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Sample records for phosphorus availability concentration

  1. Impacts of anthropic pressures on soil phosphorus availability, concentration, and phosphorus forms in sediments in a Southern Brazilian watershed

    Energy Technology Data Exchange (ETDEWEB)

    Pellegrini, Joao Batista Rossetto; Rheinheimer dos Santos, Danilo; Goncalves, Celso Santos; Copetti, Andre Carlos Cruz [Dept. de Solos, Univ. Federal de Santa Maria, Centro de Ciencias Rurais, Santa Maria, RS (Brazil); Bortoluzzi, Edson Campanhola [Faculdade de Agronomia e Medicina Veterinaria da Univ. de Passo Fundo, RS (Brazil); Tessier, Daniel [Inst. National de la Recherche Agronomique, Versailles (France)

    2010-04-15

    Purpose: The transfer of soil sediments and phosphorus from terrestrial to aquatic systems is a common process in agricultural lands. The aims of this paper are to quantify the soil phosphorus availability and to characterize phosphorus forms in soil sediments as contaminant agents of waters as a function of anthropic pressures. Materials and methods On three subwatersheds with different anthropic pressure, water and sediment samples were collected automatically in upstream and downstream discharge points in six rainfall events during the tobacco growing season. Phosphorus desorption capacity from soil sediments was estimated by successive extractions with anion exchange resins. First-order kinetic models were adjusted to desorption curves for estimating potentially bioavailable particulate phosphorus, desorption rate constant, and bioavailable particulate phosphorus. Results and discussion The amount of bioavailable particulate phosphorus was directly correlated with the iron oxide content. The value of desorption rate constant was directly related with the total organic carbon and inversely with the iron oxide contents. Phosphate ions were released to solution, on average, twice as rapidly from sediments collected in subwatersheds with low anthropic activity than from those ones of highly anthropic subwatersheds. Anthropic pressure on watershed can engender high sediment discharge, but these solid particles seem to present low phosphorus-releasing capacity to water during transport due to the evidenced high affinity between phosphorus and iron oxide from sediments. Conclusions Anthropic pressure was related with sediment concentration and phosphorus release to aquatic systems. While natural vegetation along streams plays a role on soil and water depuration, it is unable to eliminate the phosphorus inputs intrinsic to the agricultural-intensive systems. Recommendations and perspectives The contamination of water in watershed by phosphates is facilitated by the

  2. phosphorus sorption capacity as a guide for phosphorus availability

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    drained, light yellowish brown, loamy sand ... Dongola 2 Akked series: Deep, dark grayish brown, clay ... energy. Statistical analysis. Data collected were statistically analysed using ANOVA of MStatc ... phosphorus sorbed versus phosphorus.

  3. Total Nitrogen and Available Phosphorus Dynamics in Soils ...

    African Journals Online (AJOL)

    Total nitrogen and available phosphorus concentration of soils in three secondary forest fields aged 1, 5 and 10 years of age regenerating from degraded abandoned rubber plantation (Hevea brasiliensis) and a mature forest in the west African Rainforest belt in southern Nigeria were investigated in order to determine the ...

  4. Availability for plants of phosphorus in some virgin peat samples

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    Armi Kaila

    1958-01-01

    Full Text Available The availability to plants of native peat phosphorus was studied by chemical methods and by a pot experiment in which three successive oat crops were grown with peat as the only source of phosphorus. The eight samples were collected from virgin peat lands. They were air-dried and ground. The samples were found to represent three different types of phosphorus condition: the first group contained relatively high amounts of inorganic phosphorus which was fairly easily available; the second group had a very high capacity to fix phosphorus which made its high quantity of inorganic phosphorus difficultly available; the third group was very poor in total and inorganic phosphorus but the latter was easily soluble and available to plants. On the basis of the capacity and intensity factors determined according to the method by Teräsvuori and also on the basis of inorganic phosphorus extractable by water fairly reliable predictions could be made of the mutual order of the samples as phosphorus supplyer to the plants in the pot experiment. In an incubation experiment at 27°C the amounts of organic phosphorus mineralized during the period of four months were in some of the samples quite marked, even 40 mg/l, and in most of the samples they corresponded to 5 to 15 per cent of the organic phosphorus. The amounts of phosphorus taken up by the oat crops under the favourable conditions of the pot experiment varied from 11 to 60 mg/l or from 20 to 120 kg/ha.

  5. Reaching ultra low phosphorus concentrations by filtration techniques

    NARCIS (Netherlands)

    Scherrenberg, S.M.

    2011-01-01

    This research deals with tertiary treatment techniques used for the removal of phosphorus from wastewater treatment plant (WWTP) effluent. The main objective of this research is to obtain ultra low total phosphorus (<0.15 mg total phosphorus/L) concentrations by coagulation, flocculation and

  6. Phosphorus availability from different sources for sheep

    International Nuclear Information System (INIS)

    Vitti, D.M.S.S.; Abdalla, A.L.; Meirelles, C.F.

    1991-01-01

    An assay was carried out with 12 sheep to determine the endogenous losses of P and the true absorption of this element from rock phosphate (TP), diammonium phosphate (DP) and bone meal (BM). Animals received the experimental diet for 30 days and after this period 200μCi 32 P was injected in each one. Blood and faeces samples were collected to determine specific activity. Faecal endogenous P and P availability were estimated. P availability was 58.39, 69.71 and 75.03 per cent for TP, DP and BM, respectively. (author). 1 fig., 2 tabs., 9 refs

  7. Relationship among Phosphorus Circulation Activity, Bacterial Biomass, pH, and Mineral Concentration in Agricultural Soil

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    Dinesh Adhikari

    2017-12-01

    Full Text Available Improvement of phosphorus circulation in the soil is necessary to enhance phosphorus availability to plants. Phosphorus circulation activity is an index of soil’s ability to supply soluble phosphorus from organic phosphorus in the soil solution. To understand the relationship among phosphorus circulation activity; bacterial biomass; pH; and Fe, Al, and Ca concentrations (described as mineral concentration in this paper in agricultural soil, 232 soil samples from various agricultural fields were collected and analyzed. A weak relationship between phosphorus circulation activity and bacterial biomass was observed in all soil samples (R2 = 0.25, and this relationship became significantly stronger at near-neutral pH (6.0–7.3; R2 = 0.67. No relationship between phosphorus circulation activity and bacterial biomass was observed at acidic (pH < 6.0 or alkaline (pH > 7.3 pH. A negative correlation between Fe and Al concentrations and phosphorus circulation activity was observed at acidic pH (R2 = 0.72 and 0.73, respectively, as well as for Ca at alkaline pH (R2 = 0.64. Therefore, bacterial biomass, pH, and mineral concentration should be considered together for activation of phosphorus circulation activity in the soil. A relationship model was proposed based on the effects of bacterial biomass and mineral concentration on phosphorus circulation activity. The suitable conditions of bacterial biomass, pH, and mineral concentration for phosphorus circulation activity could be estimated from the relationship model.

  8. Fire intensity and phosphorus availability in Sumatra

    International Nuclear Information System (INIS)

    Ketterings, Q.M.; Bigham, J.M.; Noordwijk, M. van

    1999-01-01

    Fire is still widely used as a tool for land clearing in Indonesia. The environmental problems caused by these became an international issue in the fall of 1997 when smoke originating from land clearing activities in Sumatra and West Kalimantan blanketed not only large parts of Indonesia but also the neighboring countries of Malaysia, Singapore, Brunei, the Philippines and Thailand. Alternatives must be found. For alternatives to slash-and-burn to be acceptable, they should address both the problems and the benefits of burning as a land clearing method for small rubber and oil palm farmers. A social/economic/agronomic survey conducted in Sepunggur, Jambi Province, Sumatra, indicated that burning: 1) was the cheapest and easiest way to create space to plant and walk in the field; 2) added free fertilizer in the form of ash; 3) improved soil structure allowing faster establishment of seedlings; 4) reduced weed/tree competition; and 5) reduced problems with pest/diseases. Farmers also indicated that harveys delays and yield reductions would lead to an increase in poverty, mainly due to a loss in ash (fertilizer) addition if fire was no longer used. Slash-sell wood-and-burn is a alternative that has the advantage of maintaining at least part of the benefits of burning while reducing air pollution. The sale of wood (if permitted) could supply the farmer with an extra source of income. Before this alternative can be promoted, it should be known what a reduction in fuel load and fire intensity will mean for soil fertility and plant growth and thus for the economic situation of farmers that depend on it. Two questions need to be answered: 1) how is fir intensity related to nutrient availability; and 2) how important are short-term fertilizer (ash) additions versus longer lasting, heat induced changes in soil mineralogical properties? Refs. 11 (author)

  9. Competition between Free-Floating Plants Is Strongly Driven by Previously Experienced Phosphorus Concentrations in the Water Column.

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    Edwin T H M Peeters

    Full Text Available Nutrients can determine the outcome of the competition between different floating plant species. The response of floating plants to current phosphorus levels may be affected by previously experienced phosphorus concentrations because some species have the ability to store excess phosphorus for later use. This might have an impact on their competition. Here, we investigate the effect of previous and actual phosphorus concentrations on the growth rate of free-floating plant species (Azolla filiculoides, Lemna minor/gibba and Ricciocarpus natansand the effect of phosphorus history on the competition between L. minor/gibba and A. filiculoides and between L. minor/gibba and R. natans. As expected, plant growth was lower when previously kept at low instead of high phosphorus concentrations. Growth of L. minor/gibba and A. filiculoides with a phosphorus rich history was comparable for low and high actual phosphorus concentrations, however, internal phosphorus concentrations were significantly lower with low actual phosphorus concentration. This indicates that both species perform luxury phosphorus uptake. Furthermore, internal P concentration in Azolla and Lemna increased within two weeks after a period of P deficit without a strong increase in growth. A. filiculoides in a mixture with L. minor/gibba grew faster than its monoculture. Morphological differences may explain why A. filiculoides outcompeted L. minor/gibba and these differences may be induced by phosphorus concentrations in the past. Growth of L. minor/gibba was only reduced by the presence of A. filiculoides with a high phosphorus history. Growth of L. minor/gibba and R. natans in mixtures was positively affected only when they had a high phosphorus history themselves and their competitor a low phosphorus history. These observations clearly indicate that phosphorus history of competing plants is important for understanding the outcome of the competition. Therefore, actual and previously

  10. Assessment of the minimal available phosphorus needs of laying hens: Implications for phosphorus management strategies.

    Science.gov (United States)

    Jing, M; Zhao, S; Rogiewicz, A; Slominski, B A; House, J D

    2018-03-28

    The oversupply of dietary phosphorus (P) leads to increased feed costs and discharge of excessive P to the environment, thus directly impacting the sustainability of egg production practices. The present study was conducted to better define the minimal available P needs of laying hens. Fifty-six Lohmann white laying hens were individually caged and fed one of 7 diets with graded levels of available P (0.15, 0.20, 0.25, 0.30, 0.35, 0.40, or 0.45%) for 12 weeks. Records were maintained for body weight, feed intake, and egg production during the experimental period. Blood and egg samples were collected and digestibility studies conducted at wk 6 and 12 of the experiment. At the end of the experiment, tibia characteristics and expression of the P transporters in the small intestine and kidney were determined. Lowering dietary available P from 0.45 to 0.15% generally reduced plasma P concentrations (P data indicate that reducing dietary available P up to 0.15% is adequate to maintain health and performance of layers. As such, this minimal available P estimate should serve as a benchmark for the assessment of P contents of commercial laying hen rations, with the goal of enhancing the sustainability of egg production.

  11. Phosphorus availability and microbial respiration across biomes :  from plantation forest to tundra

    OpenAIRE

    Esberg, Camilla

    2010-01-01

    Phosphorus is the main limiting nutrient for plant growth in large areas of the world and the availability of phosphorus to plants and microbes can be strongly affected by soil properties. Even though the phosphorus cycle has been studied extensively, much remains unknown about the key processes governing phosphorus availability in different environments. In this thesis the complex dynamics of soil phosphorus and its availability were studied by relating various phosphorus fractions and soil ...

  12. Determinants of total and available phosphorus in forested Alfisols and Ultisols of the Ozark Highlands, USA

    Science.gov (United States)

    Gurbir Singh; Keith W. Goyne; John M. Kabrick

    2015-01-01

    Phosphorus is an important nutrient limiting forest growth in many parts of world, and soil P forms and concentrations may be associated with a host of soil and environmental attributes in a complex soil landscape. The objective of this study was to identify key environmental and soil properties influencing total and available soil P concentrations in a mixed oak (

  13. Ethylene: a regulator of root architectural responses to soil phosphorus availability

    NARCIS (Netherlands)

    Borch, K.; Bouma, T.J.; Lynch, J.P.; Brown, K.M.

    1999-01-01

    The involvement of ethylene in root architectural responses to phosphorus availability was investigated in common bean (Phaseolus vulgaris L,) plants grown with sufficient and deficient phosphorus. Although phosphorus deficiency reduced root mass and lateral root number, main root length was

  14. Efecto de distintas alternativas de fertilización fosfatada en la secuencia trigo - soja sobre el fósforo asimilable y los rendimientos en la provincia de Tucumán, Argentina Effect of different phosphorus fertilization alternatives on available soil phosphorus concentration and yields in a soybean - wheat cropping system in Tucumán, Argentine

    Directory of Open Access Journals (Sweden)

    Carlos F. Hernández

    and 7.8 ppm phosphorus (P-Bray 1. The objective of this trial was to estimate the effect of each fertilization alternative on available phosphorus concentration in two soil layers, 0-5 cm and 5-25 cm, over five years (from 2002 to 2007, and on soybean and wheat yields. Evaluated treatments consisted in applying 30, 45 and 60 kg P2O5/ha as triple superphosphate yearly only to soybean, only to wheat and to both crops. P residual effect was found for both crops when 45 kg P2O5/ha was applied. Available soil phosphorus concentration increased over 13 ppm (critical P-Bray 1 concentration for soybean when 45 and 60 kg P2O5/ha rates were applied to both crops, reaching at the same time the highest residual phosphorus uptake efficiency. Soybean yields were higher when P was applied to soybean, as compared to wheat treated with the same P rates. Soybean highest P uptake efficiency was found when P was applied to soybean.

  15. Improving Phosphorus Availability in an Acid Soil Using Organic Amendments Produced from Agroindustrial Wastes

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    Huck Ywih Ch’ng

    2014-01-01

    Full Text Available 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.

  16. Improving phosphorus availability in an acid soil using organic amendments produced from agroindustrial wastes.

    Science.gov (United States)

    Ch'ng, Huck Ywih; Ahmed, Osumanu Haruna; Majid, Nik Muhamad Ab

    2014-01-01

    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.

  17. Influence of phosphorus availability on the community structure and physiology of cultured biofilms.

    Science.gov (United States)

    Li, Shuangshuang; Wang, Chun; Qin, Hongjie; Li, Yinxia; Zheng, Jiaoli; Peng, Chengrong; Li, Dunhai

    2016-04-01

    Biofilms have important effects on nutrient cycling in aquatic ecosystems. However, publications about the community structure and functions under laboratory conditions are rare. This study focused on the developmental and physiological properties of cultured biofilms under various phosphorus concentrations performed in a closely controlled continuous flow incubator. The results showed that the biomass (Chl a) and photosynthesis of algae were inhibited under P-limitation conditions, while the phosphatase activity and P assimilation rate were promoted. The algal community structure of biofilms was more likely related to the colonization stage than with the phosphorus availability. Cyanobacteria were more competitive than other algae in biofilms, particularly when cultured under low P levels. A dominance shift occurred from non-filamentous algae in the early stage to filamentous algae in the mid and late stages under P concentrations of 0.01, 0.1 and 0.6 mg/L. However, the total N content, dry weight biomass and bacterial community structure of biofilms were unaffected by phosphorus availability. This may be attributed to the low respiration rate, high accumulation of extracellular polymeric substances and high alkaline phosphatase activity in biofilms when phosphorus availability was low. The bacterial community structure differed over time, while there was little difference between the four treatments, which indicated that it was mainly affected by the colonization stage of the biofilms rather than the phosphorus availability. Altogether, these results suggested that the development of biofilms was influenced by the phosphorus availability and/or the colonization stage and hence determined the role that biofilms play in the overlying water. Copyright © 2015. Published by Elsevier B.V.

  18. Effect of phosphorus dopant concentration on the carrier mobility in ...

    African Journals Online (AJOL)

    This study investigated the effect of phosphorus dopant concentration on mobility of crystalline silicon (c-Si). It considers different temperature ranges, from 100 K to 500 K, and dopant concentration from 1012 cm-3 to 1020 cm-3 in relation to its effect on the mobility of the crystalline silicon. This study indicates that the ...

