scholarly journals Effect of extractant pH on the release of soil phosphorus, aluminium and iron by ammonium fluoride

1989 ◽  
Vol 61 (2) ◽  
pp. 67-72 ◽  
Author(s):  
Raina Niskanen

Release of P, Al and Fe of five mineral soils in four-hour extraction by 0.1 M NH4F, pH 4.2—8.6, generally increased with decreasing pH of the extractant. Fluoride was a rather selective extractant of Al at pH 6.1—8.6 where the extractability of iron was low. NH4F, pH 4.2, released a great part of P solubilized in fractionation of inorganic soil P, and Al was extracted more than by Tamm’s acid ammonium oxalate. Acid fluoride solutions released OH- ions from soils. The initial pH of fluoride was 4.2—5.2, and it rose in the filtrates of all soils.

1999 ◽  
Vol 79 (4) ◽  
pp. 615-625 ◽  
Author(s):  
Suzanne Beauchemin ◽  
R. R. Simard

Many agricultural fields contain excessive labile soil P in regard to crop needs. Its environmental fate must be assessed. The concept of P saturation degree is meaningful as it describes the portion of the soil binding sites already covered with P, and indicates the potential desorbability of soil P. The first objective of this study was to review different indices that have been proposed to estimate the degree of soil P saturation and the relationships between soil P saturation degree and P solubility. The second objective is to discuss their suitability as environmental indicators for P management in the province of Québec, Canada. In the Netherlands, the P saturation index is defined as the ratio of P to Al + Fe contents extracted by ammonium oxalate [Pox/( Alox + Feox ) or ( Pox/0.5( Alox + Feox )]. This approach has been mainly used with non-calcareous soils. In Québec, the ratio of Mehlich-III extractable P to Al (M3P/AlM3) is proposed as an alternative, which relies on routine laboratory test. However, the suitability of the M3P/AlM3 ratio has yet to be determined for some specific soil groups (e.g. gleyed soils, soils with Alox content >6 g kg−1) and for subsoil horizons. Regardless of the chosen index, it is suggested that the best way to manage the risk of water contamination by P in Québec (namely, defining critical levels of soil P saturation) may be to form homogeneous soil groups to account for their distinctive behaviour and characteristics. Key words: Phosphorus, saturation, management


1978 ◽  
Vol 50 (4) ◽  
pp. 305-316 ◽  
Author(s):  
Erkki Aura

Phosphorus uptake by oats in pot experiments was compared with phosphorus test values obtained for experimental soils. Phosphorus was extracted from the soil using acid ammonium acetate solution, Bray 1 solution, Olsen solution, ammonium fluoride, distilled water and anion exchange resin. Intensity values were determined by equilibrating the soils with 0.01 M CaCl2 solution. Soil samples were collected from 30 mineral soils. The best test for phosphorus status proved to be the anion exchange resin method. Good results were also obtained with simple water extraction. An advantage of the water and resin method is that the microstructure of the soil is not substantially changed when using these methods. An intensity measurement was not in itself sufficient for analysis of the phosphorus status, since the intensity drops rapidly when soil releases phosphorus.


1987 ◽  
Vol 59 (2) ◽  
pp. 141-145
Author(s):  
Raina Niskanen

Release of phosphorus, aluminium and iron by a modified Chang and Jackson procedure was studied in five mineral soils. Quantities of aluminium and iron released during the procedure and extracted by acid ammonium oxalate were compared. The extractability of P, Al and Fe by 1 M NH4CI and that of Al and Fe by alkaline 0.5 M NH4F was poor. Proportions of P extracted by 0.5 M NH4F (0.2—10.4 mmol/kg soil) and 0.1 M NaOH (0.1— 9.8 mmol/kg soil) were related to the molar ratio of oxalate-extractable iron and aluminium. P extracted by 0.25 M H2SO4 amounted to 2.1—12.2 mmol/kg soil. Al extracted by 0.1 M NaOH (7—174 mmol/kg soil) and 0.25 M H2SO4 (17—112 mmol/kg soil) amounted to 55—94 % and 16—245 % of oxalate-extractable Al, respectively. Fe released by 0.1 M NaOH (1—10 mmol/kg soil) and 0.25 M H2SO4 (30—196 mmol/kg soil) amounted to 1—13 % and 62—272 % of oxalate-extractable Fe, respectively. In total, 91—309 % of oxalate-extractable Al and 70—285 % of oxalate-extractable Fe were released by NaOH and H2SO4.


