scholarly journals Phosphorus dynamics during early soil development in a cold desert: insights from oxygen isotopes in phosphate

SOIL ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 1-15
Author(s):  
Zuzana Frkova ◽  
Chiara Pistocchi ◽  
Yuliya Vystavna ◽  
Katerina Capkova ◽  
Jiri Dolezal ◽  
...  

Abstract. At the early stages of pedogenesis, the dynamics of phosphorus (P) in soils are controlled by microbial communities, the physicochemical properties of the soil and the environmental conditions. While various microorganisms involved in carrying out biogeochemical processes have been identified, little is known about the actual contribution of microbial processes, such as organic P hydrolysis and microbial P turnover, to P cycling. We thus focused on processes driven by microbes and how they affect the size and cycling of organic and inorganic soil P pools along a soil chronosequence in the Chamser Kangri glacier forefield (Western Himalayas). The rapid retreat of the glacier allowed us to study the early stages of soil formation under a cold arid climate. Biological P transformations were studied with the help of the isotopic composition of oxygen (O) in phosphate (δ18OP) coupled to sequential P fractionation performed on soil samples (0–5 cm depth) from four sites of different age spanning 0 to 100–150 years. The P bound to Ca, i.e., 1 M HCl-extractable P, still represented 95 % of the total P stock after approximately 100 years of soil development. Its isotopic composition was similar to the parent material at the most developed site. Primary phosphate minerals, possibly apatite, mostly comprised this pool. The δ18OP of the available P and the NaOH-extractable inorganic P instead differed from that of the parent material, suggesting that these pools underwent biological turnover. The δ18OP of the available P was mostly controlled by the microbial P, suggesting fast exchanges occurred between these two pools possibly fostered by repeated freezing–thawing and drying–rewetting cycles. The release of P from organic P becomes increasingly important with soil age, constituting one-third of the P flux to available P at the oldest site. Accordingly, the lighter isotopic composition of the P bound to Fe and Al oxides at the oldest site indicated that this pool contained phosphate released by organic P mineralization. Compared to previous studies on early pedogenesis under alpine or cold climate, our findings suggest a much slower decrease of the P-bearing primary minerals during the first 100 years of soil development under extreme conditions. However, they provide evidence that, by driving short-term P dynamics, microbes play an important role in controlling the redistribution of primary P into inorganic and organic soil P pools.

2021 ◽  
Author(s):  
Zuzana Frkova ◽  
Chiara Pistocchi ◽  
Yuliya Vystavna ◽  
Katerina Capkova ◽  
Jiri Dolezal ◽  
...  

Abstract. At the early stages of pedogenesis, the dynamics of phosphorus (P) in soils are controlled by microbial communities, the physicochemical properties of the soil and the environmental conditions. While various microorganisms involved in carrying out biogeochemical processes have been identified, little is known about the actual contribution of microbial processes, such as organic P hydrolysis and microbial P turnover, to P cycling. We thus focused on processes driven by microbes and how they affect the size and cycling of organic and inorganic soil P pools along a soil chronosequence in the Chamser Kangri glacier forefield (Western Himalayas). The rapid retreat of the glacier allowed us to study the early stages of soil formation under cold arid climate. Biological P transformations were studied with the help of the isotopic composition of oxygen (O) in phosphate (δ18OP) coupled to sequential P fractionation performed on soil samples from four sites of different age spanning 0 to 100–150 years. The mineral P, i.e. 1M HCl-extractable P, represented still 95 % of the total P stock after approximately 100 years of soil development. Its isotopic composition was similar to the parent material also at the most developed site. Primary phosphate minerals, therefore, mostly composed this pool. The δ18OP of the available P and the P bound to Fe and Al oxides instead differed from that of the parent material, suggesting that these pools underwent biological turnover. The isotopic composition of O in of the available P was mostly controlled by the microbial P, suggesting fast exchanges occurred between these two pools possibly fostered by repeated freezing-thawing and drying-rewetting cycles. The release of P from organic P become increasingly important with soil age, constituting one third of the P flux to available P at the oldest site. Accordingly, the lighter isotopic composition of the P bound to Fe and Al oxides at the oldest site indicated that this pool contained phosphate released by organic P mineralization. Compared to previous studies on early pedogenesis under alpine or cold climate, our findings suggest a much slower decrease of the P-bearing primary minerals during the first 100 years of soil development under extreme condition. However, they provide evidence that, by driving short-term P dynamics, microbes play an important role in controlling the redistribution of primary P into inorganic and organic soil P pools.


