Agronomy, modelling and economics of reactive phosphate rocks as slow-release phosphate fertilizers for grasslands

1993 ◽  
Vol 36 (3) ◽  
pp. 229-238 ◽  
Author(s):  
A. G. Sinclair ◽  
P. D. Johnstone ◽  
L. C. Smith ◽  
M. B. O'Connor ◽  
L. Nguyen
Keyword(s):  
Slow Release ◽  
Phosphate Rocks ◽  
Phosphate Fertilizers ◽  
Reactive Phosphate

Use of partially acidulated phosphate rocks as phosphate fertilizers

1993 ◽  
Vol 35 (1-2) ◽  
pp. 47-59 ◽  
Author(s):  
S. S. S. Rajan ◽  
B. C. Marwaha
Keyword(s):  
Phosphate Rocks ◽  
Phosphate Fertilizers ◽  
Partially Acidulated Phosphate Rocks

scholarly journals Uranium, thorium and potassium contents and radioactive equilibrium states of the uranium and thorium series nuclides in phosphate rocks and phosphate fertilizers.

RADIOISOTOPES ◽  
1985 ◽  
Vol 34 (10) ◽  
pp. 529-536 ◽  
Author(s):  
Kazuhisa KOMURA ◽  
Mikio YANAGISAWA ◽  
Jiro SAKURAI ◽  
Masanobu SAKANOUE
Keyword(s):  
Equilibrium States ◽  
Phosphate Rocks ◽  
Phosphate Fertilizers ◽  
Radioactive Equilibrium ◽  
Thorium Series

Determination of total arsenic and arsenic (III) in phosphate fertilizers and phosphate rocks by HG-AAS after multivariate optimization based on Box-Behnken design

Talanta ◽  
2009 ◽  
Vol 80 (2) ◽  
pp. 974-979 ◽  
Author(s):  
Samuel M. Macedo ◽  
Raildo M. de Jesus ◽  
Karina S. Garcia ◽  
Vanessa Hatje ◽  
Antonio F. de S. Queiroz ◽  
...  
Keyword(s):  
Total Arsenic ◽  
Phosphate Rocks ◽  
Multivariate Optimization ◽  
Phosphate Fertilizers ◽  
Box Behnken Design

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.

National Reactive Phosphate Rock Project —aims, experimental approach and site characteristics

1997 ◽  
Vol 37 (8) ◽  
pp. 885 ◽  
Author(s):  
M. J. McLaughlin ◽  
N. K. Fleming ◽  
P. G. Simpson ◽  
M. D. A. Bolland ◽  
R. J. Gilkes ◽  
...  
Keyword(s):  
North Carolina ◽  
Formic Acid ◽  
Phosphate Rock ◽  
Soil Phosphorus ◽  
Triple Superphosphate ◽  
Phosphate Rocks ◽  
Agronomic Effectiveness ◽  
North Carolina Phosphate Rock ◽  
Reactive Phosphate ◽  
Reactive Phosphate Rock

Summary. Field-based cutting trials, which formed part of the National Reactive Phosphate Rock Project, were established across Australia in a range of environments to evaluate the agronomic effectiveness of 5 phosphate rocks, and 1 partially acidulated phosphate rock, relative to either single superphosphate or triple superphosphate. The phosphate rocks differed in reactivity. Sechura (Bayovar) and North Carolina phosphate rocks were highly reactive (>70% solubility in 2% formic acid), whilst Khouribja (Moroccan) and Hamrawein (Egypt) phosphate rock were moderately reactive. Duchess phosphate rock from Queensland was relatively unreactive (<45% solubility in 2% formic acid). Phosphate rock effectiveness was assessed by measuring pasture production over a range of phosphorus levels, and by monitoring bicarbonate-soluble phosphorus extracted from soil samples collected before the start of each growing season. Other treatments included single large applications of triple superphosphate, partially acidulated phosphate rock and North Carolina phosphate rock applied at 2 rates, and the application of monocalcium phosphate and North Carolina phosphate rock sources without sulfur to evaluate the importance of sulfur in the potential use of phosphate rock fertilisers at each site. A broad range of environments were represented over the 30 sites which were based on pastures using annual and/or perennial legumes and perennial grasses. Rainfall across the network of sites ranged from 560 to 4320 mm, soil pH (CaCl2) from 4.0 to 5.1, and Colwell-extractable phosphorus ranged from 3 to 47 µg/g before fertiliser application. Two core experiments were established at each site. The first measured the effects of phosphate rock reactivity on agronomic effectiveness, while the second measured the effects of the degree of water solubility of the phosphorus source on agronomic effectiveness. The National Reactive Phosphate Rock Project trials gave the opportunity to confirm the suitability of accepted procedures to model fertiliser response and to develop new approaches for comparing different fertiliser responses. The Project also provided the framework for subsidiary studies such as the effect of fertiliser source on soil phosphorus extractability, cadmium and fluorine concentrations in herbage, evaluation of soil phosphorus tests, and the influence of particle size on phosphate rock effectiveness. The National Reactive Phosphate Rock Project presents a valuable model for a large, Australia-wide, collaborative team approach to an important agricultural issue. The use of standard and consistent experimental methodologies at every site ensured that maximum benefit was obtained from data generated. The aims, rationale and methods used for the experiments across the network are presented and discussed.

