Extractable iron and aluminium predict the P sorption capacity of Thai soils

Soil Research ◽  
2005 ◽  
Vol 43 (6) ◽  
pp. 757 ◽  
Author(s):  
W. Wiriyakitnateekul ◽  
A. Suddhiprakarn ◽  
I. Kheuruenromne ◽  
R. J. Gilkes

The objective of this study was to determine if dithionite- and oxalate-extractable Fe and Al can be used to predict the P sorption capacity of Thai soils. Forty-five samples from diverse soil types were taken from surface and subsurface horizons of soils on sandstone, shale/limestone, granite, and basalt. The samples were analysed for P sorption, dithionite- and oxalate-extractable Fe and Al (Fed, Feo, Ald, Alo), specific surface area (SSA), and other soil properties. Generally P sorption data for these soils were slightly better fitted by the Langmuir equation than the Freundlich equation. The Langmuir P sorption maximum ranged from 35 to 1111 μg/g with a median value of 370 μg/g soil. Soils developed on basalt had higher values of P sorption maximum (xm) (range 400–1111 μg/g, median 597 μg/g) than soils on other parent materials. Fed concentrations in soils (4–74 g/kg) were much higher than Feo concentrations (0.2–13.8 g/kg) with values of Feo/Fed ranging from 0.01 to 0.28 (median 0.09), indicating that most of the free iron oxides were crystalline. Amounts of Ald and Alo were about equal with median values of 1.6 and 1.0 g/kg, respectively. About 80% of the samples had SSA values <40 m2/g. Both the P sorption maximum and Freundlich k were linearly related to SSA (R2 = 0.77, 0.74), Ald (R2 = 0.78, 0.79), Alo (R2 = 0.64, 0.74), Fed (R2 = 0.48, 0.41), Feo (R2 = 0.43, 0.72), and clay content (R2 = 0.48, 0.36). Stepwise regression indicated that 81% of the variability in P sorption by these soils could be explained by a combination of dithionite and oxalate Fe and Al, however, Ald alone is almost as effective in predicting the P sorption capacity of Thai soils.

1991 ◽  
Vol 71 (4) ◽  
pp. 453-463 ◽  
Author(s):  
Y. K. Soon

Phosphate solubility and sorption characteristics of 39 agricultural soils in the northwestern Canadian Prairie were studied to gain insights into the retention of fertilizer P added to soil. The soils were mostly acidic with base saturation of 59–95%. The solubility of P as determined by the equilibrium P concentration and phosphoric acid potential was low and appeared to be controlled by sorption of phosphate by soil components. The mean equilibrium solution P concentration was 0.03 mg L−1. Phosphorus concentration in saturation extracts was about one order of magnitude higher, but would have included organic and colloidal P since P analysis in these extracts was done by ICP. Sorption capacity of P as determined by Langmuir isotherm was greater for the Dark Gray and Black soils and gleysols, i.e., soils with higher amounts of organic matter, than the Gray Luvisolic and Solodic soils by about 30%. Partial correlation showed that clay content, Al-organic matter complexes (AlOM) and amorphous iron oxide (FeOX) were significantly correlated with P sorption capacity. When both topsoils and subsoils were considered, clay content was the most important soil property influencing P sorption capacity, followed by AlOM and FeOX (standard partial regression coefficients, b′, of 0.47, 0.39 and 0.38, respectively). When only topsoils were considered, AlOM and FeOX became more important than clay content in influencing P sorption (b′ = 0.47, 0.47, and 0.33, respectively). Native P, estimated by oxalate and anion-resin extractions, was associated with the hydrous iron oxides only, although soil pH also affected the resin-extractable P fraction. Key words: P retention, solubility, Luvisols, solodic soils


Soil Research ◽  
1991 ◽  
Vol 29 (5) ◽  
pp. 603 ◽  
Author(s):  
B Singh ◽  
RJ Gilkes

The P sorption characteristics of 97 soils that are representative of the agricultural areas of Western Australia were described using Langmuir and Freundlich equations. The Langmuir P maximum (xm) ranged from 11 to 2132 �g g-1 soil and the Freundlich k coefficient ranged from 1 to 1681. Clay content, DCB Fe and Al, oxalate Fe and AL, and pyrophosphate Al were positively related to xm and k. By using stepwise regression analysis, the combination of DCB and oxalate-soluble A1 predicted more than 75% Of the variation in the P sorption coefficients. Reactive Al compounds may thus be responsible for much of the P sorption by these soils. Soil pH in 1 M NaF (pH 8.2), which is normally used for the detection of allophanic material, was strongly related to the P sorption coefficients and might therefore be used as a quick test for predicting the P sorption capacity of soils.


1990 ◽  
Vol 62 (1) ◽  
pp. 1-8
Author(s):  
Raina Niskanen

The sorption capacity of phosphate in seven soil samples (clay content 1—70 %, organic carbon content 0.8—10.7 %, soil pH 4.2—5.3, oxalate-extractable Al 11—222 and Fe 11—202 mmol/kg soil) was studied by means of sorption isotherms. The soils were equilibrated, for two to seven days at +5 and +20°C, with solutions containing phosphate 0—10 mmol/l (0—200 mmol/kg soil) at a constant ionic strength of 0.01 . Prolongation of the reaction time increased the sorption of phosphate only partially. The rise in temperature, from +5 to +20°C, increased the sorption from higher phosphate concentrations. At +20°C, the sorption curves of three soils showed a sorption maximum of 4, 19 and 34 mmol/kg soil. The sorption data of six soils was in accordance with the Langmuir equation; the sorption maximum ranged from 15 to 119 mmol/kg soil, and were of the same magnitude as the maximums determined experimentally.


