significantly altered only by drastic changes in land use. In annually fertilised soils, amounts of inorganic P increased with time. However, the potential utilisation of this residual inorganic P is limited by its apparent stability in the soil. Keywords grazed pasture, irrigation, fertiliser P, soil inorganic P, soil organic P, soil P fractionation

THE INFLUENCE OF TOPOGRAPHY ON THE DISTRIBUTION OF ORGANIC AND INORGANIC SOIL PHOSPHORUS ACROSS A NARROW ENVIRONMENTAL GRADIENT

1985 ◽  
Vol 65 (4) ◽  
pp. 651-665 ◽  
Author(s):  
T. L. ROBERTS ◽  
J. W. B. STEWART ◽  
J. R. BETTANY
Keyword(s):  
Environmental Gradient ◽  
Soil Phosphorus ◽  
Regional Distribution ◽  
Extraction Procedure ◽  
Distribution Patterns ◽  
Organic P ◽  
Inorganic P ◽  
Soil P ◽  
Lower Slope ◽  
Total P

A sequential extraction procedure was used to determine phosphorus fractions (resin, bicarbonate, hydroxide, sonicated hydroxide, acid and acid-peroxide digest with separate organic and inorganic P determinations) in surface and subsurface horizons taken from the upper, mid- and lower slope positions of four catenas (representing Brown, Dark Brown and Black Chernozemic soils, and a Luvisolic soil) which encompass a narrow environmental gradient of climate (annual precipitation: 300–475 mm) and vegetation. Trends in the local distribution of organic and inorganic soil P between upper and lower slope positions in any one catena were similar to the regional distribution patterns across all soil zones. Concentration of organic P, in both the surface and subsurface horizons, increased from the upper to the lower slope positions and from the Brown to the Black soils, while inorganic P decreased. The largest single organic fraction (hydroxide extractable) accounted for up to 22 and 17% of the total P (surface and subsurface horizons, respectively). Acid extractable P dominated the inorganic fractions, accounting for 40–63% of the total P (surface and subsurface horizons, respectively). The distribution of organic P along the catenas and among the soil zones was related to the transformations of inorganic P caused by differences in weathering intensity between slope positions and across the Province. Key words: Catena, climo-toposequence, sequential P extraction

INFLUENCE OF TEXTURE AND MANAGEMENT PRACTICES ON THE FORMS AND DISTRIBUTION OF SOIL PHOSPHORUS

1987 ◽  
Vol 67 (1) ◽  
pp. 147-163 ◽  
Author(s):  
J. W. B. STEWART ◽  
I. P. O'HALLORAN ◽  
R. G. KACHANOSKI
Keyword(s):  
Management Practices ◽  
Soil Phosphorus ◽  
Organic P ◽  
Sand Content ◽  
P Fractions ◽  
P Fractionation ◽  
Inorganic P ◽  
Soil P ◽  
Total Soil ◽  
Labile Organic P

Changes in soil phosphorus (P) forms, as determined by a sequential fractionation procedure, were used to assess the influence of soil texture and management practices on the forms and distribution of soil P in a Brown Chernozemic loam soil at Swift Current, Saskatchewan. Significant proportions of the variability of all P fractions except residual-P could be attributed to changes in sand content. Changes in the forms and distribution of soil P with decreasing sand content followed patterns similar to those associated with a weathering sequence. The proportion of total soil P in inorganic and organic extractable forms that were extractable sequentially with anion exchange resin (resin-Pi), sodium bicarbonate (bicarb-Pi and -Po), and sodium hydroxide (NaOH-Pi and -Po) increased with decreasing sand content. Acid-extractable inorganic P (HCl-Pi) was the only P fraction positively correlated with sand content. The presence of a crop increased the proportion of soil P present as the more labile organic-P fractions (bicarb-Po and NaOH-Po) but not as total soil organic P (soil-Po). The presence of a crop also increased the proportion of soil P present as the labile inorganic fractions (resin-Pi and bicarb-Pi), possibly due to a decrease in soil pH. Application of inorganic-P fertilizer caused significant increases in the proportion of soil P as these labile inorganic-P fractions (resin-Pi and bicarb-Pi) and as total soil organic-P (soil-Po), but did not affect the more labile organic-P fractions. Key words: P fractionation, labile P, organic P, inorganic P, texture, management practices

scholarly journals Comparison of soil phosphorus and phosphatase activity under long-term no-tillage and maize residue management

2019 ◽  
Vol 65 (No. 8) ◽  
pp. 408-415 ◽  
Author(s):  
Xiaozhu Yang ◽  
Xuelian Bao ◽  
Yali Yang ◽  
Yue Zhao ◽  
Chao Liang ◽  
...  
Keyword(s):  
Soil Phosphorus ◽  
Soil Layer ◽  
Residue Management ◽  
Available P ◽  
No Tillage ◽  
Organic P ◽  
Inorganic P ◽  
Phosphatase Activities ◽  
Soil P ◽  
Soil Available P

