scholarly journals Field evaluation of water or citrate soluble phosphorus in modified phosphate rocks for soybean

2001 ◽  
Vol 58 (1) ◽  
pp. 165-170 ◽  
Author(s):  
Luís Ignácio Prochnow ◽  
José Francisco da Cunha ◽  
Ariel Francisco Candiotti Ventimiglia

Ten P fertilizers were collected (commercial fertilizers) or synthesized (experimental sources) in order to obtain single superphosphates varying in water and citrate solubility. A standard source of P was also produced by crystallization of the water-soluble fraction of a triple superphosphate. Eleven P sources were band applied to a medium textured Xanthic Hapludox, in Bahia, Brazil (low content of resin-extractable P) at a rate of 80 kg ha-1 of NAC + H2O (neutral ammonium citrate plus water) soluble P2O5, with soybean as the crop which was grown to maturity. A check plot (control) was included in the study. Three of the P sources [single superphosphate produced from Araxa phosphate rock (PR), low-grade single superphosphate produced from Lagamar PR and the standard source of P] were also applied at rates to provide 40 and 120 kg ha-1 of NAC + H2O soluble P2O5. Yield of soybean was evaluated by analysis of variance with mean comparison performed utilizing LSD lines, considering the P sources applied at a rate of 80 kg ha-1 of P2O5 + control. Regression procedures were used to study the relation between yield of soybean and rates of P2O5. The fertilizers tested performed equally well as a source of P for soybean. The level of water-soluble P did not influence fertilizer performance.

2010 ◽  
Vol 10 ◽  
pp. 1679-1693
Author(s):  
E. W. Gikonyo ◽  
A. R. Zaharah ◽  
M. M. Hanafi ◽  
A. R. Anuar

The effectiveness of different soil tests in assessing soil phosphorus (P) in soils amended with phosphate rocks (PRs) is uncertain. We evaluated the effects of triple superphosphate (TSP) and PRs on extractable P by conventional soil tests (Mehlich 3 [Meh3] and Bray-1 [B1]) and a nonconventional test (iron oxide–impregnated paper, strip). Extracted amounts of P were in the order: Meh3 >B1 > strip. All the tests were significantly correlated (p= 0.001). Acidic reagents extracted more P from TSP than PRs, while the strip removed equal amounts from the two sources. The P removed by the three tests was related significantly to dry matter yield (DMY), but only in the first harvest, except for B1. Established critical P levels (CPLs) differed for TSP and PRs. In PR-fertilized soils, CPLs were 27, 17, and 12 mg P kg-1soil for Meh3, B1, and strip, respectively, and 42, 31, and 12 mg P kg-1soil, respectively, in TSP-fertilized soils. Thus, the strip resulted in a common CPL for TSP and PRs (12 mg P kg-1soil). This method can be used effectively in soils where integrated nutrient sources have been used, but there is need to establish CPLs for different crops. For cost-effective fertilizer P recommendations based on conventional soil tests, there is a need to conduct separate calibrations for TSP- and PR-fertilized soils.


2003 ◽  
Vol 128 (4) ◽  
pp. 615-620 ◽  
Author(s):  
B. Huang ◽  
S. Kuo ◽  
R. Bembenek

Cadmium (Cd) concentrations in some phosphorus (P) fertilizers may be high enough to cause significant Cd accumulation in plants. A 2-year field experiment was conducted on a Sultan silt loam (Aquandic Xerochrept) to determine how the availability to cucumber (Cucumis sativus L.) of Cd from a triple superphosphate (TSP) and a western phosphate rock (PR) was affected by rate of Cd input and liming. A water-soluble Cd salt, CdCl2, was included for comparison. Cucumber vine growth increased with increasing TSP application rates but was unaffected by the application of PR or CdCl2. Cucumber fruit yield, however, was unaffected by the application of either P fertilizer or CdCl2. Concentrations of Cd in cucumber vine or fruit responded to increased Cd inputs from PR, TSP, or CdCl2, and the vine was the primary sink for Cd that accumulated in the plant. Both vine and fruit Cd correlated better with soil total Cd than with labile Cd extractable by 0.05 m CaCl2 or DTPA (diethylenetriaminepentaacetic acid). A unique characteristic of cucumber vine- or fruit-Cd is that it was unaffected (P > 0.05) by lime rate and Cd source and not closely related to labile or exchangeable Cd as measured by 0.05 m CaCl2, in contrast to previous findings for other vegetable or grain crops. Root exudates could have controlled the solubility of Cd in the soil. The low availability of Cd from these sources to the plant was evidenced by the low uptake coefficient of Cd (0.461 to 1.059) from the soil to the cucumber fruit and low Cd recovery (0.43%) in both vine and fruit of Cd added.


Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1224 ◽  
Author(s):  
Muhammad Izhar Shafi ◽  
Muhammad Adnan ◽  
Shah Fahad ◽  
Fazli Wahid ◽  
Ahsan Khan ◽  
...  

In calcareous soil, the significant portion of applied phosphorus (P) fertilizers is adsorbed on the calcite surface and becomes unavailable to plants. Addition of organic amendments with chemical fertilizers can be helpful in releasing the absorbed nutrients from these surfaces. To check out this problem, a field experiment was conducted for two years to determine the effect of P fertilizers and humic acid (HA) in enhancing P availability in soil and their ultimate effect on growth, yield and P uptake of wheat in calcareous soils. The experiment was comprised of five levels of P (0, 45, 67.5, 90 and 112.5 kg P2O5 ha−1) as a single superphosphate (SSP) and 2 levels of locally produced humic acid (with and without HA) arranged in a two factorial randomized complete block design (RCBD) with three replications. Wheat plant height, spike length, number of grains per spike, 1000-grain weight, grain, straw and biological yield were significantly improved by the addition of HA with SSP. Very often, the performance of 67.5 kg P2O5 ha−1 with HA were either similar or better than 90 or even 112.5 kg P2O5 ha−1 applied without HA. Post-harvest soil organic matter, AB-DTPA extractable and water-soluble P, plant P concentration and its uptake were also significantly improved by the addition of HA with SSP compared to sole SSP application. It was evident that P efficiency could be increased with HA addition and it has the potential to improve crop yield and plants P uptake in calcareous soils.


2001 ◽  
Vol 137 (1) ◽  
pp. 45-54 ◽  
Author(s):  
M. C. MANNA ◽  
P. K. GHOSH ◽  
B. N. GHOSH ◽  
K. N. SINGH

Low organic matter concentration coupled with low native soil phosphorus (P) concentrations is a major constraint limiting the productivity of a soybean–wheat system on Vertisols in the Indian semi-arid tropics. In a 3-year field study (1996–99), the performance of four different composts obtained from legume straw (Glycine max Merr.L), cereal straw (Triticum aestivum), oilseed straw (Brassica juncea L.) and city rubbish were compared, and also with chemical fertilizers in terms of degree of maturity, quality of compost, improvement in soil organic matter, biological activities of soil and yields of soybean and wheat. Phospho-sulpho-nitrocomposts (phosphocomposts) were prepared containing approximately 2·5 to 4·2% P and 1·4 to 2·3% N, in an aerobic decomposition process for 4 months by adding an aqueous slurry of 1:1 (dry weight) cow dung, 2·2% P in the form of low grade Mussorie phosphate rock (7·5% P), 10% pyrite (S, 22·2%) and 0·5% urea N, and bioinoculums such as the cellulose decomposers Paecilomyces fusisporus and Aspergillus awamori, and P-solubilizing organisms i.e. Bacillus polymyxa and Pseudomonas striata. The maturity indexes were strongly associated with the source of materials, chemical composition and degree of decomposition. The matured composts had lower C/N ratios (8·2 to 21·7) and water soluble carbohydrates (0·23 to 0·43%) and larger ratios of cation exchange capacity/total organic carbon (CEC/TOC) and lignin/cellulose than the initial. The matured compost increased total P, water soluble P, citrate soluble P, total N and NO3-N and the application of phosphocompost at the rate of 10 t/ha gave plant growth dry matter accumulation, seed yield and P uptake by soybean equivalent to single superphosphate at 26·2 kg P/ha. The continuous turnover of enriched phosphocompost increased soil microbial biomass C and the activity of enzymes compared to application of chemical fertilizer.


1980 ◽  
Vol 63 (3) ◽  
pp. 546-550 ◽  
Author(s):  
Rose A Sweeney

Abstract A modification of the direct available extraction procedure for P2O5 in fertilizer is presented. The modified extraction is used in our laboratory as a screening procedure to reduce work load associated with the lengthy official method. It is applicable to samples containing diammonium phosphate or other materials except triple superphosphate. Phosphorus is extracted from fertilizers with neutral ammonium citrate without prior removal of the water-soluble fraction. Samples are extracted by shaking 1 hr at 65°C on a water bath. The extract is cooled, diluted to volume, mixed, and an aliquot is taken for analysis. Average recovery of P2O5 from 9 selected Magruder samples by the modified extraction vs. the current official extraction was 99.5%, with a range of 98.7–99.9%. This study shows that the recovery of available P2O5 is not influenced by the level of CI P2O5 in the sample. Relative standard deviations for the modified extraction ranged from 0.20 to 0.86% with an average of 0.58%; relative standard deviation for the official extraction ranged from 0.30 to 0.89% with an average of 0.57%.


