Phosphorus forms and response to changes in pH in acid-sensitive soils on the Precambrian Shield

2015 ◽  
Vol 95 (2) ◽  
pp. 95-108 ◽  
Author(s):  
Scott R. Baker ◽  
Shaun A. Watmough ◽  
M. Catherine Eimers
Keyword(s):  
Soil Ph ◽  
Forested Catchments ◽  
Solution Ph ◽  
P Fractionation ◽  
Precambrian Shield ◽  
Soil P ◽  
P Sorption ◽  
South Central ◽  
Phosphorus Forms ◽  
Outlet Stream

Baker, S. R., Watmough, S. A. and Eimers, M. C. 2015. Phosphorus forms and response to changes in pH in acid-sensitive soils on the Precambrian Shield. Can. J. Soil Sci. 95: 95–108. Soil acidification may explain declines in total phosphorus (TP) levels that have been observed in surface waters in central Ontario, Canada, but much of the research on phosphorus (P) mobility in pH manipulated soils has been performed at high P concentrations (i.e., >500 µM). This study investigated P fractionation in acidic (pH≤4.6) soils in south-central Ontario and relationships between soil pH and P sorption at relatively low P concentrations to test whether long-term declines in soil pH could have increased soil P sorption. Soils from three forested catchments that vary naturally in soil pH and outlet stream [TP] (0.1–0.4 µM in 2008) had very similar soil P concentrations and distributions (Hedley fractionation). Only hydrochloric-acid extractable P (i.e., apatite) differed amongst catchments and was greatest at the catchment with the highest stream [TP]. The fraction of P present as labile/soluble P did not decline with pH as expected and experiments indicated that P sorption at P concentrations between 4.52 and 452.1 µM was insensitive to manipulated solution pH. Soils were, however, able to sorb >90% of P added in sorption experiments at [P]≤452.1 µM. These results suggest that acidification-induced P sorption in upland soils has not contributed to observed decreases in surface water TP concentrations.

Mechanisms for altering phosphorus sorption characteristics induced by low-molecular-weight organic acids

2016 ◽  
Vol 96 (3) ◽  
pp. 289-298 ◽  
Author(s):  
Yongzhuang Wang ◽  
Joann K. Whalen ◽  
Xin Chen ◽  
Yanhong Cao ◽  
Bin Huang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Organic Acids ◽  
Low Molecular Weight ◽  
Minor Effect ◽  
Phosphorus Sorption ◽  
Sorption Data ◽  
P Fractionation ◽  
Soil P ◽  
P Sorption ◽  
A Minor

Exudation of low-molecular-weight organic acids (LMWOAs) from plant roots enhances phosphorus (P) acquisition from soil, either by dissolving P fixed in secondary minerals or by reducing P sorption to organo-minerals. How LMWOAs may modify P sorption in soils with contrasting pH is not well understood, much less the mechanisms involved. The effects of three common LMWOAs (oxalic, citric, and malic acids) on P sorption in calcareous, neutral, and acidic soils were studied in batch experiments, followed by sequential P fractionation to elucidate the mechanisms whereby LMWOAs alter P sorption. The sorption data of the three soils fitted better to the Freundlich equation (r2 = 0.325–0.994, P < 0.05) than the Langmuir and linear equations. Oxalic, citric, and malic acids at 10 mmol kg−1 soil decreased the Freundlich P sorption parameters Kf and n, which represent P sorption capacity and energy, due to the fact that LMWOAs reduced P sorption in NaHCO3-Pi (soil soluble and exchangeable Pi, 23.8–30.9%) and NaOH-Pi (Fe-Pi and Al-Pi, 21.6–54.2%) fractions of the three soils. Comparing acidified P-LMWOAs solutions with the pH-adjusted P-LMWOAs solutions (pH = 7) had a minor effect on P sorption. Our results indicated that the reduction in soil P sorption was due to ligand exchange and chelation of LMWOAs with Fe and Al minerals, and the acid strength of LMWOAs had a minor effect on P sorption in calcareous, neutral, and acid soils.

