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Showing 10 results for Phosphate

S. Farrahi-Ashtiani, M. Mahdiyeh, I. Nahvi,
Volume 6, Issue 2 (7-2002)
Abstract

In order to increase ketocarotenoid astaxanthin production by Haematococcus pluvialis, the effects of salinity, phosphate deprivation and eosin on growth and astaxanhin production were examined. The experiments were carried out in the growth chamber at 20oC under sterile conditions. The results showed that under salinity, phosphate deprivation and eosin supply, encystment was induced, and at the same time, astaxanthin formation and dry weight increased. Furthermore, by adding histidine to culture medium as a quencher of singlet oxygen, astaxanthin production significantly reduced. Therefore, it can be claimed that accumulation of astaxanthin may be related to antioxidative responses, which increased survival of algal cells under environmental stress conditions.
Sh. Mahmood-Soltani, A. Samadi,
Volume 7, Issue 3 (10-2003)
Abstract

Knowledge of forms of phosphorus (P) is important in the evaluation of soil P status and also in understanding soil genesis and fertility. Amounts and distribution of P in different organic and inorganic fractions were examined in 39 soil samples of Fars province. Soils were sequentially extracted to determine organic P and inorganic P fractions. Total P with an average of 597 mg/kg soil was lower in the light soils (482 mg/kg) as compared with the heavy soils (690 mg/kg). Organic P constituted considerable portions of TP (27%). Calcium phosphates with an average of 424 mg/kg soil and being comprised of 71% inorganic P was the dominant form of soil phosphorus. Simple regression analysis indicated that there were significant positive relationships between organic P, Ca phosphates and Al-Fe phosphate values with CEC and clay content. Stepwise multiple regression analysis showed that a combination of soil properties such as clay content and equivalent calcium carbonate (CCE) increased correlation coefficients (R). Alghough multiple regression model was significant (at P<0.05), the relative contribution of each soil property in Al-Fe-P fraction was not considerable.
L. Rasipour, N. Aliasgharzadeh,
Volume 11, Issue 40 (7-2007)
Abstract

Certain microorganisms in soil have phosphate solubilizing ability. Phosphorus has an important role in plant nutrition and N2 fixation in legumes. The interactive effect of three phosphate solubilizing bacteria (PSB) and Bradyrhizobium japonicum on yield and N, P, K uptake and nodulation of soybean root (Glycin max L. CV. Harcor) was studied under greenhouse conditions. In greenhouse experiment treatments consisted of a factorial combination of four levels of PSB (without PSB M0 ,Pseudomonas putida M1 , Aeromonas hydrophila M2 , Pseudomonas fluorescens M3) and two levels of B.japonicum (without bacterium B0 and with bacterium B1) and three levels of P(P0 = 0 , P1=29, P2 = 58 mg triple superphosphate/Kg soil) in a randomized complete block design with four replications. At harvest, shoot dry weight, seed weight, nodule number, dry and fresh weight of nodules and concentrations of N, P, K in shoot dry matter were measured. PSB significantly increased shoot dry weight, N, P, K concentrations in shoot, fresh and dry weight and number of root nodules. B.japonicum had positive significant effect on these parameters as well as on seed weight. Dual inoculation of plants with PSB and B.japonicum had significant effect on shoot dry weight, P and N concentrations in shoot. Increasing phosphorus levels significantly increased plant dry weight, shoot P concentration and seed weight. Highest P concentration in shoot was obtained at P2 level but in plants inoculated with P.putida, dry weight at P1 level was not significantly different from P2 level.
A. Moshgeli , J. Pourreza, A. Samie,
Volume 12, Issue 43 (4-2008)
Abstract

This experiment was conducted to determine the phosphorus relative bioavailability of eight samples of dicalcium phosphate. Bioavailability of Samples of dicalcium phosphate was evaluated and their effects on performance of laying hens were investigated. Commercial samples of Dicalcium Phosphate were provided from the following manufacturers: Iran Phosphate, Partove Bashash, Godaze, Poya Khojaste, Dan Razy Kimia, Phosphore Iran, Golbar Shimi and Dan Avar. The Parameters measured were shell strength, shell thickness, shell ash percentage, shell percentage, shell calcium and phosphorus percentage, Haugh unit, egg weight, egg production, egg output, feed consumption, feed conversion ratio, tibial ash, and tibial calcium and phosphorus. One hundred and six, and 36 weeks old white Leghorn hens, from strain Hi-line W-36, were randomly allocated to 8 dietary treatments and 4 blocks in a completely randomized block design. The experiment lasted for 3 months, starting in the 36th week and ended in the 48week of age. Shell thickness, shell ash percentage, shell percentage, feed consumption, tibial ash and tibial calcium percentage were significantly different (P< 0.05) among treatments. Effect of experimental period on shell calcium and phosphorus percentage, egg weight, egg production, feed consumption, egg output was significant (P< 0.05). Relative bioavailability of samples ranged from 85 to 105.7%. Overall, samples of Phosphate Iran (F) were considered most effective with regard to relative bioavailability and performance.
A Esfahani, A Hoseyn Zade, J Asghari, M Naghizadeh, B Rabiee,
Volume 13, Issue 48 (7-2009)
Abstract