The use of substitution values for characterising fertiliser performance

1997 ◽  
Vol 37 (8) ◽  
pp. 913
Author(s):  
D. A. Ratkowsky ◽  
S. B. Tennakoon ◽  
P. W. G. Sale ◽  
P. G. Simpson
Keyword(s):  
Phosphate Rock ◽  
Statistical Tests ◽  
Effective Means ◽  
Field Trials ◽  
Water Soluble ◽  
Soluble Phosphate ◽  
Phosphate Rocks ◽  
High Performing ◽  
Reactive Phosphate ◽  
Reactive Phosphate Rock

Summary. The substitution value, or horizontal comparison between a fertiliser and some high-performing reference fertiliser, is shown to be a powerful and effective means of ranking the performance of various reactive phosphate rock fertilisers relative to a water-soluble phosphate such as a superphosphate. To take account of the variability due to random error in fertiliser field trials, the use of a standardised score, one measuring the relative departure of the substitution value from that expected for the standard fertiliser, is shown to be a suitable statistic for general use. Cluster analyses using these z-scores as input data can lead to appropriate decision making such as, for example, grouping experimental sites into: (i) those which perform as well as water-soluble phosphate, (ii) those which are somewhat worse than water-soluble phosphate, and (iii) those which are much worse than water-soluble phosphate. Substitution values obtained for different reactive phosphate rocks were compared both within and between sites, using appropriate statistical tests of significance. This approach assisted in ranking the performance of the 5 reactive phosphate rocks and the partially acidulated phosphate rock studied in the National Reactive Phosphate Rock Project, and helped predict which ones are likely to be suitable for use in differing environments.

scholarly journals Long-term fate of fertilizer sulfate- and elemental S in co-granulated fertilizers

2021 ◽  
Author(s):  
Fien Degryse ◽  
Roslyn Baird ◽  
Ivan Andelkovic ◽  
Michael J. McLaughlin
Keyword(s):  
Slow Release ◽  
First Year ◽  
Warm Climate ◽  
Monoammonium Phosphate ◽  
Phosphate Fertilizers ◽  
Organic S ◽  
Slow Release Fertilizer ◽  
S Uptake ◽  
S Cycling

AbstractIn previous studies, we assessed sulfur (S) uptake by crops from elemental S (ES) and sulfate-S (SO4-S) in S-fortified monoammonium phosphate fertilizers over two years. The recovery by the crop ranged from 16 to 28% for ES and from 9 to 86% for SO4-S. Here, we used a model which takes into account organic S cycling, SO4-S leaching and ES oxidation to explain the observed recoveries. Higher recoveries of ES than SO4-S in two of the four sites could be explained by partial leaching of SO4-S and relatively fast oxidation of ES, due to a warm climate and high S-oxidizing soils. The same model was used for longer-term (5-year) predictions, and a sensitivity analysis was carried out. The size of the labile soil S pool and total S uptake strongly affected the recovery of both SO4-S and ES. Predicted recoveries after 5 years were over threefold higher for a small than for a large labile organic S pool and for a high-uptake than for a low-uptake scenario. Leaching mainly affected SO4-S, with predicted recoveries halved under a high-leaching scenario. Slow oxidation resulted in recoveries in the first year being fourfold lower for ES than for SO4-S or even lower in case of a long lag-time. However, it is predicted that total recoveries of ES will eventually reach those of SO4-S or exceed them if there is SO4-S leaching. Our model demonstrates that long-term trials are needed to evaluate the true effectiveness of a slow-release fertilizer source such as ES.

Radiological characterization of phosphate rocks, phosphogypsum, phosphoric acid and phosphate fertilizers in Morocco: An assessment of the radiological hazard impact on the environment

2020 ◽  
Vol 27 ◽  
pp. 3234-3242 ◽  
Author(s):  
K. Qamouche ◽  
A. Chetaine ◽  
A. Elyahyaoui ◽  
A. Moussaif ◽  
R. Touzani ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Radiological Hazard ◽  
Phosphate Rocks ◽  
Phosphate Fertilizers ◽  
Radiological Characterization

Liming effect of reactive phosphate rocks: A laboratory evaluation

1995 ◽  
pp. 641-645 ◽  
Author(s):  
P. Loganathan ◽  
M. J. Hedley ◽  
S. Saggar
Keyword(s):  
Laboratory Evaluation ◽  
Phosphate Rocks ◽  
Reactive Phosphate

Radiological impact of natural radioactivity in Egyptian phosphate rocks, phosphogypsum and phosphate fertilizers

2017 ◽  
Vol 123 ◽  
pp. 121-127 ◽  
Author(s):  
S.M. El-Bahi ◽  
A. Sroor ◽  
Gehan Y. Mohamed ◽  
N.S. El-Gendy
Keyword(s):  
Natural Radioactivity ◽  
Phosphate Rocks ◽  
Phosphate Fertilizers ◽  
Radiological Impact
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