Phosphorus Compounds In Soils Research Articles

The phosphate-solubilising fungi in sustainable agriculture: unleashing the potential of fungal biofertilisers for plant growth.

Phosphate-solubilising fungi (PSF) are beneficial microorganisms that play a pivotal role in plant growth by increasing the availability of phosphorus (P) in soil. Although phosphorus is an essential nutrient for plants, it often becomes inaccessible as it binds into insoluble forms. PSF effectively facilitate the release of this bound phosphorus through diverse mechanisms. Numerous fungal species demonstrate the ability to solubilise various types of phosphate compounds. Among the commonly researched PSF are Penicillium, Aspergillus, Rhizopus, Fusarium, Trichoderma, and Sclerotium. Moreover, yeasts such as Saccharomyces cerevisiae can potentially be leveraged as PSF. PSF secrete organic acids that chelate phosphate ions, thereby increasing their solubility in the soil. Moreover, PSF contribute to the decomposition of organic phosphorus compounds in soil by employing enzymes such as phosphatases, phytases, and phosphonatases. Furthermore, PSF can interact with other soil microorganisms, including nitrogen-fixing bacteria and arbuscular mycorrhizal fungi (AM-fungi), fostering synergistic effects that further enhance plant growth and nutrient absorption. The utilisation of PSF as biofertilisers offers numerous advantages over chemical fertilisers, including environmental friendliness, cost-effectiveness, and enhanced fertiliser utilisation efficiency. Furthermore, PSF can prove beneficial in challenging environments characterised by high phosphate sorption. Hence, this review serves as an updated study aimed at broadening the understanding of PSF and its potential applications in P solubilisation. This review also focuses on the diversity of PSF, the mechanisms underlying solubilisation, ecological roles of PSF in soil microbiome, and the benefits of sustainable agriculture. By delving into the ecological roles of PSF and their potential as biofertilisers, this study contributes to a deeper understanding of sustainable agriculture practices and addresses challenges in phosphate-scarce environments.

Speciation and microscale distribution of phosphorus compounds accumulated in continuously fertilized greenhouse soils

AbstractThe overuse of phosphate fertilizer results in the accumulation of surplus phosphorus (P) compounds in soil, and this trend is particularly intense in greenhouse farming. We aimed to characterize P compounds in greenhouse soils by comparing their speciation in soil samples collected from greenhouses and an open field. Two soil types with different phosphate sorption abilities, namely, Ultisol and Andisol, were considered. Phosphorus compounds in the soil were characterized by bulk soil analysis via acid extraction; molecular‐scale analyses by solid‐state 31P nuclear magnetic resonance and P K‐edge X‐ray absorption near edge structure and spatially resolved analyses by electron probe microanalyzer and micro‐X‐ray absorption near edge structure. Spectroscopic results showed that a larger proportion of P compounds associated with inorganic P compounds associated with calcium (Ca‐P) was present in the greenhouse soil than in the open‐field soil. Some P compounds in the greenhouse Andisol were Ca‐P, even though Andisol has a high phosphate sorption ability due to an abundance of aluminum‐bearing sorbents. Heterogeneously distributed spots of Calcium phosphate, most likely hydroxyapatite or tricalcium phosphate, were found at the microscale in the greenhouse Ultisol soil grain. In addition to the detection of poorly‐soluble Ca‐P, a larger proportion of Ca‐P was potentially plant available. Spatially resolved analyses showed that organic amendments containing Ca‐P were incorporated into the Andisol soil grains. Our study demonstrated that Ca‐P with different solubilities can serve as a source of phosphate even in soils of high phosphate sorption ability under greenhouse conditions.

Interrelationships between soil phosphorus compounds and their dependence on soil chemical and physical attributes

Interrelationships between soil phosphorus compounds and their dependence on soil chemical and physical attributes