  19. High plant availability of phosphorus and low availability of cadmium in four biomass combustion ashes

    International Nuclear Information System (INIS)

    Li, Xiaoxi; Rubæk, Gitte H.; Sørensen, Peter

    2016-01-01

    For biomass combustion to become a sustainable energy production system, it is crucial to minimise landfill of biomass ashes, to recycle the nutrients and to minimise the undesirable impact of hazardous substances in the ash. In order to test the plant availability of phosphorus (P) and cadmium (Cd) in four biomass ashes, we conducted two pot experiments on a P-depleted soil and one mini-plot field experiment on a soil with adequate P status. Test plants were spring barley and Italian ryegrass. Ash applications were compared to triple superphosphate (TSP) and a control without P application. Both TSP and ash significantly increased crop yields and P uptake on the P-depleted soil. In contrast, on the adequate-P soil, the barley yield showed little response to soil amendment, even at 300–500 kg P ha"−"1 application, although the barley took up more P at higher applications. The apparent P use efficiency of the additive was 20% in ryegrass - much higher than that of barley for which P use efficiencies varied on the two soils. Generally, crop Cd concentrations were little affected by the increasing and high applications of ash, except for relatively high Cd concentrations in barley after applying 25 Mg ha"−"1 straw ash. Contrarily, even modest increases in the TSP application markedly increased Cd uptake in plants. This might be explained by the low Cd solubility in the ash or by the reduced Cd availability due to the liming effect of ash. High concentrations of resin-extractable P (available P) in the ash-amended soil after harvest indicate that the ash may also contribute to P availability for the following crops. In conclusion, the biomass ashes in this study had P availability similar to the TSP fertiliser and did not contaminate the crop with Cd during the first year. - Highlights: • Effects of four biomass ashes vs. a P fertiliser (TSP) on two crops were studied. • Ashes increased crop yields with P availability similar to TSP on P-depleted soil.

  20. High plant availability of phosphorus and low availability of cadmium in four biomass combustion ashes

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiaoxi, E-mail: Xiaoxi.Li@agro.au.dk; Rubæk, Gitte H.; Sørensen, Peter

    2016-07-01

    For biomass combustion to become a sustainable energy production system, it is crucial to minimise landfill of biomass ashes, to recycle the nutrients and to minimise the undesirable impact of hazardous substances in the ash. In order to test the plant availability of phosphorus (P) and cadmium (Cd) in four biomass ashes, we conducted two pot experiments on a P-depleted soil and one mini-plot field experiment on a soil with adequate P status. Test plants were spring barley and Italian ryegrass. Ash applications were compared to triple superphosphate (TSP) and a control without P application. Both TSP and ash significantly increased crop yields and P uptake on the P-depleted soil. In contrast, on the adequate-P soil, the barley yield showed little response to soil amendment, even at 300–500 kg P ha{sup −1} application, although the barley took up more P at higher applications. The apparent P use efficiency of the additive was 20% in ryegrass - much higher than that of barley for which P use efficiencies varied on the two soils. Generally, crop Cd concentrations were little affected by the increasing and high applications of ash, except for relatively high Cd concentrations in barley after applying 25 Mg ha{sup −1} straw ash. Contrarily, even modest increases in the TSP application markedly increased Cd uptake in plants. This might be explained by the low Cd solubility in the ash or by the reduced Cd availability due to the liming effect of ash. High concentrations of resin-extractable P (available P) in the ash-amended soil after harvest indicate that the ash may also contribute to P availability for the following crops. In conclusion, the biomass ashes in this study had P availability similar to the TSP fertiliser and did not contaminate the crop with Cd during the first year. - Highlights: • Effects of four biomass ashes vs. a P fertiliser (TSP) on two crops were studied. • Ashes increased crop yields with P availability similar to TSP on P-depleted soil

  1. Photometric determination of phosphorus in zircon concentrate and potassium hexafluorozirconate

    International Nuclear Information System (INIS)

    Polonskaya, I.A.; Fominykh, N.L.

    1978-01-01

    A method for direct photometric phosphorus determination in the materials, containing considerable zirconium amounts is developed. Phosphorus is determined in a form of reduced heteropolyacid with the use of ascorbic acid and potassium antimonyltartrate in sulfuric acid medium. To remove zirconium effect, a graduation diagram is drawn at the background of zirconium, which is bound into a stable fluoride complex in the presence of H 3 BO 3 . Under the above conditions the coloring developes after 30-40 min and remains stable for 24 hrs. A proportional dependence between phosphorus concentration and optical density is observed in the range of 10-160 mg of Zr. The method sensitivity is 5x10 -5 %

  2. Effect Of Wood-Based Biochar And Sewage Sludge Amendments For Soil Phosphorus Availability

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    Frišták Vladimír

    2015-06-01

    Full Text Available This study investigated the effects of two biochars (pyrolysed wood chips and garden clippings on phosphorus (P availability in a heavy-metal contaminated soil poor in phosphorus. Short-term 14-days incubation experiments were conducted to study how applications of biochars at different rates (1 and 5 % in combination with (1:1 and without dried sewage sludge from a municipal waste water treatment plant (WWTP affected the content of soil extractable P. For P-availability analyses deionized water, calcium acetate lactate (CAL, Mehlich 3 and Olsen extraction protocols were applied. In addition, the content of total and mobile forms of potentially toxic heavy metals (PTHM was studied. Application of both biochars caused a significant decrease of PTHM available forms in sewage sludge amended soil samples. The concentration of total and available P increased with higher biochar and sewage sludge application rates.

  3. Phosphorus recycling and availability in the western Wadden Sea

    NARCIS (Netherlands)

    De Freixo Leote, C.M.

    2014-01-01

    Phosphorus is a main and often limiting nutrient for phytoplankton growth, as suggested for the western Wadden Sea. In this area, freshwater discharge was a major nutrient source in the past. However, pollution reduction measures dramatically reduced its contribution, particularly for phosphorus. In

  4. Serum Phosphorus Concentrations in the Third National Health and Nutrition Examination Survey (NHANES III)

    Science.gov (United States)

    de Boer, Ian H.; Rue, Tessa C.; Kestenbaum, Bryan

    2011-01-01

    Background Higher serum phosphorus concentrations within the normal laboratory range have been associated with cardiovascular events and mortality in large prospective cohort studies of individuals with and without kidney disease. Reasons for interindividual variation in steady-state serum phosphorus concentrations are largely unknown. Study Design Cross-sectional study. Setting & Participants 15,513 participants in the Third National Health and Nutrition Examination Survey. Predictors Demographic data, dietary intake measured by means of 24-hour dietary recall and food-frequency questionnaire, and established cardiovascular risk factors. Outcome & Measurements Serum phosphorus concentration. Results Mean serum phosphorus concentrations were significantly greater in women (+0.16 mg/dL versus men; P phosphorus and phosphorus-rich foods were associated only weakly with circulating serum phosphorus concentrations, if at all. Higher serum phosphorus levels were associated with lower calculated Framingham coronary heart disease risk scores, which are based on traditional atherosclerosis risk factors. In aggregate, demographic, nutritional, cardiovascular, and kidney function variables explained only 12% of the variation in circulating serum phosphorus concentrations. Limitations Results may differ with advanced kidney disease. Conclusions Serum phosphorus concentration is weakly related to dietary phosphorus and not related to a diverse array of phosphorus-rich foods in the general population. Factors determining serum phosphorus concentration are largely unknown. Previously observed associations of serum phosphorus concentrations with cardiovascular events are unlikely to be a result of differences in dietary intake or traditional cardiovascular risk factors. PMID:18992979

  5. Spatial temporal determination of phosphorus concentration in Lake Tota

    International Nuclear Information System (INIS)

    Cordero, Ruben D; Ruiz, J Efraim; Vargas, Edgar F

    2005-01-01

    The lapse from July to November of 2003 a study was made to determine the spatial and temporal concentration of phosphorus in the lake of Tota (Boyaca, Colombia). Samples were taken with a Van-Dorn bottle of the horizontal type of two-liter capacity in the superficial stratum up to 20 cm in the water column and at 10 m depth. The different forms of phosphorus studied, show that there are significant differences in their concentrations, the highest values being found in the sector known as Lago Chico and the lowest in the area of Lago Grande; this behavior is found to be closely related to the agricultural uses of the land in the littoral zone and additionally with the climatic factors especially the precipitation in the area investigated

  6. Soil phosphorus dynamics and availability and irrigated coffee yield

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    Thiago Henrique Pereira Reis

    2011-04-01

    Full Text Available Research data have demonstrated that the P demand of coffee (Coffea arabica L. is similar to that of short-cycle crops. In this context, the objective of this study was to evaluate the influence of annual P fertilization on the soil P status by the quantification of labile, moderately labile, low-labile, and total P fractions, associating them to coffee yield. The experiment was installed in a typical dystrophic Red Latosol (Oxisol cultivated with irrigated coffee annually fertilized with triple superphosphate at rates of 0, 50, 100, 200, and 400 kg ha-1 P2O5. Phosphorus fractions were determined in two soil layers: 0-10 and 10-20 cm. The P leaf contents and coffee yield in 2008 were also evaluated. The irrigated coffee responded to phosphate fertilization in the production phase with gains of up to 138 % in coffee yield by the application of 400 kg ha-1 P2O5. Coffee leaf P contents increased with P applications and stabilized around 1.98 g kg-1, at rates of 270 kg ha-1 P2O5 and higher. Soil P application caused, in general, an increase in bioavailable P fractions, which constitute the main soil P reservoir.

  7. Effect of phosphate solubilizing bacteria on the phosphorus availability and yield of cotton (gossypium)

    International Nuclear Information System (INIS)

    Akhtar, N.; Iqbal, A.; Qureshi, M.A.; Khan, K.H

    2010-01-01

    Phosphate solubilizing bacteria (PSB) and plants have symbiotic relationship, as bacteria provide soluble phosphate for the plants and plants supply root borne carbon compounds which can be metabolized for bacterial growth. PSB solubilize the applied and fixed soil phosphorus resulting in higher crop yield. Intensive cropping has resulted in wide spread deficiency of Phosphorus in our soils and situation is becoming more serious because of a drastic increase in the cost of phosphatic fertilizers. Keeping in view the capabilities of microbes (Bacillus sp.), a field experiment was conducted on cotton at farmer field district Faisalabad in 2008. Effect of PSM (Bacillus spp.) was studied at three phosphorus levels i.e.20, 40 and 60 kg ha-l while N was applied at recommended dose (120 kg ha/sup -1/). Bacillus spp. was applied as seed coating to the cotton crop (Var. BT 121). Recommended plant protection measures were adopted. Results revealed that Bacillus spp. significantly increased the seed cotton yield; number of boll plant-I, boll weight, plant height, GOT (%), staple length, plant P and available P in the soil. Maximum seed cotton yield 4250 kg ha/sup -l/ was obtained with Bacillus inoculation along with 60 kg of P followed by 4162 kg ha/sup -1/ with Bacillus inoculation and 40 kg of P compared with their respective controls i.e.4093 and 3962 kg ha/sup -1/ respectively. Soil P was improved from 8.1 to 9.5 ppm by Bacillus inoculation. Phosphorus in plant matter was also higher (0.39%) as compare with control (0.36%). Rhizosphere soil pH was found slightly decreased (8.12 to 8.0) by Bacillus inoculation compare with control. It is concluded that PSB inoculation not only exerts beneficial effect on crop growth but also enhances the phosphorus concentration in the plant and soil. (author)

  8. Effect of available phosphorus in paddy soils on phosphorus uptake of rice

    International Nuclear Information System (INIS)

    Liu Delin; Zhu Zhaomin

    1996-01-01

    Relation between available phosphorus in 6 types of paddy soil in Hunan Province and its uptake by rices was studied by 32 P tracing. The result indicated that the P uptake by rices varied with available P content in the paddy soils. When the content was high, the rice absorbed more P nutrient from the soil and decreased the P uptake from the P fertilizer, which showed a poor contribution of the P fertilizer to the rice yield increase, and vice versa. The recovery of the P fertilizer varied with the soil types. Ranked the first was in paddy soils derived from lacustrine deposite but little rice yield increased. While in paddy soils derived from limestone, the yield greatly increased although the recovery of P fertilizer was the lowest. Rice absorbed P nutrient during its whole growth duration. No matter the different uptake amount due to the P supply by the different soils, rice plant generally had the greatest P nutrient uptake from tillering stage to elongation stage, and along with the rise of the rices dry matter, amount of P uptake was gradually increased but the P content in unit dry matter was tended to decrease. (author). 5 refs., 3 figs., 6 tabs

  9. Phosphorus contents and availability of technogenic substrates for soil construction

    Science.gov (United States)

    Nehls, Thomas; Lydia, Paetsch; Sarah, Rokia; Schwartz, Christophe; Wessolek, Gerd

    2014-05-01

    Urban areas lack of green and of soil substrates to support this green. A great variety of solid waste materials can be seen as technogenic substances (TS) for the construction of soil-similar plant substrates. Biomass production in the city and the use of waste materials as nutrient sources can help to close regional nutrient cycles. The most important waste materials have been studied for their phosphorus contents, availabilities and diffusion rates in the rhizosphere by combining their analyzed chemical and physical properties. Compost, concrete, green wastes, paper mill sludge, street-sweepings, mix of rubble, bricks, track ballasts and charcoal have (i) been analyzed their P release properties (HF extraction, Olsen-P, adsorption isotherms); (ii) the physical properties (water retention function, saturated hydraulic conductivity) were analyzed at 80 % of the proctor density; (iii) The P availability of the TMs to the roots were simulated for different pressure heads (pF = 1.3, 1.8 and 3.0) using HYDRUS 1-D. We compared the results for TS with these for agricultural soils. Ptot varies from 710 to 21 000 mg kg-1 for bricks and compost, while POlsen varies from 19 to 1 090 mg kg-1 for charcoal and green wastes. The diffusion rates of TSs (pF = 1.3) are up to 10 times higher compared to those of soils, with green wastes showing highest and bricks the lowest P diffusion rates. We conclude that the investigated TS are appropriate for construction of soil similar planting substrates because of their P delivery potential and their favourable physical properties.

  10. Do earthworms affect phosphorus availability to grass? A pot experiment.

    NARCIS (Netherlands)

    Vos, M.J.; Ros, M.B.H.; Koopmans, G.F.; Groenigen, van J.W.

    2014-01-01

    The largest part of phosphorus (P) in soil is bound by the soil solid phase; its release to the soil solution therefore often does not meet the demand of plants. Since global P fertilizer reserves are declining, it becomes increasingly important to better utilize soil P. We tested whether earthworm

  11. Available phosphorus levels for 95 to 120 kg barrows genetically selected for lean gain

    Directory of Open Access Journals (Sweden)

    Cláudio Luís Corrêa Arouca

    2012-06-01

    Full Text Available With the objective of evaluating available phosphorus (aP levels in diets for barrows selected for lean meat deposition, eighty commercial hybrid pigs with initial weight of 94.05±1.05 kg were used in this experiment. Pigs were allotted in a completely randomized block design, with five treatments (0.092, 0.156, 0.220, 0,284, and 0.348% of aP, eight replicates and two pigs per experimental unit. The average daily weight gain of pigs increased and the feed conversion improved quadratically with increasing aP in the diets up to the estimated levels of 0.21 and 0.20%, respectively. There was no effect of the dietary aP on average daily feed intake. However, aP intake, bone strength and concentration of phosphorus in the bones increased linearly with increasing aP in the diets. The levels of aP did not affect carcass traits; however, the alkaline phosphatase activity was improved and the values of serum inorganic phosphorus increased quadratically up to the estimated levels of 0.26 and 0.27% of aP, respectively. The available phosphorus levels of 0.21, 0.27, and 0.35%, corresponding to daily aP intakes of 6.34, 8.13, and 10.44 g result, respectively, in greatest performance, blood and bone parameters of 95 to 120 kg barrows selected for lean gain.

  12. Improving Phosphorus Availability in an Acid Soil Using Organic Amendments Produced from Agroindustrial Wastes

    OpenAIRE

    Ch’ng, Huck Ywih; Ahmed, Osumanu Haruna; Majid, Nik Muhamad Ab.

    2014-01-01

    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 mixt...

