Phosphorus sorption-desorption by some sediments of the Johnstone Rivers catchment, northern Queensland

1992 ◽  
Vol 43 (6) ◽  
pp. 1535 ◽  
Author(s):  
C Pailles ◽  
PW Moody

Phosphorus (P) sorption-desorption characteristics were determined for 11 sediments from the Johnstone Rivers catchment, northern Queensland. Sediments were selected to cover a range in values of Bray extractable P from 0.1 to 10.4 mg P kg-1. P sorption curves were determined by using 0.01 M NaCl to simulate fluvial water conditions and, on a restricted number of sediments, 0.5 M NaCl to simulate sea water. The amounts of P released in 10 successive extractions for 30 min with 0.01 M CaCl2 were determined for each sediment. The amounts of P desorbed either declined to nondetectable levels or declined to a constant amount. These desorption curves were used to delineate 'rapidly desorbable' P from 'slowly desorbable' P. Bray extractable P and adsorption characteristics (equilibrium solution P concentration and P buffer capacity) were poorly correlated with 'rapidly desorbable' P. Most sediments in the suite would act as P sinks in both fluvial and marine environments because their equilibrium P concentrations are lower than the dissolved inorganic P concentrations of their respective water columns. For those sediments acting as potential sources (5 from 11 in 0.01 M NaC1, 2 from 6 in 0.5 M NaCl), amounts of P that could potentially be desorbed into the fluvial water column ranged from 0.1 to 3.9 mg P kg-1 sediment.

Soil Research ◽  
2008 ◽  
Vol 46 (8) ◽  
pp. 676 ◽  
Author(s):  
L. L. Burkitt ◽  
P. W. G. Sale ◽  
C. J. P. Gourley

Soil phosphorus (P) sorption is an important and relatively stable soil property which dictates the equilibrium between sorbed and solution P. Soil P sorption measures are commonly adjusted for the effect of current P fertility on the amount of P a soil sorbs. In the case of highly fertilised agricultural soils, however, this adjustment is likely to be inappropriate as it may mask changes in a soil’s capacity to sorb P, which could affect future P fertiliser applications. A study was undertaken to compare adjusted or unadjusted methods of measuring P sorption using 9 pasture soils sampled from southern Victoria which had previously received P fertiliser and lime. The P sorption assessment methods included: P sorption isotherms, P-buffering capacity (PBC) measures (slope between equilibrium P concentration of 0.25 and 0.35 mg P/L), and single-point P-buffering indices (PBI), with methods either adjusted or unadjusted for current P fertility. A single application of 280 kg P/ha, 6 months before sampling, resulted in a general negative displacement of unadjusted P sorption isotherm curves, indicating reduced P sorption on 8 of the 9 soils. Adding the Colwell extractable P concentration to the amount of P sorbed before calculating the slope (PBC+ColP), tended to negate this fertiliser effect and, in 2 of the 9 soils, resulted in a significant increase in PBC+ColP values. Increasing rates of P fertiliser application (up to 280 kg P/ha) resulted in a consistent trend to decreasing PBI values (unadjusted for Colwell P), which was significant at 4 of the 9 sites after 6 months. However, only minimal changes in PBI values were determined when PBI was adjusted for current P fertility (PBI+ColP). Phosphorus sorption properties appeared reasonably stable over time, although 2 soils, both Ferrosols, indicated significant linear increases in PBI values when these sites remained unfertilised for 30 months. Lime significantly increased both PBI and PBI+ColP values at all sites 6 months after application, but the effect generally diminished after 30 months, suggesting PBI measurements should not be taken immediately after liming. These results demonstrate that unadjusted measures of P sorption are more likely to accurately reflect changes in soil P sorption capacity following P fertiliser applications and suggest that the unadjusted PBI be used in commercial soil testing rather that the currently adjusted PBI+ColP.


2000 ◽  
Vol 9 (1) ◽  
pp. 61-70 ◽  
Author(s):  
R. UUSITALO ◽  
H.-R. TUHKANEN

The aim of this study was to test whether phosphorus saturation of surface sorption sites of (oxyhydr)oxides of aluminium (Al) and iron (Fe) in Finnish soils can be assessed using a single oxalate extraction and, if so, whether the results are closely related to the P forms likely to influence the P concentration in runoff waters. Ten soil samples with varying clay content and P status were studied. Desorption tests were conducted by submitting the soils sequentially to nine anion exchange resin (AER) extractions. Sorption of P was studied by shaking the soils in P standard solutions (0-250 ppm). Soil inorganic P was characterised by sequentially extracting P from the fractions assumed to be connected to Al and Fe compounds and present as the stable apatitic form. The desorption studies and the fractioning of inorganic P suggested that oxalate solution dissolves apatitic P and/or other relatively stable P-bearing compounds, probably referring to the sum of inorganic P fractions rather than labile P. The amount of P desorbed in the nine AER extractions was about 80-280 mg/kg, whereas oxalate extracted about 490-1100 mg P/kg, which approximated the sum of the inorganic P fractions. Therefore, in soils high in apatitic P, oxalate-extractable P does not seem to be a reliable measure of the P saturation of Al and Fe oxide surfaces that regulate the P concentration in soil solution and runoff water.;