2006 ◽  
Vol 63 (4) ◽  
pp. 333-340 ◽  
Author(s):  
Luís Ignácio Prochnow ◽  
Jack Fernando Santos Quispe ◽  
Eros Artur Bohac Francisco ◽  
Graziela Braga

Phosphate fertilizers should match soil attributes to enhance agronomic effectiveness and recovery by plants. The purpose of this study was to test the agronomic effectiveness of P sources varying in water solubility on two soils differing widely in P adsorption capacity (PAC). Soils selected for the study were Oxisols with very low available P and presenting low and high PAC (Ox-LPAC and Ox-HPAC, respectively). Both were limed to pH 5.4 in a greenhouse study conducted utilizing corn as the test crop. Treatments consisted of the two soils interacting with five P sources (monocalcium phosphate - MCP, low-grade single superphosphate - LG-SSP, multimagnesium phosphate - MMP, Arad phosphate rock - PR and a P impurity in triple superphosphate - H14), and four rates of P (12.5, 25.0, 50.0 and 100.0 mg kg-1). A control with no P was added for each soil. The treatments were arranged as blocks with three replicates. Plants were harvested 45 d after germination. Dry-matter yield and P uptake were measured and the relative agronomic effectiveness (RAE) compared with MCP as the standard. When applied in low rates of P (12.5 and 25.0 mg kg-1) the RAE of the alternative sources was higher in the soil with high PAC (45, 66, 39 and 65% in the Ox-HPAC for the LG-SSP, MMP, PR and H14, respectively, as opposed to 24, 40, 14 and 47% in the Ox-LPAC). Results suggest that sources of P with low water solubility can be agronomically more effective in soils with high PAC.


Soil Research ◽  
2002 ◽  
Vol 40 (7) ◽  
pp. 1213 ◽  
Author(s):  
L. L. Burkitt ◽  
C. J. P. Gourley ◽  
P. W. G. Sale

Field studies were established on 9 different soil types used for pasture production in the high rainfall zones of southern Victoria. Sites were selected to represent a range of phosphorus (P) buffering capacities (PBC) and were analysed for a series of chemical and physical properties before receiving P fertiliser treatments. A single application of P fertiliser in the form of triple superphosphate (TSP), single superphosphate (SSP), or TSP and lime (5 t/ha) was applied at amounts ranging from 0 to 280 kg P/ha at the start of the experiment, whilst treatments of 35 and 70 kg P/ha were reapplied at 6-monthly intervals. Soils were analysed for bicarbonate-extractable P concentration, using both the Olsen P and Colwell P methods, 6, 12, 18, 24, and 30 months after P fertiliser was applied. A strong positive linear relationship existed at all sites and time periods between the amounts of P applied as a single application and both the Olsen P and Colwell P concentrations. The slopes of these relationships measured the change in extractable P concentration per unit of P applied (ΔEP) and the rate of decline in ΔEP values represented the decline in the effectiveness of the P fertiliser with increasing time from application. The decline in these ΔEP values varied with soil type. The ΔEP values of some low to moderate P buffered soils remained 2–3 times higher compared with the most highly buffered soils, after 30 months. Despite this, the decline in ΔEP values between 6 and 30 months was difficult to predict using a single soil property. Multiple linear regressions involving a measure of PBC and either organic carbon or exchangeable hydrogen were useful methods of predicting the decline in ΔEP values across the 9 field sites examined in this study. In general, the reapplication of P fertiliser every 6 months resulted in significantly higher extractable P concentrations compared with the same rates applied in a single application, across all sites and rates of P applied. The application of SSP, TSP, and TSP and lime had little impact on ΔEP values 18–30 months after treatments were applied.