The exchange of inorganic phosphorus between soil solution and matrix might largely affect the model predictions of terrestrial carbon cycle

2020 ◽  
Author(s):  
Lin Yu ◽  
Bernhard Ahrens ◽  
Thomas Wutzler ◽  
Marion Schrumpf ◽  
Julian Helfenstein ◽  
...  
Keyword(s):  
Langmuir Isotherm ◽  
Terrestrial Ecosystems ◽  
Strongly Correlated ◽  
The Novel ◽  
P Fractionation ◽  
Inorganic P ◽  
Soil P ◽  
P Sorption ◽  
P Cycling ◽  
Study Sites

&lt;p&gt;Phosphorus (P) availability may influence the response of terrestrial ecosystems to environmental and climate change. Soil biogeochemical (organic) and geophysical (inorganic) P cycling processes are the key players in this regulation. There has been a continuous effort to include P cycling processes into terrestrial biosphere models (TBMs) and many modelling studies agreed on the significance of organic P cycling processes to terrestrial ecosystems. However, the role of inorganic P cycling processes remains unclear. Although the model representations of inorganic P cycling in most TBMs are similar, their parameterisations differ greatly, and none of TBMs have been validated against soil P measurements.&lt;/p&gt;&lt;p&gt;In this study, we developed a new algorithm based on the two-surface Langmuir isotherm to describe the inorganic P exchange between soil solution and soil matrix in the QUINCY TBM, and tested both the novel and conventional models at five beech forest sites in Germany along a soil P stock gradient, which are the main study sites of the German Research Foundation (DFG) funded priority programme 1685.&lt;/p&gt;&lt;p&gt;We conducted a literature review on Langmuir P sorption parameters, which indicates that the P sorption capacity (S&lt;sub&gt;max&lt;/sub&gt;) is strongly correlated with soil texture and the Langmuir coefficient (k&lt;sub&gt;m&lt;/sub&gt;) is strongly correlated with soil pH and organic matter (OM) content. We divided soil P sorption sites into the OM-rich clay and silty sites and OM-poor sandy sites and extracted empirical equations to calculate their S&lt;sub&gt;max&lt;/sub&gt; and k&lt;sub&gt;m&lt;/sub&gt;.&lt;/p&gt;&lt;p&gt;The two-surface Langmuir isotherm approach was implemented to QUINCY, and both the novel and conventional (one-surface Langmuir isotherm) models were applied to the study sites. The models were evaluated with observed soil inorganic P fractionations, foliar N and P contents, and normalized vegetation carbon (C) without calibration. The novel model significantly improved the goodness of model fit to P fractionation measurements at all sites. Both models were able to adequately capture the observed foliar N and P contents, but only the novel one reproduced the observed pattern of vegetation C along the soil P gradient.&lt;/p&gt;&lt;p&gt;We further tested the effect of both models on the responses to CO&lt;sub&gt;2&lt;/sub&gt; addition, P addition and C&amp;P addition at all study sites. The conventional model showed stronger ecosystem responses to P and C&amp;P additions than the two-surface Langmuir one, especially at P-poor sites. It is probably due to that plants store more added P in the conventional model than the novel one. We also tested the sensitivity of both models to the P cycling parameterisation at one low-P site. Despite better model fit to the observed soil P fractionation, the novel model also produced higher and more robust gross primary production, foliar P content and vegetation C than the conventional one.&lt;/p&gt;&lt;p&gt;In summary, we showed that the two-surface Langmuir isotherm approach adequately reproduced the observed soil P fractionations and the pattern of vegetation C along a soil P gradient, owing to its better representation of inorganic P cycling and thus C-P interactions, particularly at low-P ecosystems.&lt;/p&gt;

SOIL AND SOLUTION pH AND SODIUM:CALCIUM RATIO: EFFECTS ON CATION EXCHANGE PROPERTIES OF A SODIUM-SATURATED CHERNOZEMIC SOIL

1984 ◽  
Vol 64 (1) ◽  
pp. 139-146
Author(s):  
THERON G. SOMMERFELDT
Keyword(s):  
Cation Exchange ◽  
Soil Ph ◽  
Irrigation Water ◽  
Polynomial Equation ◽  
Exchangeable Sodium Percentage ◽  
Exchangeable Sodium ◽  
Solution Ph ◽  
Chernozemic Soil ◽  
Sodium Percentage ◽  
Exchange Properties