2019 ◽  
Vol 103 (1) ◽  
pp. 43-45 ◽  
Author(s):  
Carlos Crusciol ◽  
João Rigon ◽  
Juliano Calonego ◽  
Rogério Soratto

Some crop species could be used inside a cropping system as part of a strategy to increase soil P availability due to their capacity to recycle P and shift the equilibrium between soil P fractions to benefit the main crop. The release of P by crop residue decomposition, and mobilization and uptake of otherwise recalcitrant P are important mechanisms capable of increasing P availability and crop yields.


Biology ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 158
Author(s):  
Jiang Tian ◽  
Fei Ge ◽  
Dayi Zhang ◽  
Songqiang Deng ◽  
Xingwang Liu

Phosphorus (P) is a vital element in biological molecules, and one of the main limiting elements for biomass production as plant-available P represents only a small fraction of total soil P. Increasing global food demand and modern agricultural consumption of P fertilizers could lead to excessive inputs of inorganic P in intensively managed croplands, consequently rising P losses and ongoing eutrophication of surface waters. Despite phosphate solubilizing microorganisms (PSMs) are widely accepted as eco-friendly P fertilizers for increasing agricultural productivity, a comprehensive and deeper understanding of the role of PSMs in P geochemical processes for managing P deficiency has received inadequate attention. In this review, we summarize the basic P forms and their geochemical and biological cycles in soil systems, how PSMs mediate soil P biogeochemical cycles, and the metabolic and enzymatic mechanisms behind these processes. We also highlight the important roles of PSMs in the biogeochemical P cycle and provide perspectives on several environmental issues to prioritize in future PSM applications.


2014 ◽  
Vol 38 (5) ◽  
pp. 1487-1495 ◽  
Author(s):  
Ciro Antonio Rosolem ◽  
Alexandre Merlin

Phosphorus fixation in tropical soils may decrease under no-till. In this case, P fertilizer could be surface-spread, which would improve farm operations by decreasing the time spend in reloading the planter with fertilizers. In the long term, less soluble P sources could be viable. In this experiment, the effect of surface-broadcast P fertilization with both soluble and reactive phosphates on soil P forms and availability to soybean was studied with or without fertilization with soluble P in the planting furrow in a long-term experiment in which soybean was grown in rotation with Ruzigrass (Brachiaria ruziziensis). No P or 80 kg ha-1 of P2O5 in the form of triple superphosphate or Arad reactive rock phosphate was applied on the surface of a soil with variable P fertilization history. Soil samples were taken to a depth of 60 cm and soil P was fractionated. Soybean was grown with 0, 30, and 60 kg ha-1 of P2O5 in the form of triple phosphate applied in the seed furrow. Both fertilizers applied increased available P in the uppermost soil layers and the moderately labile organic and inorganic forms of P in the soil profile, probably as result of root decay. Soybean responded to phosphates applied on the soil surface or in the seed furrow; however, application of soluble P in the seed furrow should not be discarded. In tropical soils with a history of P fertilization, soluble P sources may be substituted for natural reactive phosphates broadcast on the surface. The planting operation may be facilitated through reduction in the rate of P applied in the planting furrow in relation to the rates currently applied.


2017 ◽  
Vol 14 (8) ◽  
pp. 2055-2068 ◽  
Author(s):  
Jie Zhang ◽  
Arthur H. W. Beusen ◽  
Dirk F. Van Apeldoorn ◽  
José M. Mogollón ◽  
Chaoqing Yu ◽  
...  

Abstract. Phosphorus (P) plays a vital role in global crop production and food security. In this study, we investigate the changes in soil P pool inventories calibrated from historical countrywide crop P uptake, using a 0.5-by-0.5° spatially explicit model for the period 1900–2010. Globally, the total P pool per hectare increased rapidly between 1900 and 2010 in soils of Europe (+31 %), South America (+2 %), North America (+15 %), Asia (+17 %), and Oceania (+17 %), while it has been stable in Africa. Simulated crop P uptake is influenced by both soil properties (available P and the P retention potential) and crop characteristics (maximum uptake). Until 1950, P fertilizer application had a negligible influence on crop uptake, but recently it has become a driving factor for food production in industrialized countries and a number of transition countries like Brazil, Korea, and China. This comprehensive and spatially explicit model can be used to assess how long surplus P fertilization is needed or how long depletions of built-up surplus P can continue without affecting crop yield.


