The Slow Reaction which Continues After Phosphate Adsorption: Kinetics and Equilibrium in Some Tropical Soils

Munns, D. N.; Fox, R. L.

doi:10.2136/sssaj1976.03615995004000010016x

Cited by 89 publications

(57 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Firstly, the reaction has been associated with the formation of amorphous coatings containing P on the surface of the adsorbents (Rajan and Fox, 1972). Secondly, it has been suggested that molecular rearrangement of the adsorbed P occurs leading to the development of a new more strongly adsorbed phase on the surface (Munns and Fox, 1976). Thirdly, the absorbent dissolves leading to the precipitation of amorphous and crystalline phosphate (Van Riemsdijk and Lyklema 1980).…”

Section: Reactions Of Phosphorus In Soilmentioning

confidence: 99%

A critical review on the role of mycorrhizal fungi in the uptake of phosphorus by plants

1991

View full text Add to dashboard Cite

The beneficial effects of mycorrhizae on plant growth have often been related to the increase in the uptake of immobile nutrients, especially phosphorus (P). In this review the mechanisms for the increase in the uptake of P by mycorrhizae and the sources of soil P for mycorrhizal and non-mycorrhizal plants are examined.Various mechanisms have been suggested for the increase in the uptake of P by mycorrhizal plants. These include: exploration of larger soil volume; faster movement of P into mycorrhizal hyphae; and solubilization of soil phosphorus. Exploration of larger soil volume by mycorrhizal plants is achieved by decreasing the distance that P ions must diffuse to plant roots and by increasing the surface area for absorption. Faster movement of P into mycorrhizal hyphae is achieved by increasing the affinity for P ions and by decreasing the threshold concentration required for absorption of P. Solubilization of soil P is achieved by the release of organic acids and phosphatase enzymes. Mycorrhizal plants have been shown to increase the uptake of poorly soluble P sources, such as iron and aluminium phosphate and rock phosphates. However, studies in which the soil P has been labelled with radioactive 32p indicated that both mycorrhizal and non-mycorrhizal plants utilized the similarly labelled P sources in soil.

show abstract

Section: Reactions Of Phosphorus In Soilmentioning

confidence: 99%

A critical review on the role of mycorrhizal fungi in the uptake of phosphorus by plants

1991

View full text Add to dashboard Cite

show abstract

“…Past research has shown that the reaction of P with soils is not instantaneous. The first stage proceeds relatively rapidly and this is followed by a slower sorption phase which continues for a long time (Rajan & Fox 1972;Chen et al 1973;Munns & Fox 1976;Ryden et al 1977;Ibrahim & Pratt 1982;Bolan et al 1985). An equilibrium state may or may not be reached.…”

Section: Introductionmentioning

confidence: 99%

Kinetic studies on phosphorus sorption by selected soil amendments for septic tank effluent renovation

Cheung

Venkitachalam

2006

Environ Geochem Health

View full text Add to dashboard Cite

A systematic kinetic study of phosphorus (P) sorption by various materials in the soil infiltration system of septic tanks was undertaken by following the time course of P sorption by sorbents in contact with various P solutions over periods up to 360 days. Uptake of P seemed to consist of two distinct stages. Initial uptake was very rapid and this phase was completed in 4 days or less. A slower removal stage followed for some materials over many months. Phosphorus sorption during the fast reaction stage appeared to be associated with the soluble Ca content of the materials. The fast reaction of calcareous materials accounted for the bulk (>70%) of the total P removed. Merribrook loamy sand exhibited the highest proportion of P sorption during the slow phase. It should be noted, however, that for solution P concentrations in the range found in typical effluents (approximately 20 mg L(-1)) the fast reaction phase seemed to be responsible for virtually all P removed. None of the six kinetic formulae examined possessed the sophistication and detail needed to portray accurately the time course of P sorption for all the sorbents investigated. The Elovich equation and the kinetic modification of the Freundlich isotherm expression appeared to provide a reasonable fit of the experimental data.

show abstract

“…** Fax no: +9167524361 in a week, where P is adsorbed to the soil surfaces. The second is a slow reaction resulting in a continued, long-term decline of P in soil solution (Munns and Fox, 1976). Although the mechanism for the slow reaction is not well understood, its influence on residual P effectiveness is important in developing efficient long-term management strategies (Munns and Fox, 1976).…”

Section: Introductionmentioning

confidence: 99%

Residual phosphorus and long-term management strategies for an Ultisol

et al. 1996

View full text Add to dashboard Cite

Knowledge of residual benefits from previously applied P is crucial to maximize economic returns to current P inputs. We measured the residual benefits of P fertilizer on three summer soybean crops grown on a Hawaiian Ultisol over a three-year period. Four rates of P had been applied to four crops (P build-up phase) prior to the residual phase of this experiment.The P inputs during the build-up phase were (kg P ha-I per crop): control (0P)=no P inputs; low P (LP)=50, 35, 35, 35; moderate P (MP)=100, 70, 70, 70; and high P (HP)=300, 210, 210, 210. Dry matter yield (DMY) and P uptake in all P regimes declined with each successive crop during the residual phase.The relative decline was greatest in the LP regime where DMY declined by 61% and P uptake by 71% during the residual phase. Even with cumulative P inputs of 930 kg P ha -1 (HP), DMY and P uptake declined by 15% ad 36%, respectively, during the residual phase.The decline in P uptake with time was not related to Mehlich-1 extractable P (M1P), Olsen P, or P extracted by iron-oxide impregnated filter paper (FeO-P). Initially, optimum DMY was achieved with a M1P value of 2 mg P kg -1 , however, this value increased with time so that by the end of the experiment an M1P value greater than 5 mg P kg -1 did not support maximum yields.The rapid decline of residual P benefits in this soil is in contrast to many reports of the lasting residual P benefits in highly weathered soils. Our results suggest that to sustain crop productivity frequent, small applications of P to this soil may be more economical in the long-term than applying large amounts of P.

show abstract

The Slow Reaction which Continues After Phosphate Adsorption: Kinetics and Equilibrium in Some Tropical Soils

Cited by 89 publications

References 0 publications

A critical review on the role of mycorrhizal fungi in the uptake of phosphorus by plants

A critical review on the role of mycorrhizal fungi in the uptake of phosphorus by plants

Kinetic studies on phosphorus sorption by selected soil amendments for septic tank effluent renovation

Residual phosphorus and long-term management strategies for an Ultisol

Contact Info

Product

Resources

About