How effective are Calciphos and Phospal?

Bolland, M. D. A.; Gilkes, R. J.

doi:10.1007/bf01315107

Cited by 19 publications

(9 citation statements)

References 24 publications

(28 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…the relation between the yield or the plant uptake and increasing rates of P application for different forms of P fertilizers; (ii) to compare the regression constants of the equation fitted to the response curves; and (iii) to express the results in relation to a standard form of P fertilizer which is water-soluble in order to calculate the Relative Agronomic Effectiveness (RAE) of the tested P fertilizer. Although the factors involved in the RAE of the various P fertilizer forms relating to soil properties have been studied more than a century, it is apparent in the literature on the agronomical evaluation of P fertilizers that it is still an actual agronomic problem since the sets of RAE values of a given P form are often contradictory (Bolland and Gilkes, 1987). Many methodological factors can explain this discrepancy, but it basically indicates this approach doesn't take into account the complexity of the process and the interactions involved between the rate of P application and its effects on agronomic response.…”

Section: Consequently Ss/sf Values [Ss/ Sf = (Riwt)/(r/f)]mentioning

confidence: 99%

Is the isotopically exchangeable phosphate of a loamy soil the plant-available P?

Morel¹,

Plenchette²

1994

Plant Soil

View full text Add to dashboard Cite

This study compared the validity of using the isotopically exchangeable phosphorus (P) as an accurate measurement of plant available P by comparing the specific activity of P, i.e. the 32P/31P ratio, in soil solution (Ss) against the specific activity of P in plants (Sp) growing in a loamy soil after applying a 32P-labelled fertilizer (NaH,P0,2H,O) at different rates (F) and specific activities (Sf). Non-mycorrhizal and mycorrhizal (Glomus intraradices) plants of two species (soybean and barley) were grown in greenhouse experiments. Ss values were determined on 1: 10 soil suspension after periods of incubation ranged from 1 min to 35 d. At a given rate of P application, the Sp values of both non-mycorrhizal and mycorrhizal soybean and barley did not show significant difference although the plant P uptake varied 18 fold for all the (crop species x mycorrhizal infection) treatments over soil solution P values ranging from 0.02 to 5.46 mg P L-l (0.6-176 pA4). Ss values decreased with time and reached a steady state after 35 d of equilibration period. Both SpiSf and Ss/Sf increased with applied P and there is a 1: 1 correspondence between Sp/Sf and Ss/Sf values. The identity between the isotopic composition of both P in soil solution and in plant indicates that the isotopically exchangeable P (E = F(Sf/Ss-1)) is the only source of phosphate in solid soil phase which replenishes P of the soil solution after P has been removed by the plant, i.e. the only source of P which participates in plant nutrition. The isotopically exchangeable P of a loamy soil is the P available to growing plants and mycorrhizal fungi increases the P uptake giving plants wider access to isotopically exchangeable P in soil, and not making previously non-exchangeable P available. An immediate application of the 1: 1 correspondence between a soil parameter (Ss/Sf) and a plant parameter (Sp/Sf) concerns the agronomic evaluation of P fertilizers.Abbreviations: R -amount of 32P associated with the amount of 31P (F) in fertilizer, Rp -amount of 32P taken up by plant, Rs -amount of 32P in soil solution, Qf -amount of 31P taken up by plant from the fertilizer (Qf = FRp/R), Qs -amount of 31P taken up by plant from the soil, Qt -total amount of 31P taken up by plant (Qt = Qs + Qf), Wf -amount of 31P in soil solution derived from the fertilizer (Wf = FRs/R), Ws -amount of 31P in soil solution originated from the soil, Wt -total amount of 3*P in soil solution (Wt = Ws + Wf), Sf -specific activity of P in the applied fertilizer (Sf = R/F), Ss -specific activity of P in the soil solution (Ss = Rs/Wt), Sp -specific activity of P taken up by the plant (Sp = Rp/Qt). A value -FQs/Qf, L value -F(Sf/Sp-1), E value -F(Sf/Ss-1).

show abstract

Section: Consequently Ss/sf Values [Ss/ Sf = (Riwt)/(r/f)]mentioning

confidence: 99%

Is the isotopically exchangeable phosphate of a loamy soil the plant-available P?