2013 ◽  
Vol 37 (3) ◽  
pp. 667-677 ◽  
Author(s):  
Irio Fernando de Freitas ◽  
Roberto Ferreira Novais ◽  
Ecila Mercês de Albuquerque Villani ◽  
Sarah Vieira Novais

Despite the large number of studies addressing the quantification of phosphorus (P) availability by different extraction methods, many questions remain unanswered. The aim of this paper was to compare the effectiveness of the extractors Mehlich-1, Anionic Resin (AR) and Mixed Resin (MR), to determine the availability of P under different experimental conditions. The laboratory study was arranged in randomized blocks in a [(3 x 3 x 2) + 3] x 4 factorial design, with four replications, testing the response of three soils with different texture: a very clayey Red Latosol (LV), a sandy clay loam Red Yellow Latosol (LVA), and a sandy loam Yellow Latosol (LA), to three sources (triple superphosphate, reactive phosphate rock from Gafsa-Tunisia; and natural phosphate from Araxá-Minas Gerais) at two P rates (75 and 150 mg dm-3), plus three control treatments (each soil without P application) after four contact periods (15, 30, 60, and 120 days) of the P sources with soil. The soil acidity of LV and LVA was adjusted by raising base saturation to 60 % with the application of CaCO3 and MgCO3 at a 4:1 molar ratio (LA required no correction). These samples were maintained at field moisture capacity for 30 days. After the contact periods, the samples were collected to quantify the available P concentrations by the three extractants. In general, all three indicated that the available P-content in soils was reduced after longer contact periods with the P sources. Of the three sources, this reduction was most pronounced for triple superphosphate, intermediate for reactive phosphate, while Araxá phosphate was least sensitive to the effect of time. It was observed that AR extracted lower P levels from all three soils when the sources were phosphate rocks, while MR extracted values close to Mehlich-1 in LV (clay) and LVA (medium texture) for reactive phosphate. For Araxá phosphate, much higher P values were determined by Mehlich-1 than by the resins, because of the acidity of the extractor. For triple superphosphate, both resins extracted higher P levels than Mehlich-1, due to the consumption of this extractor, particularly when used for LV and LVA.


1962 ◽  
Vol 42 (2) ◽  
pp. 254-265 ◽  
Author(s):  
J. D. Beaton ◽  
D. W. L. Read ◽  
W. C. Hinman

The effect of phosphate source and soil moisture during the initial soil-fertilizer reaction period on subsequent phosphorus uptake by alfalfa was investigated in a growth chamber. Phosphate-treated soils with moisture adjusted to four different tensions were stored at approximately 18 °C. for 10 weeks. Following this storage interval phosphorus uptake by alfalfa was measured using a short-term technique.Phosphorus content and phosphorus uptake by both tops and roots increased significantly when water-soluble materials such as ammonium polyphosphate, monoammonium and monocalcium phosphate were applied. Less soluble sources, i.e., hydroxyapatite and anhydrous dicalcium phosphate, were much less effective. Calcium metaphosphate produced intermediate results.Moisture content of the soil during the reaction period did not greatly alter subsequent P uptake. The water-soluble sources of phosphorus were affected to the greatest degree.Uptake of P was significantly correlated with the amount of P extracted by NaHCO3 from the treated soils. The highest degree of correlation occurred with ammonium polyphosphate treated soil. A significant negative correlation occurred with calcium metaphosphate. With the exception of the 0.8 bar treatment, moisture tension had little influence on the correlation of P uptake with NaHCO3 extractable-P.


Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1124
Author(s):  
Dawei Yu ◽  
Fuhui Cui ◽  
Yunxiang Cong ◽  
Chunxi Zhang ◽  
Qinghua Tian ◽  
...  

Metallurgical processing of low-grade manganese ore with high iron content is gaining increasing attention due to the gradual depletion of high-grade Mn ores, amid the difficulties in its efficient extraction for both Mn and Fe values in an environmentally-friendly manner. Attempting to tackle the difficulties, this paper describes an innovative process for selectively chlorinating and reducing the high-Fe manganese ore in a simultaneous manner, aiming to produce water-soluble MnCl2 and metallic Fe. After pre-mixing with carbonaceous reductant, CaCl2 and MgCl2 as the chlorinating agent, the Mn ore was heated at 1000 °C. As much as 89.4% Mn can be chlorinated in its water-soluble form, with dissolution of only 3.0% Fe. The presence of CaCl2 during carbothermic reduction resulted in significant promotion in both the Fe reduction rate and formation of large metallic Fe particles due to the segregation effect, facilitating subsequent separation. Selective Mn chlorination by MgCl2 took place with or without the involvement of SiO2, forming MgSiO4 or MgO, respectively.


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