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.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Ashebir Getie ◽  
Alemayehu Kiflu ◽  
Gashaw Meteke

Crop response to phosphorus (P) application is often erratic in most acidic soil types. The main processes for P losses from agricultural fields are fixation, crop removal, erosion, surface runoff, and subsurface leaching. The purpose of this experiment was to evaluate adsorption properties of selected soils, determine the external phosphorous requirements (EPRs) of the soils, and identify factors contributing to P sorption in two soils in North Ethiopia. In this experiment, separately weighed 1 g soil samples were equilibrated with KH2PO4 at rates of 0.5, 5, 10, 20, 30, 40, and 50 mg PL−1. The P sorption data were fitted well with both Langmuir and Freundlich models with average r2 values of 0.91 and 0.88, respectively. The adsorption maximum (Xm) of the Langmuir isotherm ranged from 588.20 mg P kg−1 soil in Luvisols to 833.3 mg P kg−1 soil in Nitisols. The EPRL values ranged between 86.20 to 93.28 mg P kg−1 for soils of the study area. Among the soil properties, clay content and Ex. Al were positively correlated with Xm. The path analysis revealed that clay, pH, and Av. P had a direct effect on P sorption parameters. The EPRL of the studied soils was 3.44 to 3.6 times greater than the blanket P fertilizer rate recommendation. It is concluded that P sorption models can effectively be used to discriminate soils based on P fixation ability. The result further indicates that the current P fertilizer application rate of 50 kg P ha−1 being practiced across all soil types should be revised after validating the models and EPR values estimated in this study for each soil both under greenhouse and in-the-field conditions.


1990 ◽  
Vol 62 (1) ◽  
pp. 9-15
Author(s):  
Raina Niskanen

The dependence of the indicator of phosphate sorption capacity on extractable Al and Fe and other soil properties was studied in a material consisting of 102 mineral soil samples. The sum of P adsorbed on soil during two days from a solution containing P 5 mmol/l and P extracted by 0.02 M EDTA (pH 5.3) as an estimate of the initial P content in the soil was used as the indicator of P sorption capacity. In clay and silt soils (n = 51), the Al and Fe extracted by 0.05 M oxalate (pH 2.9) together with the organic C content explained 85 %, the Al and Fe extracted by 0.05 M K4P2O7 (pH 10) together with the clay content 87 %, the Al and Fe extracted by 0.02 M EDTA (pH 5.3) 91 %, and the Al extracted by 1 M CH3COONH4 (pH 4.8) together with the organic C and clay contents 78 % of the variation of the indicator of phosphate sorption capacity. In coarse soils (n = 51), the variation of the indicator was explained well only by oxalate-extractable metals, which together with soil pH and clay content explained 80 % of the variation. Extractable Al was generally the most important explainer of variation. The results suggest that forms of extractable Al and Fe explaining the variation of the indicator of P sorption capacity in clay and silt soils are partially different from those in coarse soils.


2020 ◽  
Vol 20 (4) ◽  
pp. 1882-1890 ◽  
Author(s):  
Gilmar Luiz Mumbach ◽  
Luciano Colpo Gatiboni ◽  
Daniel João Dall’Orsoletta ◽  
Djalma Eugênio Schmitt ◽  
Patrícia Pretto Pessotto ◽  
...  

1997 ◽  
Vol 35 (5) ◽  
pp. 103-108 ◽  
Author(s):  
T. Zhu ◽  
P. D. Jenssen ◽  
T. Mæhlum ◽  
T. Krogstad

Five light-weight aggregates (LWAs), suitable for filter media in subsurface flow constructed wetlands, were tested for potential removal of phosphorus (P). P-sorption variation is dependent on the chemical characteristics of the LWA. All LWAs exhibited high pH and high total metal content; however, P-sorption capacity varied by two orders of magnitude. Of the LWAs' chemical characteristics (total metal content, cation exchange capacity, and oxalate soluble Fe and Al), total metal content has the closest relationship with the P-sorption capacity. Among the four major metal ions (Mg, Ca, Fe and Al), Ca has the strongest correlation with the P-sorption capacity.


Soil Research ◽  
2004 ◽  
Vol 42 (1) ◽  
pp. 89 ◽  
Author(s):  
L. L. Burkitt ◽  
C. J. P. Gourley ◽  
P. W. G. Sale

Five field sites established in the high rainfall zone of southern Victoria were used to examine the downwards vertical movement of phosphorus (P) fertiliser on soils which ranged in P sorption capacity. Fertiliser was applied either as a single application of 280 kg P/ha at the beginning of the experiment (April 1998), or as 35�kg�P/ha reapplied every 6 months (totalling 210 kg P/ha by the end of the third year). Soil cores were sampled in June 2001 to a depth of 40 cm, and soil at depths of 0–5, 5–10, 10–20, 20–30, and 30–40 cm was analysed for a range of soil properties and total P concentration.Total P concentration changed very little down the profile, indicating that there was minimal vertical movement of P fertiliser below the 10 cm layer of 5 pasture soils following the single application of 280 kg P/ha or 35 kg P/ha reapplied every 6 months. Soils with low to moderate surface P sorption capacity showed a trend for higher total P concentrations at depth. However, quantitative relationships between vertical P movement and soil properties at depth were poor. A P audit resulted in variable recovery of the applied P (45–128%) in the surface 40 cm at each of the 5 sites. Consistently low P recoveries were achieved at one site, where the surface soil had a high P sorption capacity. Some applied P may have bypassed the high P sorbing surface layers at this site through macropore flow and moved beyond the 40 cm sampling zone, or have been lost to surface runoff. These results question the usefulness of P audit or mass-balance methods for accounting for P movement in a pasture-based system, as spatial heterogeneity of soil properties, both horizontally and vertically, was high in the current study.


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