The effects of soil and solution pH and Na:Ca ratio in solution on the exchangeable Na, Ca, and (Na + Ca) of a Na-saturated Dark Brown Chernozemic soil were studied. At soil pH 9.0, the exchangeable Na, Ca, and (Na + Ca) were 14.5, 25.4, and 21.8% greater than at soil pH 6.0. Solution pH (6.0–9.0) had small but statistically significant effects on the amount of Na and Ca adsorbed by the soil. The logarithm of exchangeable sodium percentage (ESP) was related to the Na fraction in the solution by a polynomial equation, log ESP = 0.93 [Na/(Na + Ca)]2 + 0.16 [Na/(Na + Ca)] + 0.82. Not only is replacement of exchangeable Na with Ca important in the reclamation of this soil, should it become sodic and have a high pH, but also lowering of its surface charge, through lowering of its pH, would be an important factor in its reclamation. It appears impractical to reduce soil pH by applying acidified irrigation water. Acidic amendments such as gypsum and sulfur may be more suitable. Key words: Cation exchange, solution pH, soil pH

scholarly journals Modifications of phosphorus in Latosol as a function of humic acids and acidity

2018 ◽  
Vol 22 (7) ◽  
pp. 488-492 ◽  
Author(s):  
Márcia H. Beck ◽  
Pedro A. V. Escosteguy ◽  
Deborah P. Dick
Keyword(s):  
Factorial Design ◽  
Humic Acids ◽  
Soil Ph ◽  
Crucial Role ◽  
Soil Acidity ◽  
Ph Value ◽  
P Availability ◽  
Soil P ◽  
P Content

ABSTRACT The effect of humic acids (HA) on phosphorus (P) availability is still contradictory; thus, it is necessary to identify the conditions that play a crucial role in this effect. The aim of this study was to investigate the effect of HA application, combined with doses of P, on the content of this nutrient in a Latosol with and without acidity correction. Two experiments were carried out, one with HA from peat and another with HA from mineral charcoal (leonardite). Doses of these acids (0; 1.12 and 5.62 mg C g-1 of soil) and P (26.2 and 104.7 mg P g-1 of soil, 1 and 4-fold higher than recommended, respectively) were tested at soil pH 4.5 and 7.0, in a three-factorial design. The soil was incubated for 20 days and the soil-P content was measured by Mehlich-1 and remaining-P tests. The effect of HAs on P availability varied with the P doses and soil acidity. Humic acids application increases P content in Latosol when P dose is higher than recommended and there is no acidity correction (pH 4.5). However, there is no effect of HAs application on soil-P content when applying the recommended amount of this nutrient, irrespective of the pH value.

scholarly journals Phosphorus forms in leaves and their relationships with must composition and yield in grapevines

2017 ◽  
Vol 52 (5) ◽  
pp. 319-327 ◽  
Author(s):  
Rogério Piccin ◽  
Rafael da Rosa Couto ◽  
Roque Júnior Sartori Bellinaso ◽  
Luciano Colpo Gatiboni ◽  
Lessandro De Conti ◽  
...  
Keyword(s):  
The Other ◽  
Available P ◽  
Anthocyanin Content ◽  
P Fractionation ◽  
Cabernet Franc ◽  
Phosphorus Forms ◽  
Yield Parameters ◽  
P Content ◽  
Total P

Abstract: The objective of this work was to evaluate phosphorus forms in grape leaves and their relationships with must composition and yield in grapevines grown in a Typic Hapludalf with different available P contents. Two experiments were carried out with Vitis viniferacultivars, one with 'Tannat' and the other with 'Cabernet Franc' grapes. Experiment 1 consisted of two vineyards of 'Tannat', with the following P content in the soil: V1, 11.8 mg kg-1 P; and V2, 34.6 mg kg-1 P. Experiment 2 consisted of two vineyards of 'Cabernet Franc', with the following P content in the soil: V1, 16.0 mg kg-1 P; and V2, 37.0 mg kg-1 P. Leaves were collected at flowering (FL) and veraison (V), and, after their preparation, P forms were evaluated. Yield and must composition were assessed. The highest yield was observed in V2 of experiment 1 and in V2 of experiment 2. Total P content and P forms in leaves at FL and V have no relationship with yield parameters; however, total P content in leaves has a relationship with anthocyanin content in the must of 'Tannat' grapevines. Therefore, P fractionation in leaves predicts neither grapevine yield nor must composition.