FEATURES OF THE ANALYSIS OF PHOSPHORUS CONTENT IN SOILS

The article describes the biological and toxic role of Phosphorus and considers the causes of Phosphorus deficiency in soils in the territory of Ukraine. It has been established that for the functioning of living organisms, in particular plants, the lack of Phosphorus significantly affects the processes of growth, metabolism and photosynthesis, etc. The toxic effect of Phosphorus is manifested in the accumulation of agricultural products. The excess of Phosphorus has a negative effect on the consumers of these products and can manifest itself both in the form of food poisoning and in the form of serious diseases. The main forms of existence of Phosphorus compounds in soils (mobile form, immobile and fixed forms), their composition and the relationship between them, the availability of each of the forms for absorption and use by plants, soil characteristics that affect the mobility of Phosphorus compounds are considered. The existing methods and methods of analysis of the content of various forms of phosphorus compounds in soils are summarized. In general, the following methods of analysis are usually used to determine Phosphorus: photometric, titrimetric, and atomic absorption. The methods presented by us (Kirsanov’s method, Machigin’s method, and Chirikov’s method) have certain differences, but they are all based on the photo-colorimetric method. To determine the gross phosphorus content, a modified method according to Ginzburg, Shcheglova, and Wulfius is used. When choosing a method and method of analysis, the main factor is the provision of the laboratory with the necessary materials and reagents and access to devices. The dependence of the choice of the method of analysis of phosphorus content on the parameters of the soil under study was established. The authors concluded that during the analysis of phosphorus content in soils, the choice of methodology should be based on the type of soil under investigation. Mobile compounds of Phosphorus are prioritized for analysis, as they are the most used by plants.

Mobilization hard-to-reach phosphorus compounds in soil and influence growth processes of microbiological association

The article presents results of research of monocultures and association of lactic-oxide bacteria, purple nonsulfur bacteria and yeast on indicators of stimulation of growth processes, nitrogen fixation and phosphate mobilization for 2 crops: one-year and longterm. The research was carried out in both laboratory and production conditions. It is shown that milk-oxide and purple nonsulfur bacteria stimulate growth processes of wheat variety Nador in aquatic culture by 20-30%, and their consortium with yeast - by 30%. In comparison with control, an increase of 3.4 t/ha in the yield of Golden Delishes apples was detected with 2fold treatment based on a consortium of lactic oxide, purple nonsulfur bacteria and sucromycetes. It was determined that all the strains of the above-mentioned groups of microorganisms studied mobilized hard-to-soluble compounds of phosphorus, and only purple nonsulfur bacteria were capable of nitrogen fixation.

Cycling of reduced phosphorus compounds in soil and potential impacts of climate change

AbstractSoil phosphorus (P) remains an ever‐increasing topic of importance, notably for its key role as a nutrient for driving food production but with parallel concerns over damaging water quality, all against a backdrop of uncertainty of long‐term rock phosphate supplies. Soil is a key interface that holds P and regulates its onward flow to plants or leakage to waters. Often overlooked are a ubiquitous group of P compounds that exist in alternative oxidation states to that of phosphate (+5). Redox cycling, and the behaviour that chemically reduced P compounds exhibit in soils, introduces alternative routes of cycling P that may become more important as the soil system itself alters, especially due to the external pressures of climate change, bringing about critical dynamics in rainfall and runoff and also wetting and drying. All of these factors are known to affect soil redox potential and consequently the oxidation state of soil P. This review considers the chemically reduced species in the P cycle, exploring their sources and sinks, while considering their importance within the primary global biogeochemical cycling of P and how this may be impacted by climate change in the temperate climate of the northern hemisphere.Highlights This paper addresses how climate change will affect soil phosphorus cycling. This review is novel as it considers the reduced phosphorus forms when discussing P transfer in soils. Climate change is likely to increase prevalence of reduced P and free phosphate in northern hemisphere temperate soils. Phosphorus cycling relies partly on redox P processes. Their importance will increase as climate alters soils.

Construction of a new plant expression vector and the development of maize germplasm expressing the Aspergillus ficuum phytase gene PhyA2

Phytases, which belong to a special category of orthophosphoric monoester phosphohydrolases, degrade inositol hexaphosphate to produce lower-grade inositol phosphate derivatives and inorganic phosphate. Thus, phytases may improve phosphorus utilization, eliminate the anti-nutrient properties of phytic acid, and mitigate environmental pollution due to phosphorus contamination. In this study, we constructed a new root-specific expression vector by inserting the Aspergillus ficuum phytase gene PhyA2 into pCAMBIA3301-ZmGLU1P-Nos. The subsequent molecular analysis confirmed that six T4 generation transgenic plants carried and expressed PhyA2. A quantitative real-time PCR analysis indicated PhyA2 was highly expressed in the transgenic roots. Additionally, the phytase activity was 10.9-fold higher in the transgenic roots (peak activity of 5.432 U/g) than in the control roots. Moreover, compared with the control rhizosphere, the organic phosphorus content in the rhizosphere of the transgenic plants decreased significantly (by up to 5.21 mg/kg). An agronomic trait analysis indicated that PhyA2 expression can increase maize seed weight by up to 25.8 g. Therefore, the integration of PhyA2 into the maize genome can enhance the ability of maize plants to use the phosphorus compounds in soil, while also improving the plant growth status and increasing the seed yield.

