CHARACTERIZATION OF MODEL AND SOIL ORGANIC MATTER METAL-PHOSPHATE COMPLEXES

1969 ◽  
Vol 49 (3) ◽  
pp. 365-373 ◽  
Author(s):  
M. Lévesque
Keyword(s):  
Organic Matter ◽  
Fulvic Acid ◽  
Organic Phosphorus ◽  
Inorganic Phosphorus ◽  
Chelating Resin ◽  
Alkaline Media ◽  
Phosphorus Compounds ◽  
Metal Phosphate ◽  
Reaction Products ◽  
Soil Extracts

Fulvic acid–metal–phosphate complexes prepared in the laboratory and corresponding complexes extracted (0.1 N NaOH and chelating resin) from a soil were characterized by means of electrophoresis, Sephadex gel filtration, and methods for differentiation of organic and inorganic phosphorus. The findings can be summarized as follows:(1) The prepared material in aqueous solution (after purification by dialysis) comprised three different entities: a fulvic acid–metal–phosphate complex, a fulvic acid–metal complex, and unbonded inorganic phosphate. These entities were reaction products obtained during the formation of fulvic acid–metal–phosphate complexes.(2) Upon hydrolysis in mild alkaline media, the metal–phosphate bonds of the fulvic acid–metal–phosphate complexes were broken; the fulvic acid–metal complexes, freed from the phosphate, remained intact.(3) While metal ions were necessary for bridging phosphorus and fulvic acid, phosphorus in turn may have bridged the fulvic acid–metal units.(4) Significant amounts of complexed inorganic phosphorus were found intermixed with organic phosphorus compounds in soil extracts; this suggested the existence of organic matter metal–phosphate complexes in soil.

scholarly journals REACTIVITY OF NUCLEOPHILES AND α-EFFECT IN SUBSTITUTION PROCESSES AT ELECTRON - DEFICIENCY CENTERS

2020 ◽  
Vol 86 (7) ◽  
Author(s):  
Anatolii Popov ◽  
Illia Kapitanov ◽  
Anna Serdyuk ◽  
Aleksandr Sumeiko
Keyword(s):  
Organic Phosphorus ◽  
Organophosphorus Pesticides ◽  
Reaction Rates ◽  
Hydroxamic Acids ◽  
Phosphorus Compounds ◽  
Reaction Products ◽  
Electron Pairs ◽  
Alkyl Derivatives ◽  
Solvent Type ◽  
Electron Deficiency

The review analyzes issues related to the reactivity of nucleophiles and the manifestation of the α-effect in substitution processes at electron-deficient centers. The fundamental aspects of this phenomenon, as well as the possibilities and prospects of using α-nucleophiles in systems for the highly efficient degradation of substrates - ecotoxicants of various natures, are discussed. In the first part of the review such aspects were observed: inorganic α-nucleophiles as the most effective class of reagents for the decomposition of organic phosphorus compounds, hydroxylamine, its N-alkyl derivatives, oximes, and hydroxamic acids, reactivity of the НОО– anion in the processes of acyl group transfer, reactivity of oximate ions, inorganic α-nucleophiles as the basis of formulations for the degradation of neurotoxins, vesicants, and organophosphorus pesticides, design of inhibited acetylcholinesterase reactivators based on hydroxylamine derivatives, ways of structural modification of α-nucleophiles and systems based on them. The data on the reactivity of typical inorganic α-nucleophiles in the cleavage of acyl-containing substrates, including phosphorus acid esters, which provide abnormally high reaction rates in comparison with other supernucleophiles, are analyzed. Various types of such α-nucleophiles, features of their structure and reactivity are considered. It was shown that an important feature of hydroxylamine, oximes, and hydroxamic acids is the presence of a fragment with adjacent O and N (–N – O – H) atoms containing one or more lone electron pairs, which determines their belonging to the class of α-nucleophiles. It has been shown that a many of factors can be responsible for the manifestation of the α-effect and its magnitude, the main of which is the destabilization of the ground state of the nucleophile due to repulsion of lone electron pairs, stabilization of the transition state, the unusual thermodynamic stability of reaction products, solvation effects of the solvent, type of hybridization of the electrophilic center, etc.