scholarly journals Influence of soil pH on inorganic phosphorus sorption and desorption in a humid brazilian Ultisol

2005 ◽  
Vol 29 (5) ◽  
pp. 685-694 ◽  
Author(s):  
Shinjiro Sato ◽  
Nicholas Brian Comerford
Keyword(s):  
Soil Ph ◽  
Ph Value ◽  
Tropical Soils ◽  
Inorganic Phosphorus ◽  
Phosphorus Sorption ◽  
Tropical Regions ◽  
P Sorption ◽  
Phosphorus Desorption ◽  
P Desorption ◽  
P Bioavailability

Liming is a common practice to raise soil pH and increase phosphorus (P) bioavailability in tropical regions. However, reports on the effect of liming on P sorption and bioavailability are controversial. The process of phosphorus desorption is more important than P sorption for defining P bioavailability. However few studies on the relationship between soil pH and P desorption are available, and even fewer in the tropical soils. The effects of soil pH on P sorption and desorption in an Ultisol from Bahia, Brazil, were investigated in this study. Phosphorus sorption decreased by up to 21 and 34 % with pH increases from 4.7 to 5.9 and 7.0, respectively. Decreasing Langmuir K parameter and decreasing partition coefficients (Kd) with increasing pH supported this trend. Phosphorus desorption was positively affected by increased soil pH by both the total amount of P desorbed and the ratio of desorbed P to initially sorbed P. A decreased K parameter and increased Kd value, particularly at the highest pH value and highest P-addition level, endorsed this phenomenon. Liming the soil had the double effect of reducing P sorption (up to 4.5 kg ha-1 of remaining P in solution) and enhancing P desorption (up to 2.7 kg ha-1 of additionally released P into solution).

Influence of soil texture on fertilizer and soil phosphorus transformations in Gleysolic soils

2003 ◽  
Vol 83 (4) ◽  
pp. 395-403 ◽  
Author(s):  
Z. Zheng ◽  
L. E. Parent ◽  
J. A. MacLeod
Keyword(s):  
Soil Texture ◽  
Agricultural Soils ◽  
Sandy Loam ◽  
Clay Content ◽  
P Uptake ◽  
Hordeum Vulgare L ◽  
P Fractionation ◽  
Soil P ◽  
Plant P Uptake ◽  
Heavy Clay

The P dynamics in soils should be quantified in agricultural soils to improve fertilizer P (FP) efficiency while limiting the risk of P transfer from soils to water bodies. This study assessed P transformations following FP addition to Gleysolic soils. A pot experiment was conducted with five soils varying in texture from sandy loam to heavy clay, and receiving four FP rates under barley (Hordeum vulgare L.)-soybean (Glycine max L.) rotations. A modified Hedley procedure was used for soil P fractionation. Soil resin-P and NaHCO3-Pi contents were interactively affected by texture and FP. The NaHCO3-Po, NaOH-Po, HCl-P and H2SO4-P were only affected by soil texture. Proportions of 78 and 90% of the variation in labile and total P were, respectively, related to soil clay content. The FP addition increased resin-P, NaHCO3-Pi and NaOH-Pi and -Po contents in coarse-textured soils, but the amount added was not sufficient to mask the initial influence of soil texture on the sizes of soil P pools. Plant P uptake was proportional to FP rate but less closely linked to clay content. The average increase in labile P per unit of total FP added in excess of plant exports was 0.85, 0.8 2 , 0.73, 0.55 and 0.24 for the sandy loam, loam, clay loam, clay and heavy clay soil, respectively. The results of this study stress the important of considering soil texture in Gleysolic soils when assessing P accumulation and transformations in soils, due to commercial fertilizers applied in excess of crop removal. Key words: P fractions, clay content, fertilizer P, plant P uptake, soil texture

scholarly journals Bone char effects on soil: sequential fractionations and XANES spectroscopy

