The effect of chemical extractant on the estimation of rock phosphate fertilizer dissolution

Soil Research ◽  
1984 ◽  
Vol 22 (4) ◽  
pp. 475 ◽  
Author(s):  
JC Hughes ◽  
RJ Gilkes
Keyword(s):  
Solid Solution ◽  
Rock Phosphate ◽  
Acid Soils ◽  
Barium Chloride ◽  
Phosphate Fertilizer ◽  
Direct Application ◽  
Rock Phosphates ◽  
Chemical Extractants ◽  
The Difference ◽  
The Tropics

Rock phosphates have been widely used in the acid soils of the tropics as direct application fertilizers. To estimate their rate and extent of dissolution various chemical extractants have been used. However, the acidic or inadequately buffered nature of these extractants promote extensive dissolution of the apatite and may result in a gross overestimate of the amount of rock phosphate dissolved. To overcome this problem, it is proposed that the soil is shaken for 1 h in 2 M barium chloride buffered at pH 8.1 with triethanolamine (solid : solution ratio of 1:10) and calcium determined in the filtered supernatant. The difference in extractable calcium between fertilized and unfertilized soil is a measure of the dissolution of the rock phosphate.

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.

Granular reactive apatite rock phosphate is not an effective phosphorus fertilizer in the short term on lateritic soils in south-western Australia.

1986 ◽  
Vol 26 (2) ◽  
pp. 217 ◽  
Author(s):  
MDA Bolland ◽  
AJ Weatherley ◽  
RJ Gilkes ◽  
JW Bowden
Keyword(s):  
Western Australia ◽  
Rock Phosphate ◽  
Field Experiments ◽  
Maximum Yield ◽  
Subterranean Clover ◽  
Phosphate Fertilizer ◽  
Carbonate Apatite ◽  
Rock Phosphates ◽  
Fertilizer Effectiveness ◽  
Eastern Australia

The effectiveness, as a phosphate fertilizer, of granular reactive rock phosphate (carbonate substituted apatite from North Carolina, U.S.A.), granular triple superphosphate and partly powdered Duchess non-reactive rock phosphate (low carbonate apatite from north-eastern Australia) was compared in three field experiments on different soil types in different climatic regions of south-western Australia. Calciphos (finely ground calcined crandallite rock phosphate from Christmas Island) was included in one experiment. The rock phosphates were incorporated into the soil and their effectiveness was compared with both topdressed and incorporated superphosphate. Different species were grown at each site (barley, triticale and subterranean clover). As determined on the basis of relative amounts of fertilizer required for constant yield, the effectiveness of all the rock phosphates relative to incorporated superphosphate was very low at each site throughout the growth of each species. Fertilizer effectiveness of rock phosphates was about one-fifth that of superphosphate for barley, and one-tenth for triticale and clover. The maximum yield obtained from rock phosphate was generally 88-100% that obtained from superphosphate. Incorporation did not greatly affect the effectiveness of superphosphate.

Variasi Penambahan Tepung Daun Kelor (Moringa Oleifera Lam.) pada Pembuatan Flakes Ditinjau dari Sifat Fisik, Sifat Organoleptik dan Kadar Kalsium

2017 ◽  
Vol 19 (1) ◽  
pp. 31-35
Author(s):  
Frieda Rosita Majid ◽  
Nur Hidayat ◽  
Waluyo Waluyo
Keyword(s):  
Physical Characteristic ◽  
Nutritional Value ◽  
Calcium Content ◽  
Organoleptic Characteristics ◽  
High Calcium ◽  
Randomized Experimental Design ◽  
Leaf Powder ◽  
The Difference ◽  
The Tropics ◽  
Moringa Oleifera Lam