  13. Increasing phytoplankton-available phosphorus and inhibition of macrophyte on phytoplankton bloom.

    Science.gov (United States)

    Dai, Yanran; Wu, Juan; Ma, Xiaohang; Zhong, Fei; Cui, Naxin; Cheng, Shuiping

    2017-02-01

    We assembled mesocosms to address the coherent mechanisms that an increasing phosphorus (P) concentration in water columns coupled with the phytoplankton bloom and identify the performance gap of regulating phytoplankton growth between two macrophyte species, Ceratophyllum demersum L. and Vallisneria spiralis L. Intense alkaline phosphatase activities (APA) were observed in the unplanted control, with their predominant part, phytoplankton APA (accounting for up to 44.7% of the total APA), and another large share, bacterial APA. These correspond with the large average concentration of total phosphorus (TP), total dissolved phosphorus (TDP) and soluble reactive (SRP) as well as high phytoplankton density in the water column. The consistency among P concentrations, phytoplankton density and APA, together with the positive impact of phytoplankton density on total APA revealed by the structural equation modelling (SEM), indicates that facilitated APA levels in water is an essential strategy for phytoplankton to enhance the available P. Furthermore, a positive interaction between phytoplankton APA and bacteria APA was detected, suggesting a potential collaboration between phytoplankton and bacteria to boost available P content in the water column. Both macrophyte species had a prominent performance on regulating phytoplankton proliferation. The phytoplankton density and quantum yield in C. demersum systems were all significantly lower (33.8% and 24.0%) than those in V. spiralis systems. Additionally, a greater decoupling effect of C. demersum on the relationship between P, APA, phytoplankton density, bacteria dynamic and quantum yield was revealed by SEM. These results imply that the preferred tactic of different species could lead to the performance gap. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Estimating and mapping grass phosphorus concentration in an African savanna using hyperspectral image data

    NARCIS (Netherlands)

    Mutanga, O.; Kumar, L.

    2007-01-01

    We tested the utility of imaging spectroscopy and neural networks to map phosphorus concentration in savanna grass using airborne HyMAP image data. We also sought to ascertain the key wavelengths for phosphorus prediction using hyperspectral remote sensing. The remote sensing of foliar phosphorus

  15. Effect of supplemented fungal phytase on performance and phosphorus availability by phosphorus-depleted juvenile rainbow trout (Oncorhynchus mykiss), and on the magnitude and composition of phosphorus waste output

    DEFF Research Database (Denmark)

    Dalsgaard, Anne Johanne Tang; Schøn Ekmann, K.; Pedersen, Per Bovbjerg

    2009-01-01

    The effect of a supplemental fungal phytase on performance and phosphorus availability by juvenile rainbow trout fed diets with a high inclusion of plant based protein and on the magnitude and composition of the waste phosphorus production was tested in a 2 × 3 factorial design at a temperature....../suspended phosphorus waste output from fish fed the phytase supplemented diet containing 0.71% available phosphorus, suggesting that the phosphorus requirement was reached at this phosphorus level. Consistent with this, there was a substantial increase in the dissolved/suspended phosphorus waste output from fish fed...... the phytase supplemented diet containing 0.81% available phosphorus, suggesting that the phosphorus requirement was exceeded in this group. This study demonstrated that phytase supplementation will be advantageous to the fish and the environment if supplemented to low-phosphorus diets containing a large share...

  16. [Effects of selective cutting on soil phosphorus forms and availability in Korean pine broad-leaved forest in Xiaoxing'an Mountains of China.

    Science.gov (United States)

    Zhang, Xin; Gu, Hui Yan; Chen, Xiang Wei

    2018-02-01

    In order to clarify the effects of selective cutting on soil phosphorus availability in Korean pine broad-leaved forest, surface soil (0-10 cm) samples from original Korean pine broad-leaved forest and natural forests with mild, medium and intensive cutting disturbances were collected. The Sui modified Hedley phosphorus fractionation method was used to continuously extract soil samples and analyzed the differences and changes of soil phosphorus fractions from different experimental stands. The results showed that the soil total phosphorus content of Korean pine broad-leaved forest varied from 1.09 to 1.66 g·kg -1 , with the original stand and intensive cutting disturbance stand being the maximum and minimum one, respectively. The differences of soil total phosphorus content among cutting disturbance levels were significant. The Olsen phosphorus and phosphorus activation coefficients changed with an amplitude of 7.26-17.79 mg·kg -1 and 0.67%-1.07%, respectively. Both of them significantly decreased with the increase of selective cutting disturbance level. The concentrations of all P fractions except HCl-P o , i.e., H 2 O-P i , NaHCO 3 -P, NaOH-P, HCl-P i , Residual-P, decreased with increasing cutting disturbance levels compared with original forest. The correlation coefficient between H 2 O-P i and soil Olsen phosphorus was the highest (0.98), though it only accounted for 1.5%-2.2% of the total phosphorus. NaOH-P content contributed to more than 48.0% of the total phosphorus, acknowledged as the potential source of soil phosphorus. In conclusion, selective cutting disturbance could constrain phosphorus storage and soil phosphorus availabi-lity of the Korean pine broad-leaved forests by significantly reducing the content of soil inorganic phosphorus and NaOH-P o , and such trends were positively dependent on the intensity of selective cutting.

  17. Effect of low levels of dietary available phosphorus on phosphorus utilization, bone mineralization, phosphorus transporter mRNA expression and performance in growing pigs.

    Science.gov (United States)

    Pokharel, Bishwo B; Regassa, Alemu; Nyachoti, Charles M; Kim, Woo K

    2017-06-03

    A study was conducted to examine the effects of different dietary levels of available phosphorus (aP) on P excretion, bone mineralization, performance and the mRNA expression of sodium-dependent P transporters in growing pigs. Sixty-day old growing pigs (n = 54) with an average initial BW of 19.50 ± 1.11 kg were randomly allocated to a control diet (C) containing 0.23% available phosphorus (aP), T1 containing 0.17% aP and T2 containing 0.11% aP. There were 6 pens per treatment with 3 pigs per pen. Body weight and feed intake were measured weekly. At the end of each week, one pig from each pen was housed in a metabolic crate for 24 h to collect fecal and urine samples and then sacrificed to obtain third metacarpal (MC3) bones and jejunal and kidney samples. Bones were scanned by Dual Energy X-ray Absorptiometry (DEXA). Fecal and urine samples were sub-sampled and analyzed for P content. The expression of P transporter mRNA in jejunum and kidney samples was measured using quantitative real-time polymerase chain reaction (qRT-PCR). Data were analyzed using GLM procedure of the Statistical Analysis System (SAS Institute version 9.2). Pigs fed the T2 diet had reduced (P reduced (P reduced (P reduced ADG, bone mineralization and urinary P level, but moderate reduction in dietary P up to 0.17% aP in the diet has the potential to reduce environmental pollution by reducing P concentration in swine manure and without compromising performance.

  18. Does assimilate supply limit expansion in wheat grown in the field under low phosphorus availability

    NARCIS (Netherlands)

    Rodriguez, D.; Andrade, F.H.; Goudriaan, J.

    2000-01-01

    Under conditions of phosphorus deficiency, reductions in plant leaf area have been attributed to both direct effects of phosphorus (P) on the individual leaf expansion rate and a reduced availability of assimilates for leaf growth. Simulation techniques have been used to test the hypothesis of a

  19. Evaluation of potential effects of soil available phosphorus on soil arsenic availability and paddy rice inorganic arsenic content.

    Science.gov (United States)

    Jiang, Wei; Hou, Qingye; Yang, Zhongfang; Zhong, Cong; Zheng, Guodong; Yang, Zhiqiang; Li, Jie

    2014-05-01

    The transfer of arsenic from paddy field to rice is a major exposure route of the highly toxic element to humans. The aim of our study is to explore the effects of soil available phosphorus on As uptake by rice, and identify the effects of soil properties on arsenic transfer from soil to rice under actual field conditions. 56 pairs of topsoil and rice samples were collected. The relevant parameters in soil and the inorganic arsenic in rice grains were analyzed, and then all the results were treated by statistical methods. Results show that the main factors influencing the uptake by rice grain include soil pH and available phosphorus. The eventual impact of phosphorus is identified as the suppression of As uptake by rice grains. The competition for transporters from soil to roots between arsenic and phosphorus in rhizosphere soil has been a dominant feature. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Associations of socioeconomic status and processed food intake with serum phosphorus concentration in community-living adults: the Multi-Ethnic Study of Atherosclerosis (MESA).

    Science.gov (United States)

    Gutiérrez, Orlando M; Katz, Ronit; Peralta, Carmen A; de Boer, Ian H; Siscovick, David; Wolf, Myles; Diez Roux, Ana; Kestenbaum, Bryan; Nettleton, Jennifer A; Ix, Joachim H

    2012-09-01

    Higher serum phosphorus concentrations are associated with cardiovascular disease events and mortality. Low socioeconomic status is linked with higher serum phosphorus concentration, but the reasons are unclear. Poor individuals disproportionately consume inexpensive processed foods commonly enriched with phosphorus-based food preservatives. Accordingly, we hypothesized that excess intake of these foods accounts for a relationship between lower socioeconomic status and higher serum phosphorus concentration. Cross-sectional analysis. We examined a random cohort of 2,664 participants with available phosphorus measurements in the Multi-Ethnic Study of Atherosclerosis, a community-based sample of individuals free of clinically apparent cardiovascular disease from across the United States. Socioeconomic status, the intake of foods commonly enriched with phosphorus-based food additives (processed meats, sodas), and frequency of fast-food consumption. Fasting morning serum phosphorus concentrations. In unadjusted analyses, lower income and lower educational achievement categories were associated with modestly higher serum phosphorus concentration (by 0.02 to 0.10 mg/dL, P fast-food consumption with serum phosphorus. In contrast, each serving per day higher soda intake was associated with 0.02 mg/dL lower serum phosphorus concentration (95% confidence interval, -0.04, -0.01). Greater intake of foods commonly enriched with phosphorus additives was not associated with higher serum phosphorus concentration in a community-living sample with largely preserved kidney function. These results suggest that excess intake of processed and fast foods may not impact fasting serum phosphorus concentrations among individuals without kidney disease. Copyright © 2012 National Kidney Foundation, Inc. All rights reserved.

  1. Effects of salinity, temperature and phosphorus concentration on the chemical composition of Gelidium crinale (Turner Lamouroux (Gelidiaceae, Rhodophyta

    Directory of Open Access Journals (Sweden)

    Lúcia Rebello Dillenburg

    2005-05-01

    Full Text Available The effects of different culture conditions (temperature, salinity and dissolved inorganic phosphorus were investigated for seven days, under controlled conditions. The maximum production of proteins occurred in cultures where the temperature was 25°C, with concentrations of 5.0 and 10.0 µM of dissolved inorganic phosphorus and salinity between 15 and 20 psu, with values varying from 2.62 to 2.83% of algae dry weight. For carbohydrates, a third-order interaction was not observed in the statistical analysis; only a second order interaction was observed between temperature and inorganic phosphorus concentrations Efeito dos parâmetros abióticos em cultivo de G. crinale (P < 0.005 and between temperature and salinity (P < 0.000. The greatest phosphorus increase in the thalli (0.80 % occurred in the lowest temperature (15 °C, associated with low salinity (10 psu and high inorganic phosphorus concentration (10.0 µM. The Pearson’s correlation coefficient revealed positive correlations (P < 0.001 among protein content, temperature and inorganic phosphorus available in the growth medium. For carbohydrates, correlations were positive with all three abiotic parameters. For tissue phosphorus, a positive correlation occurred only with dissolved inorganic phosphorus; with temperature and salinity, the correlations were negative. Among the chemical components present in the algae, proteins and carbohydrates showed a positive correlation, while tissue phosphorus presented a negative correlation with both, although this correlation was not significant with regard to protein.

  2. Recycling phosphorus by fast pyrolysis of pig manure: concentration and extraction of phosphorus combined with formation of value-added pyrolysis products

    NARCIS (Netherlands)

    Azuara, M.; Kersten, Sascha R.A.; Kootstra, A.M.J.

    2013-01-01

    In order to recycle phosphorus from the livestock chain back to the land, fast pyrolysis of concentrated pig manure at different temperatures (400 °C, 500 °C, 600 °C), was undertaken to concentrate the phosphorus in the char fraction for recovery. Results show that 92%–97% of the phosphorus present

  3. Considerations regarding the dominance of Cylindrospermopsis raciborskii under low light availability in a low phosphorus lake

    Directory of Open Access Journals (Sweden)

    Denise Tonetta

    2015-09-01

    Full Text Available ABSTRACTAlthough many studies have shown that the dispersion, increased abundance and dominance of cyanobacteria can be attributed to nutrient enrichment, we discuss features contributing to the dominance of Cylindrospermopsis raciborskii in a shallow, polymictic, subtropical coastal lake with low phosphorus and light limitation (Peri Lake. The presence and dominance of C. raciborskii in an environment with such characteristics emphasizes the idea that nutrients alone do not explain the high density of this cyanobacterium. Other features should be considered in explaining this species dominance, such as phosphorus storage and physiological flexibilitywhich seem to be key features to high densities in low phosphorus systems.

  4. Survival of Mycobacterium avium in drinking water biofilms as affected by water flow velocity, availability of phosphorus, and temperature.

    Science.gov (United States)

    Torvinen, Eila; Lehtola, Markku J; Martikainen, Pertti J; Miettinen, Ilkka T

    2007-10-01

    Mycobacterium avium is a potential pathogen occurring in drinking water systems. It is a slowly growing bacterium producing a thick cell wall containing mycolic acids, and it is known to resist chlorine better than many other microbes. Several studies have shown that pathogenic bacteria survive better in biofilms than in water. By using Propella biofilm reactors, we studied how factors generally influencing the growth of biofilms (flow rate, phosphorus concentration, and temperature) influence the survival of M. avium in drinking water biofilms. The growth of biofilms was followed by culture and DAPI (4',6'-diamidino-2-phenylindole) staining, and concentrations of M. avium were determined by culture and fluorescence in situ hybridization methods. The spiked M. avium survived in biofilms for the 4-week study period without a dramatic decline in concentration. The addition of phosphorus (10 microg/liter) increased the number of heterotrophic bacteria in biofilms but decreased the culturability of M. avium. The reason for this result is probably that phosphorus increased competition with other microbes. An increase in flow velocity had no effect on the survival of M. avium, although it increased the growth of biofilms. A higher temperature (20 degrees C versus 7 degrees C) increased both the number of heterotrophic bacteria and the survival of M. avium in biofilms. In conclusion, the results show that in terms of affecting the survival of slowly growing M. avium in biofilms, temperature is a more important factor than the availability of nutrients like phosphorus.

  5. High plant availability of phosphorus and low availability of cadmium in four biomass combustion ashes

    DEFF Research Database (Denmark)

    Li, Xiaoxi; Rubæk, Gitte Holton; Sørensen, Peter

    2016-01-01

    and ash significantly increased crop yields and P uptake on the P-depleted soil. In contrast, on the adequate-P soil, the barley yield showed little response to soil amendment, even at 300–500 kg P ha− 1 application, although the barley took up more P at higher applications. The apparent P use efficiency...... of the additive was 20% in ryegrass - much higher than that of barley for which P use efficiencies varied on the two soils. Generally, crop Cd concentrations were little affected by the increasing and high applications of ash, except for relatively high Cd concentrations in barley after applying 25 Mg ha− 1 straw...... ash. Contrarily, even modest increases in the TSP application markedly increased Cd uptake in plants. This might be explained by the low Cd solubility in the ash or by the reduced Cd availability due to the liming effect of ash. High concentrations of resin-extractable P (available P) in the ash...

  6. Amending triple superphosphate with chicken litter biochar improves phosphorus availability

    Directory of Open Access Journals (Sweden)

    Audrey Asap

    2018-04-01

    Full Text Available The reaction of H2PO42- and HPO4- with Al and Fe in acid soils to form a precipitate reduces P availability. Chicken litter biochar has been used to improve soil P availability for maize production but with limited information on optimum rates of biochar and Triple Superphosphate (TSP to increase P availability. This study determined the optimum amount of chicken litter biochar and TSP that could increase P availability. Different rates of chicken litter biochar and TSP were evaluated in an incubation study for 30, 60, and 90 days. Selected soil chemical properties before and after incubation were determined using standard procedures. Soil pH, total P, available P, and water soluble P increased in treatments with 75% and 50% biochar. Total acidity, exchangeable Al3+, and Fe2+ were significantly reduced by the chicken litter biochar. The chicken litter biochar also increased soil CEC and exchangeable cations (K, Ca, Mg and Na. The use of 75% and 50% of 5 t ha-1 biochar with 25% TSP of the existing recommendation can be used to increase P availability whilst minimizing soil Al and Fe content. This rates can be used to optimize chicken litter biochar and TSP use in acid soils for crop production especially maize and short term vegetables.

  7. Availability of phosphorus in cow slurry using isotopic labelling technique

    International Nuclear Information System (INIS)

    Pongsakul, P.; Bertelsen, F.; Gissel-Nielsen, G.

