Effectiveness of two partially acidulated rock phosphates, coastal superphosphate and Ecophos, compared with North Carolina reactive rock phosphate and superphosphate

1994 ◽  
Vol 38 (1) ◽  
pp. 29-45 ◽  
Author(s):  
M. D. A. Bolland
Keyword(s):  
North Carolina ◽  
Rock Phosphate ◽  
Rock Phosphates ◽  
Coastal Superphosphate

scholarly journals ALTERNATIVE PHOSPHATIC FERTILISERS FOR HILL COUNTRY

1984 ◽  
pp. 107-115
Author(s):  
N.S. Percival ◽  
M.B. O'Connor ◽  
J.P. Every ◽  
S.S.S. Rajan
Keyword(s):  
North Carolina ◽  
Rock Phosphate ◽  
Residual Effects ◽  
Agronomic Effectiveness ◽  
Single Superphosphate ◽  
Rock Phosphates ◽  
Hill Country ◽  
Phosphorus Sources ◽  
Second Year

The role of alternative phosphorus sources to single superphosphate as a maintenance fertiliser for hill country was evaluated in five experiments between 1986 1982. The experiments were located at Gisborne, Rotorua and Te Kuiti. Reactive rock phosphate-sulphur granules (previously known as biosuper) were as effective as superphosphate in the year of application, but the reactive rock phosphates applied alone were as effective on only two of the sites. Superphosphate/reactive rock mixtures were less effective than superphosphate. While most fertilisers had substantial residual effects in the second year after application there was no clear pattern between materials. When taken over two years, a single biennial application of all fertilisers was at least as effective as two annual dressings at half the rate. The role of alternative phosphorus fertilisers is discussed in terms of their cost and agronomic effectiveness, the requirements for other elements,and the structure of the present fertiliser industry. Keywords: superphosphate, phosphorus, phosphatic fertilisers, biosuper, hill country, Sechura, North Carolina, Jordan.

scholarly journals Phosphorus availability of rock phosphates as compared with feed-grade phosphates for swine

2009 ◽  
Vol 38 (1) ◽  
pp. 90-98 ◽  
Author(s):  
Luiz Waldemar de Oliveira Souza ◽  
Anibal de Sant'Anna Moretti ◽  
Fernanda Marcussi Tucci ◽  
Nedilse Helena de Souza ◽  
Paulo Ademar Martins Leal ◽  
...  
Keyword(s):  
Rock Phosphate ◽  
Breaking Strength ◽  
Basal Diet ◽  
Relative Bioavailability ◽  
Phosphorus Addition ◽  
Rock Phosphates ◽  
Bone Parameters ◽  
Bone Ash ◽  
Calcium Phosphorus ◽  
Made In

One hundred ninety two swine were used in a trial to assess the relative bioavailability of phosphorus (RBP) in six phosphate sources. Phosphates were three feed grade phosphates (FP), two made in Brasil, and one USA made, and three rock phosphate samples (RP) originated from two mines sites in Brasil, and one mine site in Israel. Levels of calcium, phosphorus and fluorine in RP were 29, 12 and 1.7% (RP source 1), 33, 14 and 1.4% (RP source 2), and 30, 14 and 3.6% (RP source 3), respectively. Pigs were fed a corn-soybean meal basal diet (18% CP, 0.95% Lys, 0.75% Ca, 0.37% P) or the basal diet with 0.15% P from a standard purified grade calcium phosphate (SP), or with 0.15% P from experimental FP or RP. Each diet was fed to six pen replicates of four pigs per pen for 35 days (14.4 to 39.9 kg). Weight gain (WG), feed/gain (FG), plasma P (PP), bone ash (BA), and breaking strength of metacarpals and metatarsals (BS-MM) and femurs (BS-F) were improved by phosphorus addition. However, performance and bone parameters were depressed by RP, as compared to FP dietary supplementation. WG, BA, BS-MM and BS-F were regressed to P added, and slope-ratios were calculated to assess RBP in the FP and RP sources. The average bioavailability of P in the FP and RP sources, relative to SP, were 89 and 49% (WG), 112 and 49% (BA), 78 and 28% (BS-MM), and 101 and 52% (BS-F), respectively. Low animal performance and bone strength related to toxicity should be expected if rock phosphates are used to feed pigs.

scholarly journals Field experiments on phosphate fertilizers: A joint investigation

1956 ◽  
Vol 48 (1) ◽  
pp. 74-103 ◽  
Author(s):  
G. W. Cooke
Keyword(s):  
Rock Phosphate ◽  
Field Experiments ◽  
Acid Soils ◽  
Water Soluble ◽  
Dicalcium Phosphate ◽  
Low Grade ◽  
Basic Slag ◽  
Phosphate Fertilizers ◽  
Rock Phosphates ◽  
Joint Investigation

