Статті в журналах: "Bioavailable phosphoru"

1

Kulhánek, Martin, Jindřich Černý, Jiří Balík, Ondřej Sedlář, and Filip Vašák. "Changes of soil bioavailable phosphorus content in the long-term field fertilizing experiment." Soil and Water Research 14, No. 4 (October 9, 2019): 240–45. http://dx.doi.org/10.17221/175/2018-swr.

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The aim of this study is to describe the changes of bioavailable phosphorus content in soil in long-term 18 years field experiments with different fertilizing systems. The field experiments are located at three sites with different soil and climatic conditions in the Czech Republic (Červený Újezd, Humpolec and Prague-Suchdol). Same fertilizing systems and crop rotation (potatoes (maize) – winter wheat – spring barley) are realized at each site with following fertilizing treatments: (1) unfertilized treatment (control), (2) farmyard manure (FYM), (3) and (4) sewage sludge (SS 1 and SS 3), (5) mineral nitrogen (N), (6) mineral nitrogen with straw (N + straw) and (7) mineral nitrogen with phosphorus and potassium (NPK). The long-term fertilizing effect on available P content changes in soil was observed. Bioavailable phosphorus content in soil increased in treatments with organic fertilization after 18 year experiment at all sites. The treatments SS 3 had the highest increase at all sites. The highest bioavailable P content increase compared to control (258 mg/kg) was determined at site Červený Újezd. On the contrary, available phosphorus content decreased at treatments with mineral fertilization and control treatment among all sites. Bioavailable P content decrease in the treatment NPK was observed, although phosphorus was applied. The lowest differences in available P content among all fertilizing treatments were observed at the location Prague-Suchdol.

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2

Nakajima, J., Y. Murata, and M. Sakamoto. "Comparison of several methods for BAP measurement." Water Science and Technology 53, no. 2 (January 1, 2006): 329–36. http://dx.doi.org/10.2166/wst.2006.067.

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It has been more important for management of water quality to estimate the amount of bioavailable phosphorus (BAP) in suspended solids (SS) entering lakes and estuaries. AGP test or extraction by 0.1 mol l−1 NaOH (C-BOD) is widely used. Recently, highly bioavailable phosphorus (HBAP) was introduced to indicate a more easily soluble and bioavailable fraction using successive extraction by 0.1 mol l−1 HCl and 0.1 mol l−1 NaOH. New biologically measured BAP (B-BAP) using bacterial respiration activity was introduced in this paper. B-BAP was estimated from oxygen uptake rate (OUR), which was measured by a respiratory meter for BOD measurement using a pressure sensor. B-BAP is useful for a rapid and direct measurement of phosphorus bioavailability. B-BAP, HBAP and C-BAP in river SS were measured and compared with each other. The percentages of HBAP and B-BAP to PP were large in the urban river, while the percentage of NaOH-P or C-BAP was large in the rivers flowing in agricultural areas. By comparison with phosphorus fractions in paddy soil and activated sludge it was suggested that SS in the rivers flowing in agricultural areas mainly consisted of clay, silt or sand, while the SS in the urban river consisted of a large percentage of organic particles as well. Phosphorus in SS was suggested to be more easily bioavailable in the urban river than the rivers in agricultural areas. The ratio of C-BAP/B-BAP was large in the rivers in agricultural areas and small in the urban river. As HBAP contents were almost similar to B-BAP contents in the river SS, HBAP can be a suitable index of phosphorus indicating easily and rapidly the bioavailable fraction in SS. Keywords Bacterial respiration; bioavailable phosphorus; eutrophication; lake water management; oxygen uptake rate; phosphate analysis

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3

Thien, S. J., and R. Myers. "Determination of Bioavailable Phosphorus in Soil." Soil Science Society of America Journal 56, no. 3 (May 1992): 814–18. http://dx.doi.org/10.2136/sssaj1992.03615995005600030023x.

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4

Soares, Ana R. A., Ann-Kristin Bergström, Ryan A. Sponseller, Joanna M. Moberg, Reiner Giesler, Emma S. Kritzberg, Mats Jansson, and Martin Berggren. "New insights on resource stoichiometry: assessing availability of carbon, nitrogen, and phosphorus to bacterioplankton." Biogeosciences 14, no. 6 (March 24, 2017): 1527–39. http://dx.doi.org/10.5194/bg-14-1527-2017.

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Abstract. Boreal lake and river ecosystems receive large quantities of organic nutrients and carbon (C) from their catchments. How bacterioplankton respond to these inputs is not well understood, in part because we base our understanding and predictions on total pools, yet we know little about the stoichiometry of bioavailable elements within organic matter. We designed bioassays with the purpose of exhausting the pools of readily bioavailable dissolved organic carbon (BDOC), bioavailable dissolved nitrogen (BDN), and bioavailable dissolved phosphorus (BDP) as fast as possible. Applying the method in four boreal lakes at base-flow conditions yielded concentrations of bioavailable resources in the range 105–693 µg C L−1 for BDOC (2 % of initial total DOC), 24–288 µg N L−1 for BDN (31 % of initial total dissolved nitrogen), and 0.2–17 µg P L−1 for BDP (49 % of initial total dissolved phosphorus). Thus, relative bioavailability increased from carbon (C) to nitrogen (N) to phosphorus (P). We show that the main fraction of bioavailable nutrients is organic, representing 80 % of BDN and 61 % of BDP. In addition, we demonstrate that total C : N and C : P ratios are as much as 13-fold higher than C : N and C : P ratios for bioavailable resource fractions. Further, by applying additional bioavailability measurements to seven widely distributed rivers, we provide support for a general pattern of relatively high bioavailability of P and N in relation to C. Altogether, our findings underscore the poor availability of C for support of bacterial metabolism in boreal C-rich freshwaters, and suggest that these ecosystems are very sensitive to increased input of bioavailable DOC.

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5

Klement, Rejšek. "The Quantitative Estimate of Bioavailable Inorganic Phosphorus Content in Forest Soils by the Modification of the Anion-Exchange Resin Method." Soil and Water Research 1, No. 4 (January 7, 2013): 117–26. http://dx.doi.org/10.17221/6513-swr.

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The anion-exchange resin (AER) method for the estimation of bioavailable phosphorus was slightly optimised for soils with high contents of readily soluble organic compounds as well as for those having very different clay and sand contents. The method based on a strong base anion exchanger, the active group of trimethyl benzyl ammonium, the field moist soil, and the enclosure of resin beds in a bag was very different soils under relatively uniform outer conditions where the determination of the absorbance of (blue) phosphate-molybdate complex at 870 nm is used. The motivation of the proposed method comes from distinctive features of forest soils where marked differences are commonly encountered between clay/silt/sand contents, pH-values, and the contents of organic substances. A modestly new methodology was applied for the evaluation of seasonal phosphorus dynamics in a forest environment. The recommended rapid assay for available phosphorus was statistically compared with other procedures. Considerable seasonal effects on the bioavailable P contents were demonstrated.