Background:Moringa (Moringaoleifera Lam.) Is a plant of high nutritional value, grows scattered in the tropics and sub-tropics, but utilization is still low. Each section has its benefits Moringa one part is the Moringa leaves contain a high calcium. In 100 grams of material, fresh Moringa leaves contain as much as 440 mg of calcium in the form of flour whereas if it contains as much as 2,003 mg of calcium. One of its use in the manufacture of flakes added. Objective: Know the difference physical harateristi, organoleptic characteristic and calcium levels in flakes variations addition of Moringa leaf powder. Methods: The study is a randomized experimental design with simple, includes four kinds of treatments, two replications with two experimental units. Observations of physical characteristic were analyzed by descriptive, the organoleptic characteristic of data analysis using statistical test Kruskal-Wallis continued Mann-Whitney and methods of test calcium content using permanganometri then the data were analyzed descriptive. Results: The physical characteristics of flakes greenish-yellow, slightly fragrant aroma typical of flakes, rather unpleasant taste typical of Moringa leaves and a slightly crunchy texture. Organoleptic characteristics the color of flakes with moringa leaf powder 5%, the aroma of the flakes without addition moringa leaf powder, the flavour of flakes with additions moringa leaf powder 5% and the texture of flakes with additions moringa leaf powder 7,5% most prefered panelist and high levels calcium of flakes with additions 10% moringa leaf powder. Conclusion: There is a difference variations addition of moringa leaf powder on physical, organoleptic characteristic (color) and the level of calcium flakes.Flakes with the addition of 5% moringa leaf powder is the most prefered panelist.   Keywords:Moringa Leaf Flour, Flakes, Physical characteristic, organoleptic, Calcium

ETUDE DU POUVOIR NUTRITIF EN PHOSPHORE DE CERTAINS SOLS DU QUEBEC A L'AIDE DU 32P

1976 ◽  
Vol 56 (3) ◽  
pp. 285-291
Author(s):  
B. TOUATI ◽  
C. PLENCHETTE ◽  
M. TABI
Keyword(s):  
Soil Phosphorus ◽  
Phosphate Fertilizer ◽  
Soil Types ◽  
K Value ◽  
Type Experiment ◽  
A Value ◽  
The Difference ◽  
The Way

In a pot-type experiment with ryegrass, 32P was used to label isotopically exchangeable soil phosphorus as well as a phosphate fertilizer. The tagging of both forms of phosphorus enable us to determine the pool (L) for soil reserves and the A value which is the availability of these reserves in the presence of fertilizer. The authors establish correlations between the ratio K = L/A and the assimilable phosphorus as determined by the Bray II method, and also between K and the "extra" phosphorus. The authors state that the latter was the difference between the plant phosphorus with and without fertilizer. From this study it is concluded: (1) that the K value seems to be a better criterion than the amount of assimilable phosphorus to estimate the phosphorus fertility of a soil; (2) that the study of the variation of the K value according to the soil types informs us about the reserves behavior and about the way of nutrition for the plant. The calculation of the K value is aimed toward a more adequate fertilization for given types of soil.

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 Selection of inorganic-based fertilizers in forward osmosis for water desalination

2015 ◽  
Vol 4 (2) ◽  
pp. 319-329 ◽  
Author(s):  
Tripti Mishra ◽  
RK Srivastava
Keyword(s):  
Molecular Weight ◽  
Water Flux ◽  
Forward Osmosis ◽  
Direct Application ◽  
Water Desalination ◽  
Performance Ratio ◽  
Low Molecular Weight ◽  
Inorganic Fertilizers ◽  
The Difference ◽  
Selection Of

The current study aims at the selection of an appropriate draw solute for forward osmosis process. Separation and recovery of the draw solute are the major criteria for the selection of draw solute for forward osmosis process. Therefore in this investigation six inorganic fertilizers draws solute were selected. The selections of inorganic fertilizers as draw solute eliminate the need of removal and recovery of draw solute from the final product. The final product water of forward osmosis process has direct application in agricultural as nutrient rich water for irrigation. These inorganic fertilizers were tested based on their water extraction (water flux) capacity. This experimental water flux was compared with the observed water flux. It was noted that the observed water flux is much higher than the attained experimental water flux. The difference of these two fluxes was used to calculate the performance ratio of each selected fertilizer. Highest performance ratio was shown by low molecular weight compound ammonium nitrate (22.73) and potassium chloride (21.03) at 1 M concentration, whereas diammonium phosphate (DAP) which has highest molecular weight among all the selected fertilizer show the lowest performance ratio (10.02) at 2 M concentration. DOI: http://dx.doi.org/10.3126/ije.v4i2.12660 International Journal of Environment Vol.4(2) 2015: 319-329

scholarly journals Estimating the Ice Crystal Enhancement Factor in the Tropics

2011 ◽  
Vol 68 (7) ◽  
pp. 1424-1434 ◽  
Author(s):  
Xiping Zeng ◽  
Wei-Kuo Tao ◽  
Toshihisa Matsui ◽  
Shaocheng Xie ◽  
Stephen Lang ◽  
...  
Keyword(s):  
Ice Crystal ◽  
Middle Latitudes ◽  
Ice Nuclei ◽  
Significant Difference ◽  
Physically Based ◽  
Cloud Resolving Model ◽  
The Difference ◽  
The Tropics ◽  
Cloud Condition

