Phosphorus supplying capacity of phosphate rocks as influenced by compaction with water-soluble P fertilizers

2004 ◽  
Vol 68 (1) ◽  
pp. 73-84 ◽  
Author(s):  
Mamata Begum ◽  
G. Narayanasamy ◽  
D.R. Biswas
Keyword(s):  
Water Soluble ◽  
Phosphate Rocks ◽  
Water Soluble P ◽  
Soluble P ◽  
P Fertilizers

scholarly journals Obtaining the partially acidulated phosphate rocks by means of intermediate-grade phosphate and diluted phosphoric acid: Influence of some parameters

2016 ◽  
Vol 18 (3) ◽  
pp. 39-43
Author(s):  
Abbes Mizane ◽  
Ahmed Boumerah ◽  
Noureddine Dadda ◽  
Rabah Rehamnia ◽  
Salah Belhait
Keyword(s):  
Phosphoric Acid ◽  
Reaction Times ◽  
Water Soluble ◽  
Particle Sizes ◽  
Phosphate Rocks ◽  
Partially Acidulated Phosphate Rocks ◽  
Water Soluble P ◽  
Conversion Rates ◽  
Soluble P ◽  
Phosphoric Acid Concentration

Abstract In this work, some parameters during the partial acidulation by phosphoric acid of phosphate 53.75% BPL (bone phosphate of lime) having different particle sizes are determined. P2O5 recovery is obtained by performing a series of reactions using phosphoric acid diluted from 10 to 40 wt.% and with reaction times ranging from 10 to 50 minutes. The best conversion rates are obtained with the following reaction parameters: phosphates size: 88-177 μm, reaction time: 50 minutes and phosphoric acid concentration: 40 wt.%. In the second part, the water-soluble P2O5 of PAPRs (Partially Acidulated Phosphate Rocks) obtained with phosphoric acid 30% and 40 wt.% is measured. The results of experiments showed that the water-soluble P2O5 has reached 15.2% for PAPRs obtained by reacting phosphate 88 μm with phosphoric acid 40 wt%.

Effect of reactive phosphate rocks and water-soluble phosphorus fertilisers on extractable phosphorus concentrations in soil

1997 ◽  
Vol 37 (8) ◽  
pp. 1009 ◽  
Author(s):  
N. K. Fleming ◽  
M. D. A. Bolland ◽  
M. A. Gilbert
Keyword(s):  
Phosphate Rock ◽  
Water Soluble ◽  
Soil Test ◽  
Phosphate Rocks ◽  
Water Soluble P ◽  
Reactive Phosphate ◽  
Soluble Phosphorus ◽  
Soil Test P ◽  
Soluble P ◽  
Pasture Yield

Summary. Soil samples were collected each year from all plots at all sites in the National Reactive Phosphate Rock Project and analysed for bicarbonate-soluble phosphorus (P) using the Colwell procedure (soil test P). The relationship between soil test P and the level of P applied was adequately described by a linear equation. The slope coefficient of this equation provides a measure of the extractability of P from soil treated with a particular fertiliser and has been termed the ‘extractability’ for that particular fertiliser at that site. Extractability values were used to estimate phosphate rock effectiveness; this was done by dividing the extractability for each phosphate rock by the extractability of the reference water-soluble P fertiliser to provide a relative soil extractability (RSE). There was a good agreement between the RSE for a phosphate rock and its substitution value for water-soluble P fertiliser, which is a measure of fertiliser effectiveness based on pasture yield. Estimates of fertiliser effectiveness, based on increases in soil test P values, also agreed with estimates based on pasture yield with respect to the ranking of different P fertilisers, and the ranking of phosphate rocks in order of their reactivity. Simple and multiple linear regression analyses were used to identify relationships between a range of soil properties and extractability values across sites, but no relationships were found.

scholarly journals The influence of long-term sewage sludge application on the activity of phosphatases in the rhizosphere of plants