An attempted fractionation of the soil phosphorus

1938 ◽  
Vol 28 (2) ◽  
pp. 234-246 ◽  
Author(s):  
L. A. Dean
Keyword(s):  
Sodium Hydroxide ◽  
Organic Phosphorus ◽  
Soil Phosphorus ◽  
Inorganic Phosphorus ◽  
Soil Extracts ◽  
Soil Calcium ◽  
Soluble Phosphorus ◽  
Total Soil Phosphorus ◽  
Continued Use ◽  
Phosphatic Fertilizers

1. Extractions of soils with sodium hydroxide, followed by an acid, have been used in an attempt to fractionate the soil phosphorus.2. Colorimetric methods for the estimation of the organic and inorganic phosphorus in alkali soil extracts have been suggested.3. The amount of soil phosphorus soluble in sodium hydroxide is affected by the active soil calcium. It is suggested that sodium-saturated soils be used when studying the alkali-soluble phosphorus.4. The acid-soluble phosphorus remaining in soil after extraction with sodium hydroxide was determined. This fraction appears by analogy to be similar to the apatites.5. The largest fraction of the total soil phosphorus was not dissolved by the sodium hydroxide and acid extractions. This fraction was not increased by the long-continued use of phosphatic fertilizers at Rothamsted and Woburn.6. Relatively large amounts of organic phosphorus were found in soils and the amounts were closely related to the carbon contents.

scholarly journals Abstract for the Organic Phosphorus 2013 conference - Panama City, Panama

2021 ◽  
Author(s):  
Vito Abbruzzese
Keyword(s):  
Agricultural Production ◽  
Mycorrhizal Fungi ◽  
Metal Ion ◽  
Inositol Phosphates ◽  
Organic Phosphorus ◽  
Inorganic Phosphorus ◽  
Phosphorus Compounds ◽  
Bacterial Strains ◽  
Dominant Form ◽  
Livestock Farms

Organic phosphorus (Po) compounds in soil often comprise a large component of soil total P (up to 84% for pasture), and represent a potentially significant source of P for agricultural production. Information on the quantities and forms of soil Po remains relatively limited, but we do know that inositol phosphates and their numerous metal-ion derivatives often constitute the dominant form of soil total Po. In addition, other phosphate esters, such as sugar phosphates, phospholipids and nucleic acids have often been identified in smaller quantities within soils. Various soil microorganisms, such as mycorrhizal fungi and phosphate-solubilising microorganisms (PSMs), can access inositol phosphates and other Po compounds. These microorganisms play an important role in the mineralisation of soil Po and the release of inorganic phosphorus compounds to soil solution or for direct plant uptake. Our research aims to explore the extent to which the coupled microbial and enzyme system with agricultural soils might be manipulated in order to increase the value derived from soil Po compounds as part of agricultural production. Specifically, we describe research focussed on inoculation experiments in which selected fungal and bacterial strains, alongside extracellular phosphatase enzymes, are trialled for their efficacy with respect to the mineralisation and solubilisation of Po compounds within soils. For example, arbuscular mycorrhizas (AMs) belonging to the phylum Glomeromycota could be introduced to soil ecosystems in order to benefit from the symbiotic endobacteria living inside the fungus whose genes are involved in mineral P acquisition. Such AMs could be mixed with strains of some of the most beneficial PSMs for Po mineralisation, e.g. Azospirillum spp., Bacillus spp., Penicillium spp. and Rhizobium spp. In addition, bacterial strains such as Bacillus amyloliquefaciens FZB24, FZB42 and FZB45, could be inoculated in soils due to their ability to secrete extracellular phosphatase enzymes. Our research focuses on the extent to which inoculations could increase the availability of phosphorus within soils for agricultural production, focussing largely on livestock farms and associated grass quality and yields. In particular, we will examine whether inoculation of livestock slurries and manures provides a vector for indirect manipulation of soil microbial and enzyme systems within livestock farms. The ultimate aim of this approach is to reduce the reliance of agricultural production on finite inorganic phosphorus fertiliser reserves.