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6

Nausch, M., and G. Nausch. "Bioavailable dissolved organic phosphorus and phosphorus use by heterotrophic bacteria." Aquatic Biology 1 (November 29, 2007): 151–60. http://dx.doi.org/10.3354/ab00012.

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7

Nolan, AL, GA Lawrance, and M. Maeder. "Phosphorus speciation in the Williams River, New South Wales: Eutrophication and a chemometric analysis of relationships with other water quality parameters." Marine and Freshwater Research 46, no. 7 (1995): 1055. http://dx.doi.org/10.1071/mf9951055.

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Phosphorus concentrations as both total phosphorus and partitioned (dissolved, 'bioavailable' and 'available-reactive') phosphorus have been determined in a quality-controlled study of the Williams River in the Hunter Valley, Australia, at Boags Hill during a five-month period. Complementary analyses of each sample for a range of standard water quality parameters were also obtained. Strong interrelationships between total phosphorus and partitioned phosphorus suggest that total phosphorus alone may be as adequate an indicator of potential algal growth as bioavailable phosphorus in this river system, an outcome supported by limited algal bioassay results. Principal component or factor analysis of the complete data set allowed qualitative insight into the relationship between the different concentrations (relevant cations and anions) and other measurements (colour (apparent), turbidity, etc.). Compounds from similar sources are clustered in the principal component plots. The samples taken over a specific time period have been analysed in a similar way, with clustering according to rainfall patterns being clearly indicated.

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8

Herndon, Elizabeth, Lauren Kinsman-Costello, Nicolle Di Domenico, Kiersten Duroe, Maximilian Barczok, Chelsea Smith, and Stan D. Wullschleger. "Iron and iron-bound phosphate accumulate in surface soils of ice-wedge polygons in arctic tundra." Environmental Science: Processes & Impacts 22, no. 7 (2020): 1475–90. http://dx.doi.org/10.1039/d0em00142b.

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9

Sharpley, Andrew N., W. W. Troeger, and S. J. Smith. "The Measurement of Bioavailable Phosphorus in Agricultural Runoff." Journal of Environmental Quality 20, no. 1 (January 1991): 235–38. http://dx.doi.org/10.2134/jeq1991.00472425002000010037x.

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10

Sharpley, Andrew N., S. J. Smith, O. R. Jones, W. A. Berg, and G. A. Coleman. "The Transport of Bioavailable Phosphorus in Agricultural Runoff." Journal of Environmental Quality 21, no. 1 (January 1992): 30–35. http://dx.doi.org/10.2134/jeq1992.00472425002100010003x.

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11

Sharpley, Andrew N., and S. J. Smith. "Prediction of Bioavailable Phosphorus Loss in Agricultural Runoff." Journal of Environmental Quality 22, no. 1 (January 1993): 32–37. http://dx.doi.org/10.2134/jeq1993.00472425002200010004x.

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12

Ciopińska, Joanna, Elżbieta Bezak–Mazur, Renata Stoińska, and Bartosz Szeląg. "The impact of Bacillus megaterium on the solubilisation of phosphorus from sewage sludge." E3S Web of Conferences 86 (2019): 00032. http://dx.doi.org/10.1051/e3sconf/20198600032.

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The aim of this work was to analyse the influence of Bacillus megaterium bacteria on the solubilisation of phosphorus in a sewage sludge. The tests were carried out for two different temperature conditions, i.e. 21 and 36ºC. In the experiment, lasting 23 days, the course of phosphorus solubilization under the influence of a changing population of bacteria was determined using Golterman’s speciation analysis. This method allows to estimating the fraction of bioavailable phosphorus in the tested samples. The obtained results allow one to state that the population size of Bacillus megaterium bacteria changes, while the intensity of these changes depends on temperature and organic acids produced in metabolic processes change the pH of the environment, which affects phosphorus solubilisation and its speciation. The increase in the population of bacteria is accompanied by the increase in bioavailable phosphorous forms, and thus the release of phosphorus contained in the form of sparingly soluble forms in soil. The above fact is extremely important when considering the use of sewage sludge for natural purposes.

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13

Auer, Martin, Cory McDonald, Anika Kuczynski, Chenfu Huang, and Pengfei Xue. "Management of the Phosphorus–Cladophora Dynamic at a Site on Lake Ontario Using a Multi-Module Bioavailable P Model." Water 13, no. 3 (January 31, 2021): 375. http://dx.doi.org/10.3390/w13030375.

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The filamentous green alga Cladophora grows to nuisance proportions in Lake Ontario. Stimulated by high phosphorus concentrations, nuisance growth results in the degradation of beaches and clogging of industrial water intakes with attendant loss of beneficial uses. We develop a multi-module bioavailable phosphorus model to examine the efficacy of phosphorus management strategies in mitigating nuisance algal growth. The model platform includes modules simulating hydrodynamics (FVCOM), phosphorus-phytoplankton dynamics (GEM) and Cladophora growth (GLCMv3). The model is applied along a 25 km stretch of the Lake Ontario nearshore, extending east from Toronto, ON and receiving effluent from three wastewater treatment plants. Simulation results identify the Duffin Creek wastewater treatment plant effluent as a driving force for nuisance conditions of Cladophora growth, as reflected in effluent bioavailable phosphorus concentrations and the dimensions of the plant’s phosphorus footprint. Simulation results demonstrate that phosphorus removal by chemically enhanced secondary treatment is insufficient to provide relief from nuisance conditions. Tertiary treatment (chemically enhanced secondary treatment with ballasted flocculation) is shown to eliminate phosphorus-saturated conditions associated with the Duffin Creek wastewater treatment plant effluent, providing local relief from nuisance conditions. Management guidance presented here has wider application at sites along the highly urbanized Canadian nearshore of Lake Ontario.

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14

Nenes, A., M. D. Krom, N. Mihalopoulos, P. Van Cappellen, Z. Shi, A. Bougiatioti, P. Zarmpas, and B. Herut. "Atmospheric acidification of mineral aerosols: a source of bioavailable phosphorus for the oceans." Atmospheric Chemistry and Physics Discussions 11, no. 2 (February 21, 2011): 6163–85. http://dx.doi.org/10.5194/acpd-11-6163-2011.