2008 ◽  
Vol 53 (No. 9) ◽  
pp. 375-381 ◽  
Author(s):  
J. Balík ◽  
D. Pavlíková ◽  
V. Vaněk ◽  
M. Kulhánek ◽  
B. Kotková
Keyword(s):  
Sewage Sludge ◽  
Fertilizer Application ◽  
Water Soluble ◽  
Organic Fertilizers ◽  
Lower Content ◽  
Alkaline Phosphatases ◽  
Soil P ◽  
Water Soluble P ◽  
Soluble P

Model experiments using rhizoboxes were carried out in order to evaluate the influence of different plants (wheat, rape) on the changes in water extractable contents of P, the pH/H2O value and the activity of acidic and alkaline phosphatase in soil of plant rhizosphere. For this experiment, a Cambisol with different long-term fertilizing systems was used: (i) control (with no fertilizer application), (ii) sewage sludge, and (iii) manure. A lower content of water-soluble P was observed in close vicinities of root surfaces (up to 2 mm) at all the studied variants. The control (non-treated) variant reflected a significantly lower content of water-soluble P in the rhizosphere compared to the fertilized ones. The activities of the acidic and alkaline phosphatases were significantly higher in the rhizosphere compared to the bulk soil (soil outside the rhizosphere). The long-term application of organic fertilizers significantly increased phosphatase activity; the activity of the acidic phosphatase was significantly higher in the rhizosphere of rape plants compared to wheat. The variant treated with manure exhibited an increased activity of both the acidic and alkaline phosphatases compared to the variant treated with sewage sludge. In the case of the variant treated long-term with sewage sludge, the portion of inorganic P to total soil P content proportionally increased compared to the manure-treated variant. Soil of the rape rhizosphere showed a trend of lower pH/H<sub>2</sub>O value of all variants, whereas the wheat rhizosphere showed an opposite pH tendency.

Water-soluble p-carboxybenzylated beechwood 4-O-methylglucuronoxylan: structural features and properties

2000 ◽  
Vol 42 (2) ◽  
pp. 123-131 ◽  
Author(s):  
A. Ebringerová ◽  
J. Alföldi ◽  
Z. Hromádková ◽  
G.M. Pavlov ◽  
S.E. Harding
Keyword(s):  
Structural Features ◽  
Water Soluble ◽  
Water Soluble P ◽  
Soluble P

A route to virtually unlimited functionalization of water-soluble p-sulfonatocalix[4]arenes

2020 ◽  
Vol 56 (29) ◽  
pp. 4122-4125
Author(s):  
Alexander Gorbunov ◽  
Anna Iskandarova ◽  
Kirill Puchnin ◽  
Valentine Nenajdenko ◽  
Vladimir Kovalev ◽  
...  
Keyword(s):  
Water Soluble ◽  
Reaction Sequence ◽  
Water Soluble P ◽  
Cuaac Reaction ◽  
Soluble P

Diverse narrow-rim derivatives can be easily prepared from p-sulfonatocalix[4]arenes using the propargylation/CuAAC reaction sequence.

Mechanochemical Activation and Characterization of Low-Medium Grade Phosphorite Ore

2013 ◽  
Vol 690-693 ◽  
pp. 3529-3532
Author(s):  
Yu Xing ◽  
Hong Gao ◽  
Yuan Fang Ying ◽  
De Zheng Qu
Keyword(s):  
Mechanochemical Activation ◽  
Planetary Mill ◽  
Water Soluble ◽  
Particle Sizes ◽  
Leaching Rate ◽  
Activation Time ◽  
Activation Effect ◽  
Water Soluble P ◽  
Soluble P

The activation effect of ball-to-powder ratio and activation time on phosphorite ore that takes place in mechanochemical activation has been investigated in present paper, which is carried out in a planetary mill AGO-II. The results show that, particle sizes decreased after activation; the leaching rate of water-soluble P2O5 increased 4.6 percentage as ball-to-powder ratio rose from 8:1 to 40:1; the activated particle of samples has been highly dispersed, while the leaching rate of water-soluble P2O5 reached 10.1% after milling 15 minutes during activation, which was 4 times as high as the un-activated samples. The results show a potential utilization of low-medium grade phosphorite ore with mechanochemical activation directly.

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