Dissolved organic and inorganic phosphorus compounds in pig slurry: effect of drying

1978 ◽  
Vol 90 (1) ◽  
pp. 39-45 ◽  
Author(s):  
R. G. Gerritse ◽  
R. Eksteen
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Organic Molecules ◽  
Organic Phosphorus ◽  
Alkali Treatment ◽  
Gel Filtration ◽  
Inorganic Phosphorus ◽  
Phosphorus Compounds ◽  
Pig Slurry ◽  
Acid And Alkali Treatment

SUMMARYFrom gel filtration studies it has been found that more than 50% of organic phosphorus dissolved in pig slurry is contained in compounds of high molecular weight. Various ions, e.g. calcium, copper, orthophosphate, are bound by these compounds. From the purine and pyrimidine base composition and resistance to acid and alkali treatment it follows that these organic compounds probably are complexes derived from polydeoxyribonucleotides (DNA).The effect of drying pig slurry at various temperatures (0–100 °C) on the solubility of phosphorus, calcium and copper after redispersion of the dried slurry was investigated. The solubility of organic phosphorus was not affected by drying and redispersion in water, but the amount of phosphorus contained in dissolved organic molecules of high molecular weight decreased on drying at higher temperatures. The solubility of copper was also not affected by heat treatment. The solubility of inorganic phosphorus is mainly related to the solubility constants of mineral phosphates. On the other hand the total solubility of the cations involved is determined by complex formation.

scholarly journals REACTIVITY OF NUCLEOPHILES AND α-EFFECT IN SUBSTITUTION PROCESSES AT ELECTRON - DEFICIENCY CENTERS (Part 2)

2020 ◽  
Vol 86 (8) ◽  
pp. 77-100
Author(s):  
Anatolii Popov ◽  
Illia Kapitanov ◽  
Anna Serdyuk ◽  
Aleksandr Sumeiko
Keyword(s):  
Organic Phosphorus ◽  
Organophosphorus Pesticides ◽  
Reaction Rates ◽  
Hydroxamic Acids ◽  
Phosphorus Compounds ◽  
Reaction Products ◽  
Electron Pairs ◽  
Alkyl Derivatives ◽  
Solvent Type ◽  
Electron Deficiency

The review analyzes issues related to the reactivity of nucleophiles and the manifestation of the α-effect in substitution processes at electron-deficient centers. The fundamental aspects of this phenomenon, as well as the possibilities and prospects of using α-nucleophiles in systems for the highly efficient degradation of substrates - ecotoxicants of various natures, are discussed. In the first part of the review such aspects were observed: inorganic α-nucleophiles as the most effective class of reagents for the decomposition of organic phosphorus compounds, hydroxylamine, its N-alkyl derivatives, oximes, and hydroxamic acids, reactivity of the НОО– anion in the processes of acyl group transfer, reactivity of oximate ions, inorganic α-nucleophiles as the basis of formulations for the degradation of neurotoxins, vesicants, and organophosphorus pesticides, design of inhibited acetylcholinesterase reactivators based on hydroxylamine derivatives, ways of structural modification of α-nucleophiles and systems based on them. The data on the reactivity of typical inorganic α-nucleophiles in the cleavage of acyl-containing substrates, including phosphorus acid esters, which provide abnormally high reaction rates in comparison with other supernucleophiles, are analyzed. Various types of such α-nucleophiles, features of their structure and reactivity are considered. It was shown that an important feature of hydroxylamine, oximes, and hydroxamic acids is the presence of a fragment with adjacent O and N (–N – O – H) atoms containing one or more lone electron pairs, which determines their belonging to the class of α-nucleophiles. It has been shown that a many of factors can be responsible for the manifestation of the α-effect and its magnitude, the main of which is the destabilization of the ground state of the nucleophile due to repulsion of lone electron pairs, stabilization of the transition state, the unusual thermodynamic stability of reaction products, solvation effects of the solvent, type of hybridization of the electrophilic center, etc.

scholarly journals Dissolved organic matter stimulates N2 fixation and nifH gene expression in Trichodesmium