    1988-01-01

    A pot experiment was conducted to evaluate the influence of cow slurry on P uptake by corn and to estimate the readily available P in the slurry by using an isotopic labelling techique. Water-soluble P in soil was increased and isotopic equilibrium of available P was attained after labelled slurry was mixed thoroughly throughout the soil. Labelled slurry applied at planting increased the P uptake by corn, whereas the same amount applied one week before harvest did not affect the P uptake. It was estimated that 46-54% of the total P uptake in plants is derived from the slurry. The readily available P (the L-value) in the slurry was at least 26 mg/kg which equals 3.7% of the total P. (author)

  8. Comparison Of Six Extractants For Assessing Available Phosphorus ...

    African Journals Online (AJOL)

    ... 0.01M CaCl2, Bray-1 and electro-ultra-filtration (EUF) technique] for simultaneous assessment of the availability of these nutrients in selected Nigerian soils was evaluated using guinea-corn (Sorghum bicolor) as test crop in Neubauer experiment. The respective average amounts of P, Zn and Mn extracted by 1N NH4OAc ...

  9. Increasing temperature reduces the coupling between available nitrogen and phosphorus in soils of Chinese grasslands

    Science.gov (United States)

    Geng, Yan; Baumann, Frank; Song, Chao; Zhang, Mi; Shi, Yue; Kühn, Peter; Scholten, Thomas; He, Jin-Sheng

    2017-03-01

    Changes in climatic conditions along geographical gradients greatly affect soil nutrient cycling processes. Yet how climate regimes such as changes in temperature influence soil nitrogen (N) and phosphorus (P) concentrations and their stoichiometry is not well understood. This study investigated the spatial pattern and variability of soil N and P availability as well as their coupling relationships at two soil layers (0-10 and 10-20 cm) along a 4000-km climate transect in two grassland biomes of China, the Inner Mongolian temperate grasslands and the Tibetan alpine grasslands. Our results found that in both grasslands, from cold to warm sites the amounts of soil total N, total P and available P all decreased. By contrast, the amount of available N was positively related to mean annual temperature in the Tibetan grasslands. Meanwhile, with increasing temperature ratio of available N to P significantly increased but the linear relationship between them was considerably reduced. Thus, increasing temperature may not only induce a stoichiometric shift but also loose the coupling between available N and P. This N-P decoupling under warmer conditions was more evident in the Tibetan alpine grasslands where P limitation might become more widespread relative to N as temperatures continue to rise.

  10. Competition between Free-Floating Plants Is Strongly Driven by Previously Experienced Phosphorus Concentrations in the Water Column

    Science.gov (United States)

    Peeters, Edwin T. H. M.; Neefjes, Rozemarijn E. M.; van Zuidam, Bastiaan G.

    2016-01-01

    Nutrients can determine the outcome of the competition between different floating plant species. The response of floating plants to current phosphorus levels may be affected by previously experienced phosphorus concentrations because some species have the ability to store excess phosphorus for later use. This might have an impact on their competition. Here, we investigate the effect of previous and actual phosphorus concentrations on the growth rate of free-floating plant species (Azolla filiculoides, Lemna minor/gibba and Ricciocarpus natans)and the effect of phosphorus history on the competition between L. minor/gibba and A. filiculoides and between L. minor/gibba and R. natans. As expected, plant growth was lower when previously kept at low instead of high phosphorus concentrations. Growth of L. minor/gibba and A. filiculoides with a phosphorus rich history was comparable for low and high actual phosphorus concentrations, however, internal phosphorus concentrations were significantly lower with low actual phosphorus concentration. This indicates that both species perform luxury phosphorus uptake. Furthermore, internal P concentration in Azolla and Lemna increased within two weeks after a period of P deficit without a strong increase in growth. A. filiculoides in a mixture with L. minor/gibba grew faster than its monoculture. Morphological differences may explain why A. filiculoides outcompeted L. minor/gibba and these differences may be induced by phosphorus concentrations in the past. Growth of L. minor/gibba was only reduced by the presence of A. filiculoides with a high phosphorus history. Growth of L. minor/gibba and R. natans in mixtures was positively affected only when they had a high phosphorus history themselves and their competitor a low phosphorus history. These observations clearly indicate that phosphorus history of competing plants is important for understanding the outcome of the competition. Therefore, actual and previously experienced phosphorus

  11. Competition between Free-Floating Plants Is Strongly Driven by Previously Experienced Phosphorus Concentrations in the Water Column.

    Science.gov (United States)

    Peeters, Edwin T H M; Neefjes, Rozemarijn E M; Zuidam, Bastiaan G van

    2016-01-01

    Nutrients can determine the outcome of the competition between different floating plant species. The response of floating plants to current phosphorus levels may be affected by previously experienced phosphorus concentrations because some species have the ability to store excess phosphorus for later use. This might have an impact on their competition. Here, we investigate the effect of previous and actual phosphorus concentrations on the growth rate of free-floating plant species (Azolla filiculoides, Lemna minor/gibba and Ricciocarpus natans)and the effect of phosphorus history on the competition between L. minor/gibba and A. filiculoides and between L. minor/gibba and R. natans. As expected, plant growth was lower when previously kept at low instead of high phosphorus concentrations. Growth of L. minor/gibba and A. filiculoides with a phosphorus rich history was comparable for low and high actual phosphorus concentrations, however, internal phosphorus concentrations were significantly lower with low actual phosphorus concentration. This indicates that both species perform luxury phosphorus uptake. Furthermore, internal P concentration in Azolla and Lemna increased within two weeks after a period of P deficit without a strong increase in growth. A. filiculoides in a mixture with L. minor/gibba grew faster than its monoculture. Morphological differences may explain why A. filiculoides outcompeted L. minor/gibba and these differences may be induced by phosphorus concentrations in the past. Growth of L. minor/gibba was only reduced by the presence of A. filiculoides with a high phosphorus history. Growth of L. minor/gibba and R. natans in mixtures was positively affected only when they had a high phosphorus history themselves and their competitor a low phosphorus history. These observations clearly indicate that phosphorus history of competing plants is important for understanding the outcome of the competition. Therefore, actual and previously experienced phosphorus

  12. Evaluation of available phosphorus and cadmium associated with phosphate rock for direct application

    International Nuclear Information System (INIS)

    Chien, S.H.

    2002-01-01

    Three greenhouse experiments were conducted to evaluate available P and Cd associated with the use of phosphate rock (PR) for direct application. These experiments were: (1) 'Estimation of Phosphorus Availability to Maize and Cowpea From Phosphate Rock as Enhanced by Water-Soluble Phosphorus'; (2) 'Modified Iron Oxide-Impregnated Paper Strip (Pi) Test for Soils Treated With Phosphate Fertilizers'; and (3) 'Effect of Acidulation of High Cadmium Containing Phosphate Rocks on Cadmium Uptake by Upland Rice'. In the first experiment, a medium-reactive Central Florida phosphate rock (PR) was used. The effectiveness of P sources in terms of increasing dry-matter yield and P uptake followed the order of TSP≥(PR+TSP)>PR for maize and TSP=(TSP+PR)>PR for cowpea. P uptake from PR in the presence of TSP was higher than P uptake from PR applied alone. With respect to P uptake from PR applied alone, the corresponding relative increase in P uptake from PR due to TSP influence was 165% for maize and 72% for cowpea. In the second experiment, a highly reactive North Carolina PR was used. Both Bray I and the Pi test (with CaCl 2 ) underestimated available P from PR with respect to TSP. Available P estimated by the Pi test with KCl was more closely related to P uptake with both PR and TSP. More P was extracted from PR by the Pi test with KCl than with CaCl 2 , whereas no effect was observed for TSP. In the third experiment, a low-reactive Togo PR and a highly reactive North Carolina PR were used. Both PRs were fully acidulated to SSP and Togo PR was also partially acidulated with H 2 SO 4 at 50% level to PAPR. Cd uptake by rice grain followed the order of NC-SSP > NC-PR and Togo-SSP > Togo PAPR > Togo PR. The results also showed that most of the Cd uptake was retained in rice root and straw. Total uptake of Cd, Ca, and P by the rice plant was higher from NC-PR than from Togo-PR. Cd concentration in rice grain showed no significant difference between NC-PR and Togo-PR, whereas Cd

  13. Phosphorus reduces the zinc concentration in cereals pot-grown on calcareous Vertisols from southern Spain.

    Science.gov (United States)

    Sánchez-Rodríguez, Antonio Rafael; Del Campillo, María Carmen; Torrent, José

    2017-08-01

    Zinc deficiency, a major problem in crops grown on soils low in available Zn, is even more important in phosphorus-rich soils. This work aimed to elucidate the effects of soil P and Zn levels, and of fertilizer application, on yield and Zn concentration in cereal grains. Wheat and barley were successively pot-grown on 20 calcareous Vertisols low in available Zn and ranging widely in available P. Grain yield in the plants grown on the native soils was positively correlated with Olsen P but not with diethylenetriaminepentaacetic acid (DTPA)-extractable Zn except for wheat on P-rich soils. Grain Zn concentration was negatively correlated with Olsen P. Grain Zn uptake differed little among soils. Application of P to the soils increased grain yield insignificantly and P concentration significantly; however, it reduced grain Zn concentration (particularly at low Olsen P values). Applying Zn alone only increased grain Zn concentration, whereas applying P and Zn in combination increased yield and grain Zn concentration at low and high Olsen P values, respectively. Applying P alone to plants grown on calcareous Vertisols low in available P and Zn may in practice reduce grain Zn concentrations while not increasing grain yield significantly. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  14. Phosphorus availability from bottom sediments of lakes using a nuclear technique

    International Nuclear Information System (INIS)

    Flores, F.; Facetti, J.F.

    1991-01-01

    Availability of phosphorus from the bottom sediments of a lake plays an import role in the development of aquatic biota and in the enhancement of eutrophication process. In this work the 31 P↔ 32 P isotopic exchange (E values) technique was applied to assess the potential influence of this phosphorus reservoir on the water quality of Acaray and Yguazu Dams, at the Eastern Region of Paraguay. Samples analyzed were taken from the bottom sediments of the water bodies at different sites as well as from the shores. The method is reliable and yields information of ecological significance

  15. Phosphorus availability from bottom sediments of lakes using a nuclear technique

    International Nuclear Information System (INIS)

    Flores, F.; Facetti, J.F.

    1992-01-01

    Availability of phosphorus from the bottom sediments of a lake plays an import role in the development of aquatic biota and in the enhancement of the eutrophication process. In this work, the 31 P- 32 P isotopic exchange (E values) technique was applied to assess the potential influence of this phosphorus 'reservoir' on the water quality of the Acaray and Yguazu Dams in the Easter Region of Paraguay. Samples analyzed were taken from the bottom sediments of the water body at different sites as well as from the shores. The method is reliable and yields information of potential ecological significance. (author) 14 refs.; 2 tabs

  16. [Influence of decomposition of Cladophora sp. on phosphorus concentrations and forms in the overlying water].

    Science.gov (United States)

    Hou, Jin-Zhi; Wei, Quan; Gao, Li; Sun, Wei-Ming

    2013-06-01

    Sediments were sampled in the dominated zone of Cladophora sp. in Rongcheng Swan Lake, and cultivated with algae in the laboratory to reveal the influence of Cladophora decomposition on concentrations and forms of phosphorus in the overlying water. Concentrations of total phosphorus (TP), dissolved total phosphorus (DTP), soluble reactive phosphorus (SRP), particulate phosphorus (PP) and dissolved organic phosphorus (DOP) in overlying water were investigated, and some physicochemical parameters, such as dissolved oxygen (DO), pH and conductivity were monitored during the experiment. In addition, the influence of algae decomposition on P release from sediments was analyzed. Due to the decomposition of Cladophora, DO concentration in the overlying water declined remarkably and reached the anoxic condition (0-0.17 mg x L(-1)). The pH value of different treatments also decreased, and treatments with algae reduced by about 1 unit. Concentrations of TP and different P forms all increased obviously, and the increasing extent was larger with the adding algae amount. TP concentrations of different treatments varied from 0.04 mg x L(-1) to 1.34 mg x L(-1). DOP and PP were the main P forms in the overlying water in algae without sediments treatments, but SRP concentrations became much higher in algae with sediments treatments. The result showed that P forms released from decomposing Cladophora were mainly DOP and PP, and the Cladophora decomposition could also promote the sediments to release P into the overlying water.

  17. Measurement of in situ phosphorus availability in acidified soils using iron-infused resin.

    Czech Academy of Sciences Publication Activity Database

    Tahovská, K.; Čapek, P.; Šantrůčková, H.; Kaňa, Jiří; Kopáček, Jiří

    2016-01-01

    Roč. 47, č. 4 (2016), s. 487-494 ISSN 0010-3624 R&D Projects: GA ČR(CZ) GAP504/12/1218 Institutional support: RVO:60077344 Keywords : acidification * aluminium * forest soil * ion exchange resin * iron * phosphorus availability Subject RIV: DF - Soil Science Impact factor: 0.589, year: 2016

  18. How Phosphorus Availability Affects the Impact of Nitrogen Deposition on Sphagnum and Vascular Plants in Bogs

    NARCIS (Netherlands)

    Limpens, J.; Berendse, F.; Klees, H.

    2004-01-01

    To elucidate the impact of high nitrogen (N) deposition on intact bog vegetation, as affected by phosphorus (P) availability, we conducted a 4-year fertilization experiment with N and P at six sites, one with moderate N deposition and five with high N deposition. During the growing season, N (40 kg

  19. Available phosphorus for 15- to 30-kg pigs kept in hot environment

    Directory of Open Access Journals (Sweden)

    Leandro Alebrante

    2011-12-01

    Full Text Available This experiment was conducted to determine the requirement of available phosphorus (aP for pigs kept in hot environment. Seventy-two pigs (36 castrated males and 36 females with initial weight of 15.10±0.31 kg were allotted in a completely randomized block design with six treatments (0.107, 0.214, 0.321, 0.428, 0.535, and 0.642% of aP, six replicates and two pigs (1 castrated male and 1 female per experimental unit. Pigs were kept in a hot environment with temperature of 34.1±0.8 ºC. The levels of aP influenced the daily weight gain, which increased quadratically up to the estimated level of 0.477%, and feed conversion, which improved quadratically up to the estimated level of 0.457%. The levels of aP also influenced the content of phosphorus in the bone, which increased quadratically up to the estimated level of 0.529%. The available phosphorus requirement of 15- to 30-kg pigs kept in a hot environment, for the best results of daily weight gain, feed conversion and bone parameters are 0.477, 0.457, and 0.529%, corresponding to the estimated daily available phosphorus intakes of 4.75; 4.55 and 5.27 g, respectively.

  20. Improvement of phosphorus availability by microbial phytase in broilers and pigs

    NARCIS (Netherlands)

    Simons, P.C.M.; Versteegh, H.A.J.; Jongbloed, A.W.; Kemme, P.A.; Slump, P.; Bos, K.D.; Wolters, M.G.E.; Beudeker, R.F.; Verschoor, G.J.

    2005-01-01

    Techniques have been developed to produce microbial phytase for addition to diets for simple-stomached animals, with the aim to improve phosphorus availability from phytate-P in plant sources. The activityof the crude microbial phytase showed pH optima at pH 5-5 and 2·5. The enzyme was able to

  1. Identification of soybean purple acid phosphatase genes and their expression responses to phosphorus availability and symbiosis

    Science.gov (United States)

    Background and Aims Purple acid phosphatases (PAPs) are members of the metallo-phosphoesterase family and have been known to play important roles in phosphorus (P) acquisition and recycling in plants. Low P availability is a major constraint to growth and production of soybean, Glycine max. Comparat...

  2. Predicting phosphorus concentrations in British rivers resulting from the introduction of improved phosphorus removal from sewage effluent

    International Nuclear Information System (INIS)

    Bowes, Michael J.; Neal, Colin; Jarvie, Helen P.; Smith, Jim T.; Davies, Helen N.

    2010-01-01

    Phosphorus (P) concentration and flow data gathered during the 1990s for a range of British rivers were used to determine the relative contributions of point and diffuse inputs to the total P load, using the Load Apportionment Model (LAM). Heavily urbanised catchments were dominated by sewage inputs, but the majority of the study catchments received most of their annual phosphorus load from diffuse sources. Despite this, almost 80% of the study sites were dominated by point source inputs for the majority of the year, particularly during summer periods when eutrophication risk is greatest. This highlights the need to reduce sewage P inputs to improve the ecological status of British rivers. These modelled source apportionment estimates were validated against land-use data and boron load (a chemical marker for sewage). The LAM was applied to river flow data in subsequent years, to give predicted P concentrations (assuming no change in P source inputs), and these estimates were compared with observed concentration data. This showed that there had been significant reductions in P concentration in the River Thames, Aire and Ouse in the period 1999 to 2002, which were attributable to the introduction of P stripping at sewage treatment works (STW). The model was then used to forecast P concentrations resulting from the introduction of P removal at STW to a 2 or 1 mg l -1 consent limit. For the urbanised rivers in this study, the introduction of phosphorus stripping to a 1 mg l -1 consent level at all STW in the catchment would not reduce P concentrations in the rivers to potentially limiting concentrations. Therefore, further sewage P stripping will be required to comply with the Water Framework Directive. Diffuse P inputs may also need to be reduced before some of the highly nutrient-enriched rivers achieve good ecological status.