The dark septate endophytic fungus Phialocephala fortinii is a potential decomposer of soil organic compounds and a promoter of Asparagus officinalis growth

There is limited information as to whether dark septate endophytic (DSE) fungi are able to degrade organic carbon, nitrogen and phosphorus compounds in soil and if these fungi have a significant role in nutrient cycles in nature, especially under organic nutrient conditions. In order to further knowledge in this area, 25 DSE fungi were isolated and tested for their promotion of Asparagus officinalis seedling growth. Three Phialocephala fortinii isolates were found to be most effective in increasing the growth of A. officinalis plants compared with uninoculated controls. These isolates had the ability to degrade all carbon and nitrogen compounds tested except for lignin. Using organic phosphorus and nitrogen sources, the three P. fortinii isolates were able to promote the growth of A. officinalis compared with control plants. The isolates were also able to promote the growth of A. officinalis seedlings on semi-organic and organic media. Our findings demonstrate that P. fortinii has a role in the promotion of A. officinalis growth under organic nutrient conditions, possibly by decomposing organic phosphorus and nitrogen compounds in soil.

Characterization of phosphorus compounds in soils by deep ultraviolet (DUV) Raman microspectroscopy

Deep ultraviolet Raman microspectroscopy was successfully investigated as a new approach to analyze the chemical state of phosphorus compounds directly in soil. We demonstrate that ultraviolet excitation has the advantage to avoid the interference with the strong fluorescence, which occurs in the visible spectral range caused by organic matter in soils. Furthermore, the spatial resolution of <1 μm2 enables the detection of very small phosphorus particles. For some organic phosphorus compounds (β‐glycerophosphate, aminomethylphosphonic acid), sample cooling to −100 °C is found to strongly reduce the rate of degradation induced by the illumination with the ultraviolet excitation light. However, phytic acid and adenosine monophosphate degraded even with cooling. Our results reveal the capability of deep ultraviolet Raman microspectroscopy as a high‐resolution benchtop imaging technique for the analysis of local interactions between soil compounds with the potential to become an analytical key to improve the understanding of transformation mechanisms of phosphates as well as other mineral phases in soils. Copyright © 2017 John Wiley & Sons, Ltd.

Soil phosphorus compounds in integrated crop-livestock systems of subtropical Brazil

Soil phosphorus (P) utilization may be affected by agricultural complexity, in particular when combining annual crops and livestock grazing on the same land area and at overlapping times. Our objectives were to qualify and quantify soil organic and inorganic P compounds using sodium hydroxide-ethylenediaminetetraacetic acid (NaOH-EDTA) extraction and 31P nuclear magnetic resonance spectroscopy (31P NMR) in response to increasing complexity with integrated crop-livestock systems (ICLS) in subtropical Brazil. Soil at a depth of 0–5cm was collected from three long-term (7 to 12years) cropping studies with and without ruminant grazing of cover crops. All sites were managed under no tillage, and treatments with livestock were managed with moderate grazing intensity. In these agro-ecosystems, grazing compared with no-grazing had greater soil P content as total and bioavailable orthophosphate and lower soil organic P and fewer monoesters, including inositol phosphates. Grazing increased P bioavailability and reduced recalcitrant organic P concentration in soil; therefore, cropping systems that integrate livestock (ICLS) can be a sustainable alternative to improve P use in farming systems of subtropical Brazil.

Spiking Improved Solution Phosphorus‐31 Nuclear Magnetic Resonance Identification of Soil Phosphorus Compounds

Chemical characterization of soil organic P using 31P nuclear magnetic resonance (NMR) spectroscopy relies on the correct assignment of resonances. We examined eight Australian soils and identified the main orthophosphate monoester peaks by spiking model organic P compounds (α‐ and β‐glycerophosphate, ethanolamine phosphate, phytate, scyllo‐inositol hexakisphosphate, and choline phosphate) into NaOH–ethylenediaminetetraacetic acid (EDTA) soil extracts. For five of the soils, the strongest monoester resonances were identified as being due to phytate, while for the other three soils, the strongest resonances were identified as being due to α‐ and β‐glycerophosphate. Importantly, the appearance of spectra dominated by phytate and those dominated by glycerophosphate were deceptively similar because the separation between the two strongest phytate resonances was very similar to the separation between the α‐ and β‐glycerophosphate resonances. We believe this may have resulted in the misidentification of these species in some previous studies. Identification of these species is hindered by the sensitivity of their chemical shifts to pH and electrolyte concentration. Our spiking methodology, in which we add only enough of the compound to approximately double the native concentration, overcomes this problem. We also investigated the alkaline hydrolysis of phospholipids as a likely source of α‐ and β‐glycerophosphate. We found that the rate of phospholipid hydrolysis was dependant on NaOH concentration and that the presence of glycerophosphate resonances in soil extracts probably results from the extraction and redissolution procedures rather than the presence of native glycerophosphate in the soils. We also identified an intermediate diester product that may have previously been misidentified as the phospholipid itself.