Soil Research ◽  
2004 ◽  
Vol 42 (1) ◽  
pp. 115 ◽  
Author(s):  
S. R. Aarons ◽  
H. M. Hosseini ◽  
L. Dorling ◽  
C. J. P. Gourley

Changes in dung and soil inorganic and organic P pools were measured in an experiment investigating the effects of dung on soil properties in 2 grazed dairy pasture systems (low and high input). Total dung P and bicarbonate-extractable P pools were measured in decomposing pads and compared with the changes in inorganic and organic bicarbonate-extractable soil P, P sorption, and microbial P flush of soils beneath dung pads and control 'pads' where nothing was applied. Bicarbonate-extractable total P in the dung pads declined to the same level in both systems by the last sample date. Organic P comprised a similar proportion (36%) of the bicarbonate-extractable total P pool in dung from both low and high input systems. However, the transformations of dung P were different in each system, with the bicarbonate-extractable total P in the low input dung increasing by 25% before declining, and a greater decrease in percentage bicarbonate-extractable organic P in this system.Bicarbonate-extractable soil organic P did not vary under dung pads despite the large increases in Olsen and Colwell P observed. Soil Olsen P trends observed in the low and high input systems indicate a potential for leaching losses of P in high input systems compared with low. This increase in soil Olsen P was not due to decreased P sorption as dung did not reduce the sorption capacity of the soil. Microbial soil P increased under dung pads only after 60 days in this experiment. Neither the organic P nor microbial P pools contributed significantly to soil labile P pools in these temperate dairy pasture systems. The transformations of P thought to occur during the decomposition of dung are discussed.


1981 ◽  
Vol 61 (2) ◽  
pp. 373-385 ◽  
Author(s):  
B. S. CHAUHAN ◽  
J. W. B. STEWART ◽  
E. A. PAUL

The effect of labile inorganic phosphate (Pi) status of the soil on the decomposition of added cellulose and on the immobilization, mineralization, and redistribution of native and added P in soils was studied in a greenhouse incubation experiment. Cellulose was added at 765 μg C∙g−1 soil with and without P (9 μg∙g−1 soil) every 30 days under adequate N, H2O, and constant tempreature to two soils of different available P status. Lack of P eventually slowed down decomposition of added C, but this effect was partially compensated for by increased mineralization of organic P (Po) forms. Added P was redistributed to both P, (58–69%) and Po (42–31%) forms; higher amounts of Po were found in the soil with the highest Pi status. The correlation between microbial P uptake and solution P values was significant, and microbial C:P ratios ranged from 12:1 under high available P conditions to 45:1 where P was in low supply.


2016 ◽  
Vol 3 (1) ◽  
pp. 17-24
Author(s):  
Shiferaw Boke ◽  
Sheleme Beyene ◽  
Heluf Gebrekidan

Data from 12 surface soils (0 – 15 cm depth)of three cropping systems (enset, maize and grazing land) and path analysis was used to evaluate effects of soil properties: pH, texture (Clay, silt and sand) , organic carbon (OC) cation exchange capacity (CEC),citrate-dithionite-bicarbonate (CDB) extractable Fe and Al (Fed and Ald) on total phosphorous (Pt), organic phosphorous (Po), Olsen P (Available P) and Chang and Jackson (1957) inorganic phosphorous (Pi) fractions. Correlation analysis was performed to study the relationships between soil properties and different soil P pools while path analysis model was used to evaluate direct and indirect effect of these soil properties on the P pools. Only soil properties that significantly contribute to the fit of the model were used. High significant values of coefficient of determination (R2) and low values of uncorrelated residual (U) values indicate the path analysis model explains most of the variations in soil Pt, Po, Olsen-P, Saloid-P, Ca-P, Al-P, and Fe-P pools. Soil pH had significantly high and positive direct effect (D = 0.618*) on Pt, (D = 1.044***) on saloid P, and (D = 1.109***) on Fe-P with modest and negative indirect effect (D= -0.478 and -0.405) on saloid P and Fe-P, respectively, through OC. The direct effect of clay on Ca-P, Al-P and Fe-P (readily available P forms) was significant and negative with a relatively higher indirect effect on Fe-P through pH suggesting that clay is dominant soil property that influences readily available P pools in Nitisols of the study area. Fed had significant and negative direct effect (D = -0.430*) on Olsen available P with low negative indirect effect ( D = -0.154) through pH results in significant and negative correlation (r = -0.657*). The significant and negative direct effect of Fed on Olsen P indicates that crystalline iron is the sink for available P. Relative influence of the soil properties on the soil P pools was in the order: pH > clay > Fed > OC.  These results show that most of P pools of Nitisols of Wolayita are best predicted from pH, clay (texture), Fed and OC. On the other hand, our data also show that the inclusion of other soil variables is needed to fully predict Ca-P and stable P pools.