The results of over 400 field experiments testing different kinds of phosphate fertilizers are summarized and are discussed with special reference to the reactions of the soils used. The classifications were:‘very acid’ soils—pH below 5·5, ‘acid soils’— pH 5·6 to 6·5, neutral soils—pH over 6·5. All comparisons are made in terms of fertilizers supplying the same amounts of total phosphorus.In war-time experiments Gafsa and Morocco rock phosphates were about two-thirds as efficient as superphosphate for swedes and turnips grown on very acid soils. In 1951–3 experiments on very acid and acid soils Gafsa phosphate was practically equivalent to superphosphate for swedes, but for potatoes it was as effective as only one-third as much phosphorus supplied as superphosphate; on neutral soils Gafsa phosphate was useless. For establishing grassland on acid soils Gafsa and Morocco phosphate were equivalent to about onethird as much phosphorus supplied as high-soluble basic slag. Rock phosphates were somewhat more effective for promoting growth of established grassland but they remained inferior to high-soluble basic slags and to superphosphate. Curacao rock phosphate was roughly equivalent to Gafsa phosphate for swedes and grass. Florida pebble phosphate was much less effective and was judged unsuitable for direct application. Mixtures of rock phosphate with superphosphate were not more efficient than equivalent amounts of the separate components used correctly.Silicophosphate was practically as effective as superphosphate for swedes grown on very acid and acid soils; it was less efficient on neutral soils. For potatoes silicophosphate was nearly as effective as superphosphate on very acid soils; it was much less efficient on acid and neutral soils. Silicophosphate was roughly equivalent to high-soluble basic slag for grassland.Mixtures of superphosphate with lime, serpentine, and low-grade basic slag were prepared, most of the water-soluble phosphorus being converted to insoluble forms. In experiments on swedes and potatoes these basic superphosphates were not superior to untreated superphosphate. For establishing grassland on very acid soils, the mixtures were slightly superior to ordinary superphosphate.Dicalcium phosphate was practically equivalent to superphosphate for swedes on all groups of soils. For potatoes dicalcium phosphate was more efficient than superphosphate on very acid soils, on less acid and neutral soils it was inferior to superphosphate.

Residual value for wheat of phosphorus from calciphos, Duchess rock phosphate and triple superphosphate on a lateritic soil in south-western Australia

1985 ◽  
Vol 25 (1) ◽  
pp. 198 ◽  
Author(s):  
MDA Bolland
Keyword(s):  
Western Australia ◽  
Rock Phosphate ◽  
Phosphorus Content ◽  
Lateritic Soil ◽  
Triple Superphosphate ◽  
Phosphorus Fertilizer ◽  
Rock Phosphates ◽  
Christmas Island ◽  
Residual Values ◽  
North Western

The residual values of phosphorus from triple superphosphate and from three rock phosphates were compared in a 4-year field experiment with wheat, grown on a phosphorus deficient lateritic soil in south-western Australia. The three rock phosphate fertilizers were an apatitic rock phosphate originating from the Duchess deposit in north-western Queensland, and calcined (500�C) Christmas Island C-grade ore as a powder and as pellets. Five rates of each fertilizer were applied at the commencement of the experiment and their effectiveness was calculated from data on yield of dried plant tops, grain yield, and bicarbonate soluble phosphorus extracted from the soil. Triple superphosphate was the most effective phosphorus fertilizer initially, but its effectiveness decreased markedly with time. The effectiveness of the three rock phosphates was initially very low, and remained approximately constant for the duration of the experiment. The yield of dried plant tops depended upon their phosphorus content and this relationship was independent of the phosphorus fertilizer used.

scholarly journals Solubility of Rock Phosphate and its Effect to the Growth and Yield of Maize on Ultisols

2008 ◽  
Vol 13 (1) ◽  
pp. 11-22
Author(s):  
Antonius Kasno ◽  
Diah Setyorini ◽  
Sutisni Dwiningsih
Keyword(s):  
Rock Phosphate ◽  
Acid Soil ◽  
Block Design ◽  
Soil Samples ◽  
Growth And Yield ◽  
Content Increase ◽  
Rock Phosphates ◽  
Maize Growth ◽  
P Content ◽  
P Fertilizer

Phosphor is a macro nutrients and it becomes the main limiting factor for maize growth on Ultisols. Rock phosphate is one of P fertilizer sources contains high P and Ca content, slow release and soluble under acid condition, suitable for acid soil. The objective of this research is to study the solubility of rock phosphate and its influence to the growth and yield of maize on Ultisols.  This research was conducted in the research laboratory and the green house of Indonesia Soil Research Institute (ISRI). Ultisols soil samples were taken from oil palm plantation in North Sumatera. Christmas Island Rock Phosphate (CIRP) and Tunisia rock phosphate was used in this research. There are two activity conducted simultaneously, which is application of rock phosphate on Ultisols under plant indicator and without plant. The experimental design is randomized complete block design with 5 treatments and 3 replications. The pot experiment without plant was conducted using1 kg of soil sample mixed with rock phosphate treatment and placed into plastic plot.  During 3 months of incubation, soil water content was maintained under field capacity by aquadest.  The dosages of P fertilizer were 0, 157.6 and 315.2 kg P2O5 ha-1. Soil samples were taken on 1, 2, and 3 months after P fertilization for measuring pH, P content (by HCl 25 %, Bray 1 and Olsen extraction), P-inorganic fractionation (Al-P, Fe-P, Rs-P and Ca-P), exchangeable acidity (Al and H), Al and free of Fe oxide. The pot experiments with maize were conducted using 7.5 kg soil samples mixed with 2 different rock phosphates as a treatment. The dosages of rock phosphate were similar with experiment 1. Urea 300 kg and 150 kg KCl ha1 were applied as a basal fertilizer. Maize was planted two seed per pot and maintain until harvest time. The result of the research shows that soil P content increase with RP application, Tunisia rock phosphate give higher response than the CIRP. Direct application of rock phosphate with Fe and Al content did not increase significantly the Aldd, Al2O3 and Fe2O3 content on soil.  Application of CIRP and Tunisia rock phosphate increased maize growth and yield significantly.