Morel¹,

Plenchette²

1994

Plant Soil

View full text Add to dashboard Cite

show abstract

“…It can be concluded from these experimental data that the hypothesis P, = P, used for the P fertilizer evaluation by the standard method without isotopic tracers is not valid. This explains many contradictory conclusions published concerning P fertilizer evaluation using the standard response curve method (Bolland and Gilkes, 1987;Ghosh and Gilkes, 1987;Morel et Fardeau, 1988).…”

Section: Effect Of Soil-p Bioavailability On Phosphorus Uptake From Smentioning

confidence: 98%

“…However, problems of choice have arisen because of the large number of new sources which have appeared on the market (Hammond et al, 1986) and, above all, because of contradictory results published concerning comparative measurements of agronomic efficiency of various P fertilizers in field experiments (Bolland and Gilkes, 1987;Ghosh and Gilkes, 1987;Prince, 1953;Stephen and Condron, 1986). In many cases, the contradictions can be explained either by results obtained on soils where there is no agronomical response or by inadequate methods of fertilizer assessment (Bolland and Gilkes, 1987;Morel and Fardeau, 1988;Palmer et al, 1979). We have recently demonstrated that, when the rate and kind of applied P fertilizer vary, the total amount of P taken up by crops in the presence of P fertilizer can mask differences in the evaluated efficiency of the fertilizers (Morel and Fardeau, 1989).…”

Section: Introductionmentioning

confidence: 99%

Uptake of phosphate from soils and fertilizers as affected by soil P availability and solubility of phosphorus fertilizers

Morel

Fardeau

1990

Plant Soil

View full text Add to dashboard Cite

Fertilizers labelled with 32p were used to measure amounts of phosphorus, Ps and PF, taken up by Lolium perenne from available soil P and from P fertilizer respectively, when applied at a rate of 66 mg P. (kg soil-~ ) in greenhouse experiments. The quantity Ps of phosphorus taken up from soil in the presence of P fertilizer was compared to the quantity Po taken up from soil without P fertilizer. The quantity (P~ -Po) is positive for low Po values, i.e. in soils poor in available phosphorus, but is negative for high Po values indicating that an input of P fertilizer can induce a decrease in the utilization of available soil phosphorus. Moreover, for a given soil, the quantity (Ps -Po) depends on the chemical form of the fertilizer. The standard method of evaluation of P fertilizer efficiency is based on the assumption that P~ = Po, but P~ can differ from Po. This result can explain the contradictory data published from field experiments about the efficiency of the various P fertilizers.

show abstract

“…The relative agronomic effectiveness (RAE) of these materials under different soil conditions presented divergent results. Bolland and Gilkes (1987) summarized data from 194 published pot and field experiments done with those two P fertilizers and found that a wide range of RAE values relative to superphosphate were reported for freshly applied fertilizers. Low RAE values were observed in experiments on highly P-responsive soils, whereas high RAE values only occurred for sandy soils in which watersoluble P was rapidly leached.…”

Section: Introductionmentioning

confidence: 95%

Agronomic Evaluation of Calcined Crandallite from Three Brazilian Phosphate Deposits

Francisco

Prochnow

Toledo

et al. 2008

Communications in Soil Science and Plant Analysis

View full text Add to dashboard Cite

Samples from the weathering mantle containing crandallite of three Brazilian phosphate deposits, Tapira, Catalão, and Juquiá, were characterized, calcined, and agronomically evaluated. The calcination process increased total phosphorus (P) and neutral ammonium citrate soluble (NAC) P contents of all samples. The NAC solubility of original Tapira, Catalão, and Juquiá was about 5% of total P, whereas for calcined samples it was 54, 16, and 53%, respectively. In a greenhouse study, rates of P were applied at 0, 10, 20, 40, 80, and 120 mg P kg 21 from the calcined materials and MCP (monocalcium phosphate) to an Ultisol cropped with upland and flooded rice for 65 days. The results showed that the calcined P samples increased dry-matter yield and P uptake with increasing rates of P applied for both crops. Tapira and Juquiá were more effective for flooded than for upland rice. The calculated values of relative agronomic effectiveness of Tapira, Catalão, and Juquiá with respect to MCP were 57, 48, and 53% in dry-matter yield for upland rice and 64, 50, and 69% for flooded rice, respectively.

show abstract

How effective are Calciphos and Phospal?

Cited by 19 publications

References 24 publications

Is the isotopically exchangeable phosphate of a loamy soil the plant-available P?

Is the isotopically exchangeable phosphate of a loamy soil the plant-available P?

Uptake of phosphate from soils and fertilizers as affected by soil P availability and solubility of phosphorus fertilizers

Agronomic Evaluation of Calcined Crandallite from Three Brazilian Phosphate Deposits

Contact Info

Product

Resources

About