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Abstract. Primary productivity of continental and marine ecosystems is often limited or co-limited by phosphorus. Deposition of atmospheric aerosols provides the major external source of phosphorus to surface waters. However, only a fraction of deposited aerosol phosphorus is water soluble and available for uptake by phytoplankton. We propose that atmospheric acidification of aerosols is a prime mechanism producing soluble phosphorus from soil-derived minerals. Acid mobilization is expected to be pronounced where polluted and dust-laden air masses mix. Our hypothesis is supported by the soluble compositions and reconstructed pH values for atmospheric particulate matter samples collected over a 5-year period at Finokalia, Crete. At least tenfold increase in soluble phosphorus is observed when Saharan soil and dust were acidified in laboratory experiments which simulate atmospheric conditions. Aerosol acidification links bioavailable phosphorus supply to anthropogenic and natural acidic gas emissions, and may be a key regulator of ocean biogeochemistry.

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15

Nenes, A., M. D. Krom, N. Mihalopoulos, P. Van Cappellen, Z. Shi, A. Bougiatioti, P. Zarmpas, and B. Herut. "Atmospheric acidification of mineral aerosols: a source of bioavailable phosphorus for the oceans." Atmospheric Chemistry and Physics 11, no. 13 (July 1, 2011): 6265–72. http://dx.doi.org/10.5194/acp-11-6265-2011.

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Abstract. Primary productivity of continental and marine ecosystems is often limited or co-limited by phosphorus. Deposition of atmospheric aerosols provides the major external source of phosphorus to marine surface waters. However, only a fraction of deposited aerosol phosphorus is water soluble and available for uptake by phytoplankton. We propose that atmospheric acidification of aerosols is a prime mechanism producing soluble phosphorus from soil-derived minerals. Acid mobilization is expected to be pronounced where polluted and dust-laden air masses mix. Our hypothesis is supported by the soluble compositions and reconstructed pH values for atmospheric particulate matter samples collected over a 5-yr period at Finokalia, Crete. In addition, at least tenfold increase in soluble phosphorus was observed when Saharan soil and dust were acidified in laboratory experiments which simulate atmospheric conditions. Aerosol acidification links bioavailable phosphorus supply to anthropogenic and natural acidic gas emissions, and may be a key regulator of ocean biogeochemistry.

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16

Szara, Ewa, Tomasz Sosulski, and Magdalena Szymańska. "Impact of long-term liming on sandy soil phosphorus sorption properties." Soil Science Annual 70, no. 1 (March 1, 2019): 13–20. http://dx.doi.org/10.2478/ssa-2019-0002.

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Abstract The static fertilisation experiment conducted in Skierniewice (Central Poland) since 1923 investigates the effect of mineral fertilisation with lime (CaNPK) or without lime (NPK) on the accumulation and release of phosphorus in reference to phosphorus sorption properties in the sandy soil profile. In the case of application of same doses of mineral fertilisers, the content of total phosphorus was higher in NPK than CaNPK soil. Parameters related to sorption capacity and bonding energy from Langmuir and Freundlich model of P sorption were significantly lower in CaNPK than NPK soil profile. This was particularly caused by a lower content of poorly crystallised hydro(oxide) aluminium and iron forms in CaNPK than NPK soil. Higher content of oxide-extractable and bioavailable phosphorus extracted with double lactate solution, dissolved reactive phosphorus in water solution as well as degree of phosphorus saturation in the CaNPK soil profile suggests higher mobility and possibility of occurrence of losses of phosphorus from the profile of limed soil than from acidified soil. Therefore, management of phosphate fertilizers on permanently limed sandy soils requires the optimisation of phosphorus doses to a greater degree corresponding to the actual take-off of the element with crop. An additional finding of the study was evidence of the possibility of re-estimating contents of bioavailable phosphorus and, as a consequence, the degree of phosphorus saturation with Mehlich3 method in strongly acid soil receiving P mineral fertilisers, which can make it difficult to use the test for fertiliser recommendation.

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17

Shepherd, Heather A. M., Matt T. Trentman, Jennifer L. Tank, Jennifer Praner, Anissa Cervantes, Priya Chaudhary, Jonah Gezelter, et al. "Development of a Yeast-Based Assay for Bioavailable Phosphorus." ACS ES&T Water 1, no. 9 (August 26, 2021): 2020–28. http://dx.doi.org/10.1021/acsestwater.1c00111.

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18

Jansson, Mats, Martin Berggren, Hjalmar Laudon, and Anders Jonsson. "Bioavailable phosphorus in humic headwater streams in boreal Sweden." Limnology and Oceanography 57, no. 4 (July 2012): 1161–70. http://dx.doi.org/10.4319/lo.2012.57.4.1161.

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19

Xuan, Meng Ru, Meng Zhao, Shuai Bing, and Xue Song Li. "Forms and Bioavailability of Phosphorus in the Suspended Solids of A²/O Process." Advanced Materials Research 955-959 (June 2014): 561–64. http://dx.doi.org/10.4028/www.scientific.net/amr.955-959.561.

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To investigate the potential bioavailability and mobility of phosphorus (P) in suspended solids, the Standards, Measurements and Testing (SMT) programmers was employed to characterize the distribution of P in suspended solids from different treatment stage of KunmingWWTP.Results showed that: the main form of total phosphorus (TP) in suspended solids was inorganic phosphorus (IP) ,which accounted for 47%~60%.Amongdifferent forms of inorganic phosphorus, Iron-phosphorus was the dominant forms accounted for 82 % of total phosphorus while calcium-phosphorus was only the minor par. Throughout the process, the trend of changes in content is close between total phosphorus and organ phosphorus. Bioavailable phosphorus in suspended solids ranged from 5.903 mg·g-1to7.376mg·g-1 and occupied 89.64%to94.16% of the total phosphorus pool.

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20

Lutsey, Pamela L., Christina M. Parrinello, Jeffrey R. Misialek, Andy N. Hoofnagle, Clark M. Henderson, Thomas J. Laha, Erin D. Michos, John H. Eckfeldt, and Elizabeth Selvin. "Short-term Variability of Vitamin D–Related Biomarkers." Clinical Chemistry 62, no. 12 (December 1, 2016): 1647–53. http://dx.doi.org/10.1373/clinchem.2016.261461.