In order to evaluate the effects of sulphur fertilizer sources and amounts on growth indices and yield of peanut (Arachis hypogaea L. CV. NC2), a field experiment was conducted in Bandar Kiaashahr, Guilan province, Iran in 2004. The experiment was laid out in a factorial arrangement with two factors including sulphur sources (gypsum and single super phosphate) and sulphur rates (0, 30, 60 and 90 kg.h-1) in a completely randomized block design with three replications. Results showed that sulphur application greatly enhanced peanut growth and yield. The application of 90 kg.h-1 sulphur (in both forms) performed significantly better than the rest. The highest pod yield and grain yield were obtained in 90 kg.h-1 sulphur in gypsum form (6400 and 5200 kg.h-1, respectively). The highest LAI (6.6), CGR (20.2 g.m-2.12GDD-1) and PGR (16 g.m-2.12GDD-1) were obtained in 90 kg sulphur in the form of gypsum after 1142, 1142 and 1289 of accumulation, respectively. According to the results of the present experiment, it could be concluded that sulphur may considerably increase peanut grain yield and yield components. Thus, it could be expected that the application of 90 kg sulphur per hectare in the form of gypsum may result in better growth indices and higher grain yield of peanut.
A. Samadi, E. Sepehr,
Volume 17, Issue 65 (12-2013)
Abstract

In order to determine optimum equilibrium solution phosphorus (P) concentration using P adsorption isotherm and obtain model(s) by integrating soil solution P concentration, physicochemical properties, and soil P test (available P) which predict standard P requirements to achieve maximum yield, laboratory and glasshouse experiments were conducted on 36 soil samples belonging to 15 soil series and 14 soil samples, respectively. Using wheat as a test crop, the glasshouse experiment was laid out with five P levels in a completely randomized design with three replications. Concentrations of P in solution established by adding P in the pots estimated from the sorption curve ranged from 0.2 to 1.2 mg P/L including check treatment (no P). The results showed that equilibrium solution P concentration (EPC) was almost low in comparison with the requirement for most crops (<0.2 mg/L). The amount of P adsorbed by the soils at 0.2 mg/L EPC ranged from 5 to 114 mg/kg soil. The phosphate adsorption was well described by Freundlich (R2 = 0.96) and Langmuir (R2 = 0.88) isotherms. Langmuir maximum adsorption (Xm) and Freundlich coefficient (aF) estimated from Langmuir and Freundlich equations ranged from 127 to 238 mg P /kg soil and from 43 to 211 mg P/kg, respectively. Yield of wheat in all soils approached maximum as adjusted P levels were increased to 0.4 mg P/L. The results showed that some soils studied were adequate in available P by the NaHCO3 test, but required an amount of P fertilizer by the isotherm P requirement test to obtain maximum biomass production. Soil clay content was significantly related to the soil P sorption indices, P0.4 (P sorbed at 0.4 mg P/L EPC) (R = 0.40, P<0.01), PBC (P buffering capacity) (R = 0.54, P<0.001), aF (R = 0.48, P<0.01), and Xm (R = 0.40, P<0.01). Total CaCO3 and Active CaCO3 were found to be less important factors affecting P adsorption. Using stepwise regression analysis resulted in a useful regression model including the combination of Olsen P and clay content for the prediction of standard P requirement (P0.4).
M. Amouzegar, A. Abbaspour, Sh. Shahsavani, H. R. Asghari , M. Parsaeiyan,
Volume 19, Issue 74 (1-2016)
Abstract

Soil contamination by Pb leads to a reduction in the quality and quantity of crop yield, because it is highly toxic in soluble ionic forms. The availability of this element for plant roots can reduce by the formation of compounds with low solubility and their sedimentation by phosphorous amendments.. Root symbiosis with mycorrhizal fungi can also increase plant resistance against heavy metals. This study was carried out as a factorial experiment in a randomized complete block design asa greenhouse experiment on sunflower plant at Shahrood University. Treatments included mycorrhizal fungi with two levels of inoculation, (with and without inoculation), organic and inorganic phosphorous fertilizers such as humic acid, diammonium phosphate, bone meal and bone meal+humic acid. The results showed that inoculation with mycorrhizal fungi resulted in a significant increase (P&ge0.05) in percentage of mycorrhizal colonization and an increase in soil EC,shootdry weight and phosphous uptake by the plant. Phosphorus fertilizers significantly increased the available phosphorus in soil, dry weight and uptake of phosphorus by the shoots. The interaction effects of mycorrhiza and phosphorus fertilizers on soil exchange able Pbwere significant. The application of diammonium phosphate and mycorrhiza had the greatest impacton the reduction of Pb (by 25.48percent) in the soil exchange. Mycorrhizal plants had a lower rate of lead concentrations in shoots, which was equal to 78/14%, and also the application of phosphorus fertilizers significantly reduced Pb in plant shoots.