2020 ◽  
Vol 367 (4) ◽  
Author(s):  
Mar Benavides ◽  
Solange Duhamel ◽  
France Van Wambeke ◽  
Katyanne M Shoemaker ◽  
Pia H Moisander ◽  
...  
Keyword(s):  
Gene Expression ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
N2 Fixation ◽  
Organic Phosphorus ◽  
Nifh Gene ◽  
South Pacific ◽  
Inorganic Phosphorus ◽  
Nitrogen And Phosphorus ◽  
Tropical Oceans

ABSTRACT Mixotrophy, the combination of heterotrophic and autotrophic nutrition modes, is emerging as the rule rather than the exception in marine photosynthetic plankton. Trichodesmium, a prominent diazotroph ubiquitous in the (sub)tropical oceans, is generally considered to obtain energy via autotrophy. While the ability of Trichodesmium to use dissolved organic phosphorus when deprived of inorganic phosphorus sources is well known, the extent to which this important cyanobacterium may benefit from other dissolved organic matter (DOM) resources is unknown. Here we provide evidence of carbon-, nitrogen- and phosphorus-rich DOM molecules enhancing N2 fixation rates and nifH gene expression in natural Trichodesmium colonies collected at two stations in the western tropical South Pacific. Sampling at a third station located in the oligotrophic South Pacific Gyre revealed no Trichodesmium but showed presence of UCYN-B, although no nifH expression was detected. Our results suggest that Trichodesmium behaves mixotrophically in response to certain environmental conditions, providing them with metabolic plasticity and adding up to the view that mixotrophy is widespread among marine microbes.

The accumulation of soil organic matter under pasture and its effect on soil properties

1969 ◽  
Vol 9 (39) ◽  
pp. 437 ◽  
Author(s):  
NJ Barrow
Keyword(s):  
Organic Matter ◽  
Soil Nitrogen ◽  
Cation Exchange Capacity ◽  
Organic Phosphorus ◽  
Inorganic Phosphorus ◽  
Exchange Capacity ◽  
Buffering Capacity ◽  
Exchangeable Cations ◽  
Cent Increase ◽  
Exchange Acidity

Comparisons of paired virgin and pasture samples of Coolup sand showed that nitrogen had accumulated in the top 12.5 cm under pasture at an average of 24 p.p.m. per year. Carbon, sulphur, and organic phosphorus also accumulated to give C : N : S : P ratios of 118 : 10 : 1.2 : 0.47. The accumulation of sulphur accounted for about a quarter of the sulphur added in fertilizer and the accumulation of organic phosphorus accounted for about a tenth of the phosphorus added. Inorganic phosphorus had also accumulated but the amount varied between soils. The cation exchange capacity, as measured by summation of exchangeable cations and exchange acidity, increased by an average of 44 m-equiv. per g increase in nitrogen or 3.7 m-equiv. per g increase in carbon. Most of the increase was due to increases in exchange acidity. However, the buffering capacity of the soil for potassium was only slightly affected by the increase in organic matter. The water held by the soil between 0.1 bar and 15 bar suction increased by an average of 3.3 per cent per 0.1 per cent increase in soil nitrogen. When the soils were incubated the ratio of nitrogen mineralized to sulphur mineralized was large, especially when the incubation period was short. In the field there was a strong annual cycle of nitrogen and sulphur availability. Values were high in autumn, low in winter, and rose again at the end of spring.

A METHOD FOR THE DETERMINATION OF ORGANIC PHOSPHORUS IN SOILS AND SOIL EXTRACTS

1939 ◽  
Vol 17b (7) ◽  
pp. 199-205 ◽  
Author(s):  
C. L. Wrenshall ◽  
W. J. Dyer
Keyword(s):  
Hydrochloric Acid ◽  
Organic Phosphorus ◽  
Soil Phosphorus ◽  
Ammonium Hydroxide ◽  
Inorganic Phosphorus ◽  
Considerable Proportion ◽  
Alkaline Soil ◽  
Colour Reaction ◽  
Soil Extracts ◽  
The Difference