SOIL ◽  
2018 ◽  
Vol 4 (1) ◽  
pp. 23-35 ◽  
Author(s):  
Mohsen Morshedizad ◽  
Kerstin Panten ◽  
Wantana Klysubun ◽  
Peter Leinweber
Keyword(s):  
Xanes Spectroscopy ◽  
Bone Char ◽  
Reduced Sulfur Compounds ◽  
Sequential Fractionation ◽  
P Fractionation ◽  
Edge Structure ◽  
Amended Soils ◽  
Soil P ◽  
P Fraction ◽  
Sequential P Fractionation

Abstract. The acceptability of novel bone char fertilizers depends on their P release, but reactions at bone char surfaces and impacts on soil P speciation are insufficiently known. By using sequential fractionation and synchrotron-based X-ray absorption near-edge structure (XANES) spectroscopy we investigated whether and how the chemical composition of bone char particles has been altered in soil and has consequently affected the P speciation of amended soils. Therefore, two different kinds of bone char particles (BC produced by the pyrolysis of degreased animal bone chips at 800 °C and BCplus, a BC enriched with reduced sulfur compounds) were manually separated from the soil at the end of two different experiments: incubation leaching and ryegrass cultivation. Sequential P fractionation of amended soils showed P enrichment in all fractions compared to the control. The most P increase between all treatments significantly occurred in the NaOH–P and resin-P fractions in response to BCplus application in both incubation-leaching and ryegrass cultivation experiments. This increase in the readily available P fraction in BCplus-treated soils was confirmed by linear combination fitting (LCF) analysis on P K-edge XANES spectra of BC particles and amended soils. The proportion of Ca hydroxyapatite decreased, whereas the proportion of CaHPO4 increased in BCplus particles after amended soils had been incubated and leached and cropped by ryegrass. Based on P XANES speciation as determined by LCF analysis, the proportion of inorganic Ca(H2PO4)2 increased in amended soils after BCplus application. These results indicate that soil amendment with BCplus particles leads to elevated P concentration and maintains more soluble P species than BC particles even after 230 days of ryegrass cultivation.

scholarly journals Spatial variation features description of soil available P, K, Mg and soil pH by proportional effect

2011 ◽  
Vol 52 (No. 1) ◽  
pp. 41-46 ◽  
Author(s):  
L. Brodský ◽  
J. Száková ◽  
M. Bazalová ◽  
V. Penížek
Keyword(s):  
Spatial Variation ◽  
Soil Ph ◽  
Correlation Coefficients ◽  
Available P ◽  
Relationship Strength ◽  
Soil P ◽  
Linear Relationships ◽  
Field Fluctuations ◽  
Proportional Effect ◽  
The Relationship

This paper investigates the proportional effect of selected soil properties &ndash; low spatial variation changes are related to their local magnitudes (here standard deviation vs. mean). Content of available P, K, and Mg, and soil pH were analysed on nine agricultural fields of the&nbsp;Xzech Republic. Firstly, strong direct within-field proportional effect based on Moving Window Statistics (MWS) was found for soil P and K, while Mg did not exhibit any clear proportionality. Soil pH showed indication of inverse proportional effect with high field-to-field fluctuations. The relationship strength of the effect was functionally related to the asymmetry (skewness) of distribution (r = 0.31 &times; skew 0.08). Secondly, between-field proportional effect of 9 surveyed fields, as a&nbsp;measure at different scale, showed generally parallel results with the MWS approach. Proportionality is therefore not scale dependent. However, slopes of linear relationships were different for the two scales. Finally, models for prediction of proportional variogram parameters were calculated. Correlation coefficients of relationship between semivariance parameters and mean proved that sill-nugget is more stable (r = 0.74 for P and 0.83 for K) than nugget (r = 0.30 for P and 0.53 for K).

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