Soil Research ◽  
1996 ◽  
Vol 34 (1) ◽  
pp. 81 ◽  
Author(s):  
MDA Bolland ◽  
RJ Gilkes ◽  
RF Brennan ◽  
DG Allen

Seven methods of estimating or predicting phosphorus (P) sorption capacity were compared for 47 neutral to acid Western Australian soils. Two methods, the P buffer capacity (PBC) and the Fox and Kamprath procedure, provided reliable indices of P sorption from well defined P sorption isotherms, but they are not quick routine methods because several levels of P addition are required. The other five routine procedures included two versions of the P retention index (PRI), determined by adding one level of P, and three soil properties, oxalate extractable iron (oxalate Fe), oxalate extractable aluminium (oxalate Al), and pH measured in sodium fluoride [pH (F)], that are known to indicate P sorption capacity. All the indices were well related to one another. The oxalate Fe index was the least well related to PBC whereas oxalate Al, one of the PRI indices, and pH (F) were closely related to PBC and could be used as quick, economical procedures to assess the P sorption capacity of soils.


2003 ◽  
Vol 48 (5) ◽  
pp. 93-100 ◽  
Author(s):  
T. Zhu ◽  
T. Maehlum ◽  
P.D. Jenssen ◽  
T. Krogstad

A light-weight aggregate (LWA) made of expanded clay used as a filter media in wastewater treatment, was tested for sorption of phosphorus (P) in laboratory experiments. The objectives were to investigate the different P retention pools and how grain size, time, temperature and changed P concentration influenced the P binding mechanisms in this type of filter. Three different grain sizes (0-2 mm, 2-4 mm and 0-4 mm) were tested in a batch experiment. The isotherm for the P sorbed by the contact medium (including retention and fixation) was obtained under laboratory conditions. Fifty percent of the P sorption occurred in the first 4-8 hours. Temperature did not substantially influence P sorption for 0-2 mm grain size LWA. In the LWA suspension system, P desorption did not occur when the P content in the loading solution decreased. Fractionation analysis indicated that Ca-bound P, loosely-bound P, and Al-bound P were the predominant P retention pools. The loosely-bound P pool was determined primarily by the equilibrated P concentration in the system. Fe-bound P was negligible in the P sorption of LWA.


Soil Research ◽  
2002 ◽  
Vol 40 (3) ◽  
pp. 497 ◽  
Author(s):  
L. L. Burkitt ◽  
P. W. Moody ◽  
C. J. P. Gourley ◽  
M. C. Hannah

Soil phosphorus (P) buffering capacity (PBC) is an important soil property that influences the amount of P fertiliser available for plant uptake. However, current methods of determining PBC are time-consuming and uneconomic in most commercial soil testing programs. The current study examined simpler methods of measuring the PBC of a wide range of Australian soils. Phosphorus sorption and extractable P data from 290 soils (initial data set) were collated to define the range of PBC values of Australian agricultural soils. Independently, detailed chemical and physical analyses were undertaken on a second set of 90 agricultural soils (principal data set), which were selected to represent the range of soil properties measured on the initial data set. Relationships between PBCO&S (Ozanne and Shaw 1968) values (P sorbed between solution P concentrations of 0.25 and 0.35 mg P/L) and 11 different single-point P sorption indices and selected soil properties were examined for the principal data set. Whilst relationships between PBCO&S values and selected soil properties such as oxalate-extractable iron and aluminium, and clay content, were generally poor, strong relationships existed between all of the single-point P sorption indices and PBCO&S. Results suggest that PBCO&S values were most closely related to the P buffering indices (PBI+ColP and PBI+OlsP) when a single addition of 1000 mg P/kg was added to soil and either the Colwell or 4.59 Olsen extractable P were added to the amount of P sorbed: PBI+ColP = (Ps + Colwell P)/c0.41 PBI+OlsP = (Ps + 4.59 Olsen P)/c0.41 where Ps is the amount of P sorbed (mg P/kg) from a single addition of 1000 mg P/kg, and c is the resulting solution P concentration (mg P/L). This index provides a simple and accurate method for estimating PBC, a fundamental soil property that influences the P fertiliser requirements of different soil types. phosphorus sorption capacity, single-point phosphorus sorption index, phosphorus retention index, soil properties, Colwell phosphorus, Olsen phosphorus.