Dissolved organic phosphorus may be determined, even in highly coloured alkaline soil extracts, by the application of photoelectric colorimetry to the ceruleomolybdate colour reaction of phosphate ions. Total organic phosphorus may be extracted from soil with 4 N hydrochloric acid followed by treatment of the residue with 3 N ammonium hydroxide. Inorganic phosphorus is determined by direct colorimetry in the acid extract and in the acidified alkaline extract. Total phosphorus is determined similarly in each extract after ignition. The difference between total and inorganic phosphorus is equivalent to the organically combined phosphorus content of the soil sample.The soil organic phosphorus was found to be stable under these treatments. A considerable proportion of the organic phosphorus is extracted by acid, and the total soil phosphorus is almost completely extracted by the two treatments with 4 N hydrochloric acid and 3 N ammonium hydroxide.

scholarly journals Phosphorus in various depths of some virgin peat lands

1956 ◽  
Vol 28 (1) ◽  
pp. 90-104
Author(s):  
Armi Kaila
Keyword(s):  
Total Phosphorus ◽  
Phosphorus Content ◽  
Organic Phosphorus ◽  
Total Content ◽  
Inorganic Phosphorus ◽  
Point Of View ◽  
Phosphorus Compounds ◽  
Surface Layers ◽  
P Content ◽  
As Solubility

In the present paper results are reported concerning the total content as well as solubility of organic and inorganic phosphorus in 122 peat samples which were collected from various depths of 30 peat lands. The total phosphorus content of all the samples was rather low and no regularity in the influence of the depth upon this quantity could be demonstrated. There seemed to be some tendency to an increase in the P-content with increasing depth in the peat lands of lower quality. In peat lands of higher quality the opposite often held true. A large part of the phosphorus occurred in organic form, and, almost without exception, this percentage of total phosphorus increased with the depth: in undecomposed plant material this proportion was about 50—60 per cent, in the surface layers 70 per cent, on the average, in deposits deeper than 50 cm seldom less than 80 per cent and it could even reach 95 per cent. 1he amount of organic phosphorus expressed as a percentage of organic dry matter was low in most of the samples and although it tended to increase with the depth only in 11 of all the 122 samples values higher than 0.1 per cent were obtained. Even if an allowance is made for the conditions prevailing in peat lands these low percentages of organic phosphorus indicate that, from the microbiological point of view, no rapid mineralization of the organic phosphorus compounds is probable. The inorganic phosphorus content was low and tended to decrease from the surface to deeper layers. The solubility of inorganic phosphorus, however, dropped much more drastically. Thus in the deeper layers the amount of easily extractable inorganic phosphorus could be negligible. The solubility of organic phosphorus also impaired with the depth. The phosphorus economy of peat lands was discussed on the basis of the results obtained.

DISTRIBUTION OF ORGANIC MATTER AND PHOSPHORUS FRACTIONS IN A TOPOGRAPHIC SEQUENCE OF SOILS IN SOUTHERN BRITISH COLUMBIA

1965 ◽  
Vol 45 (3) ◽  
pp. 323-329 ◽  
Author(s):  
M. J. S. Floate
Keyword(s):  
British Columbia ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Phosphorus ◽  
Inorganic Phosphorus ◽  
Similar Amount ◽  
Grassland Soils ◽  
Inorganic P ◽  
Parent Materials ◽  
C And N

In sequences of grassland soils on south-facing slopes and forested soils on north-facing slopes in southern British Columbia, pH decreased but C, N, and organic phosphorus (Po) increased with increase in elevation from 1800 to 7400 ft. At the highest elevations grassland and forested soils contained similar amounts of C, N, and Po. The surface horizons of grassland soils at the lowest elevations contained C and N in similar amount to forested soils between 4000 and 5000 ft. C, N, and Po decreased with depth in all profiles but the amount of H2SO4-soluble inorganic P (Pa) increased to its highest percentage of the total, up to 98%, in the parent materials. Although both C/N and C/Po ratios decreased with depth, the values for C/Po were not high and indicated that inorganic phosphorus supply is not limiting the accumulation of P in the soil organic matter. These properties were interpreted as the effects of climate, modified by elevation, aspect, and vegetation, on weakly weathered parent materials.

Sign in / Sign up

Export Citation Format

Share Document