The migration and transformation of soil phosphorus (P) are essential for agricultural productivity and environmental security but have not been thoroughly elucidated to date. A 10-year field study was conducted to explore the effects of conventional tillage (CT) and no-tillage with maize residue management (NT-0, NT-33%, NT-67% and NT-100%) on P contents and phosphatase activities in soil layers (0–5, 5–10, 10–20 and 20–40 cm). The results showed that soil available P content and phosphatase activities were higher in no-tillage with maize residue than CT. Soil moisture and pH were significantly positively correlated with soil available P. Higher organic P contents and lower inorganic P contents in the 0–5 cm soil layer were found in the treatment NT-67% compared with other treatments. According to the structure equation model, the source of available P was inorganic P in NT-33%, while organic P in NT-67%. This study demonstrated that the variation of dominant mechanisms involved in soil P migration and transformation were dependent on residue input amounts, and NT-67% might play an important role in the maintenance and transformation of soil organic P.

scholarly journals Comparison of fractionation methods for soil phosphorus with soils subjected to various long-term fertilization regimes on a calcareous soil

2021 ◽  
Vol 3 ◽  
pp. e3
Author(s):  
Xin Jin ◽  
Changlu Hu ◽  
Asif Khan ◽  
Shulan Zhang ◽  
Xueyun Yang ◽  
...  
Keyword(s):  
Calcareous Soil ◽  
Soil Phosphorus ◽  
Calcareous Soils ◽  
P Uptake ◽  
Organic P ◽  
P Fractions ◽  
P Fractionation ◽  
Inorganic P ◽  
Soil P

Background Diverse phosphorus (P) fractionation procedures presented varying soil P fractions, which directly affected P contents and forms, and their biological availability. Purpose To facilitate the selection of phosphorus (P) fractionation techniques, we compared two procedures based on a long-term experiment on a calcareous soil. Methods The soils containing a gradient P levels were sampled from seven treatments predictor under various long-term fertilizations. The P fractions were then separated independently with both fractionation procedures modified by Tiessen-Moir and Jiang-Gu. Results The results showed that the labile P in Jiang-Gu is significantly lower than that in Tiessen-Moir. The iron and aluminium-bounded P were greater in Jiang-Gu by a maximum of 46 mg kg−1 than Tiessen-Moir. Jiang-Gu fractionation gave similar Ca bounded P to that Tiessen-Moir did at low P level but greater contents at high P level. The two methods extracted much comparable total inorganic P. However, Tiessen-Moir method accounted less total organic P than ignition or Jiang-Gu method (the organic P (Po) estimated by subtract the total inorganic P (Pi) in Jiang-Gu fractionation from the total). P uptake by winter wheat was significantly and positively correlated with all phosphorus fractions in Jiang-Gu; Resin-P, NaHCO3-Pi, D. HCl-P, C. HCl-Pi, NaOH-Po, total-Po in Tiessen-Moir; P fraction categories of Ca-P, Fe & Al-P and total-Pi in both fractionations. Path coefficients indicated that Ca2-P in Jiang-Gu, NaHCO3-Pi and D. HCl-P in Tiessen-Moir had the higher and more significant direct contributions to P uptake among P fractions measured. Conclusions Our results suggested that Jiang-Gu procedure is a better predictor in soil P fractionation in calcareous soils, although it gives no results on organic P fractions.

A comparison of some surface soil phosphorus tests that could be used to assess P export potential

Soil Research ◽  
2007 ◽  
Vol 45 (5) ◽  
pp. 397 ◽  
Author(s):  
David Nash ◽  
Murray Hannah ◽  
Kirsten Barlow ◽  
Fiona Robertson ◽  
Nicole Mathers ◽  
...  
Keyword(s):  
Organic P ◽  
Soil Tests ◽  
Soil P ◽  
Olsen P ◽  
P Sorption ◽  
P Loss ◽  
Extractable P ◽  
Soil P Tests ◽  
Total P ◽  
Water Extractable

Phosphorus (P) exports from agricultural land are a problem world-wide and soil tests are often used to identify high risk areas. A recent study investigated changes in soil (0–20 mm), soil water and overland flow in 4 recently laser-graded (<1 year) and 4 established (laser-graded >10 years) irrigated pastures in south-eastern Australia before and after 3 years of irrigated dairy production. We use the results from that study to briefly examine the relationships between a series of ‘agronomic’ (Olsen P, Colwell P), environmental (water-extractable P, calcium chloride extractable P, P sorption saturation, and P sorption), and other (total P, organic P) soil P tests. Of the 2 ‘agronomic’ soil P tests, Colwell P explained 91% of the variation in Olsen P, and Colwell P was better correlated with the other soil tests. With the exception of P sorption, all soil P tests explained 57% or more of the total variation in Colwell P, while they explained 61% or less of Olsen P possibly due to the importance of organic P in this soil. Variations in total P were best explained by the organic P (85%), Calcium chloride extractable P (83%), water-extractable P (78%), and P sorption saturation (76%). None of the tests adequately predicted the variation in P sorption at 5 mg P/L equilibrating solution concentration. The results of this limited study highlight the variability between soil P tests that may be used to estimate P loss potential. Moreover, these results suggest that empirical relationships between specific soil P tests and P export potential will have limited resolution where different soil tests are used, as the errors in the relationship between soil test P and P loss potential are compounded by between test variation. We conclude that broader study is needed to determine the relationships between soil P tests for Australian soils, and based on that study a standard protocol for assessing the potential for P loss should be developed.

