Phosphorous Fertilizer Recommendations Considering Single-point P Sorption Capacity and Soil P Test Extraction Efficiency

In a laboratory incubation study, two soils were treated with distilled water, and flooded for a period of 0 (contr-ol), 1, 2, 3, 4, 8 weeks. P adsorption desorption characteristics of two soils were measured at the end of the incubation period. P a-dsorption increased with increasing levels of added P in two soi-ls. P adsorption of Paddy soil was comparatively lower than that of upland red soil. P adsorption data was found to fit Langmuir isotherms for two soils. Soil P adsorption maxima obtained from Langmuir isotherm varied from 1190 to 672 mg/kg for upland r-ed soil, and varied from 708 to 530 mg/kg for paddy soil. Floodi-ng decreased P adsorption capacity of upland red soil,increased soluble P (in 0.01M CaCl2) and equilibrium P concentration. For paddy soil, there was a large increase in the P sorption capacity after one week flooding, and then P sorption capacity decreased. The more adsorption maxima is, and the more desorption maxi-ma (Dm) is. Desorption rate constant (Kd) and bonding energy (b) varied inconsistently in two soils.

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Growth chamber study of phosphorus applied as drilled granules or as seed coatings to wheat sown in soils differing in P-sorption capacity

Fertilizer Research ◽

10.1007/bf01052397 ◽

1991 ◽

Vol 29 (3) ◽

pp. 281-287 ◽

Cited By ~ 15

Author(s):

J. M. Scott ◽

C. B. Hill ◽

R. S. Jessop

Keyword(s):

Sorption Capacity ◽

Growth Chamber ◽

P Sorption ◽

P Sorption Capacity ◽

Chamber Study

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Phosphorus sorption and chemical characteristics of lightweight aggregates (LWA)-potential filter media in treatment wetlands

Water Science & Technology ◽

10.2166/wst.1997.0175 ◽

1997 ◽

Vol 35 (5) ◽

pp. 103-108 ◽

Cited By ~ 38

Author(s):

T. Zhu ◽

P. D. Jenssen ◽

T. Mæhlum ◽

T. Krogstad

Keyword(s):

Sorption Capacity ◽

Metal Content ◽

Exchange Capacity ◽

Chemical Characteristics ◽

Phosphorus Sorption ◽

Filter Media ◽

Total Metal Content ◽

P Sorption ◽

P Sorption Capacity ◽

Total Metal

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.

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Phosphorus auditing cannot account for all of the phosphorus applied to different pasture soils

Soil Research ◽

10.1071/sr03025 ◽

2004 ◽

Vol 42 (1) ◽

pp. 89 ◽

Cited By ~ 10

Author(s):

L. L. Burkitt ◽

C. J. P. Gourley ◽

P. W. G. Sale

Keyword(s):

Soil Properties ◽

Sorption Capacity ◽

Vertical Movement ◽

Single Application ◽

Macropore Flow ◽

P Sorption ◽

P Sorption Capacity ◽

Sampling Zone ◽

P Movement ◽

Total P

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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Interpretation of a single-point P buffering index for adjusting critical levels of the Colwell soil P test

Soil Research ◽

10.1071/sr06056 ◽

2007 ◽

Vol 45 (1) ◽

pp. 55 ◽

Cited By ~ 70

Author(s):

P. W. Moody

Keyword(s):

Buffer Capacity ◽

Soil Phosphorus ◽

Single Point ◽

Maximum Yield ◽

P Value ◽

P Availability ◽

Soil P ◽

P Concentration ◽

Soil P Test ◽

Rate Of Increase

Soil phosphorus (P) buffer capacity is the change in the quantity of sorbed P required per unit change in solution P concentration. Because P availability to crops is mainly determined by solution P concentration, as P buffer capacity increases, so does the quantity of P required to maintain a solution P concentration that is adequate for crop demand. Bicarbonate-extractable P using the Colwell method is the most common soil P test used in Australia, and Colwell-P can be considered to estimate P quantity. Therefore, as P buffer capacity increases, the Colwell-P concentration required for maximum yield also increases. Data from several published and unpublished studies are used to derive relationships between the ‘critical’ Colwell-P value (Colwell-P at 90% maximum yield) and the single-point P buffer index (PBI) for annual medics, soybean, potato, wheat, and temperate pasture. The rate of increase in critical Colwell-P with increasing PBI increases in the order: temperate pasture < medics < wheat < potato. Indicative critical Colwell-P values are given for the 5 crops at each of the PBI categories used to describe soil P buffer capacity as it increases from extremely low to very high.

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Evaluation of P sorption capacity and P extractants for assessing P requirements of maize in Western Nigeria savannah soils.