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Abstract BACKGROUND Quantifying the variability of biomarkers is important, as high within-person variability can lead to misclassification of individuals. Short-term variability of important markers of vitamin D metabolism is relatively unknown. METHODS A repeatability study was conducted in 160 Atherosclerosis Risk in Communities study participants (60% female, 28% black, mean age 76 years). Fasting serum was drawn at 2 time points, a median of 6 (range 3–13) weeks apart. Vitamin D binding protein (VDBP) and 25-hydroxyvitamin D [25(OH)D] were measured by LC-MS, fibroblast growth factor (FGF23) and parathyroid hormone (PTH) by enzyme-linked immunoassay, and calcium and phosphorus by Roche Cobas 6000. Free and bioavailable 25(OH)D were calculated. We calculated the within-person CV (CVW), intraclass correlation coefficient (ICC), Spearman rank correlation coefficient (r), and percent reclassified. RESULTS The CVW was lowest for calcium (2.0%), albumin (3.6%), 25(OH)D (6.9%), VDBP (7.0%) and phosphorus (7.6%); intermediate for free 25(OH)D (9.0%) and bioavailable 25(OH)D (9.9%); and highest for PTH (16.7%) and FGF23 (17.8%). Reclassification was highest for PTH, VDBP, and phosphorus (all 7.5%). The ICC and r were highest (≥0.80) for 25(OH)D, free 25(OH)D, bioavailable 25(OH)D and PTH, but somewhat lower (approximately 0.60–0.75) for the other biomarkers. CONCLUSIONS Six-week short-term variability, as assessed by CVW, was quite low for VDBP, calcium and phosphorus, but fairly high for FGF23 and PTH. As such, multiple measurements of FGF23 and PTH may be needed to minimize misclassification. These results provide insight into the extent of potential misclassification of vitamin D markers in research and clinical settings.

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21

Kouyate, Aliou Badara, Ali Ibrahim, Idriss Serme, and Sidiki Gabriel Dembele. "Sorghum responses to different forms of Tilemsi rock phosphate combined with soluble fertilizers in a low-input production system in Mali." International Journal of Biological and Chemical Sciences 14, no. 9 (March 25, 2021): 3285–96. http://dx.doi.org/10.4314/ijbcs.v14i9.25.

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The deficiency in bioavailable phosphorus is one of the major constraints to cereal production in Mali. The objective of this study was to assess the combined effects of Tilemsi rock phosphate (PNT) with different doses of soluble fertilizers on the solubility of rock phosphate, the agronomic performance of sorghum and the chemical properties of the soil. The study consisted of the comparison of four (4) types of fertilization at three (3) levels of variation 0 kg.ha-1; 11 kg.ha-1, and 16 kg.ha-1 of phosphorus arranged in a complete randomized block with three replicates. The combination of PNT with sulfate ammonium (NH4) 2SO4 resulted in a significant increase in grain and biomass yields during the two years of the study. The increase of the rate of phosphate rock application lead to improve the sorghum grain yield by an average of 29%. The combined application of sulfate ammonium (NH4) 2SO4 with PNT significantly increased the phosphorus uptake indices from PNT. These results show that there is a possibility of improving the productivity of sorghum in Mali with the combined use of Tilemsi rock phosphate and soluble fertilizers, particularly sulfate ammonium. La déficience en phosphore assimilable du sol est l’une des contraintes majeures à la production céréalière au Mali. L’objectif de cette étude est d’évaluer les effets de différentes formules de fumures à base du phosphore naturel de tilemsi (PNT) et d’engrais azotés et potassiques sur les propriétés chimiques du sol et les performances agronomiques du sorgho. Pour ce faire, un dispositif factoriel en blocs complètement randomisés a été implanté. Le premier facteur est composé des 4 formules de fumures (PNT granule (P), PNT granule avec KCl , PNT granule avec (NH4)2SO4 et PNT granule avec KCl et (NH4)2SO4 ) et le second facteur les niveaux de doses de phosphore (0 kg.ha-1; 11 kg.ha-1, et 16 kg.ha-1). L’association du PNT avec le sulfate d’ammonium (NH4)2SO4 a entraîné une augmentation significative des rendements grain et biomasse pendant les deux annéesd’étude. L’augmentation de la dose d’apport du phosphore a amélioré le rendement grain de 29% en moyenne. L’application combinée du sulfate d’ammonium (NH4)2SO4 avec le PNT a augmenté significativement l’efficacité agronomique du PNT. Ces résultats montrent qu’il y a une possibilité d’améliorer la productivité du sorgho au Mali avec l’utilisation combinée de phosphore naturel de Tilemsi à la dose de 16 kg.ha-1 et les engrais solubles notamment le sulfate d’ammonium. Ainsi cette formulation pourrait être recommandée en culture de sorgho pour les producteurs à faible revenu en zone Sahélienne du Mali.

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22

Ran, Xiang-bin, Hong-tao Chen, Jun-feng Wei, Qing-zhen Yao, Tie-zhu Mi, and Zhi-gang Yu. "Phosphorus speciation, transformation and retention in the Three Gorges Reservoir, China." Marine and Freshwater Research 67, no. 2 (2016): 173. http://dx.doi.org/10.1071/mf14344.

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Damming of river systems allowing the transformation of former rivers into artificial lakes will increase the transformation and retention of dissolved and sediment-associated phosphorus (P). The reservoir is therefore a ‘filter’ or ‘converter’, reducing and delaying the transport of nutrients to marine systems. Our study of the Three Gorges Reservoir (TGR) found that no stratification of phosphorus occurred, and the high particulate phosphorus (PP) concentrations upstream decreased gradually in the reservoir. Detrital P was found in greater concentrations in the surface sediment, accounting for 39% of PP; exchangeable P was rare and contributed very little to the total P budget. P forms and their concentrations in the suspended particulate matter varied throughout the TGR, with a significant increase of bioavailable P in the <8-μm particle fraction from 27% of PP in Fuling to 60% in Yichang, and decreasing detrital P and authigenic P in each grain size class. The TGR acted as a ‘converter’ for the dissolved reactive phosphorus, and it therefore plays a minor role in trapping incoming total dissolved phosphorus; whereas the TGR behaved as a ‘filter’ for the PP, especially for the coarse fraction, which resulted in the retention of 70% of the non-bioavailable PP. The controlling mechanism of P species and retention in the reservoir is particulate settling and its associated effects.

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23

Rankinen, Katri, Eila Turtola, Riitta Lemola, Martyn Futter, and José Enrique Cano Bernal. "Nutrient Load Mitigation with Wintertime Cover as Estimated by the INCA Model." Water 13, no. 4 (February 9, 2021): 450. http://dx.doi.org/10.3390/w13040450.