Abstract The ice crystal enhancement (IE) factor, defined as the ratio of the ice crystal to ice nuclei (IN) number concentrations for any particular cloud condition, is needed to quantify the contribution of changes in IN to global warming. However, the ensemble characteristics of IE are still unclear. In this paper, a representation of the IE factor is incorporated into a three-ice-category microphysical scheme for use in long-term cloud-resolving model (CRM) simulations. Model results are compared with remote sensing observations, which suggest that, absent a physically based consideration of how IE comes about, the IE factor in tropical clouds is about 103 times larger than that in midlatitudinal ones. This significant difference in IE between the tropics and middle latitudes is consistent with the observation of stronger entrainment and detrainment in the tropics. In addition, the difference also suggests that cloud microphysical parameterizations depend on spatial resolution (or subgrid turbulence parameterizations within CRMs).

scholarly journals The 2015–2016 carbon cycle as seen from OCO-2 and the global in situ network

2019 ◽  
Vol 19 (15) ◽  
pp. 9797-9831 ◽  
Author(s):  
Sean Crowell ◽  
David Baker ◽  
Andrew Schuh ◽  
Sourish Basu ◽  
Andrew R. Jacobson ◽  
...  
Keyword(s):  
Carbon Cycle ◽  
Carbon Sink ◽  
Total Carbon ◽  
Transport Models ◽  
New Information ◽  
Global Coverage ◽  
The Difference ◽  
The Tropics

Abstract. The Orbiting Carbon Observatory-2 has been on orbit since 2014, and its global coverage holds the potential to reveal new information about the carbon cycle through the use of top-down atmospheric inversion methods combined with column average CO2 retrievals. We employ a large ensemble of atmospheric inversions utilizing different transport models, data assimilation techniques, and prior flux distributions in order to quantify the satellite-informed fluxes from OCO-2 Version 7r land observations and their uncertainties at continental scales. Additionally, we use in situ measurements to provide a baseline against which to compare the satellite-constrained results. We find that within the ensemble spread, in situ observations, and satellite retrievals constrain a similar global total carbon sink of 3.7±0.5 PgC yr−1, and 1.5±0.6 PgC yr−1 for global land, for the 2015–2016 annual mean. This agreement breaks down in smaller regions, and we discuss the differences between the experiments. Of particular interest is the difference between the different assimilation constraints in the tropics, with the largest differences occurring in tropical Africa, which could be an indication of the global perturbation from the 2015–2016 El Niño. Evaluation of posterior concentrations using TCCON and aircraft observations gives some limited insight into the quality of the different assimilation constraints, but the lack of such data in the tropics inhibits our ability to make strong conclusions there.

ESTIMATION OF THE INORGANIC AND ORGANIC pH-DEPENDENT CATION EXCHANGE CAPACITY OF THE B HORIZONS OF PODZOLIC AND BRUNISOLIC SOILS

1968 ◽  
Vol 48 (1) ◽  
pp. 53-63 ◽  
Author(s):  
J. S. Clark ◽  
W. E. Nichol
Keyword(s):  
Organic Matter ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Acid Soils ◽  
Exchange Capacity ◽  
Hydrous Oxides ◽  
Before And After ◽  
Ph Dependent ◽  
The Difference ◽  
Wyoming Bentonite

Heating in hydrogen peroxide, dilute oxalic acid, and dilute aluminum oxalate did not change the effective cation exchange capacity (CEC) or the pH-7 CEC of Wyoming bentonite and Alberni clay soil containing excess Al(OH)x. This indicated that treatment of soils with H2O2 to oxidize organic matter and the possible production of oxalates during oxidation did not change the CEC values of the inorganic fraction of soils even if some clay exchange sites were blocked by hydrous oxides of Al.With soils of pH less than approximately 5.4, oxidation of organic matter did not change the effective CECs although the pH-7 CEC values were decreased. Thus, organic matter in acid soils appeared to have little or no effective CEC. Because of this and the negligible effect of H2O2 oxidation on the CEC values of clays, the difference of the pH-7 CEC of soils before and after H2O2 oxidation provided a simple means of estimating the amount of organic pH-dependent CEC in acid soils.The amount of organically derived pH-dependent CEC was determined in a number of soils by means of peroxide oxidation. The technique provided a useful indication of the quantities of sesquioxide–organic matter complexes accumulated in medium- and fine-textured soils.

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