Communications in Soil Science and Plant Analysis ◽

10.1080/00103628209367269 ◽

1982 ◽

Vol 13 (4) ◽

pp. 295-307 ◽

Cited By ~ 1

Author(s):

O.J. Ayodele ◽

A. Agboola ◽

R.A. Sobulo

Keyword(s):

Sorption Capacity ◽

P Sorption ◽

P Sorption Capacity

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Phosphorus sorption - desorption by purple soils of China in relation to their properties

Soil Research ◽

10.1071/sr06135 ◽

2007 ◽

Vol 45 (3) ◽

pp. 182 ◽

Cited By ~ 20

Author(s):

M. Li ◽

Y. L. Hou ◽

B. Zhu

Keyword(s):

Binding Energy ◽

Single Point ◽

Phosphorus Sorption ◽

Soil P ◽

P Sorption ◽

Desorption Curve ◽

Degree Of P Saturation ◽

Soil Test P ◽

Sorption Index ◽

Water Eutrophication

The understanding of phosphorus (P) sorption and desorption by soil is important for better managing soil P source and relieving water eutrophication. In this study, sorption–desorption behaviour of P was investigated in purple soils, collected from 3 kinds of purple parent materials with different kinds of land cover, in the upper reaches of Yangtze River, China, using a batch equilibrium technique. Results showed that most of the farmed purple soils had P sorption capacity (PSC) values ranging from 476 to 685 mg P/kg, while higher PSC values were observed in the soils from forestland and paddy field. A single-point P sorption index (PSI) was found to be significantly correlated with PSC (R2 = 0.94, P < 0.001), suggesting its use in estimating PSC across different types of purple soils. The PSC of purple soils was positively and strongly related to the contents of amorphous Fe and Al oxides (r = 0.73, P < 0.001), clay (r = 0.55, P < 0.01), and organic matter (r = 0.50, P < 0.05). Furthermore, the constant relating to binding strength was positively correlated with the content of amorphous Fe and Al oxides (r = 0.66, P < 0.01), but negatively correlated with labile Ca (r = –0.43, P < 0.05) and soil pH (r = –0.53, P < 0.01). Some acidic purple soils with high binding energy featured a power desorption curve, suggesting that P release risk can be accelerated once the P sorbed exceeds a certain threshold. Other soils with low binding energy demonstrated a linear desorption curve. The P desorption percentage was significantly correlated with soil test P (r = 0.78, P < 0.01) and the degree of P saturation (r = 0.82, P < 0.01), but negatively correlated with PSC (r = –0.66, P < 0.01).

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Solubility and retention of phosphate in soils of the northwestern Canadian prairie

Canadian Journal of Soil Science ◽

10.4141/cjss91-044 ◽

1991 ◽

Vol 71 (4) ◽

pp. 453-463 ◽

Cited By ~ 9

Author(s):

Y. K. Soon

Keyword(s):

Organic Matter ◽

Sorption Capacity ◽

Agricultural Soils ◽

Clay Content ◽

Phosphorus Concentration ◽

Canadian Prairie ◽

P Sorption ◽

P Sorption Capacity ◽

P Concentration ◽

Order Of Magnitude

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

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Anoxic conditions maintained high phosphorus sorption in humid tropical forest soils

10.5194/bg-2019-62 ◽

2019 ◽

Author(s):

Yang Lin ◽

Avner Gross ◽

Christine S. O'Connell ◽

Whendee L. Silver

Keyword(s):

Tropical Forest ◽

Tropical Forests ◽

Sorption Capacity ◽

Forest Soils ◽

Soil Minerals ◽

Anoxic Conditions ◽

Soil P ◽

P Sorption ◽

Reducing Conditions ◽

Humid Tropical Forest

Abstract. The strong phosphorus (P) sorption capacity of iron (Fe) and aluminum (Al) minerals in highly weathered, acidic soils of humid tropical forests is generally assumed to be an important driver of P limitation to plants and microbial activity in these ecosystems. Humid tropical forest soils often experience fluctuating redox conditions that reduce Fe and raise pH. It is commonly thought that Fe reduction generally decreases the capacity and strength of P sorption. Here we examined the effects of 14-day oxic and anoxic incubations on soil P sorption dynamics in humid tropical forest soils from Puerto Rico. Contrary to the conventional belief, soil P sorption capacity did not decrease under anoxic conditions, suggesting that soil minerals remain strong P sinks even under reducing conditions. Sorption of P occurred very rapidly in these soils, with at least 60 % of the added P disappearing from the solution within six hours. Estimated P sorption capacities were one order of magnitude higher than the soil total P contents. However, the strength of P sorption under reducing conditions was weaker, as indicated by the increased solubility of sorbed P in NaHCO3 solution. Our results show that highly weathered soil minerals can retain P even under anoxic conditions, where it might otherwise be susceptible to leaching. Anoxic events can also potentially increase P bioavailability by decreasing the strength, rather than the capacity, of P sorption. These results improve our understanding of the redox effects on biogeochemical cycling in tropical forests.

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