scholarly journals OUR PRESENT KNOWLEDGE OF THE VALUE OF ROCK PHOSPHATES

1937 ◽  
pp. 32-41
Author(s):  
A.W. Hudson ◽  
J.W. Woodcock
Keyword(s):  
New Zealand ◽  
Rock Phosphate ◽  
Present Knowledge ◽  
Rock Phosphates ◽  
Factors Influencing

Before discussing such information as is available regarding the effectiveness and use of rock phosphates in New Zealand, a few remarks relative to the world's consumption of phosphate in different forms and the factors influencing the availability of rock phosphate, etc., will not be out of place.

Beneficiation of apatite rock phosphates by calcination: effects on chemical properties and fertiliser effectiveness

Soil Research ◽  
2001 ◽  
Vol 39 (2) ◽  
pp. 397 ◽  
Author(s):  
H. H. Lim ◽  
R. J. Gilkes
Keyword(s):  
North Carolina ◽  
Citric Acid ◽  
Surface Area ◽  
Chemical Properties ◽  
Direct Application ◽  
X Ray Diffraction ◽  
Agronomic Effectiveness ◽  
Rock Phosphates ◽  
Christmas Island ◽  
Crystal Properties

Apatitic rock phosphates (RP) are commonly calcined to remove impurities and to increase phosphorus (P) concentration but calcination decreases the agronomic effectiveness of RPs used for direct application to soils. This study investigated the effect of calcination on 6 apatite RPs (Christmas Island A-ore, Egypt, Morocco, North Carolina, Queensland, and Sechura). RPs were uncalcined (25°C) and calcined at 500°C, 900°C, and 1100°C. They were evaluated by X-ray diffraction (XRD) and BET-N 2 surface area technique. P dissolution in 2% citric acid with a 128 h extraction time was measured. Chemical results were compared with those from a plant growth experiment, where wheat was fertilised with the calcined RP products. Calcination at 1100°C reduced the agronomic effectiveness of apatite RPs by about 90%, by altering the crystal properties and the particle size of the RPs. Unit-cell a dimension increased from values of 9.324—9.375 Å to approximately 9.38 Å, indicating that the carbonate containing apatite RPs altered to less-soluble fluorapatite. Apatite average crystal size (coherently diffracting zone) more than doubled and BET-N 2 specific surface area decreased by 95%, due to crystal growth and sintering. Consequently, the extent of dissolution in 2% citric acid and agronomic effectiveness decreased substantially. Calcination at 500°C and 900°C produced similar but smaller changes in mineral properties. It is concluded that beneficiation of apatitic RP by calcination will adversely affect the agronomic effectiveness of RP used for direct application to soils.

The effect of rock phosphate-enriched compost on the yield and phosphorus nutrition of rye grass

1995 ◽  
Vol 10 (2) ◽  
pp. 82-87 ◽  
Author(s):  
C.P. Singh ◽  
A. Amberger
Keyword(s):  
Formic Acid ◽  
Rock Phosphate ◽  
Water Soluble ◽  
Single Superphosphate ◽  
Rock Phosphates ◽  
Rye Grass ◽  
Greenhouse Study ◽  
Soil Calcium ◽  
Loam Soil ◽  
Soluble P

AbstractWe evaluated the effect of compost enriched with rock phosphate on the yield and phosphate nutrition of rye grass in a calcareous clay loam soil. Enriched compost was prepared by composting either Mussoorie rock phosphate (MP) or Hyper rock phosphate (HP) separately with wheat straw for up to 120 days. A significant amount of insoluble P was solubilized from both kinds of rock phosphates and converted to water soluble, organic, and formic acid soluble P fractions during composting. MP-enriched compost (MPEC) and HP-enriched compost (HPEC) contain 0.30% and 0.34% water soluble P205, 1.94% and 1.42% organic P2O5 2.82% and 3.28% formic acid soluble P2O5, and 1.76% and 1.18% insoluble P2O5, respectively. In a greenhouse study, the yield of ryegrass (three cuttings) with both enriched composts was not significantly different from that of single superphosphate fertilizer (SSP). Phosphorus fractions of soil before sowing and after harvesting the rye grass showed that fixation of P with native soil calcium was much higher with SSP than with enriched composts. No significant differences were observed between MRP and HRP.

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