Soil Research ◽  
2001 ◽  
Vol 39 (4) ◽  
pp. 759 ◽  
Author(s):  
L. L. Burkitt ◽  
C. J. P. Gourley ◽  
P. W. G. Sale ◽  
N. C. Uren ◽  
M. C. Hannah

Nine pasture soils from high rainfall zones of southern Victoria were analysed for a range of chemical and physical properties before receiving a single application of P fertiliser in the form of triple superphosphate (TSP), single superphosphate (SSP), or TSP and lime (5 t/ha) at amounts ranging from 0 to 280 kg P/ha. Soils were analysed for bicarbonate-extractable P concentration, using both the Olsen P and Colwell P methods, 6 and 12 months after fertiliser application. A strong positive linear relationship existed at all sites between the amount of P applied and both the Olsen P and Colwell P concentrations. The slopes of these relationships measured the change in extractable P concentration (Δ EP) per unit of P applied, whilst the inverse of the ΔEP value indicated the amount of P fertiliser required above maintenance to increase the extractable P concentration by 1 mg/kg. These values ranged from 5 to 15 kg P/ha, depending on soil type. The ΔEP measured by the Olsen (Δ EP Olsen ) method was closely related to selected soil properties and P sorption measures, whilst the ΔEPColwell values were also closely related to selected soil properties and P sorption measures, but only when one particular site, an acidic sand, with a high organic carbon content was excluded from the analysis. In general, simple, direct measures of soil P sorption could allow the estimation of ΔEP values on different soil types. The application of P in the form of SSP resulted in a trend for higher ΔEP values than occurred with TSP. This difference was significant on 3 sites (P < 0.05), but depended on the method of extraction and the time after fertiliser application. The application of lime significantly (P < 0.001) increased soil pH (H2 O and CaCl 2 ) and decreased the concentration of exchangeable Al, 6 months after treatments were applied, but generally had little impact on ΔEP values.


2011 ◽  
Vol 35 (4) ◽  
pp. 1301-1310 ◽  
Author(s):  
Hemmannuella Costa Santos ◽  
Fábio Henrique Tavares de Oliveira ◽  
Ignácio Hernan Salcedo ◽  
Adailson Pereira de Souza ◽  
Valério Damásio da Mota Silva

The soil P sorption capacity has been studied for many years, but little attention has been paid to the rate of this process, which is relevant in the planning of phosphate fertilization. The purpose of this experiment was to assess kinetics of P sorption in 12 representative soil profiles of the State of Paraíba (Brazil), select the best data fitting among four equations and relate these coefficients to the soil properties. Samples of 12 soils with wide diversity of physical, chemical and mineralogical properties were agitated in a horizontal shaker, with 10 mmo L-1 CaCl2 solution containing 6 and 60 mg L-1 P, for periods of 5, 15, 30, 45, 60, 90, 120, 420, 720, 1,020, and 1,440 min. After each shaking period, the P concentration in the equilibrium solution was measured and three equations were fitted based on the Freundlich equation and one based on the Elovich equation, to determine which soil had the highest sorption rate (kinetics) and which soil properties correlated to this rate. The kinetics of P sorption in soils with high maximum P adsorption capacity (MPAC) was fast for 30 min at the lower initial P concentration (6 mg L-1). No difference was observed between soils at the higher initial P concentration (60 mg L-1). The P adsorption kinetics were positively correlated with clay content, MPAC and the amount of Al extracted with dithionite-citrate-bicarbonate. The data fitted well to Freundlich-based equations equation, whose coefficients can be used to predict P adsorption rates in soils.


