Phosphorus fractions in soil solution: Influence of soil acidity and fertiliser additions

Vaz, M. D. Ron; Edwards, Anthony C.; Shand, C. A.; Cresser, M.S.

doi:10.1007/bf00012855

Cited by 94 publications

(16 citation statements)

References 26 publications

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“…4) . A similar decrease in relative content of unreactive P in response to increasing total P was found by McDowell and Sharpley (2001b) and Ron Vaz et al (1993) In contrast to CaCl 2 –RP and CaCl 2 –TP, CaCl 2 –UP was more or less constant from Levels A to D and was not correlated to STP. However, unreactive P measured after extraction of dried soil can partly consist of P released from lysis of microbial cells since microbes can be killed by osmotic shock after rapid rewetting (Turner and Haygarth, 2001).…”

Section: Resultssupporting

confidence: 74%

“…The results obtained in this work were similar to those obtained by Sharpley (1995) The CaCl 2 –RP fraction represents mainly inorganic orthophosphate, though it may also contain small amounts of P hydrolyzed from organic substances or colloids (Sinaj et al, 1998; McDowell and Sharpley, 2001b). In the soils studied, reactive P was by far the main P form released at high CaCl 2 –TP, while CaCl 2 –UP, which represents organic P and inorganic polyphosphates (Ron Vaz et al, 1993) or colloids (Sinaj et al, 1998), was the dominant form in soils with low P status. The CaCl 2 –UP ranged from 1.7 to 96% of CaCl 2 –TP (Fig.…”

Section: Resultsmentioning

confidence: 97%

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Soil Variables for Predicting Potential Phosphorus Release in Swedish Noncalcareous Soils

2004

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The accumulation of P in agricultural soils due to fertilization has increased the risk of P losses from agricultural fields to surface waters. In risk assessment systems for P losses, both P release from soil to solution and transport mechanisms need to be considered. In this study, the overall objective was to identify soil variables for prediction of potential P release from soil to solution. Soils from nine sites of the Swedish long-term fertility experiment were used, each with four soil P levels. Phosphorus extractable with CaCl2 was used as an estimate of potential P release from soil to solution. Ammonium lactate-extractable phosphorus (P-AL) or NaHCO3-extractable phosphorus (Olsen P) could not be used alone for prediction of potential P release since soils with high phosphorus sorption capacity (PSC) released less P than soils with low PSC at the same soil test phosphorus (STP) level. Degree of phosphorus saturation (DPS) was calculated as Olsen P or P-AL as a percentage of PSC derived from P sorption isotherms or from Fe and Al extractable in ammonium oxalate. The CaCl2-extractable total phosphorus (CaCl2-TP) was exponentially related to these DPS values (r2 > or = 0.79). The CaCl2-TP was also linearly related to ratios between Olsen P or P-AL and a single-point phosphorus sorption index (PSI; r2 > or = 0.86). These ratios, which are easily determined and gave good correlations with CaCl2-TP, seemed to be the most useful estimates of potential P release for risk assessment systems.

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Section: Resultssupporting

confidence: 74%

Section: Resultsmentioning

confidence: 97%

Soil Variables for Predicting Potential Phosphorus Release in Swedish Noncalcareous Soils

2004

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“…The highest soil acidity at 50% anthesis of NH84/493 coupled with highest organic C accounted for the highest soil-available-P content in NH84/493 compared with NH84/445 and NH84/452 in this study. Organic C has been found to increase P fractions (organic P) in soils low in fertility (Ronvaz 1993;Cherdan 1997). This form of P (organic P) is derived from plant residues, excreta, and above-and below-ground soil organisms (Magid, Tiessen, and Condron 1996;Rodriguez and Herrera 2002).…”