Dynamics of phosphorus fractions in soils treated with dairy manure

Soil Research ◽  
2020 ◽  
Vol 58 (3) ◽  
pp. 289
Author(s):  
L. B. Braos ◽  
A. C. T. Bettiol ◽  
L. G. Di Santo ◽  
M. E. Ferreira ◽  
M. C. P. Cruz
Keyword(s):  
P Uptake ◽  
Dairy Manure ◽  
P Availability ◽  
Organic P ◽  
Triple Superphosphate ◽  
P Fractions ◽  
Inorganic P ◽  
Soil P ◽  
Plant P Uptake ◽  
Inorganic P Fractions

The evaluation of phosphorus (P) transformations in soil after application of manure or mineral P can improve soil management and optimise P use by plants. The objectives of the present study were to assess organic and inorganic P forms in two soils treated with dairy manure and triple superphosphate and to establish relationships between soil P fraction levels and P availability. Soil organic and inorganic P fractions were quantified using a pot experiment with two soils, a typical Hapludox and an arenic Hapludult, with three types of fertiliser treatments applied (no fertiliser application, application of dairy manure, and application of triple superphosphate, by adding 100 mg P dm–3 in the form of fertiliser in the two latter treatments) and four incubation times (15, 45, 90, and 180 days). Inorganic P was fractionated into aluminium-bound, iron-bound, occluded, and calcium-bound P. Organic P was extracted sequentially using sodium bicarbonate, hydrochloric acid, microbial biomass, sodium hydroxide, and residual organic P. After incubation, maize plants were cropped to quantify dry matter yield and absorbed P. Application of dairy manure resulted in a significant increase in most of the organic P fractions, and application of triple superphosphate led to a significant increase in inorganic P fractions. Both fertilisers raised labile organic P fractions in the two soils. The major sinks of P in Hapludox were occluded and fulvic acid-associated P. In contrast, the major sink of P in Hapludult was iron-bound P. The available P levels were stable after application of dairy manure, and decreased with time when fertilised with triple superphosphate. In the Hapludox, the organic P fractions had a significant positive correlation with P uptake by plants. The results suggest that organic P mineralisation plays a more significant role in plant P uptake in the Hapludox soil and inorganic P forms are the main contributors to plant P uptake in the Hapludult soil.

Phosphorus K-edge XANES spectroscopy has probably often underestimated iron oxyhydroxide-bound P in soils

2018 ◽  
Vol 25 (6) ◽  
pp. 1736-1744 ◽  
Author(s):  
Jörg Prietzel ◽  
Wantana Klysubun
Keyword(s):  
Linear Combination ◽  
Xanes Spectroscopy ◽  
Organic P ◽  
Iron Oxyhydroxide ◽  
Edge Structure ◽  
X Ray ◽  
Soil P ◽  
P Sorption ◽  
Fe Oxyhydroxides ◽  
X Ray Absorption

Phosphorus (P) K-edge X-ray absorption near-edge structure (XANES) spectra of orthophosphate (oPO4) bound to soil FeIII minerals (e.g. ferrihydrite, goethite) show a pre-edge signal at 2148–2152 eV. It is unknown whether organic P bound to FeIII oxyhydroxides also show this feature. Otherwise, Fe-bound soil P may be underestimated by P K-edge XANES spectroscopy, because a large portion of Fe oxyhydroxide-bound P in soils is organic P. K-edge XANES spectra were obtained for different organic P compounds present in soils [inositol hexaphosphate (IHP), glucose-6-phosphate (G6P), adenosine triphosphate (ATP)] after sorption to ferrihydrite or goethite and compared with spectra of oPO4 adsorbed to these minerals. P sorption to ferrihydrite increased in the sequence IHP ≪ G6P < oPO4 < ATP. P sorption to goethite increased in the sequence G6P < oPO4 ≪ ATP = IHP. Pre-edge signals in P K-edge XANES spectra of organic P adsorbed to Fe oxyhydroxides were markedly smaller compared with those of oPO4 adsorbed to these minerals and absent for FeIII oxyhydroxide-bound ATP as well as goethite-bound IHP. Linear combination fitting (LCF) performed on spectra of IHP, G6P or ATP adsorbed to ferrihydrite or goethite, using only spectra of FeIII oxyhydroxide-bound oPO4 as reference compounds for Fe-bound P, erroneously assigned >93% (ferrihydrite) or >41% (goethite) of Fe-bound P to non-Fe-bound P species. Inclusion of FeIII oxyhydroxide-bound IHP as reference compounds markedly increased the recovery of oxyhydroxide-bound organic P. Thus, Fe-bound soil P has probably often been underestimated by LCF in soil XANES studies where IHP adsorbed to ferrihydrite and to goethite were not included as reference compounds.

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