scholarly journals Inorganic P fractionation in Shrink-swell soils of Central India: A case study

Agropedology ◽  
2019 ◽  
Vol 27 (2) ◽  
Author(s):  
Vijay R. Jadhav ◽  
◽  
K. Karthikeyan ◽  

Inorganic P fractions in shrink-swell soils representing six soil series of Adan river basin, Darwha tehsil, Yavatmal district, Maharashtra were studied to understand the relationship between the P fractions and soil properties. These clayey soils were neutral to strongly alkaline (pH 6.70 – 9.34), calcareous and low to medium in organic carbon. The sequential extraction of inorganic soil P fractions indicated relative abundance as Ca2-P<Fe-P<Al-P<O-P<Ca8-P<Ca10-P. The plant available forms of P (Ca2-P, Al-P and Fe-P) contributed nearly 10 per cent of total inorganic P while the rest was in unavailable forms. The correlation matrix indicated that plant available forms of P had significant negative correlation with soil pH, EC and CaCO3 and significant positive correlation with organic carbon. The P fractions showed significant correlation among each other which implies that available P forms are constantly replenished by other forms of P pools in the soils.

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

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.


2012 ◽  
Vol 137 ◽  
pp. 221-229 ◽  
Author(s):  
Bin Hu ◽  
Yu Jia ◽  
Zhi-hong Zhao ◽  
Feng-min Li ◽  
Kadambot H.M. Siddique

1987 ◽  
Vol 67 (1) ◽  
pp. 147-163 ◽  
Author(s):  
J. W. B. STEWART ◽  
I. P. O'HALLORAN ◽  
R. G. KACHANOSKI

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


2021 ◽  
Vol 3 ◽  
pp. e3
Author(s):  
Xin Jin ◽  
Changlu Hu ◽  
Asif Khan ◽  
Shulan Zhang ◽  
Xueyun Yang ◽  
...  

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.


2003 ◽  
Vol 83 (4) ◽  
pp. 443-449 ◽  
Author(s):  
R. H. McKenzie ◽  
E. Bremer

Soil tests for available P may not be accurate because they do not measure the appropriate P fraction in soil. A sequential extraction technique (modified Hedley method) was used to determine if soil test P methods were accurately assessing available pools and if predictions of fertilizer response could be improved by the inclusion of other soil P fractions. A total of 145 soils were analyzed from field P fertilizer experiments conducted across Alberta from 1991 to 1993. Inorganic P (Pi) removed by extraction with an anion-exchange resin (resin P) was highly correlated with the Olsen and Kelowna-type soil test P methods and had a similar relationship with P fertilizer response. No appreciable improvement in the fit of available P with P fertilizer response was achieved by including any of the less available P fractions in the regression of P fertilizer response with available P. Little Pi was extractable in alkaline solutions (bicarbonate and NaOH), particularly in soils from the Brown and Dark Brown soil zones. Alkaline fractions were the most closely related to resin P, but the relationship depended on soil zone. Inorganic P extractable in dilute HCl was most strongly correlated with soil pH, reflecting accumulation in calcareous soils, while Pi extractable in concentrated acids (HCl and H2SO4) was most strongly correlated with clay concentration. A positive but weak relationship as observed between these fractions and resin P. Complete fractionation of soil P confirmed that soil test P methods were assessing exchangeable, plant-available P. Key words: Hedley phosphorus fractionation, resin, Olsen, Kelowna


2016 ◽  
Vol 96 (2) ◽  
pp. 191-198 ◽  
Author(s):  
M.A. Ribey ◽  
I.P. O’Halloran

Environmental indices for soil P limit P applications when soil tests and risk of P losses exceed a given threshold. Producers’ reluctance to reduce P inputs often stem from concerns regarding reduced crop production and soil fertility. Our objectives were to identify changes in soil P fractions after 4 yr of repeated manure or fertilizer P applications at rates ≤ crop removal by corn (Zea mays L.), and the impact of these applications on yields. Olsen P and soil P fractions extracted using a modified Hedley P fractionation procedure were measured. Corn yields were nonresponsive to P applications. After 4 yr, Olsen P was 16.6 and 24.6 mg kg−1 at the application rates of 0 and 33 kg P ha−1 yr−1, respectively, for the inorganic fertilizer treatment indicating that soil P drawdown was occurring. Only the most labile forms of Pi (resin and bicarbonate extractable) were affected by treatment, with greater values at higher P application rates. Adherence to Ontario’s P index recommendations for P applications at or below crop removal should not be a crop production concern. Furthermore, given the rate of soil labile P drawdown, routine soil testing (every 3–5 yr) would identify agronomically significant changes in soil test P before the crop yield is impacted.


Author(s):  
L.M. Condron ◽  
K.M. Goh

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


2019 ◽  
Vol 11 (4) ◽  
pp. 1006 ◽  
Author(s):  
Ying Han ◽  
Xiangwei Chen ◽  
Byoungkoo Choi

Freeze–thaw cycles stimulate the release of available soil phosphorus (P) in winter, and biochar as a soil amendment could improve P availability. Nevertheless, it is unclear how freeze–thaw cycles and biochar amendment interact to affect the soil P fractions and their availability in winter, particularly under different soil water conditions. We simulateda freeze–thaw cycle experimentto assess the effects of three factors on soil P fractions: soil moisture content (22%, 31%, and 45%), frequencies of freeze–thaw cycles (0, 1, 3, 6, and 12 times) and biochar amendment (soil and biochar-amended soil). Modified Hedley sequential P fractionation was conducted to measure the soil P fractions. Increasing the number of freeze–thaw cycles increased soil labile P fractions in the soil with the lowest moisture content (22%). After biochar amendment, the content of labile P decreased as the number of freeze–thaw cycles increased. Biochar amendment enhanced P availability in Mollisols owing to the direct effect of NaOH-Po, which has a large direct path coefficient. Principal components analysis showed that moisture content was a major factor influencing the variation in the P fractions. The P fractions were separated by the interactive effects of biochar amendment and freeze–thaw cycles in soils with a higher moisture content (45%), indicating that the effects of freeze–thaw cycles on P availability appear to be more pronounced in biochar-amended Mollisols of higher water contents.


2020 ◽  
Author(s):  
Lin Yu ◽  
Bernhard Ahrens ◽  
Thomas Wutzler ◽  
Marion Schrumpf ◽  
Julian Helfenstein ◽  
...  

&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;


1989 ◽  
Vol 61 (2) ◽  
pp. 55-59 ◽  
Author(s):  
Helinä Hartikainen

Surface soil samples were collected from 16 P fertilization trials before onset of the experiments and after seven years of cultivation. The changes in the inorganic P fractions were investigated in plots amended annually with 0, 30 or 60 kg of P ha-1. In the clay soils, cultivation without P fertilization depleted the NH4F-extractable and NaOH-extractable P reserves by 22—69 kg ha-1 ; in the coarser soils, the respective depletion was 8—140 kg ha-1. H2S04-soluble P decreased in seven soils by 16—34 kg ha-1. In the plots amended totally with 210 or 420 kg of P ha-1, on the other hand, these P fractions increased by 24—174 and 46—368 kg ha-1, respectively. The higher the P dressing was, the more the added P tended to accumulate in the fluoride-soluble form as compared to the alkali-soluble form.


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