  3. Simple, cost effective method for determination of phosphorus in uranium ore concentrate

    International Nuclear Information System (INIS)

    Misra, U.B.; Ramamurty, Vasantha; Dutta, M.; Balaji Rao, Y.; Subba Rao, Y.

    2015-01-01

    In this paper determination of phosphate as phosphorus in uranium ore concentrate has been described. The method used is spectrophotometric determination of phosphorus as phospho-molybdenum blue complex. As uranyl ion do not absorb in 600-900 nm range of visible region in the present medium, the phosphomolybdenum blue complex formation which is having maximum absorbance at 825 nm is exploited for determination of phosphorus. The molar absorptivity coefficient with and without the presence of uranium matrix are 2.6048 x 10 4 and 2.6730 x 10 4 lmol -1 cm -1 . The effect of matrix is not evident from the experiment carried out. (author)

  4. Plant uptake of phosphorus from sparingly available P- sources as affected by Trichoderma asperellum T34

    Directory of Open Access Journals (Sweden)

    Ana Maria Garcia-Lopez

    2015-10-01

    Full Text Available The contribution of Trichoderma asperellum T34 to the plant uptake of phosphorus (P from sparingly phytoavailable forms such as insoluble calcium (Ca phosphates and phytates was studied. Two experiments with cucumber (Cucumis sativus L. on siliceous sand were performed involving two factors, namely: (i P source, viz., KH2PO4, phytate (Ins6P, and phosphate rock (PR, and (ii inoculation with T34. Liquid pure cultures of T34 were also used. T34 increased the total content in P of cucumber roots irrespective of the particular P form and enhanced total P uptake by plants with P supplied as Ins6P or PR. The increased phytase activity observed with T34 contributes to explain its favourable influence on the uptake of P supplied as Ins6P. Solubilization of Ca phosphates from PR was favoured by the slightly acidifying effect and the increased organic anion concentration promoted by the fungus in the plant growth media. It can be concluded that T34 can improve P nutrition in plants grown on media containing phytates or insoluble Ca phosphates as dominant P forms.

  5. Dynamics of Intracellular Polymers in Enhanced Biological Phosphorus Removal Processes under Different Organic Carbon Concentrations

    Directory of Open Access Journals (Sweden)

    Lizhen Xing

    2013-01-01

    Full Text Available Enhanced biological phosphorus removal (EBPR may deteriorate or fail during low organic carbon loading periods. Polyphosphate accumulating organisms (PAOs in EBPR were acclimated under both high and low organic carbon conditions, and then dynamics of polymers in typical cycles, anaerobic conditions with excess organic carbons, and endogenous respiration conditions were examined. After long-term acclimation, it was found that organic loading rates did not affect the yield of PAOs and the applied low organic carbon concentrations were advantageous for the enrichment of PAOs. A low influent organic carbon concentration induced a high production of extracellular carbohydrate. During both anaerobic and aerobic endogenous respirations, when glycogen decreased to around 80 ± 10 mg C per gram of volatile suspended solids, PAOs began to utilize polyphosphate significantly. Regressed by the first-order reaction model, glycogen possessed the highest degradation rate and then was followed by polyphosphate, while biomass decay had the lowest degradation rate.

  6. Simultaneous denitrification and phosphorus removal by Agrobacterium sp. LAD9 under varying oxygen concentration.

    Science.gov (United States)

    Ma, Tao; Chen, Qian; Gui, Mengyao; Li, Can; Ni, Jinren

    2016-04-01

    Although efficient aerobic denitrification has received increasing attention, few studies have been made on simultaneous denitrification and phosphorus removal (SDPR) under aerobic condition. In this study, SDPR by an efficient aerobic denitrifier, Agrobacterium sp. LAD9, was firstly demonstrated. High nitrate and phosphorus removal rates of 7.50 and 1.02 mg L(-1) h(-1) were achieved in wide range of O2 concentration from 5.92 to 20.02 mg L(-1). The N2O production would be inhibited as O2 concentration exceeded 11.06 mg L(-1), while the phosphorus removal efficiency would be generally improved with increasing O2 concentration. (15)N mass spectrometry revealed that nitrogen removal accorded with the typical aerobic denitrification pathway, while (31)P nuclear magnetic resonance spectroscopy ((31)P NMR) indicated the fate of phosphorus to cells, extracellular polymeric substances (EPS), and polyphosphate (poly-P) of the denitrifier. EPS acted as a reservoir of phosphorus and the transformation of poly-P was dynamic and depended on initial orthophosphate (ortho-P) content. The aerobic SDPR would greatly simplify the conventional wastewater treatment processes which required separated considerations of nitrogen and phosphorus removal.

  7. Competition between free-floating plants is strongly driven by previously experienced phosphorus concentrations in the water column

    NARCIS (Netherlands)

    Peeters, E.T.H.M.; Neefjes, Rozemarijn; Zuidam, van B.G.

    2016-01-01

    Nutrients can determine the outcome of the competition between different floating plant species. The response of floating plants to current phosphorus levels may be affected by previously experienced phosphorus concentrations because some species have the ability to store excess phosphorus for later

  8. Modelling of in-stream nitrogen and phosphorus concentrations using different sampling strategies for calibration data

    Science.gov (United States)

    Jomaa, Seifeddine; Jiang, Sanyuan; Yang, Xiaoqiang; Rode, Michael

    2016-04-01

    It is known that a good evaluation and prediction of surface water pollution is mainly limited by the monitoring strategy and the capability of the hydrological water quality model to reproduce the internal processes. To this end, a compromise sampling frequency, which can reflect the dynamical behaviour of leached nutrient fluxes responding to changes in land use, agriculture practices and point sources, and appropriate process-based water quality model are required. The objective of this study was to test the identification of hydrological water quality model parameters (nitrogen and phosphorus) under two different monitoring strategies: (1) regular grab-sampling approach and (2) regular grab-sampling with additional monitoring during the hydrological events using automatic samplers. First, the semi-distributed hydrological water quality HYPE (Hydrological Predictions for the Environment) model was successfully calibrated (1994-1998) for discharge (NSE = 0.86), nitrate-N (lowest NSE for nitrate-N load = 0.69), particulate phosphorus and soluble phosphorus in the Selke catchment (463 km2, central Germany) for the period 1994-1998 using regular grab-sampling approach (biweekly to monthly for nitrogen and phosphorus concentrations). Second, the model was successfully validated during the period 1999-2010 for discharge, nitrate-N, particulate-phosphorus and soluble-phosphorus (lowest NSE for soluble phosphorus load = 0.54). Results, showed that when additional sampling during the events with random grab-sampling approach was used (period 2011-2013), the hydrological model could reproduce only the nitrate-N and soluble phosphorus concentrations reasonably well. However, when additional sampling during the hydrological events was considered, the HYPE model could not represent the measured particulate phosphorus. This reflects the importance of suspended sediment during the hydrological events increasing the concentrations of particulate phosphorus. The HYPE model could

  9. Interaction of Peat Soil and Sulphidic Material Substratum: Role of Peat Layer and Groundwater Level Fluctuations on Phosphorus Concentration

    Directory of Open Access Journals (Sweden)

    Benito Heru Purwanto

    2014-09-01

    Full Text Available Phosphorus (P often becomes limiting factor for plants growth. Phosphorus geochemistry in peatland soil is associated with the presence of peat layer and groundwater level fluctuations. The research was conducted to study the role of peat layer and groundwater level fluctuations on P concentration in peatland. The research was conducted on deep, moderate and shallow peat with sulphidic material as substratum, peaty acid sulphate soil, and potential acid sulphate soil. While P concentration was observed in wet season, in transition from wet to dry season, and in dry season. Soil samples were collected by using peat borer according to interlayer and soil horizon. The results showed that peat layer might act as the main source of P in peatland with sulphidic material substratum. The upper peat layer on sulphidic material caused by groundwater level fluctuations had no directly effect on P concentration in the peat layers. Increased of P concentration in the lowest sulphidic layer might relate to redox reaction of iron in the sulphidic layer and precipitation process. Phosphorus concentration in peatland with sulphidic material as substratum was not influenced by peat thickness. However, depletion or disappearance of peat layer decreased P concentration in soil solution. Disappearance of peat layer means loss of a natural source of P for peatland with sulphidic material as substratum, therefore peat layer must be kept in order to maintain of peatlands.

  10. Low-to-moderate nitrogen and phosphorus concentrations accelerate microbially driven litter breakdown rates

    Science.gov (United States)

    John S. Kominoski; Amy D. Rosemond; Jonathan P. Benstead; Vladislav Gulis; John C. Maerz; David Manning

    2015-01-01

    Particulate organic matter (POM) processing is an important driver of aquatic ecosystem productivity that is sensitive to nutrient enrichment and drives ecosystem carbon (C) loss. Although studies of single concentrations of nitrogen (N) or phosphorus (P) have shown effects at relatively low concentrations, responses of litter breakdown rates along gradients of low-to-...

  11. Phosphorus availability from the solid fraction of pig slurry is altered by composting or thermal treatment

    DEFF Research Database (Denmark)

    Christel, Wibke; Bruun, Sander; Magid, Jakob

    2014-01-01

    The alteration of easily available phosphorus (P) from the separated solid fraction of pig slurry by composting and thermal processing (pyrolysis or combustion at 300-1000. °C) was investigated by water and acidic extractions and the diffusive gradients in thin films (DGT) technique. Temporal...... changes in P availability were monitored by repeated DGT application in three amended temperate soils over 16. weeks. P availability was found to decrease in the order: drying. >. composting. >. pyrolysis. >. combustion with increasing degree of processing. Water extractions suggested that no P would....... Composting and thermal treatment produced a slow-release P fertilizer, with P availability being governed by abiotic and biotic mechanisms....

  12. Calcium levels and calcium: available phosphorus ratios in diets for white egg layers from 42 to 58 weeks of age

    Directory of Open Access Journals (Sweden)

    Silvana Marques Pastore

    2012-12-01

    Full Text Available The experiment was conducted to determine the nutritional requirement of calcium and the best calcium:available phosphorus ratio for commercial layers at the post-laying peak. A total of 324 Hy-Line W-36 laying hens were utilized in the period from 42 to 58 weeks of age, distributed in a completely randomized design in a 3 × 3 factorial arrangement, composed of three levels of calcium (39, 42 and 45 g/kg and three calcium:phosphorus ratios (12.12:1; 10.53:1; and 9.30:1, totaling nine treatments with six replications and six birds per experimental unit. There was no significant effect from the calcium levels × calcium:phosphorus ratio interaction for any of the variables studied. The calcium levels and the calcium:phosphorus ratios did not affect the variables performance or egg and bone quality. At the evaluation of the calcium:phosphorus balance, as the levels of calcium of the diet were raised, the intake of calcium and phosphorus and the contents of mineral matter and calcium in the excreta increased linearly, and the retention of calcium by birds decreased linearly. With the reduction of the calcium:phosphorus ratios of the diet, intake, retention and excretion of phosphorus by layers increased. Diets containing calcium at 39 g/kg and a calcium:phosphorus ratio of 12.12:1, corresponding to an increase in calcium of 3.51 g/bird/day and available phosphorus of 289 mg/bird/day, meet the requirements of calcium and available phosphorus of white egg layers in the period from 42 to 58 weeks of age.

  13. Effects of high nitrogen concentrations on the growth of submersed macrophytes at moderate phosphorus concentrations.

    Science.gov (United States)

    Yu, Qing; Wang, Hong-Zhu; Li, Yan; Shao, Jian-Chun; Liang, Xiao-Min; Jeppesen, Erik; Wang, Hai-Jun

    2015-10-15

    Eutrophication of lakes leading to loss of submersed macrophytes and higher turbidity is a worldwide phenomenon, attributed to excessive loading of phosphorus (P). However, recently, the role of nitrogen (N) for macrophyte recession has received increasing attention. Due to the close relationship between N and P loading, disentanglement of the specific effects of these two nutrients is often difficult, and some controversy still exists as to the effects of N. We studied the effects of N on submersed macrophytes represented by Vallisneria natans (Lour.) Hara in pots positioned at three depths (0.4 m, 0.8 m, and 1.2 m to form a gradient of underwater light conditions) in 10 large ponds having moderate concentrations of P (TP 0.03 ± 0.04 mg L(-1)) and five targeted concentrations of total nitrogen (TN) (0.5, 2, 10, 20, and 100 mg L(-1)), there were two ponds for each treatment. To study the potential shading effects of other primary producers, we also measured the biomass of phytoplankton (ChlaPhyt) and periphyton (ChlaPeri) expressed as chlorophyll a. We found that leaf length, leaf mass, and root length of macrophytes declined with increasing concentrations of TN and ammonium, while shoot number and root mass did not. All the measured growth indices of macrophytes declined significantly with ChlaPhyt, while none were significantly related to ChlaPeri. Neither ChlaPhyt nor ChlaPeri were, however, significantly negatively related to the various N concentrations. Our results indicate that shading by phytoplankton unrelated to the variation in N loading and perhaps toxic stress exerted by high nitrogen were responsible for the decline in macrophyte growth. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Using hyper-spectral indices to detect soil phosphorus concentration for various land use patterns.

    Science.gov (United States)

    Lin, Chen; Ma, Ronghua; Zhu, Qing; Li, Jingtao

    2015-01-01

    The management of nonpoint source pollution requires accurate information regarding soil phosphorus concentrations for different land use patterns. The use of remotely sensed information provides an important opportunity for such studies, and the previous studies showed that soil phosphorus shows no clear spectral response feature, while the phosphorus concentrations can be indirectly detected from the normalised difference vegetation indices (NDVI). Therefore, this study uses an optimised index in the RED and near-infrared (NIR) wavelengths to estimate total phosphorus and Olsen-P concentrations. The prediction accuracy is not entirely satisfactory with respect to a mixed land use dataset in which the determination coefficient was maintained at approximately 0.6, with particularly poor performance obtained for forest land group. However, the prediction accuracy increases markedly with the separation of samples into broad land use categories, even the R(2) was exceeded 0.8 for tea plantation group. The soil phosphorus prediction effect showed obvious variance for different land use patterns, which was related to vegetation growth conditions and critical soil properties including soil organic matter and mechanical composition.

  15. Effects of Land Use on Concentrations and Chemical Forms of Phosphorus in Different-Size Aggregates

    Science.gov (United States)

    Ahmad, E. H.; Demisie, W.; Zhang, M.

    2017-12-01

    Land use has been recognized as an important driver of environmental change on all spatial and temporal scales. This study was conducted to determine the effects of land uses on phosphorus concentration in bulk soil and in water-stable aggregates in different soils. The study was conducted on three soil types (Ferrosols, Cambosols, and Primosols), which were collected from three different locations from southeast China and under three land uses (Uncultivated, Vegetable and forest land) the region is characterized as a hill and plain area. Accordingly, a total of 24 soil samples were collected. The results showed that average contents of total P were 0.55-1.55 g/kg, 0.28-1.03 g/kg and 0.14-0.8 g/kg for the soils: Cambosols, Ferrosols and Primosols respectively. Vegetable and forest land led to higher total phosphorus contents in these soils than in the uncultivated land. An aggregate fraction of >2 mm under forest land made up the largest percentage (30 up to 70%), whereas the size fraction phosphorus, organic phosphorus and Olsen P and phosphorus forms in the soils. It implies that the conversion of natural ecosystem to vegetable land increased the phosphorus proportion in the soils, which could have negative impact on the environmental quality.

  16. Responses of root architecture development to low phosphorus availability: a review.

    Science.gov (United States)

    Niu, Yao Fang; Chai, Ru Shan; Jin, Gu Lei; Wang, Huan; Tang, Cai Xian; Zhang, Yong Song

    2013-07-01

    Phosphorus (P) is an essential element for plant growth and development but it is often a limiting nutrient in soils. Hence, P acquisition from soil by plant roots is a subject of considerable interest in agriculture, ecology and plant root biology. Root architecture, with its shape and structured development, can be considered as an evolutionary response to scarcity of resources. This review discusses the significance of root architecture development in response to low P availability and its beneficial effects on alleviation of P stress. It also focuses on recent progress in unravelling cellular, physiological and molecular mechanisms in root developmental adaptation to P starvation. The progress in a more detailed understanding of these mechanisms might be used for developing strategies that build upon the observed explorative behaviour of plant roots. The role of root architecture in alleviation of P stress is well documented. However, this paper describes how plants adjust their root architecture to low-P conditions through inhibition of primary root growth, promotion of lateral root growth, enhancement of root hair development and cluster root formation, which all promote P acquisition by plants. The mechanisms for activating alterations in root architecture in response to P deprivation depend on changes in the localized P concentration, and transport of or sensitivity to growth regulators such as sugars, auxins, ethylene, cytokinins, nitric oxide (NO), reactive oxygen species (ROS) and abscisic acid (ABA). In the process, many genes are activated, which in turn trigger changes in molecular, physiological and cellular processes. As a result, root architecture is modified, allowing plants to adapt effectively to the low-P environment. This review provides a framework for understanding how P deficiency alters root architecture, with a focus on integrated physiological and molecular signalling.