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Increased nutrient loading causes deterioration of receiving surface waters in areas of intensive agriculture. While nitrate and particulate phosphorus load can be efficiently controlled by reducing tillage frequency and increasing vegetation cover, many field studies have shown simultaneously increased loading of bioavailable phosphorus. In the latest phase of the Rural Programme of EU agri-environmental measures, the highest potential to reduce the nutrient loading to receiving waters were the maximum limits for fertilization of arable crops and retaining plant cover on fields with, e.g., no-till methods and uncultivated nature management fields. Due to the latter two measures, the area of vegetation cover has increased since 1995, suggesting clear effects on nutrient loading in the catchment scale as well. We modeled the effectiveness of agri-environmental measures to reduce phosphorus and nitrogen loads to waters and additionally tested the performance of the dynamic, process-based INCA-P (Integrated Nutrients in Catchments—Phosphorus) model to simulate P dynamics in an agricultural catchment. We concluded that INCA-P was able to simulate both fast (immediate) and slow (non-immediate) processes that influence P loading from catchments. Based on our model simulations, it was also evident that no-till methods had increased bioavailable P load to receiving waters, even though total P and total N loading were reduced.

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24

Johnstone, P. R., T. K. Hartz, M. D. Cahn, and M. R. Johnstone. "Lettuce Response to Phosphorus Fertilization in High Phosphorus soils." HortScience 40, no. 5 (August 2005): 1499–503. http://dx.doi.org/10.21273/hortsci.40.5.1499.

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Decades of heavy phosphorus (P) fertilization of vegetable crops in the Salinas Valley of California has increased soil test P (STP) levels, with bicarbonate-extractable P (Pbc) values >50 mg·kg–1 now common. To evaluate the response of lettuce (Lactuca sativa L.) to P fertilization in fields with elevated STP levels, 12 trials were conducted in commercial fields during 2002–03. Initial Pbc at the trial sites varied from 53 to 171 mg·kg–1. In each trial, four replicate plots receiving the growers' P application were compared with paired plots in which no P was applied. Leaf P was monitored at midseason and at harvest. At harvest, mean whole and marketable plant mass and percent of marketable plants were recorded. A significant increase in lettuce yield with P fertilization was achieved at only one trial site, a spring planting with 54 mg·kg–1 Pbc; at all other sites, including three with Pbc <60 mg·kg–1, P application resulted in no significant yield increase. Phosphorus application resulted in only a marginal increase in plant P uptake; in the nonresponsive fields leaf P concentration of nonfertilized plots was in excess of established sufficiency levels. In a laboratory study, the correlation of Pbc to bioavailable P (Pba) was evaluated using 30 representative Salinas Valley soils; Pbc varied among these soils from 15 to 177 mg·kg–1. Pba was estimated by P adsorption on an anion resin membrane during a 16 hour incubation. The effect of temperature on P bioavailability in six of these soils was estimated by conducting the Pba incubation at 5, 15, and 25 °C. Pba was highly correlated with Pbc (r = 0.89), and increased about 40% across soils with each 10 °C increase in soil temperature. Therefore, Pbc was determined to be an accurate reflection of bioavailable P in these soils, although the addition of a temperature correction factor in setting threshold values is desirable.

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Liu, Ling, Ying Zhang, Aris Efting, Tadd Barrow, Bao Qian, and Zejian Fang. "Modeling bioavailable phosphorus via other phosphorus fractions in sediment cores from Jiulongkou Lake, China." Environmental Earth Sciences 65, no. 3 (August 23, 2011): 945–56. http://dx.doi.org/10.1007/s12665-011-1295-2.

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Bradford, Marie E., and Robert Henry Peters. "The relationship between chemically analyzed phosphorus fractions and bioavailable phosphorus1." Limnology and Oceanography 32, no. 5 (September 1987): 1124–37. http://dx.doi.org/10.4319/lo.1987.32.5.1124.

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TEZUKA, Yasuhiko. "Is the Suspended Particulate Phosphorus in Lake Biwa Potentially Bioavailable?" Japanese Journal of Limnology (Rikusuigaku Zasshi) 55, no. 2 (1994): 171–74. http://dx.doi.org/10.3739/rikusui.55.171.

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28

Poirier, Simon-C., Joann K. Whalen, and Aubert R. Michaud. "Bioavailable Phosphorus in Fine‐Sized Sediments Transported from Agricultural Fields." Soil Science Society of America Journal 76, no. 1 (January 2012): 258–67. http://dx.doi.org/10.2136/sssaj2010.0441.

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Prestigiacomo, Anthony R., Steven W. Effler, Rakesh K. Gelda, David A. Matthews, Martin T. Auer, Benjamin E. Downer, Anika Kuczynski, and M. Todd Walter. "Apportionment of bioavailable phosphorus loads entering Cayuga Lake, New York." JAWRA Journal of the American Water Resources Association 52, no. 1 (November 14, 2015): 31–47. http://dx.doi.org/10.1111/1752-1688.12366.

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30

Dijkstra, Marcel L., Martin T. Auer, Anika Kuczynski, and Renn Lambert. "Determination of bioavailable phosphorus in water samples using bioassay methods." MethodsX 7 (2020): 100807. http://dx.doi.org/10.1016/j.mex.2020.100807.

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31

Ngoc, Nguyen Minh, Takanobu Inoue, and Kuriko Yokota. "Ultrasonic extraction method for quantifying bioavailable phosphorus in particulate form." Journal of Environmental Chemical Engineering 5, no. 3 (June 2017): 2498–507. http://dx.doi.org/10.1016/j.jece.2017.04.047.

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Grace, Michael R., Todd R. Scicluna, Chamindra L. Vithana, Peter Symes, and Katrina P. Lansdown. "Biogeochemistry and cyanobacterial blooms: investigating the relationship in a shallow, polymictic, temperate lake." Environmental Chemistry 7, no. 5 (2010): 443. http://dx.doi.org/10.1071/en10042.

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Environmental context.Effective mitigation of algal blooms, and their associated detrimental impacts on flora and fauna, requires an understanding of the factors leading to bloom development, including nutrients, light and hydrodynamics. We investigated a shallow, freshwater lake and demonstrate that there is sufficient bioavailable phosphorus to annually generate a large algal biomass. Extensive, seasonal phosphorus release from sediments is controlled by the interactions of the biogeochemical cycles of nitrogen, carbon, oxygen, iron and sulfur. Abstract.The shallow, polymictic Ornamental Lake in the Royal Botanic Gardens, Melbourne, Australia, has suffered significant blooms of toxic Anabaena then Microcystis species every summer over the last decade. Although the hydrodynamic conditions of the water column are conducive for algal growth, the prolific growth is controlled by the bioavailable phosphorus concentration. Springtime phosphorus fluxes of 0.1–0.2 mmol m–2 day–1 from the sediment contribute to bloom development. These rates are also observed in anoxic sediment core incubations. Diel stratification, combined with high oxygen consumption associated with organic carbon loading, favour P release. Release rates may be amplified by the effects of sulfate reduction on P sorption onto FeIII (oxyhydroxide) surfaces. Sulfate concentrations are at the threshold where methanogenesis is inhibited in anoxic conditions. Effective bloom mitigation will require a >100-fold reduction in P concentrations, which may be achieved through macrophyte planting and inducing greater water flow through the lake system.