2003 ◽  
Vol 60 (3) ◽  
pp. 559-564 ◽  
Author(s):  
Edemar Joaquim Corazza ◽  
Michel Brossard ◽  
Takashi MuraokaI ◽  
Maurício Antonio Coelho Filho

Studies on soil phosphorus (P) of low productivity cultivated pastures in Cerrado (Brazilian Savanna) areas and surveys on other possible problems related to P are scarce. The spatial variability of soil phosphorus content of a Rhodic Ferralsol was studied in a low productivity pasture of Brachiaria brizantha (BB) grown for 10 years, without fertilizer application, in an experimental area at Planaltina (GO), Brazil. Soil samplings were performed on a regular grid of 10 by 10 meters, with 98 sampling points before (between tussocks and under tussocks) and after the establishment of the experiment (after fertilizing). On the same grid, forage plants were collected and separated into fractions for N and P content analyses. Soil available phosphate was determined by the resin method (Pr) and complemented by the 32P isotopic exchange kinetics analysis. Descriptive statistical and geostatistical analyses were utilized to describe the spatial variability. The Pr content on soil samples under tussocks presented mean and median values 45% larger than in soil samples taken between tussocks. The higher variation is probably related to the greater concentration of BB roots, soil organic matter content and soil P recycled through the plants tussocks. The spatial variability of Pr in this soil was high especially after fertilizer application. This variable did not present spatial dependence for the regular 10 m sampling. The generated knowledge on P variability of soils under low productivity cultivated pastures revealed problems related to the sampling methodology traditionally utilized and to P application.


Author(s):  
Tomáš Lošák ◽  
Jaroslav Hlušek ◽  
Ivana Lampartová ◽  
Jakub Elbl ◽  
Gabriela Mühlbachová ◽  
...  

The pot experiment was established in vegetation hall in the year 2015. Spring barley, variety KWS Irina, was grown. Two different soils – chernozem from Brno (with a low phosphorus content and alkali soil reaction – 7.37) and haplic luvisol from Jaroměřice nad Rokytnou (with a high phosphorus content and slightly acid soil reaction – 6.01) were used for comparison. The rates of phosphorus in the form of triple superphosphate (45 % P2O5) were increased from 0.3 – 0.6 – 1.2 g per pot (5 kg of soil – Mitscherlich pots). Nitrogen was applied in the form of CAN (27 % N) at a rate of 1 g N per pot in all the treatments incl. the control. Using statistical analysis, significant differences were found between the two soil types both in terms of the postharvest soil P content and yields of aboveground biomass. The content of post‑harvest soil phosphorus increased significantly with the applied rate (96 – 141 – 210 mg/kg in chernozem and 128 – 179 – 277 mg/kg in haplic luvisol). Dry matter yields of the aboveground biomass grown on chernozem were the lowest in the control treatment not fertilised with P (38.97 g per pot) and increased significantly with the P rate applied (46.02 – 47.28 g per pot), although there were no significant differences among the fertilised treatments. On haplic luvisol phosphorus fertilisation was not seen at all, demonstrating that the weight of the biomass in all the treatments was balanced (48.12 – 49.63 g per pot).


2015 ◽  
Vol 39 (3) ◽  
pp. 637-642 ◽  
Author(s):  
Philippe C. Baveye

In recent years, many researchers have claimed that world reserves of rock phosphate were getting depleted at an alarming rate, putting us on the path to scarcity of that essential resource within the next few decades. Others have claimed that such alarmist forecasts were frequent in the past and have always been proven unfounded, making it likely that the same will be true in the future. Both viewpoints are directly relevant to the level of funding devoted to research on the use of phosphate fertilizers. In this short essay, it is argued that information about future reserves of P or any other resource are impossible to predict, and therefore that the threat of a possible depletion of P reserves should not be used as a key motivation for an intensification of research on soil P. However, there are other, more compelling reasons, both geopolitical and environmental, to urgently step up our collective efforts to devise agricultural practices that make better use of P than is the case at the moment.


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