1968 ◽  
Vol 48 (3) ◽  
pp. 289-295 ◽  
Author(s):  
T. G. Alexander ◽  
J. A. Robertson

Inorganic P forms in 18 profiles representing five great groups of Alberta soils were determined by the modified Chang and Jackson procedure. Ca-P is dominant in the Chernozemic Brown and Black soils and in the C horizons containing CaCO3, while Fe-P and Al-P or Occl-P are the main forms in the Podzolic soils. Three series high in available P contain appreciable amounts of Al-P and Fe-P in their surface horizons. The organic P content is relatively high in the soils exhibiting the least pedogenic development.With increasing degree of soil development, Fe-P and Occl-P tend to increase. However, parent materials have a marked influence on the distribution of inorganic P forms and a close relationship between soil development and distribution of inorganic P forms does not appear to exist in these soils. The Al-P and Fe-P forms seem to be the major sources of available P in the soils studied.


2016 ◽  
Vol 53 (2) ◽  
pp. 308-319 ◽  
Author(s):  
D. M. S. B. DISSANAYAKA ◽  
W. M. K. R. WICKRAMASINGHE ◽  
BUDDHI MARAMBE ◽  
JUN WASAKI

SUMMARYThe capability of some plant species to mobilize phosphorus (P) from poorly available soil P fractions can improve P availability for P-inefficient plant species in intercropping. White lupin (Lupinus albus) has been investigated as a model P-mobilizing plant for its capability of enhancing the P acquisition of neighbouring species under P-limited conditions. To date, investigations have led to contrasting findings, where some reports have described a positive effect of intercropped lupins on companion plants, whereas others have revealed no effects. This review summarizes the literature related to lupin–cereal intercropping. It explores the underpinning mechanisms that influence interspecific facilitation of P acquisition. The P-mobilization-based facilitation by lupins to enhance P-acquisition of co-occurring plant species is determined by both available P concentration and P-sorption capacity of soil, and the root intermingling capacity among two plant partners enabling rhizosphere overlapping. In lupin–cereal intercropping, lupin enhances the below-ground concentration of labile P pools through mobilization of P from sparingly available P pools, which is accomplished through carboxylate exudation, where neighbouring species acquire part of the mobilized P. The non-P-mobilizing species benefit only under P-limited conditions when they immediately occupy the maximum soil volume influenced by P-mobilizing lupin. Positive effects of mixed cropping are apparent in alkaline, neutral and acidic soils. However, the facilitation of P acquisition by lupins to companion species is eliminated when soil becomes strongly P-sorbing. In such soils, the limitation of root growth can result in poorer root intermingling between two species. The P mobilized by lupins might not be acquired by neighbouring species because it is bound to P-sorbing compounds. We suggest that the lupins can be best used as P-mobilizing plant species to enhance P acquisition of P-inefficient species under P-limited conditions when plant species are grown with compatible crops and soil types that facilitate sharing of rhizosphere functions among intercropped partners.


1990 ◽  
Vol 114 (1) ◽  
pp. 1-9 ◽  
Author(s):  
L. M. Condron ◽  
K. M. Goh

SUMMARYThe nature and availability of phosphorus in long-term fertilized pasture soils was investigated in a series of field trials, which included liming, N fertilizer and cultivation and involved monitoring plant P uptake and changes in topsoil (0–7·5 cm) P fractions for 2 years (1982–83). Liming increased soil organic P mineralization. This was indicated by significant decreases in extractable organic P and concomitant increases in microbial biomass P in the limed soils, although these changes in soil P had no significant effect on pasture yield and P uptake. On the other hand, N fertilizer increased pasture yield and P uptake but had little effect on the amounts of P in the different soil P fractions. In the cultivated soils, increases in plant-available inorganic P were attributed to the release of P during decomposition of plant residues, while the maintenance of fallow conditions decreased amounts of microbial P in these soils.


2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Nina Siebers ◽  
Liming Wang ◽  
Theresa Funk ◽  
Sabine von Tucher ◽  
Ines Merbach ◽  
...  