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33

Ka Ling, Ting, Kuriko Yokota, Makoto Saga, and Takanobu Inoue. "Extraction of bioavailable phosphorus in soils and sediments using an ultrasonic washing machine." Water Science and Technology 83, no. 4 (January 8, 2021): 762–70. http://dx.doi.org/10.2166/wst.2021.014.

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Abstract For improving the management of watershed eutrophication, methods for measuring bioavailable phosphorus (BAP) are more important than measurements of total phosphorus (TP). BAP in particulate form (P-BAP) is an important substance that promotes eutrophication, especially during rainy seasons. Only a portion of particulate phosphorus (PP) is taken up by algae that contribute to eutrophication. Erosion and runoff associated with rainfall transport PP bound to sediments and soil particles to surface waters, thus increasing PP concentration. This research evaluated an extraction method using an ultrasonic washing machine for extraction time and frequency. Extraction at a frequency of 28–45 kHz and an extraction time of 1 min resulted in extracted P concentrations almost the same as concentrations extracted using conventional methods. This new method requires less time and is more efficient than conventional methods because it extracts P from multiple samples in a single step. Results indicate that extraction using an ultrasonic washing machine is a promising method for rapidly obtaining BAP from sediments and soil particles.

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Kulhánek, M., J. Balík, J. Černý, and V. Vaněk. "Evaluation of phosphorus mobility in soil using different extraction methods." Plant, Soil and Environment 55, No. 7 (August 16, 2009): 267–72. http://dx.doi.org/10.17221/43/2009-pse.

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Soil samples (from Czech and German long-term field experiments) were used to estimate different soil phosphorus (P) fractions. More than 200 topsoil (0–30 cm) samples from different fertilizing treatments were taken. These were analyzed for P in soil solution (PCaCl2) [0.01M CaCl2 extract], exchangeable sorbed P (Pex) [anion exchange (AE) membranes] and bioavailable P [Doppel-Lactat and Mehlich 3 (PDL and PM3)]. Other fractions analyzed were total inorganic (Pin), total (PM-tot) and organic (Porg) P [fractionation after Marks], P sorbed on Fe and Al (PFeAl) [fractionation after Schwertmann] and residual P (Par) [aqua regia extract]. Comparison of medians appeared to be better for evaluating extraction abilities. Phosphorus fractions were in the following order: (Par = 100%); PCaCl2 (0.2%) < Pex (9%) < PDL (10%) < PM3 (16%) < Pin (24%) < Porg (37%) < PFeAl (55%) < PM-tot (59%). Low amounts of Pin, Porg and PM-tot did not verify the applicability of the Marks’ fractionation for the set of studied soils. Close correlations at P ≤ 0.001 were found for all methods for estimating the fractions of bioavailable phosphates (PCaCl2, Pex, PDL and PM3). Statistically significant relations were observed between Pin with Par, PM-tot and PFeAl.

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35

Nogueirol, Roberta Corrêa, Wanderley José de Melo, Edna Ivani Bertoncini, and Luís Reynaldo Ferracciú Alleoni. "Effectiveness of Extractants for Bioavailable Phosphorus in Tropical Soils Amended with Sewage Sludge." Applied and Environmental Soil Science 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/720167.

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Urban wastes such as sewage sludge can be an economically viable alternative source for providing macro- and micronutrients to plants in tropical conditions. Sewage sludge is normally rich in phosphorus (P), which is present in soils mainly in organic forms, so that it is very important to establish methods for estimating its availability to plants. This study aimed to test three extractants that simulate P-uptake by maize (Zea mays) cropped in plots after 13 consecutive years of fertilization with sewage sludge, in a cycle of fertilized sugarcane (SaccharumL.) amended with sewage sludge and organic compost. Soil samples were collected at depths of 0–10, 10–20, and 20–40 cm in March 2010 from the two experimental areas. Soil P was extracted via ion exchange resin, Mehlich-I, and 0.025 M H2SO4and determined via colorimetry. Maize and sugarcane diagnostic leaves were collected in the experiments, subjected to nitric-perchloric digestion, and the leaf-P content was determined via colorimetry. No significant correlations were found between phosphorus extracted from soils and phosphorus concentrations in diagnostic leaves. Resin extracted larger amounts of P in the short-term experiment, while acidic extractants yielded larger amounts in the long-term experiment.

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36

Preisner, Michał, Elena Neverova-Dziopak, and Zbigniew Kowalewski. "Mitigation of eutrophication caused by wastewater discharge: A simulation-based approach." Ambio 50, no. 2 (May 25, 2020): 413–24. http://dx.doi.org/10.1007/s13280-020-01346-4.

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AbstractMitigation of eutrophication, intensified by excessive nutrient load discharge in wastewaters regulated by restrictive legal requirements, remains one of today’s most important global problems. Despite implementation of the Water Framework Directive, the Urban Wastewater Directive and the HELCOM recommendations, the actual condition of surface water is still not satisfactory. In response to the above, the study presents an alternative approach for surface water protection against eutrophication based on the selection of appropriate nutrient removal technologies. An activated sludge model simulation was used to enable the identification of environmentally justified nutrient removal systems with lowest eutrophication potential of treated wastewater conditioned by bioavailable nutrient forms content. Based on the outcome of the study, the 3-stage Bardenpho system was identified as the most efficient for bioavailable phosphorus removal, while the Johannesburg system proved to have the highest efficiency for bioavailable nitrogen removal. The proposed eutrophication mitigation approach underlines the need for a reconsideration of current legal regulations which ignore nutrient bioavailability and key eutrophication limiting factors.

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37

Brembu, Tore, Alice Mühlroth, Leila Alipanah, and Atle M. Bones. "The effects of phosphorus limitation on carbon metabolism in diatoms." Philosophical Transactions of the Royal Society B: Biological Sciences 372, no. 1728 (July 17, 2017): 20160406. http://dx.doi.org/10.1098/rstb.2016.0406.

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Phosphorus is an essential element for life, serving as an integral component of nucleic acids, lipids and a diverse range of other metabolites. Concentrations of bioavailable phosphorus are low in many aquatic environments. Microalgae, including diatoms, apply physiological and molecular strategies such as phosphorus scavenging or recycling as well as adjusting cell growth in order to adapt to limiting phosphorus concentrations. Such strategies also involve adjustments of the carbon metabolism. Here, we review the effect of phosphorus limitation on carbon metabolism in diatoms. Two transcriptome studies are analysed in detail, supplemented by other transcriptome, proteome and metabolite data, to gain an overview of different pathways and their responses. Phosphorus, nitrogen and silicon limitation responses are compared, and similarities and differences discussed. We use the current knowledge to propose a suggestive model for the carbon flow in phosphorus-replete and phosphorus-limited diatom cells. This article is part of the themed issue ‘The peculiar carbon metabolism in diatoms’.