  17. Responses of root architecture development to low phosphorus availability: a review

    Science.gov (United States)

    Niu, Yao Fang; Chai, Ru Shan; Jin, Gu Lei; Wang, Huan; Tang, Cai Xian; Zhang, Yong Song

    2013-01-01

    Background Phosphorus (P) is an essential element for plant growth and development but it is often a limiting nutrient in soils. Hence, P acquisition from soil by plant roots is a subject of considerable interest in agriculture, ecology and plant root biology. Root architecture, with its shape and structured development, can be considered as an evolutionary response to scarcity of resources. Scope This review discusses the significance of root architecture development in response to low P availability and its beneficial effects on alleviation of P stress. It also focuses on recent progress in unravelling cellular, physiological and molecular mechanisms in root developmental adaptation to P starvation. The progress in a more detailed understanding of these mechanisms might be used for developing strategies that build upon the observed explorative behaviour of plant roots. Conclusions The role of root architecture in alleviation of P stress is well documented. However, this paper describes how plants adjust their root architecture to low-P conditions through inhibition of primary root growth, promotion of lateral root growth, enhancement of root hair development and cluster root formation, which all promote P acquisition by plants. The mechanisms for activating alterations in root architecture in response to P deprivation depend on changes in the localized P concentration, and transport of or sensitivity to growth regulators such as sugars, auxins, ethylene, cytokinins, nitric oxide (NO), reactive oxygen species (ROS) and abscisic acid (ABA). In the process, many genes are activated, which in turn trigger changes in molecular, physiological and cellular processes. As a result, root architecture is modified, allowing plants to adapt effectively to the low-P environment. This review provides a framework for understanding how P deficiency alters root architecture, with a focus on integrated physiological and molecular signalling. PMID:23267006

  18. Colorimetric analyzer based on mobile phone camera for determination of available phosphorus in soil.

    Science.gov (United States)

    Moonrungsee, Nuntaporn; Pencharee, Somkid; Jakmunee, Jaroon

    2015-05-01

    A field deployable colorimetric analyzer based on an "Android mobile phone" was developed for the determination of available phosphorus content in soil. An inexpensive mobile phone embedded with digital camera was used for taking photograph of the chemical solution under test. The method involved a reaction of the phosphorus (orthophosphate form), ammonium molybdate and potassium antimonyl tartrate to form phosphomolybdic acid which was reduced by ascorbic acid to produce the intense colored molybdenum blue. The software program was developed to use with the phone for recording and analyzing RGB color of the picture. A light tight box with LED light to control illumination was fabricated to improve precision and accuracy of the measurement. Under the optimum conditions, the calibration graph was created by measuring blue color intensity of a series of standard phosphorus solution (0.0-1.0mgPL(-1)), then, the calibration equation obtained was retained by the program for the analysis of sample solution. The results obtained from the proposed method agreed well with the spectrophotometric method, with a detection limit of 0.01mgPL(-1) and a sample throughput about 40h(-1) was achieved. The developed system provided good accuracy (REphosphorus nutrient. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Phosphorus acquisition by citrate- and phytase-exuding Nicotiana tabacum plant mixtures depends on soil phosphorus availability and root intermingling.

    Science.gov (United States)

    Giles, Courtney D; Richardson, Alan E; Cade-Menun, Barbara J; Mezeli, Malika M; Brown, Lawrie K; Menezes-Blackburn, Daniel; Darch, Tegan; Blackwell, Martin Sa; Shand, Charles A; Stutter, Marc I; Wendler, Renate; Cooper, Patricia; Lumsdon, David G; Wearing, Catherine; Zhang, Hao; Haygarth, Philip M; George, Timothy S

    2018-03-02

    Citrate and phytase root exudates contribute to improved phosphorus (P) acquisition efficiency in Nicotiana tabacum (tobacco) when both exudates are produced in a P deficient soil. To test the importance of root intermingling in the interaction of citrate and phytase exudates, Nicotiana tabacum plant-lines with constitutive expression of heterologous citrate (Cit) or fungal phytase (Phy) exudation traits were grown under two root treatments (roots separated or intermingled) and in two soils with contrasting soil P availability. Complementarity of plant mixtures varying in citrate efflux rate and mobility of the expressed phytase in soil was determined based on plant biomass and P accumulation. Soil P composition was evaluated using solution 31 P NMR spectroscopy. In the soil with limited available P, positive complementarity occurred in Cit+Phy mixtures with roots intermingled. Root separation eliminated positive interactions in mixtures expressing the less mobile phytase (Aspergillus niger PhyA) whereas positive complementarity persisted in mixtures that expressed the more mobile phytase (Peniophora lycii PhyA). Soils from Cit+Phy mixtures contained less inorganic P and more organic P compared to monocultures. Exudate-specific strategies for the acquisition of soil P were most effective in P-limited soil and depended on citrate efflux rate and the relative mobility of the expressed phytase in soil. Plant growth and soil P utilization in plant systems with complementary exudation strategies are expected to be greatest where exudates persist in soil and are expressed synchronously in space and time. This article is protected by copyright. All rights reserved.

  20. Variations of Growth and Toxin Yield in Cylindrospermopsis raciborskii under Different Phosphorus Concentrations

    Directory of Open Access Journals (Sweden)

    Yiming Yang

    2016-12-01

    Full Text Available The bloom-forming cyanobacteria, Cylindrospermopsis raciborskii, is a producer of the cytotoxic cylindrospermopsin (CYN. In this study, the growth, toxin yield, and expression of CYN biosynthesis genes of C. raciborskii were examined under varying phosphorus (P concentrations. The results show the cell number at 0.00 and 0.01 mg·L−1 P was significantly lower than that at higher P concentrations (≥0.5 mg·L−1. The chlorophyll a content, filament length, heterocyst, and akinete numbers at P ≤ 0.05 mg·L−1 were also significantly reduced. The intracellular and extracellular CYN concentrations and the extracellular proportions increased during the culture period, and larger values were observed at higher P concentrations. Total CYN content reached 45.34–63.83 fg·cell−1 and extracellular CYN proportion reached 11.49%–20.44% at the stationary growth phase. A significantly positive correlation was observed between CYN production and cell growth rate. Three cyr genes were expressed constantly even at P-deficient conditions. The transcription of cyr genes at P-replete conditions or after P supplementation increased from 1.18-fold to 8.33-fold. In conclusion, C. raciborskii may rapidly reorganize metabolic processes as an adaptive response to environmental P fluctuations. CYN production and cyr gene expression were constitutive metabolic processes in toxic C. raciborskii.

  1. Factors Influencing Divergent Patterns of Phosphorus Availability in NY and PA Biogeochemical `Hotspots'

    Science.gov (United States)

    Saia, S. M.; Hofmeister, K.; Regan, J. M.; Buda, A. R.; Carrick, H. J.; Walter, M. T.

    2016-12-01

    Anthropogenic alteration of the soil phosphorus (P) cycle leads to subsequent water quality issues in agricultural dominated watersheds. In the humid Northeastern United States (NE US), variably saturated areas can generate surface runoff that transports P and stimulates biogeochemical processes; these hydrologically dynamic locations are often called biogeochemical `hotspots'. Many studies have evaluated nitrogen and carbon cycling in biogeochemical hot spots but few have focused on P. We hypothesized seasonally wet parts of the landscape (i.e., hotspots) have smaller biologically available P pools because runoff events frequently carry away nutrients like P. To test this hypothesis, we generated soil wetness index (SWI) maps from soil (SURRGO) and elevation (LiDAR rescaled to 3 m) data and used these maps to direct seasonal soil sampling near Klingerstown, Pennsylvania (PA) and Ithaca, New York (NY). We collected 5cm deep soil samples in PA (bimonthly) and NY (monthly) along soil moisture gradients for a range of land cover types (forest, fallow, and cropped) from May through October. We measured soil moisture in the field and percent organic matter (OM), pH, and three increasingly strong soil P extractions (dilute-salt-extractable P, oxalate-extractable P, and total-extractable P) in the laboratory. Our results indicated a negative relationship between dilute-salt-extractable P concentrations and SWI in PA and no relationship between these same variables in NY. We also found positive relationships between each of the three P extractions in PA but only a positive relationship between oxalate-extractable P and total-extractable P in NY. Our findings in PA support our hypothesis; namely, less biologically available P (i.e. dilute-salt-extractable P) is found in wetter areas of the landscape. However, divergent P availability patterns in NY point to further complexities and confounding variables in our understanding in soil P processes. Further studies will look

  2. Lead immobilization and phosphorus availability in phosphate-amended, mine-contaminated soils.

    Science.gov (United States)

    Osborne, Lydia R; Baker, Leslie L; Strawn, Daniel G

    2015-01-01

    Over a century of mining activities in the Coeur d'Alene mining district in Idaho have contaminated soils of the downstream basin with lead, arsenic, zinc, and cadmium. Elevated soil-Pb levels are a significant hazard to the health of humans and wildlife in the region. One in situ treatment approach for remediating Pb-contaminated soils is application of phosphorus to promote the formation of lead phosphate minerals that have low solubility. However, this remediation strategy may result in excess P runoff to surface waters, which can lead to eutrophication, particularly when used in riparian areas. Research presented in this paper describes experiments in which monopotassium phosphate (KHPO) solution was applied to two Pb-contaminated soils from the Coeur d'Alene River valley to determine how P loading rates affect both Pb immobilization and P mobility and to determine if an optimal P amendment rate can be predicted. Toxicity characteristic leaching procedure extractions were used to assess changes in Pb availability for uptake by an organism or mobilization through the soil, and Bray extractions were used to assess P availability for leaching out of the soil system. For the two soils tested, increasing phosphate amendment caused decreasing Pb extractability. Phosphorus amendment rates above approximately 70 mg kg, however, did not provide any additional Pb immobilization. Phosphorus availability increased with increasing phosphate application rate. An empirical relationship is presented that predicts extractable Pb as a function of extractable P. This relationship allows for prediction of the amount of Pb that can be immobilized at specified P leaching amounts, such as regulatory levels that have been established to minimize risks for surface water degradation. Results suggest that phosphate can be used to immobilize Pb in contaminated wetland or riparian areas without posing risks of P loading to surface waters. Copyright © by the American Society of Agronomy

  3. Forty-year trends in the flux and concentration of phosphorus in British rivers

    Science.gov (United States)

    Civan, Aylin; Worrall, Fred; Jarvie, Helen P.; Howden, Nicholas J. K.; Burt, Tim P.

    2018-03-01

    Given the importance of phosphorus (P) in the eutrophication of natural waters, this study considered the long-term time series of total phosphorus (TP) and total reactive phosphorus (TRP) in British rivers from 1974 to 2012. The approach included not only trend analysis of fluxes and concentrations but also change point analysis. TP and TRP concentrations and fluxes in British rivers have declined since the mid-1980s. Over the last decade of the record the majority of individual sites did show significant downward trends in TP and TRP concentrations but, in 28% of cases for TRP concentration and 14% of cases for TP concentration, the decadal trend was a significant increase. Out of 230 sites, 136 showed a significant step decrease in TRP concentration; no sites showed a significant step increase. The modal year for the step changes for both TRP concentration and flux was 1997. Step changes are likely associated with improvements made at sewage treatment works to comply with the Urban Waste Water Treatment Directive (91/271/EEC). The decrease in TRP concentration due to the step change were in the range of 0.68% and 89% with a geometric mean of 22%, with the rest of the decrease accounted by long-term, persistent downward trend.

  4. Absolute concentration determination of phosphorus metabolites in the Langendorff-perfused rabbit heart by phosphorus-31 nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Gard, J.K.

    1984-01-01

    The concentrations of mobile high energy phosphorus metabolites and intracellular pH of Langendorff-perfused rabbit heart have been determined under control and reduced flow conditions. Absolute concentration determination was accomplished by Lorentzian lineshape analysis after development of hexachlorocyclotriphosphazene as an external intensity standard. Hearts were demonstrated to be biochemically and physiologically competent during control perfusion periods and compromised during reduced flow conditions by independent hemodynamic and metabolic measurements coincident with the NMR experiment. Reduction in perfusate flow from 20 mL/min to 5.0 mL/min (25% flow) or 2.5 mL/min (12.5% flow) demonstrated a fall in phosphocreatine and adenosine triphosphate concentrations, a rise in cytosolic inorganic phosphate concentrations, and drops in pH. Subsequent recovery upon reflow was observed. The derived values for the free concentration of ADP were very close to the reported values of the Michaelis constant for respiratory stimulation, implicating a regulatory role for this molecule in cellular respiration. Strong evidence that the creating kinase reaction was in equilibrium in the 25% flow study was seen. The NMR observable correlated closely with myocardial performance and biochemical indices of metabolic function, and supported the use of phosphocreatine as an indicator of current metabolic integrity

  5. The effect of pH on phosphorus availability and speciation in an aquaponics nutrient solution.

    Science.gov (United States)

    Cerozi, Brunno da Silva; Fitzsimmons, Kevin

    2016-11-01

    The interaction between the main ions in aquaponics nutrient solutions affects chemical composition and availability of nutrients, and nutrient uptake by plant roots. This study determined the effect of pH on phosphorus (P) speciation and availability in an aquaponics nutrient solution and used Visual MINTEQ to simulate P species and P activity. In both experimental and simulated results, P availability decreased with increase in pH of aquaponics nutrient solutions. According to simulations, P binds to several cations leaving less free phosphate ions available in solution. High pH values resulted in the formation of insoluble calcium phosphate species. The study also demonstrated the importance of organic matter and alkalinity in keeping free phosphate ions in solution at high pH ranges. It is recommended though that pH in aquaponics systems is maintained at a 5.5-7.2 range for optimal availability and uptake by plants. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Enhancing phosphorus availability in phosphorus-fertilized zones by reducing phosphate adsorbed on ferrihydrite using rice straw-derived biochar

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Hao-Jie [Chinese Academy of Sciences, Xiamen (China). Key Lab. of Urban Environment and Health; Chinese Academy of Sciences, Nanjing (China). State Key Lab. of Soil and Sustainable Agriculture; Wang, Ming Kuang [National Taiwan Univ., Taipei (China). Dept. of Agricultural Chemistry; Fu, Ming-Lai [Chinese Academy of Sciences, Xiamen (China). Key Lab. of Urban Environment and Health; Ci, En [Southwest Univ., Chongquing (China). College of Resources and Environment

    2011-10-15

    Biochar amendments can alter phosphorus (P) availability in soils, though the influencing mechanisms are not yet fully understood. This work investigated the adsorption and desorption of P on ferrihydrite (F, a Fe-oxide widely distributed in surface environments) in order to evaluate the interactions between P and Fe-oxide in the absence or presence of biochar (F or ferrihydrite-biochar (F-B) interaction) in soils. Biochar was produced by pyrolysis of rice straw at 600 C in steel ring furnaces. Two-line ferrihydrite was synthesized by dropwise addition of 1 mol L{sup -1} KOH into Fe(NO{sub 3}){sub 3} solution until the pH reached 7-8 while stirring vigorously. An F-B complex was prepared under similar conditions, except that a mixture of 10 g biochar and the Fe(NO{sub 3}){sub 3} solution was used as the starting material instead of Fe(NO{sub 3}){sub 3} alone. A batch equilibration method was used to determine sorption or desorption of P. The mechanisms of P adsorption on F and F-B complex materials were discussed. Adsorption of P on F decreased as the pH was increased from 3.0 to 10, but the adsorption capacity of F decreased by about 30-40% in the presence of biochar. The P chemisorption rates on F also decreased in the presence of biochar. The Freundlich model showed that the active adsorption sites on the surface of the F-B complex were energetically heterogeneous. The desorbability of adsorbed P on F was enhanced by combination with biochar. The mechanisms of P adsorption on F and F-B complex materials are different. The results showed that the amount and rate of P adsorption on the surface of ferrihydrite decreased with the presence of biochar, and the desorbability of adsorbed P on ferrihydrite can be enhanced when combined with biochar. Thus, the presence of biochar can decrease P adsorption on the Fe-oxides and enhance P availability in soils.