Section: Discussionmentioning

confidence: 98%

Comparative Effect of Phosphorus Sources for Grain Amaranth Production

Ojo

Akinrinde

Akoroda

2007

Comm. in Soil Sc. & Plant Analysis

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Phosphorus (P) is expensive to the sub-Saharan African resource-poor farmers; therefore, there is a need for investigation of locally available alternative P sources to enhance farmers' productivity. Optimum P rate was determined during the early and late rains of 1999. Using the optimum P rate, influences of three P sources ogun rock phosphate (ORP), sokoto rock phosphate (SRP), single super phosphate (SSP) and a control were evaluated on amaranth varieties in 2000 at the vegetable research plots of the National Horticultural Research Institute (NIHORT), Ibadan, Nigeria. In 1999, three grain amaranth varieties (NH84/452, NH84/445, and NH84/493) were combined factorially with four P rates: 0, 30, 60, and 90 kgP/ha. Application of P significantly increased plant height, number of branches, leaf dry weight, and grain yield (GY) per plant. Significant increase in GY was in the order NH/493 . NH/445 . NH/452. Optimum P rates across varieties for leaf dry-matter yield was established at 51.8 kgP/ha and for grain yield production was 48.4 kgP/ha. The experiment in the following year, 2000, was a RCB design using the optimum P determined in 1999. Three P sources (ORP, SRP, SSP) and a control were factorially combined with the three amaranth varieties. In the 2000 experiment, grain yield was 21.3, 16.9, 16.0, and 7.8 g/plant, respectively, for SSP, SRP, ORP, and the control. Growth was ranked in the order SSP . ORP . SRP . control. It was concluded for fertilizer recommendation Downloaded by [University of Western Ontario] at 07:52 04 February 2015 purposes that 50 kgP/ha is optimum for grain amaranth production and that amaranth productivity indices could be alternatively improved with indigenous P sources.

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“…Unreactive phosphorus (UP) was calculated as the difference between TP and DRP. Unreactive P represents mainly particulate P, but it may also include dissolved organic P and inorganic polyphosphates (Ron Vaz et al, 1993). Phosphorus loads were calculated by multiplying the leachate volume during a period by the corresponding concentrations of the respective P constituents.…”

Section: Methodsmentioning

confidence: 99%

Phosphorus Leaching in Relation to Soil Type and Soil Phosphorus Content

Djodjic

Börling²,

Bergström³

2004

J of Env Quality

266

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Phosphorus losses from arable soils contribute to eutrophication of freshwater systems. In addition to losses through surface runoff, leaching has lately gained increased attention as an important P transport pathway. Increased P levels in arable soils have highlighted the necessity of establishing a relationship between actual P leaching and soil P levels. In this study, we measured leaching of total phosphorus (TP) and dissolved reactive phosphorus (DRP) during three years in undisturbed soil columns of five soils. The soils were collected at sites, established between 1957 and 1966, included in a long-term Swedish fertility experiment with four P fertilization levels at each site. Total P losses varied between 0.03 and 1.09 kg ha(-1) yr(-1), but no general correlation could be found between P concentrations and soil test P (Olsen P and phosphorus content in ammonium lactate extract [P-AL]) or P sorption indices (single-point phosphorus sorption index [PSI] and P sorption saturation) of the topsoil. Instead, water transport mechanism through the soil and subsoil properties seemed to be more important for P leaching than soil test P value in the topsoil. In one soil, where preferential flow was the dominant water transport pathway, water and P bypassed the high sorption capacity of the subsoil, resulting in high losses. On the other hand, P leaching from some soils was low in spite of high P applications due to high P sorption capacity in the subsoil. Therefore, site-specific factors may serve as indicators for P leaching losses, but a single, general indicator for all soil types was not found in this study.

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Phosphorus fractions in soil solution: Influence of soil acidity and fertiliser additions

Cited by 94 publications

References 26 publications

Soil Variables for Predicting Potential Phosphorus Release in Swedish Noncalcareous Soils

Soil Variables for Predicting Potential Phosphorus Release in Swedish Noncalcareous Soils

Comparative Effect of Phosphorus Sources for Grain Amaranth Production

Phosphorus Leaching in Relation to Soil Type and Soil Phosphorus Content

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