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38

Ch’ng, Huck Ywih, Osumanu Haruna Ahmed, and Nik Muhamad Ab Majid. "Improving Phosphorus Availability in an Acid Soil Using Organic Amendments Produced from Agroindustrial Wastes." Scientific World Journal 2014 (2014): 1–6. http://dx.doi.org/10.1155/2014/506356.

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In acid soils, soluble inorganic phosphorus is fixed by aluminium and iron. To overcome this problem, acid soils are limed to fix aluminium and iron but this practice is not economical. The practice is also not environmentally friendly. This study was conducted to improve phosphorus availability using organic amendments (biochar and compost produced from chicken litter and pineapple leaves, resp.) to fix aluminium and iron instead of phosphorus. Amending soil with biochar or compost or a mixture of biochar and compost increased total phosphorus, available phosphorus, inorganic phosphorus fractions (soluble inorganic phosphorus, aluminium bound inorganic phosphorus, iron bound inorganic phosphorus, redundant soluble inorganic phosphorus, and calcium bound phosphorus), and organic phosphorus. This was possible because the organic amendments increased soil pH and reduced exchangeable acidity, exchangeable aluminium, and exchangeable iron. The findings suggest that the organic amendments altered soil chemical properties in a way that enhanced the availability of phosphorus in this study. The amendments effectively fixed aluminium and iron instead of phosphorus, thus rendering phosphorus available by keeping the inorganic phosphorus in a bioavailable labile phosphorus pool for a longer period compared with application of Triple Superphosphate without organic amendments.

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39

Sharpley, A. N., R. Indiati, C. Ciavatta, N. Rossi, and P. Sequi. "Interlaboratory Comparison of Iron Oxide-Impregnated Paper to Estimate Bioavailable Phosphorus." Journal of Environmental Quality 23, no. 1 (January 1994): 14–18. http://dx.doi.org/10.2134/jeq1994.00472425002300010004x.

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40

Fang, F., P. L. Brezonik, D. J. Mulla, and L. K. Hatch. "Characterization of Soil Algal Bioavailable Phosphorus in the Minnesota River Basin." Soil Science Society of America Journal 69, no. 4 (July 2005): 1016–25. http://dx.doi.org/10.2136/sssaj2003.0093.

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41

Ngoc, Nguyen Minh, Kuriko Yokota, Mbabazi James, and Takanobu Inoue. "The estimation of bioavailable phosphorus in particulate forms by ultrasonic treatment." Water and Environment Journal 31, no. 4 (June 11, 2017): 492–97. http://dx.doi.org/10.1111/wej.12270.

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42

Van Donk, E., B. A. Faafeng, D. O. Hessen, and T. Källqvist. "Use of immobilized algae for estimating bioavailable phosphorus released by zooplankton." Journal of Plankton Research 15, no. 7 (1993): 761–69. http://dx.doi.org/10.1093/plankt/15.7.761.

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43

Sharpley, Andrew N., J. S. Robinson, and S. J. Smith. "Bioavailable phosphorus dynamics in agricultural soils and effects on water quality." Geoderma 67, no. 1-2 (June 1995): 1–15. http://dx.doi.org/10.1016/0016-7061(94)00027-8.

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44

Melia, Patrick M., Andrew B. Cundy, Saran P. Sohi, Peter S. Hooda, and Rosa Busquets. "Trends in the recovery of phosphorus in bioavailable forms from wastewater." Chemosphere 186 (November 2017): 381–95. http://dx.doi.org/10.1016/j.chemosphere.2017.07.089.

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45

Lin, Zhenmei, Chen Zhong, Guolong Yu, Yishu Fu, Baohua Guan, Zhengwen Liu, and Jinlei Yu. "Effects of Sediments Phosphorus Inactivation on the Life Strategies of Myriophyllum spicatum: Implications for Lake Restoration." Water 13, no. 15 (July 31, 2021): 2112. http://dx.doi.org/10.3390/w13152112.

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Eutrophication often results in the loss of submerged vegetation in shallow lakes and turns the lake to be a turbid state. Recovery of submerged macrophytes is the key in the restoration of shallow eutrophic lakes to create a clear water state. However, internal loading control was considered as the critical process for the recovery of submerged macrophytes in shallow lakes after the external nutrient reduction. Phoslock® (Lanthanum modified bentonite) is a useful passivation material in controlling the internal loadings (release of phosphorus from the sediments), which was applied to restore the eutrophic lakes. However, the effects of Phoslock® on the growth and life strategies of submerged macrophytes are less focused so far. In the present study, we studied the responses in the growth and morphological characteristics of Myriophyllum spicatum to the addition of Phoslock® to the sediments. Our results showed that the addition of Phoslock® significantly decreased the contents of bioavailable forms of phosphorus in the sediments, such as redox-sensitive phosphorus bound to Fe and Mn compounds (BD–P), phosphorus bound to aluminum (Al–P) and organic phosphorus (Org–P). However, the concentration of the non-bioavailable forms of phosphorus in the sediments, such as calcium bound phosphorus (Ca–P), increased significantly in the Phoslock® treatments compared with the controls. At the end of the experiments, the total biomass, aboveground biomass and relative growth rate (RGR) of M. spicatum decreased significantly in the Phoslock® mesocosms compared with the controls. In contrast, the wet root biomass, root–shoot biomass ratio, root numbers and root length of M. spicatum were significantly higher in the Phoslock® treatments than that in the controls. Our results indicated that the growth of M. spicatum was suppressed by the addition of Phoslock®, and thus the biomass was decreased; however, the increase of root biomass might be beneficial to the inhibition of phosphorus release and resuspension of sediments and to the restoration of the lake ecosystem.

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46

Tanaka, Mayuki, Robert Snyder, John K. Boateng, William J. Lamont, Michael D. Orzolek, Kathleen M. Brown, and Jonathan P. Lynch. "Utility of Alumina-buffered Phosphorus Fertilizer for Vegetable Production." HortScience 41, no. 3 (June 2006): 775–79. http://dx.doi.org/10.21273/hortsci.41.3.775.