Soil Research ◽  
2003 ◽  
Vol 41 (7) ◽  
pp. 1369 ◽  
Author(s):  
M. D. A. Bolland ◽  
D. G. Allen

Soil samples collected from 8 field experiments in Western Australia to which 5–8 amounts of superphosphate had been applied once only 13–23 years previously were used to measure the phosphorus (P) buffer capacity of soil (PBC) and P sorption by several single-point indices. PBC was estimated from well-defined P sorption curves when several levels of P were added to soil suspensions, and was the amount of P sorbed when the concentration of P in the final solution was raised from 0.25 to 0.35 mg P/L. The single-point P sorption indices were measured by adding one amount of P (10 mg P/L) to soil suspensions (1 : 20, soil : 0.02 M KCl or 0.01 M CaCl2). Three indices were calculated from the amount of P sorbed by soil (S, mg P/kg soil) and the amount of P in solution (c, mg P/L)—(1) the phosphorus retention index (PRI, S/c [L/kg]), (2) the Freundlich retention index (FRI, S/c0.35 [dimensionless]), and (3) the phosphorus sorption index (PSI, S/log10 [c × 1000] [dimensionless])—to provide PRI K & Ca, FRI K & Ca, and PSI K & Ca values. P sorption was also measured by the P buffer index (PBI), the new single-point P sorption index recommended for national use, to provide PBICa values. To estimate the previous P sorbed by soil (native soil P is negligible for these soils, so previously sorbed P originates from fertiliser P applied in a previous year), the amount of P extracted by 0.5 M sodium bicarbonate from soil (Colwell soil test P) was added to the amount of P sorbed by soil to calculate PRI*K & Ca, FRI*K & Ca, PSI*K & Ca, and PBI*Ca values. In addition, previously sorbed P was estimated using the q coefficient of the Freundlich equation; q was added to P sorption to calculate PSI**, FRI**, PSI** and PBI** values to take account of previously sorbed P.For the 8 experiments, PBC values significantly decreased where more fertiliser P had been applied to the soils 13–23 years previously. This indicated that the capacity of the 8 soils to sorb P decreased as more P was applied in a previous year, and a single-point P sorption index would need to reflect this decrease. As the amount of P applied to soil in the field plots increased, the following trends occurred : (1) Colwell soil test P always increased; (2) PRIK & Ca, FRIK & Ca, PSIK & Ca, and PBICa consistently decreased; (3) PRI*K & Ca, FRI*K & Ca, PSI*K & Ca, and PBI*Ca mostly increased, but with some values being unaffected or decreasing; (4) PRI**, FRI**, PSI**, and PBI** values were largely unaffected by the amount of P applied in a previous year. Evidently, either adding Colwell soil test P or q to P sorption to calculate the single-point P sorption indices mostly overestimated P sorption by the sandy, low P sorbing soils used, but the overestimate was larger for Colwell soil test P than for q.


1997 ◽  
Vol 36 (6-7) ◽  
pp. 191-200 ◽  
Author(s):  
C. M. Carliell ◽  
A. D. Wheatley

Chemical extraction methods are used to investigate metal and phosphate speciation during anaerobic digestion of phosphorus-rich sludge. Tests were performed using model compounds to evaluate the efficacy of the reagents in the extraction sequences and these results compared with similar work by other researchers. The metal speciation method was found to be suitable for identifying shifts in metal distribution but was unrepresentative of actual metal species. The phosphate speciation method did give adequate separation of the phosphate compounds tested. Full-scale digesters treating chemical and biological phosphate removal (CPR and BPR) sludge were analysed according to the methods developed. Results show that digestion of CPR sludge did not increase the soluble P concentration in the digester and that most of the precipitated phosphorus appeared to be retained in the sludge as inorganic P. The digester treating BPR sludge showed increased soluble and water-extractable P, in comparison to the control digester. Trace metal speciation profiles were found to be affected by addition of CPR sludge.


Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 295
Author(s):  
Marina Moura Morales ◽  
Nicholas Brian Comerford ◽  
Maurel Behling ◽  
Daniel Carneiro de Abreu ◽  
Iraê Amaral Guerrini

The phosphorus (P) chemistry of biochar (BC)-amended soils is poorly understood. This statement is based on the lack of published research attempting a comprehensive characterization of biochar’s influence on P sorption. Therefore, this study addressed the kinetic limitations of these processes. This was accomplished using a fast pyrolysis biochar made from a mix of waste materials applied to a highly weathered Latossolo Vermelho distrofico (Oxisol) from São Paulo, Brazil. Standard method (batch method) was used. The sorption kinetic studies indicated that P sorption in both cases, soil (S) and soil-biochar (SBC), had a relatively fast initial reaction between 0 to 5 min. This may have happened because adding biochar to the soil decreased P sorption capacity compared to the mineral soil alone. Presumably, this is a result of: (i) Inorganic phosphorus desorbed from biochar was resorbed onto the mineral soil; (ii) charcoal particles physically covered P sorption locations on soil; or (iii) the pH increased when BC was added SBC and the soil surface became more negatively charged, thus increasing anion repulsion and decreasing P sorption.


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