  7. Existing Versus Added Soil Organic Matter in Relation to Phosphorus Availability on Lateritic Soils

    Directory of Open Access Journals (Sweden)

    Fadly Hairannoor Yusran

    2008-01-01

    Full Text Available Lateritic soils (Ultisols and Oxisols are commonly characterised by high phosphate sorbing capacity due to the type of clay and present high content of aluminium (Al and iron (Fe oxides. Addition of fresh organic matter (OM may contribute to management of these soils by releasing more bicarbonate-extractable phosphorus (BP through organic phosphorus (OP transformation, or by the soluble component of OM additions desorbing phosphate by ligand exchange. It is not known, however, whether BP results solely from addition of new OM (by either mineralisation or desorption or from transformation of inherent or pre-existing in soil. We considered that removing the existing soil OM and replacing it with an equivalent amount of new OM may help to resolve this issue, especially with respect to P transformation after OM additions. Three lateritic soils of Western Australia (including a deep regolith material with very low inherent soil OM (SOM were used, and sub-samples of the three soils were combusted (450° C to obtain soils effectively free from existing OM. A further sub-sample of the soils was not combusted. Both soil groups, receiving the same amount of organic carbon (OC, from 80 ton ha-1 biomass + soil OM or biomass equal to soil OM from peat, wheat straw (Triticum aestivum L. and lucerne hay (Medicago sativa L., were incubated for nine months. Soil bicarbonate-extractable P as well as non-extractable P (NP, measured as Total-P (TP-BP increased due to new OM application in the order lucerne hay>peat>wheat straw. The correlation between BP with soil organic carbon (SOC became more positive over time. Microbial biomass phosphorus (MBP was not well correlated with the increase of NP content and phosphatase was not related to the increase in BP. Overall, freshly applied (new OM not only contributed to the increased level of P compared with the existing OM treatment.

  8. Effect of water treatment residuals on soil phosphorus, copper and aluminium availability and toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Lombi, E., E-mail: enzo.lombi@unisa.edu.a [CSIRO Land and Water, Centre for Environmental Contaminant Research, PMB 2, Glen Osmond, SA 5064 (Australia); Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes Campus, Mawson Lakes, SA 5095 (Australia); CRC CARE, PO Box 486, Salisbury, SA 5106 (Australia); Stevens, D.P. [CSIRO Land and Water, Centre for Environmental Contaminant Research, PMB 2, Glen Osmond, SA 5064 (Australia); Arris Pty Ltd, PO Box 5143, Burnley, Victoria 3121 (Australia); McLaughlin, M.J. [CSIRO Land and Water, Centre for Environmental Contaminant Research, PMB 2, Glen Osmond, SA 5064 (Australia); Soil and Land Systems, University of Adelaide, PMB 1, Glen Osmond, SA 5064 (Australia)

    2010-06-15

    Water treatment residuals (WTRs) are produced by the treatment of potable water with coagulating agents. Beneficial recycling in agriculture is hampered by the fact that WTRs contain potentially toxic contaminants (e.g. copper and aluminium) and they bind phosphorus strongly. These issues were investigated using a plant bioassay (Lactuca sativa), chemical extractions and an isotopic dilution technique. Two WTRs were applied to an acidic and a neutral pH soil at six rates. Reductions in plant growth in amended soils were due to WTR-induced P deficiency, rather than Al or Cu toxicity. The release of potentially toxic Al from WTRs was found to be mitigated by their alkaline nature and pH buffering capacity. However, acidification of WTRs was shown to release more soluble Al than soil naturally high in Al. Copper availability was relatively low in all treatments. However, the lability of WTR-Cu increased when the WTR was applied to the soil. - The effect of water treatment residue application to soil was investigated in relation to phosphorus availability, and copper and aluminium phytotoxicity.

  9. Effect of water treatment residuals on soil phosphorus, copper and aluminium availability and toxicity

    International Nuclear Information System (INIS)

    Lombi, E.; Stevens, D.P.; McLaughlin, M.J.

    2010-01-01

    Water treatment residuals (WTRs) are produced by the treatment of potable water with coagulating agents. Beneficial recycling in agriculture is hampered by the fact that WTRs contain potentially toxic contaminants (e.g. copper and aluminium) and they bind phosphorus strongly. These issues were investigated using a plant bioassay (Lactuca sativa), chemical extractions and an isotopic dilution technique. Two WTRs were applied to an acidic and a neutral pH soil at six rates. Reductions in plant growth in amended soils were due to WTR-induced P deficiency, rather than Al or Cu toxicity. The release of potentially toxic Al from WTRs was found to be mitigated by their alkaline nature and pH buffering capacity. However, acidification of WTRs was shown to release more soluble Al than soil naturally high in Al. Copper availability was relatively low in all treatments. However, the lability of WTR-Cu increased when the WTR was applied to the soil. - The effect of water treatment residue application to soil was investigated in relation to phosphorus availability, and copper and aluminium phytotoxicity.

  10. Phosphorus availability in an acid tropical soil amended with phosphate rocks

    International Nuclear Information System (INIS)

    Zaharah, A.R.; Sharifuddin, H.A.H.

    2002-01-01

    The fate of P from phosphate rocks applied to Malaysian soils has not been studied in detail. Since the plantation sector is the major consumer of phosphate rock (PR) in Malaysia, studies on the dissolution and agronomic effectiveness of PR are of great interest to the country. Thus a series of greenhouse and laboratory experiments involving conventional chemical extractants and 32 P isotopic techniques was carried out to evaluate the agronomic effectiveness of PR sources of different reactivity. Phosphorus and other chemical properties of the soil and PRs studied were determined. The P solubility tests by 2% formic acid, 2% citric acid and neutral ammonium citrate gave positive correlation with P uptake by one-year old oil palm seedlings. Neutral ammonium citrate proved to be a better indicator of PR solubility and its correlation coefficient with P uptake improved by expressing citrate solubility as a percentage of the rock rather than as a percentage of total P 2 0 5 content. The agronomic effectiveness of TSP and 6 PR sources was evaluated in glasshouse conditions with oil palm seedlings for one year-period. The percentage of PR dissolution varied greatly among PR sources. The PR dissolution was assessed by 0.5 M NaOH, Pi strip, L-value and 1 M ammonium citrate-dissolved Ca. Irrespective of the methods used, the more reactive PR such as North Carolina and Tunisia dissolved more P than the lower reactive sources such as Christmas Island and China PR. All the four methods used gave positive correlation with plant P uptake, with 0.5M NaOH being the best indirect method for determining PR dissolution. Less than 30% of the applied P was dissolved during the one-year period, with only about 15 to 40% of the dissolved P being taken up by the oil palm seedlings. A laboratory 32 P isotopic exchange method was also carried out in this acid soil to assess the soil P status parameters. A low water soluble P concentration (Cp) was found for all PRs used. The ratio of the

  11. [Effects of combined application of biochar and inorganic fertilizers on the available phosphorus content of upland red soil].

    Science.gov (United States)

    Jing, Yan; Chen, Xiao-min; Liu, Zu-xiang; Huang, Qian-ru; LiI, Qiu-xia; Chen, Chen; Lu, Shao-shan

    2013-04-01

    Aiming at the low content of available phosphorus in upland red soil of Southern China, this paper studied the effects of combined application of biochar and inorganic fertilizers on the available phosphorus and organic carbon contents and the pH of this soil. With the combined application of biochar and inorganic fertilizers, the soil physical and chemical properties improved to different degrees. As compared with the control, the soil pH and the soil organic carbon and available phosphorus contents at different growth stages of oil rape after the combined application of biochar and inorganic fertilizers all had an improvement, with the increments at bolting stage, flowering stage, and ripening stage being 16%, 24% and 26%, 23%, 34% and 38%, and 100%, 191% and 317% , respectively. The soil pH and the soil organic carbon and available phosphorus contents were increased with the increasing amount of applied biochar. Under-the application of biochar, the soil available phosphorus had a significant correlation with the soil pH and soil organic carbon content. This study could provide scientific basis to improve the phosphorus deficiency and the physical and chemical properties of upland red soil.

  12. [Serum calcium and phosphorus concentration and alkaline phosphatase activity in healthy children during growth and development].

    Science.gov (United States)

    Savić, Ljiljana; Savić, Dejan

    2008-01-01

    Many changes happen during growth and development in an organism as a result of important hormon changes, especially biohumoral ones. These changes make a problem when interpreting biochemical results in pediatric population. The most important changes are intensive calcium and phosphorus metabolic turnover in bone tissue with changes in alkaline phosphatase activity as a result of osteoblast activity. The aim of this study was to follow the serum calcium and phosphorus concentration and alkaline phosphatase activity in children 1-15 years old in different growth and development period and of different sexes and to fortify the influence of growth and development dynamics on biohumoral status in healthy male and female children. We evaluated 117 healthy children of both sexes from 1-15 years of age and divided them into three age groups: 1-5, 6-10 and 11-15 years. We followed the serum calcium and phosphorus concentration and alkaline phosphatase activity in different groups and in different sexes. Our investigation found significantly higher values of serum calcium in boys than in girls with no important changes between the age groups and significantly higher values of serum phosphorus in the youngest age group in all children and in different sexes with no important sex differences. Alkaline phosphatase activity followed the growth spurt and was the biggest in 6-10 years group in girls and in 11-15 years group in boys.

  13. Mapping eutrophication risk from climate change: Future phosphorus concentrations in English rivers.

    Science.gov (United States)

    Charlton, Matthew B; Bowes, Michael J; Hutchins, Michael G; Orr, Harriet G; Soley, Rob; Davison, Paul

    2018-02-01

    Climate change is expected to increase eutrophication risk in rivers yet few studies identify the timescale or spatial extent of such impacts. Phosphorus concentration, considered the primary driver of eutrophication risk in English rivers, may increase through reduced dilution particularly if river flows are lower in summer. Detailed models can indicate change in catchment phosphorus concentrations but targeted support for mitigation measures requires a national scale evaluation of risk. In this study, a load apportionment model is used to describe the current relationship between flow and total reactive phosphorus (TRP) at 115 river sites across England. These relationships are used to estimate TRP concentrations for the 2050s under 11 climate change driven scenarios of future river flows and under scenarios of both current and higher levels of sewage treatment. National maps of change indicate a small but inconsistent increase in annual average TRP concentrations with a greater change in summer. Reducing the TRP concentration of final sewage effluent to 0.5mg/L P for all upstream sewage treatment works was inadequate to meet existing P standards required through the EU Water Framework Directive, indicating that more needs to be done, including efforts to reduce diffuse pollution. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Evaluation of phosphorus in thermally converted sewage sludge: P pools and availability to wheat

    DEFF Research Database (Denmark)

    Mackay, Jessica E.; Cavagnaro, Timothy R.; Jakobsen, Iver

    2017-01-01

    Aims Dried sewage sludge (SS) and the by-products of four SS thermal conversion processes (pyrolysis, incineration and two types of gasification) were investigated for phosphorus (P) availability. Methods A sequential extraction was used to determine the distribution of P among different P pools....... After mixing materials with soil, availability of the P was determined with soil P extractions and in a growth experiment with wheat. Results Thermally converted SS contained a greater proportion of P within recalcitrant pools than dried SS. Despite having very different P pool distributions......, the incinerated and dried SS provided similar amounts of P to plants. Plant P supply from dried and incinerated SS was lower than the comparable soluble P treatment (50 mg P kg−1), but higher than a soluble treatment at a lower rate (20 mg P kg−1). Plant P uptake in gasified and pyrolysed treatments was only...

  15. The potential of legume tree prunings as organic matters for improving phosphorus availability in an acid soil

    Directory of Open Access Journals (Sweden)

    I Wahyudi

    2015-01-01

    Full Text Available A study that was aimed to elucidate roles of Gliricidia sepium and Tithonia diversifolia prunings and their extracted humic and fulvic acids on improving phosphorus availability and decreasing aluminum concentration in an Ultisol was conducted in a glasshouse. Thirteen treatments consisting of two prunings, six rates of pruning application (5, 7.5, 10, 20, 40 and 80 t/ha and one control (no added prunings were arranged in a randomized block design with four replicates. Each mixture of prunings and soil was placed in a pot containing 8 kg of soil and maize of Srikandi cultivar was grown on it for 45 days. At harvest, soil pH, P content and aluminium concentration were measured. Results of the glasshouse experiment showed that application of Gliricidia and Tithonia prunings significantly increased soil pH, reduced Alo concentration, increased Alp content, increased P availability, and increased P taken up by maize grown for 45 days. The optimum rate of both Gliricidia and Tithonia pruning should be 40 t/ha. However, at the same rate, optimum production gained by Tithonia would be higher than that of Gliricidia.

  16. Availability of phosphorus from ground phosphate rocks for rape (Brassica napus L.)

    International Nuclear Information System (INIS)

    Zhu Yongyi; Yang Juncheng; Chen Jingjian; Liu Delin; Zhu Zhaomin; Wu Ming

    1996-09-01

    The availability of phosphorus from the ground phosphate rock, which is provided by Kaiyang mining plant, Guizhou Province of China, is investigated in pot experiment with acid red soil for rape (Brassica napus L. No. 13 Xingyou, Chinese Olive Group) by 32 P indirect labelling method. The results show that the yield increased significantly by applying ground phosphate rock (GPR) and the efficiency of GPR is equal to 17.1% of that from calcium superphosphate. It is calculated as that the fertilizer efficiency of 1 kg of calcium superphosphate is the same as that of 8.53 kg ground phosphate rock in Guizhou Province of China. The effect on the grain yield is evaluated by pot and field microplot experiments, and it is found that the main effect is to increase the pod number. The fertilizer efficiency in field experiment is the same as that in pot experiment. (9 refs., 1 fig., 7 tabs.)

  17. Effect of high calcium concentration influents on enhanced biological phosphorus removal process

    International Nuclear Information System (INIS)

    Montoya Martinez, T.; Aguado Garcia, D.; Ferrer Polo, J.

    2010-01-01

    In this work, the effect of calcium concentration in wastewater on the polyphosphate accumulating organisms (PAO) is investigated as well as its influence in PAO metabolism, specifically in the Y P O4 (ratio between phosphorus release and acetic acid uptake). For this study a sequencing batch reactor (SBR) anaerobic-aerobic was used, in which the PAO enriched biomass was exposed to different calcium concentrations in the influent wastewater. The results indicate that until a given calcium level in the influent wastewater (35 mg Ca/l) the metabolism is not affect, but higher calcium concentrations lead to significant Y P O4 decline. (Author) 18 refs.

  18. The role of some microorganisms on phosphorus availability from organic materials using nuclear technique

    International Nuclear Information System (INIS)

    Abou-seer, A.M.M

    2010-01-01

    Series of laboratory and field experiments were conducted at Soil Microbiology Unit and Farm of Soil and Water Research Department, Nuclear Research Center, Atomic Energy Authority, Egypt. Availability of phosphorus in Egyptian alkaline soil had been subjected to many problems related with adverse environmental conditions (biotic and abiotic factors) and human mismanagement on flied scale. The supply power of this second important element under these conditions was very low and soil become P-deficient. To overcome this problem, there are two strategies via application of chemical approach or biological management using soil microorganisms and fungi. We considered the biological approach as the most reliable strategy for reorientation of status in soil without risks on environment. This objective aims to recycling different plant and animal residues in soil which is consistent with (sustainable development) of these organic residues as organic P source for PSMs.The present work aimed to study :1- The role of PSMs as microbiological means to convert organic P into available form utilized by plant through secretion of acid and alkaline phosphatase.2-The incubation experiment to point out the best incubation period of the residues with PSMs to be chosen before application in the field experiment and the selection of applicable residues 3- The effect of PSMs on degradation of faba bean straw and sheep manure used as organic fertilizer in addition to nitrogen fixing bacteria on marjoram (as medical plant) growth, yield, nutrient uptake and essential oil yield.4- The purification of the produced enzymes from Pseudomonas aeruginosa and studying its properties in addition to the possible application pure enzyme of sequential fractionation scheme of phosphorus in soil after harvest marjoram plant.5- The effects of gamma irradiation on the chemical constituents and antimicrobial action of essential oil marjoram plant.

  19. Temporal variability in phosphorus transfers: classifying concentration-discharge event dynamics

    Science.gov (United States)

    Haygarth, P.; Turner, B. L.; Fraser, A.; Jarvis, S.; Harrod, T.; Nash, D.; Halliwell, D.; Page, T.; Beven, K.

    The importance of temporal variability in relationships between phosphorus (P) concentration (Cp) and discharge (Q) is linked to a simple means of classifying the circumstances of Cp-Q relationships in terms of functional types of response. New experimental data at the upstream interface of grassland soil and catchment systems at a range of scales (lysimeters to headwaters) in England and Australia are used to demonstrate the potential of such an approach. Three types of event are defined as Types 1-3, depending on whether the relative change in Q exceeds the relative change in Cp (Type 1), whether Cp and Q are positively inter-related (Type 2) and whether Cp varies yet Q is unchanged (Type 3). The classification helps to characterise circumstances that can be explained mechanistically in relation to (i) the scale of the study (with a tendency towards Type 1 in small scale lysimeters), (ii) the form of P with a tendency for Type 1 for soluble (i.e., <0.45 μm P forms) and (iii) the sources of P with Type 3 dominant where P availability overrides transport controls. This simple framework provides a basis for development of a more complex and quantitative classification of Cp-Q relationships that can be developed further to contribute to future models of P transfer and delivery from slope to stream. Studies that evaluate the temporal dynamics of the transfer of P are currently grossly under-represented in comparison with models based on static/spatial factors.