A. Koochekzadeh, H. Hoveizeh, A. R. Yazdipour,
Volume 22, Issue 4 (3-2019)
Abstract

Since 2001, water main drainage of sugarcane farms located in the east side of Karoon River has been deviated to Shadegan lagoon. The average discharge and salinity of the drain water in spring and summer were 20 and 20.5 m3 sec-1 and 17.1 and 13.3 dS m-1, respectively. Therefore, there have been considerable changes in the lagoon water quality when compared to the time before entering the drain water. Therefore, an experiment was performed to investigate the effects of sugarcane waste water on the quality of Lagoon’s water. The results showed that the average salinity was increased significantly before and after the entrance of the drainage into different points.  The average salinity in the sample point No.2 (along the entrance of the drainage) in summer was changed from 17.7 to 51.5 dS m-1. The results, therefore, revealed that after the  entrance of drainage water to  Lagoon, during summer time, water salinity and mineral concentrations were increased for all locations except  the points of 1 (on the northern margin of Lagoon) and 3 (influenced by Jarahi River). Phosphate ion concentration was increased at all investigated locations, but the highest phosphate concentrations were observed at the location points of 1 and 2 in summer. Given the important role of this lagoon in the protection of animal and plant spices, it is essentially important for sugarcane production companies to adopt a special measure for the protection of Lagoon from any source of pollution.

M. H. Rasouli-Sadaghiani, R. Ebrahimi Karimabad, R. Vahedi,
Volume 24, Issue 3 (11-2020)
Abstract

In order to investigate P acquisition efficiency (PACE) and P utilization efficiency (PUTE) of the corn in the presence of phosphate-solubilizing microorganisms (PSMs), a factorial experiment was carried out in a completely randomized design in the greenhouse. The factors were including P sources (tricalcium phosphate (TCP) and rock phosphate (RP)) and microbial inoculation (control, soluble P as KH2PO4 (Ps), inoculation with bacteria (PSB), inoculation with fungi (PSF), co-inoculation of PSB + PSF). At the end of growth period, plant dry weight and P content in plant and soil available-P were measured and then PACE, PUTE and phosphorus efficiency (PE) indices were calculated. The results showed that, the interaction of phosphate source and microbial inoculation was significant with respect to shoot P content, soil P, PUTE and PE. PSF-TCP treatment increased 7 times shoot phosphorus content compared to cont-RP treatment.  PUTE in Cont-TCP treatment was 2.35 times higher than the TCP-PS. The inoculation of PSF increased the PACE 1.61 times compared to co-inoculation of PSB + PSF tretment. Also, the highest PE index (99%) was obtained from SF-TCP treatment. In general, in calcareous soils with low P availability, inoculation of PSM with insoluble phosphorus sources can meet the phosphate needs of the plant.

A.r. Hossienpur, M. Barati, M.h. Salehi,
Volume 27, Issue 4 (12-2023)
Abstract

The kinetics of potassium release may be affected by P When phosphorus (P) fertilizer is applied to soils. The objective of this study was to the effect of Ca(H2Po4)2 fertilizer on the kinetics of non-exchangeable potassium (NEK) release in 10 calcareous soils. The amount of 100 mg kg-1 of P as Ca(H2Po4)2 was added to the soils. Treated and untreated soils were incubated at 70% of field capacity and 25±1°C for 90 days. After that, the NEK release was studied by 0.01 M CaCl2 extractant in 2017 hours by successive extraction methods in the treated and untreated soils. The results showed the NEK released in treated soils less than in untreated soils. The mean cumulative NEK released after 2017 h in the treated and untreated soils was 260.6 and 303.3 mg kg-1, respectively. The release of NEK in all soils was fast in the initial stages and continued at a lower speed in the later stages until the end of the experiment. The kinetics of NEK release was evaluated using kinetic equations. Based on the highest coefficients of determination (R2) and the lowest standard error (SE), the kinetics of NEK release in treated and untreated soils were described by the power function equation. The results of this research could be helpful for the precise fertilizer recommendation for the study in calcareous soils.


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