Abstract Background The phosphorus (P) stocks of arable subsoils not only influence crop production but also fertilizer P sequestration. However, the extent of this influence is largely unknown. This study aimed to (i) determine the extent of P sequestration with soil depth, (ii) analyze P speciation after long-term P fertilization, and (iii) compare soil P tests in predicting crop yields. We analyzed four long-term fertilizer trials in Germany to a depth of 90 cm. Treatments received either mineral or organic P, or a combination of both, for 16 to 113 years. We determined inorganic and organic P pools using sequential extraction, and P speciation using 31P nuclear magnetic resonance (NMR) and X-ray absorption near edge structure (XANES) spectroscopy. In addition, we applied three P soil tests, double-lactate (DL), calcium acetate lactate (CAL), and diffusive gradients in thin films (DGT). Results The results suggested that plants are capable of mobilizing P from deeper soil layers when there is a negative P budget of the topsoil. However, fertilization mostly only showed insignificant effects on P pools, which were most pronounced in the topsoil, with a 1.6- to 4.4-fold increase in labile inorganic P (Pi; resin-P, NaHCO3–Pi) after mineral fertilization and a 0- to 1.9-fold increase of organic P (Po; NaHCO3–Po, NaOH–Po) after organic P fertilization. The differences in Po and Pi speciation were mainly controlled by site-specific factors, e.g., soil properties or soil management practice rather than by fertilization. When modeling crop yield response using the Mitscherlich equation, we obtained the highest R2 (R2 = 0.61, P < 0.001) among the soil P tests when using topsoil PDGT. However, the fit became less pronounced when incorporating the subsoil. Conclusion We conclude that if the soil has a good P supply, the majority of P taken up by plants originates from the topsoil and that the DGT method is a mechanistic surrogate of P plant uptake. Thus, DGT is a basis for optimization of P fertilizer recommendation to add as much P fertilizer as required to sustain crop yields but as low as necessary to prevent harmful P leaching of excess fertilizer P.


2013 ◽  
Vol 64 (8) ◽  
pp. 825 ◽  
Author(s):  
T. I. McLaren ◽  
M. J. Bell ◽  
I. J. Rochester ◽  
C. N. Guppy ◽  
M. K. Tighe ◽  
...  

Recent studies report low and variable phosphorus (P) fertiliser use efficiency (PUE) for cotton in the northern grains region (NGR) of eastern Australia. This may be due to cotton accessing P pools that are not currently tested for in the subsoil (10–30 cm) or variation in response to P source and placement strategy. Two glasshouse studies were used to investigate this, incorporating two soil P tests to assess readily and slowly available P pools (Colwell, and a dilute acid colloquially referred to as the BSES extractant), and five different P fertiliser placement strategies in the subsoil. Eighteen Vertosols were collected across southern to central Queensland in the NGR, and then used to grow faba bean (Vicia faba L.) and cotton (Gossypium hirsutum L.) sequentially in the same 28-L pot. Readily available P pools assessed by Colwell-P were of major importance for faba bean and cotton dry matter, as well as for tissue P concentrations. Cotton was less responsive to extractable subsoil P concentrations than faba bean, suggesting either greater internal PUE or improved ability to accumulate P under conditions of limited availability. We recommend that subsoil P fertilisation should occur before sowing faba bean to maximise PUE in a cotton–faba bean rotation. Faba bean and cotton both recovered more P when the subsoil was fertilised, but no individual P fertiliser placement strategy was superior. Phosphorus extracted using the BSES method was not correlated with faba bean or cotton dry matter or tissue P concentration over the single crop cycle. We also recommend that Colwell-P be measured in the topsoil and subsoil to understand the quantity of plant-available P in Vertosols of the NGR, and that further research is needed to describe the resupply of the readily available P pool from slowly available P pools during a single crop cycle.


2019 ◽  
Vol 65 (No. 8) ◽  
pp. 408-415 ◽  
Author(s):  
Xiaozhu Yang ◽  
Xuelian Bao ◽  
Yali Yang ◽  
Yue Zhao ◽  
Chao Liang ◽  
...  

The migration and transformation of soil phosphorus (P) are essential for agricultural productivity and environmental security but have not been thoroughly elucidated to date. A 10-year field study was conducted to explore the effects of conventional tillage (CT) and no-tillage with maize residue management (NT-0, NT-33%, NT-67% and NT-100%) on P contents and phosphatase activities in soil layers (0–5, 5–10, 10–20 and 20–40 cm). The results showed that soil available P content and phosphatase activities were higher in no-tillage with maize residue than CT. Soil moisture and pH were significantly positively correlated with soil available P. Higher organic P contents and lower inorganic P contents in the 0–5 cm soil layer were found in the treatment NT-67% compared with other treatments. According to the structure equation model, the source of available P was inorganic P in NT-33%, while organic P in NT-67%. This study demonstrated that the variation of dominant mechanisms involved in soil P migration and transformation were dependent on residue input amounts, and NT-67% might play an important role in the maintenance and transformation of soil organic P.


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