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The utility of alumina-buffered phosphorus (Al-P) fertilizers for supplying phosphorus (P) to bell pepper (Capsicum annuum L.) in soils with low-P availability was evaluated. Plants were grown at low-P fertility (about 100 kg·ha–1, low-P control; LPC), with conventional P fertilization (205-300 kg·ha–1 annually, fertilizer control; FC), or with one of two Al-P sources (Martenswerke or Alcoa) in 2001–03. The two Al-P fertilizers were applied in 2001; no additional material was applied in 2002-03. Plants grown with Martenswerke Al-P had similar shoot dry weight, root dry weight, root length, leaf P concentration, and fruit yield compared with plants grown with conventional P fertilizer in both 2002 and 2003 seasons. Bell pepper grown with Alcoa Al-P had similar shoot dry weight, root dry weight, root length, leaf P concentration, and fruit yield compared with plants grown without P fertilizer in both seasons. Alcoa Al-P continuously released bioavailable P for 2 years between 2001 and 2002, while Martenswerke Al-P continuously released bioavailable P at least 3 years between 2001 and 2003. These results indicate that some formulations of Al-P can serve as long-term P sources for field vegetable production.

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47

Celikkol, Sukriye, Nathalie Fortin, Nicolas Tromas, Herinandrianina Andriananjamanantsoa, and Charles W. Greer. "Bioavailable Nutrients (N and P) and Precipitation Patterns Drive Cyanobacterial Blooms in Missisquoi Bay, Lake Champlain." Microorganisms 9, no. 10 (October 4, 2021): 2097. http://dx.doi.org/10.3390/microorganisms9102097.

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Anthropogenic activities release large amounts of nitrogen (N) and phosphorus (P) nutrients into the environment. Sources of nutrients include surface and sub-surface runoffs from agricultural practices with the application of chemical fertilizers and manure as well as combined sewer overflows (CSOs). Nutrient runoffs contribute to the eutrophication of aquatic ecosystems and enhance the growth of cyanobacteria. Precipitation is an important driving force behind the runoff of nutrients from agricultural fields into surrounding water bodies. To understand the dynamics between nutrient input, precipitation and cyanobacterial growth in Missisquoi Bay, Lake Champlain (Quebec), one location in Pike River (a major tributary into the bay) and four locations in Missisquoi Bay were monitored from April to November in 2017 and 2018. Biweekly water samples were analyzed using chemical methods and high-throughput sequencing of 16S rRNA gene amplicons. High concentrations of N and P were typically measured in April and May. Three major spikes in nutrient concentrations were observed in early and mid-summer as well as early fall, all of which were associated with intense cumulative precipitation events of 40 to 100 mm within 7 days prior to sampling. Despite the high concentrations of nutrients in the spring and early summer, the cyanobacterial blooms appeared in mid to late summer as the water temperature increased. Dolichospermum sp. was the major bloom-forming cyanobacterium during both summers. A second intense bloom event of Microcystis was also observed in the fall (October and November) for both years. Variation in the cyanobacteria population was strongly associated with inorganic and readily available fractions of N and P such as nitrites and nitrates (NOx), ammonia (NH3) and dissolved organic phosphorus (DOP). During blooms, total Kjeldahl nitrogen (TKN) and total particulate phosphorus (TPP) fractions had a substantial influence on total nitrogen (TN) and total phosphorus (TP) concentrations, respectively. The abundance of bacteria involved in the metabolism of nitrogen compared to that of phosphorus revealed the importance of nitrogen on overall microbial dynamics as well as CB formation in the bay. Our findings emphasize the combined influence of precipitation events, temperature and several bioavailable fractions of nitrogen and phosphorus on cyanobacterial bloom episodes.

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48

Tian, Xin, Haijian Bing, Yanhong Wu, He Zhu, Wei Zhao, Qingqing He, and Donghong Xiong. "Farmland abandonment decreases soil bioavailable phosphorus but increases organic phosphorus in the mid-hills of Nepal." CATENA 211 (April 2022): 106000. http://dx.doi.org/10.1016/j.catena.2021.106000.

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49

Dixon, Mary, Eric Simonne, Thomas Obreza, and Guodong Liu. "Crop Response to Low Phosphorus Bioavailability with a Focus on Tomato." Agronomy 10, no. 5 (April 27, 2020): 617. http://dx.doi.org/10.3390/agronomy10050617.

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Tomato (Solanum lycopersicum L.) is a high-value crop that has potential to enhance its P-use efficiency. While phosphorus (P) is an essential nutrient, supplies are finite and much of the P supply in agricultural soils is not bioavailable after application due to reactions such as soil adsorption, immobilization, or precipitation. Low-P bioavailability results in reduced growth, so plants may mobilize soil-bound P by altering root morphology, exuding root-derived compounds, or forming symbiosis with microorganisms. This review discusses (i) the significance of P in plants and agroecosystems, (ii) within-plant response to changing P bioavailabilities, and (iii) strategies to enhance P-acquisition efficiency (PAE). Phosphorus forms fluctuate in the soil and potential approaches to increase the bioavailable pool of P may focus on processes such as desorption, mineralization, or dissolving precipitated P-compounds. To enhance these processes, roots may alter their spatial arrangement, exude protons to acidify the rhizosphere, exude carboxylates to solubilize bound-P, exude phosphatase to mineralize organic P, or enhance symbiosis with native microbes. High PAE allows for use of accumulated soil P as opposed to relying on fertilizer application to meet crop demand.

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50

Wang, Chunlei, Herong Gui, Chen Li, Jiayu Chen, and Chen Chen. "Effect of magnetic iron-zirconium modified zeolite on the different phosphorus forms in river sediment under aerobic and anoxic conditions." Water Science and Technology 84, no. 4 (July 9, 2021): 941–53. http://dx.doi.org/10.2166/wst.2021.271.

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Abstract In this study, a magnetic iron-zirconium modified zeolite (FeZrMZ) was synthesized. Through sediment culture experiments, the influence of the addition of modified materials on the migration and transformation of phosphorus in river sediments was investigated. The results showed that the modified zeolite could not only effectively reduce the phosphorus concentration in the overlying water, but also significantly reduce the phosphorus concentration in the pore water of sediments. The addition of modified zeolite makes the unstable weakly adsorbed phosphorus (NH4Cl-P) and redox phosphorus (BD-P) transform into the more stable metal oxide-bound phosphorus (NaOH-P) and very stable residual phosphorus (Res-P). The four types of bioavailable phosphorus (BAP), including water-soluble phosphorus (WSP), readily desorbable phosphorus (RDP), algae-available phosphorus (AAP), and NaHCO3 extractable phosphorus (Olsen-P). Under anoxic conditions, they were reduced by 53.5%, 14.1%, 23.8%, and 49.9% respectively. Under aerobic conditions, they were reduced by 23.2%, 16.6%, 32.1%, and 50.0%. The addition of magnetic iron-zirconium modified zeolite could clearly reduce the release potential of phosphorus in sediment, and it could be recovered through the action of an external magnetic field, so it could be used as an effective sediment modifier to control the sediment release of phosphorus.

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