Phosphorus in the fulvate fraction of soil organic matter

The concentration of phosphorus in preparations of fulvic acids separated from soils according to a modified IHSS method varies from 0.03 to 0.23%; it is considerably lower than the concentration of phosphorus in preparations of humic acids (0.15–1.54%). A predominant part (>90%) of phosphorus-containing compounds in the fulvates is not sorbed on the polymethylmethacrylic resin Supelite DAX-8 used for the isolation of fulvic acids. These compounds are highly hydrophilic, and their sorption on the polystyrene-divinylbenzene resin XAD-4 used for the isolation of nonspecific organic compounds with a lower molecular weight and higher hydrophily does not exceed 20%. The results of the study attest to the quantitative indefiniteness of the notion of “phosphorus of fulvic acids” and cause doubt upon a hypothesis about an important role of fulvic acids in the migration of phosphorus compounds in soils and landscapes.

Sorption Dynamics of Organic and Inorganic Phosphorus Compounds in Soil

Phosphorus retention in soils is influenced by the form of P added. The potential impact of one P compound on the sorption of other P compounds in soils has not been widely reported. Sorption isotherms were utilized to quantify P retention by benchmark soils from Indiana, Missouri, and North Carolina when P was added as inorganic P (Pi) or organic P (beta-D-glucose-6-phosphate, G6P; adenosine 5'-triphosphate, ATP; and myoinositol hexaphosphate, IP6) and to determine whether soil P sorption by these organic P compounds and Pi was competitive. Isotherm supernatants were analyzed for pH and total P using standard protocols, while Pi and organic P compounds were assayed using ion chromatography. Under the controlled conditions of this study, the affinity of all soils for P sources followed the order IP6 > G6P > ATP > Pi. Each organic P source had a different potential to desorb Pi from soils, and the order of greatest to least Pi desorption was G6P > ATP > IP6. Glucose-6-phosphate and ATP competed more directly with Pi for sorption sites than IP6 at greater rates of P addition, but at the lesser rates of P addition, IP6 actually desorbed more Pi. Inositol hexaphosphate was strongly sorbed by all three soils and was relatively unaffected by the presence of other P sources. Decreased total P sorption due to desorption of Pi can be caused by relatively small additions of organic P, which may help explain vertical P movement in manured soils. Sorption isotherms performed using Pi alone did not accurately predict total P sorption in soils.

THE REACTION OF TWO LUVISOLIC FOREST SOILS TO PHOSPHATE FERTILIZATION

Response of two forested Luvisolic soils to phosphorus fertilization was compared using chemical extractants known to be effective in removing certain soil phosphorus compounds. Fifteen months following fertilization application, the Mercoal series (Bisequa Luvisol) showed total phosphorus decreases in each of the soil horizons or layers sampled. To sampling depth, phosphorus concentrations in all but the NH4F extract (mainly aluminum phosphate) were lower in fertilized than in control samples. Vegetative uptake was considered to be mainly responsible for phosphorus decreases and movement, especially noticeable in the deeper mineral horizons. The Coalspur series (Orthic Luvisol) showed an appreciable phosphorus increase in the litter layer although both mineral horizons, Ae and Bt, exhibited losses. The Coalspur soil exhibited increases in soil phosphorus susceptible to all but the NH4F extractant. The data suggest a greater mobility and movement of soil phosphorus in these Luvisolic forest soils than usually observed in cultivated soils. Following fertilization, Mercoal probably had a greater number of phosphorus compounds (reaction products perhaps) more readily available than did the Coalspur.

The Occurrence of High Molecular Weight Organic Phosphorus Compounds in Soil

AbstractAn extraction procedure using the chelating resin Dowex A‐1 after an HF‐HCl pretreatment is described for the extraction of high molecular weight organic phosphorus compounds. This procedure appears to reduce the degradation of high molecular weight compounds that occur with more drastic extraction techniques now in use

Factors influencing the determination of phosphatases in soil

(1) The method of the enzymatic hydrolysing of organic phosphorus compounds in soil was used, on the basis of determination of the release of inorganic phosphate after extraction by Truog's solution. (2) Glycerophosphate was hydrolysed much more intensively than nucleic acid. Both substrates were hydrolysed very well by sandy-loam soils (C and K), but relatively poorly by loam field soil (U) and forest soil (D). (3) The optimal temperature for glycerophosphatase activity was 55°C, except in soil K, while the optimal temperature for nuclease activity was about 42°C. (4) The percentual decomposition of both substrates was greatest up to a 500 μM substrate concentration. (5) Glycerophosphatase and nuclease activity increased up to the fifteenth hour of incubation. (6) In all soils hydrolysis of glycerophosphate and nucleic acid was highest at a neutral or mildly alkaline pH, with the exception of soil U, in which activity continued to rise with the pH. (7) Maximum sorption of phosphorus was found in humus-carbonate soil K. The test soils differed mainly in relation to the time course of sorption. The author therefore considers it important to correct every determination of phosphatases based on the release of phosphorus by the results of phosphorus sorption.

The Effect of Soil Phosphorus Compounds on Soil Test Correlation

AbstractTwenty soils representing the level upland and the depressional soils in the hydromorphic sequence of profiles of the upland and lake plain catenas were characterized by the determination of pH, organic matter, clay content, acid‐soluble phosphorus, water‐soluble phosphorus, alkali‐soluble phosphorus, organic phosphorus, and iron content.When the above variables were included in a multiple correlation analysis using yield of phosphorus as the dependent variable, a multiple correlation coefficient of 0.931 was obtained. The elimination of all variables except acid‐soluble and alkali‐soluble phosphorus gave a multiple correlation coefficient of 0.851. The simple correlation coefficient for acid‐soluble phosphorus was 0.557 and for alkali‐soluble phosphorus 0.675. The increase in correlation where both acid‐soluble and alkali‐soluble phosphorus were used over the correlation for either one alone was significant at the 1% level. Hence, the use of both acid‐soluble and alkali‐soluble phosphorus were required to explain the contribution of the different soil phosphorus compounds to yield.Solubility curves of the 20 soils indicated that the soils were heterogeneous with respect to soil phosphorus compounds. The depressional soils from the lake plain catena contained more calcium phosphate and less iron and aluminum phosphate compounds than their counterpart in the upland catena.Solubility curves for calcium phytate and other organic phosphorus compounds indicate that they are partially acid‐soluble, suggesting that an acid extraction contains phosphorus from both organic and inorganic sources. This was supported by the fact that a significant correlation was obtained between organic matter and acid‐soluble phosphorus.

A semi‐micro routine procedure for the partial fractionation of soil phosphorus

AbstractA semi‐micro procedure for the partial fractionation of soil phosphorus compounds is described, which has been developed for certain agricultural, forest and moor soils, containing down to 0.002 mg. of P per g. of soil for particular P fractions.The procedure uses a semi‐micro adaptation of McClean's acid attack for the extraction of total P, and Williams' extractants for the initial fractionation. All extracts receive similar simple preparative treatment, P then being estimated colorimetrically by reduction of phosphomolybdate with ‘ metol’.Critical steps in the procedure are discussed in brief experimental notes, and examples of fractionation data are included to demonstrate the necessity, when comparing different soil horizons, of expressing these data on a soil‐volume basis.

The effect of some silicate slags on the utilization of soil and fertilizer phosphorus

AbstractWhen certain silicates are applied to phosphorus‐deficient soils they improve crop growth. The effects of waste slags containing calcium silicate from iron and steel manufacture on crop yields and on phosphorus uptakes were investigated.In a pot experiment on barley grown on acid soil, ordinary blast‐furnace slags gave smaller increases in yields than equal weights of calcium carbonate or ‘falling’ haematite blast‐furnace slags. Slags made by special steel‐producing processes were more active than calcium carbonate and gave higher yields both with and without added phosphate.In field experiments ‘falling’ haematite blast‐furnace slags behaved in the same way as ground limestone and did not promote extra uptake of phosphorus by the crops. When no fertilizer phosphorus was applied, steel‐furnace slags were more active than ground limestone, and gave higher yields of swedes containing more phosphorus. When superphosphate was applied, steel‐furnace slags were still somewhat superior to limestone.Both ‘falling’ blast‐furnace slags and the steel‐furnace slags were active liming materials. Steel‐furnace slags had the additional property of increasing the amounts of phosphorus taken up by the crops.The reactions between silicates and soil phosphorus compounds require further study. Methods of characterizing products which promote the uptake of soil phosphorus by crops are needed.

Paper Chromatography of Inositol Phosphates

IN the course of an examination of the organic phosphorus compounds in soils, a fraction was isolated rich in a substance resembling phytic acid, and which on hydrolysis yielded meso-inositol. Since lower phosphate esters of inositol may be present in soil, a chromatographic study has been carried out on the products obtained on partial hydrolysis of authentic phytin by acid, or by an enzyme method described by S. and T. Posternak1.