  20. Enzymatic studies on phosphorus availability from phosphate compounds by microbial activities using nuclear techniques

    International Nuclear Information System (INIS)

    Abou Seer, A.M.M.

    2002-01-01

    the present study aimed to evaluate to evaluate the of phosphate solubilizing bacteria (PSB) and vesicular arbuscular mycorrhizae(VAM) as microbiological mean to convert the sparingly soluble P into available from utilized by plant through excretion of acid and alkaline phosphatase. rock phosphate as natural and a cheap source of P- fertilizer was applied in the present study. To trace the effect of microbial activity and phosphatase enzymes on phosphate availability from its compounds , set of experiments were conducted either in the lab. or green house. The obtained results could be summarized as following:- 1- phosphate solubilizing bacteria(PSB) w isolated from samples of fertile soil, 16 colonies showed positive reaction were chosen .2- bacteria , which exhibited high phosphate clearing zone (PCZ) selected to detect their efficiencies for dissolving rock phospate and select the effective one (most potent) on the basis of highest production of phosphatase and phosphorus solubilization.3- identification of the most potent (pseudomonas aeruginosa) 4- effective environmental and nutritional factors on phosphatase production by pseudomonas aeruginosa were discussed.green-house experiment: inoculation of wheat (triticum aestivum cv.sakha 8) with either PSB and /or VAM with or without rock-P fertilization was under taken. dual inoculation with psb (pseudomonas aeruginosa) and VAM improved the dry matter yield and N and P uptake by wheat as compared to other treatments. application of psb as well as VAM increased the availability of rock phosphate to be utilized by wheat

  1. Effects of phosphorus availability and vesicular-arbuscular mycorrhizas on the carbon budget of common bean (Phaseolus vulgaris)

    NARCIS (Netherlands)

    Nielsen, K.F.; Bouma, T.J.; Lynch, J.P.; Eissenstat, D.M.

    1998-01-01

    Low phosphorus availability is often a primary constraint to plant productivity in native soils. Here we test the hypothesis that root carbon costs are a primary limitation to plant growth in low P soils by assessing the effect of P availability and mycorrhizal infection on whole plant C budgets in

  2. Determination of available phosphorus in soils by using a new extraction procedure and a flow injection amperometric system.

    Science.gov (United States)

    Jakmunee, Jaroon; Junsomboon, Jaroon

    2009-09-15

    A new extraction procedure based on an off-line extraction column was proposed for extracting of available phosphorus from soils. The column was fabricated from a plastic syringe fitted at the bottom with a cotton wool and a piece of filter paper to support a soil sample. An aliquot (50 mL) of extracting solution (0.05 M HCl+0.0125 M H(2)SO(4)) was used to extract the sample under gravity flow and the eluate was collected in a polyethylene bottle. The extract was then analyzed for phosphorus contents by a simple flow injection amperometric system, employing a set of three-way solenoid valves as an injection valve. The method is based on the electrochemical reduction of 12-molybdophosphate which is produced on-line by the reaction of orthophosphate with acidic molybdate and the electrical current produced was directly proportional to the concentration of phosphate in range of 0.1-10.0 mg L(-1) PO(4)-P, with a detection limit of 0.02 mg L(-1). Relative standard for 11 replicate injections of 5 mg L(-1) PO(4)-P was 0.5%. A sample through put of 35 h(-1) was achieved, with consumption of 14 mg KCl, 10mg ammonium molybdate and 0.05 mL H(2)SO(4) per analysis. The detection system does not suffer from the interferences that are encountered in the photometric method such as colored substances, colloids, metal ions, silicate and refractive index effect (Schlieren effect). The results obtained by the column extraction procedure were well correlated with those obtained by the steady-state extraction procedure, but showed slightly higher extraction efficiency.

  3. Decline in Chinese lake phosphorus concentration accompanied by shift in sources since 2006

    Science.gov (United States)

    Tong, Yindong; Zhang, Wei; Wang, Xuejun; Couture, Raoul-Marie; Larssen, Thorjørn; Zhao, Yue; Li, Jing; Liang, Huijiao; Liu, Xueyan; Bu, Xiaoge; He, Wei; Zhang, Qianggong; Lin, Yan

    2017-07-01

    Domestic wastewater and agricultural activities are important sources of nutrient pollutants such as phosphorus and nitrogen. Upon reaching freshwater, these nutrients can lead to extensive growth of harmful algae, which results in eutrophication. Many Chinese lakes are subject to such eutrophication, especially in highly polluted areas, and as such, understanding nutrient fluxes to these lakes offers insights into the varying processes governing pollutant fluxes as well as lake water quality. Here we analyse water quality data, recorded between 2006 and 2014 in 862 freshwater lakes in four geographical regions of China, to assess the input of phosphorus from human activity. We find that improvements in sanitation of both rural and urban domestic wastewater have resulted in large-scale declines in lake phosphorus concentrations in the most populated parts of China. In more sparsely populated regions, diffuse sources such as aquaculture and livestock farming offset this decline. Anthropogenic deforestation and soil erosion may also offset decreases in point sources of pollution. In the light of these regional differences, we suggest that a spatially flexible set of policies for water quality control would be beneficial for the future health of Chinese lakes.

  4. A randomized, double-blind, placebo-controlled trial of calcium acetate on serum phosphorus concentrations in patients with advanced non-dialysis-dependent chronic kidney disease

    Directory of Open Access Journals (Sweden)

    Ho Chiang-Hong

    2011-02-01

    Full Text Available Abstract Background Hyperphosphatemia in patients with chronic kidney disease (CKD contributes to secondary hyperparathyroidism, soft tissue calcification, and increased mortality risk. This trial was conducted to examine the efficacy and safety of calcium acetate in controlling serum phosphorus in pre-dialysis patients with CKD. Methods In this randomized, double-blind, placebo-controlled trial, 110 nondialyzed patients from 34 sites with estimated GFR 2 and serum phosphorus > 4.5 mg/dL were randomized to calcium acetate or placebo for 12 weeks. The dose of study drugs was titrated to achieve target serum phosphorus of 2.7-4.5 mg/dL. Serum phosphorus, calcium, iPTH, bicarbonate and serum albumin were measured at baseline and every 2 weeks for the 12 week study period. The primary efficacy endpoint was serum phosphorus at 12 weeks. Secondary endpoints were to measure serum calcium and intact parathyroid hormone (iPTH levels. Results At 12 weeks, serum phosphorus concentration was significantly lower in the calcium acetate group compared to the placebo group (4.4 ± 1.2 mg/dL vs. 5.1 ± 1.4 mg/dL; p = 0.04. The albumin-adjusted serum calcium concentration was significantly higher (9.5 ± 0.8 vs. 8.8 ± 0.8; p p Conclusions In CKD patients not yet on dialysis, calcium acetate was effective in reducing serum phosphorus and iPTH over a 12 week period. Trial Registration www.clinicaltrials.gov NCT00211978.

  5. Effect of phosphorus and organic matter on zinc availability on rice

    International Nuclear Information System (INIS)

    Gupta, G.N.; Kamath, M.B.; Motsara, M.R.

    1977-01-01

    Pot culture experiment was conducted on grey brown podzolic soil (Palampur) and Tarai soil (Pantnagar) to study the influence of the addition of organic matter, phosphorus and zinc on the uptake and utilization of zinc by rice crop. In podzolic soils the combined application of Zn-P and Zn-organic matter resulted in reduced zinc content in crop but the crop yield was not affected. The uptake and utilization of applied zinc increased with P application. In Tarai soil, crop response to Zn, P and organic matter was obtained when applied separately. A negative zinc x P and zinc x organic matter interaction was obtained on yield. However, zinc content of the crop increased due to the application of P, organic matter and zinc. The uptake and utilization of applied zinc increased with P application. The analysis of soils after crop harvest indicated an increased amount of 0.1 N HCl extractable zinc in soils treated with zinc in Tarai soils while in podzolic soil from Palampur, the available zinc increased only under the combined application of zinc and P. (author)

  6. Effects of copper source and concentration on in vitro phytate phosphorus hydrolysis by phytase.

    Science.gov (United States)

    Pang, Yanfang; Applegate, Todd J

    2006-03-08

    Five copper (Cu) sources were studied at pH 2.5, 5.5, and 6.5 to determine how Cu affects phytate phosphorus (PP) hydrolysis by phytase at concentrations up to 500 mg/kg diet (60 min, 40-41 degrees C). Subsequently, Cu solubility with and without sodium phytate was measured. Adding Cu inhibited PP hydrolysis at pH 5.5 and pH 6.5 (P copper chloride and copper lysinate inhibited PP hydrolysis much less than copper sulfate pentahydrate, copper chloride, and copper citrate (P copper-phytin complexes.

  7. [Effects of phosphorus sources on phosphorus fractions in rhizosphere soil of wild barley genotypes with high phosphorus utilization efficiency].

    Science.gov (United States)

    Cai, Qiu-Yan; Zhang, Xi-Zhou; Li, Ting-Xuan; Chen, Guang-Deng

    2014-11-01

    High P-efficiency (IS-22-30, IS-22-25) and low P-efficiency (IS-07-07) wild barley cultivars were chosen to evaluate characteristics of phosphorus uptake and utilization, and properties of phosphorus fractions in rhizosphere and non-rhizosphere in a pot experiment with 0 (CK) and 30 mg P · kg(-1) supplied as only Pi (KH2PO4), only Po (phytate) or Pi + Po (KH2PO4+ phytate). The results showed that dry matter and phosphorus accumulation of wild barley in the different treatments was ranked as Pi > Pi + Po > Po > CK. In addition, dry matter yield and phosphorus uptake of wild barley with high P-efficiency exhibited significantly greater than that with low P-efficiency. The concentration of soil available phosphorus was significantly different after application of different phosphorus sources, which was presented as Pi > Pi + Po > Po. The concentration of soil available phosphorus in high P-efficiency wild barley was significantly higher than that of low P-efficiency in the rhizosphere soil. There was a deficit in rhizosphere available phosphorus of high P-efficiency wild barley, especially in Pi and Pi+Po treatments. The inorganic phosphorus fractions increased with the increasing Pi treatment, and the concentrations of inorganic phosphorus fractions in soil were sorted as follows: Ca10-P > O-P > Fe-P > Al-P > Ca2-P > Ca8-P. The contents of Ca2-P and Ca8-P for high P-efficiency wild barley showed deficits in rhizosphere soil under each phosphorus source treatment. In addition, enrichment of Al-P and Fe-P was observed in Pi treatment in rhizosphere soil. The concentrations of organic phosphorus fractions in soil were sorted as follows: moderate labile organic phosphorus > moderate resistant, resistant organic phosphorus > labile organic phosphorus. The labile and moderate labile organic phosphorus enriched in rhizosphere soil and the greatest enrichment appeared in Pi treatment. Furthermore, the concentrations of moderate resistant organic phosphorus and resistant

  8. Biological phosphorus and nitrogen removal in sequencing batch reactors: effects of cycle length, dissolved oxygen concentration and influent particulate matter.

    Science.gov (United States)

    Ginige, Maneesha P; Kayaalp, Ahmet S; Cheng, Ka Yu; Wylie, Jason; Kaksonen, Anna H

    2013-01-01

    Removal of phosphorus (P) and nitrogen (N) from municipal wastewaters is required to mitigate eutrophication of receiving water bodies. While most treatment plants achieve good N removal using influent carbon (C), the use of influent C to facilitate enhanced biological phosphorus removal (EBPR) is poorly explored. A number of operational parameters can facilitate optimum use of influent C and this study investigated the effects of cycle length, dissolved oxygen (DO) concentration during aerobic period and influent solids on biological P and N removal in sequencing batch reactors (SRBs) using municipal wastewaters. Increasing cycle length from 3 to 6 h increased P removal efficiency, which was attributed to larger portion of N being removed via nitrite pathway and more biodegradable organic C becoming available for EBPR. Further increasing cycle length from 6 to 8 h decreased P removal efficiencies as the demand for biodegradable organic C for denitrification increased as a result of complete nitrification. Decreasing DO concentration in the aerobic period from 2 to 0.8 mg L(-1) increased P removal efficiency but decreased nitrification rates possibly due to oxygen limitation. Further, sedimented wastewater was proved to be a better influent stream than non-sedimented wastewater possibility due to the detrimental effect of particulate matter on biological nutrient removal.

  9. Phosphorus Export Model Development in a Terminal Lake Basin using Concentration-Streamflow Relationship

    Science.gov (United States)

    Jeannotte, T.; Mahmood, T. H.; Matheney, R.; Hou, X.

    2017-12-01

    Nutrient export to streams and lakes by anthropogenic activities can lead to eutrophication and degradation of surface water quality. In Devils Lake, ND, the only terminal lake in the Northern Great Plains, the algae boom is of great concern due to the recent increase in streamflow and consequent rise in phosphorus (P) export from prairie agricultural fields. However, to date, very few studies explored the concentration (c) -streamflow (q) relationship in the headwater catchments of the Devils Lake basin. A robust watershed-scale quantitative framework would aid understanding of the c-q relationship, simulating P concentration and load. In this study, we utilize c-q relationships to develop a simple model to estimate phosphorus concentration and export from two headwater catchments of different size (Mauvais Coulee: 1032 km2 and Trib 3: 160 km2) draining to Devils Lake. Our goal is to link the phosphorus export model with a physically based hydrologic model to identify major drivers of phosphorus export. USGS provided the streamflow measurements, and we collected water samples (filtered and unfiltered) three times daily during the spring snowmelt season (March 31, 2017- April 12, 2017) at the outlets of both headwater catchments. Our results indicate that most P is dissolved and very little is particulate, suggesting little export of fine-grained sediment from agricultural fields. Our preliminary analyses in the Mauvais Coulee catchment show a chemostatic c-q relationship in the rising limb of the hydrograph, while the recession limb shows a linear and positive c-q relationship. The poor correlation in the rising limb of the hydrograph suggests intense flushing of P by spring snowmelt runoff. Flushing then continues in the recession limb of the hydrograph, but at a more constant rate. The estimated total P load for the Mauvais Coulee basin is 193 kg/km2, consistent with other catchments of similar size across the Red River of the North basin to the east. We expect

  10. Influence of the detergent formulation on the concentration of phosphorus in the sewage inflows to the WWTPs: the Brazilian experience.

    Science.gov (United States)

    Quevedo, Claudia Maria Gomes de; Piveli, Roque Passos; Paganini, Wanderley da Silva

    2018-05-01

    This work seeks to discuss the presence of phosphorus in raw sewage considering the formulation of the powder detergent for cleaning fabrics currently sold in Brazil. Based on the results of laboratory analyses performed in the sewage inflows to three wastewater treatment plants (WWTPs) located in São Paulo state, it evaluates the different fractions of this element and sizes the impact caused by the product. The average concentration of total phosphorus (total-P) in sewage inflows has shown a reduction trend over the years, and it is currently between 5.3 and 7.6 mg/L. The participation of organic phosphorus (org-P) tends to be higher than that of the inorganic phosphorus (inorg-P) with average around 64% of total-P. This situation indicates a change from the default and it may be influenced by the reduced contribution of phosphorus in the powder detergents. It was concluded that the formulation of the Brazilian products, which have a very low phosphate content, less than 0.01% by weight, may have altered the phosphorus dynamics in sewage. In other respects, results have shown the need to enhance actions aimed at controlling the sources of phosphorus in sewage, with a view to assure preventive measures to water pollution processes.

  11. The controls on phosphorus availability in a Boreal lake ecosystem since deglaciation

    Czech Academy of Sciences Publication Activity Database

    Norton, S. A.; Perry, R.H.; Saros, J.E.; Jacobson Jr, G.L.; Fernandez, I.J.; Kopáček, Jiří; Wilson, T.A.; SanClements, M.D.

    2011-01-01

    Roč. 46, č. 1 (2011), s. 107-122 ISSN 0921-2728 Institutional research plan: CEZ:AV0Z60170517 Keywords : oligotrophication * climate change * phosphorus * sediment * aluminum Subject RIV: DA - Hydrology ; Limnology Impact factor: 1.898, year: 2011

  12. Photochemical degradation of dissolved organic matter reduces the availability of phosphorus for aquatic primary producers

    Czech Academy of Sciences Publication Activity Database

    Porcal, Petr; Kopáček, Jiří

    2018-01-01

    Roč. 193, FEB (2018), s. 1018-1026 ISSN 0045-6535 R&D Projects: GA ČR GA15-09721S Institutional support: RVO:60077344 Keywords : photochemistry * phosphorus * dissolved organic matter * aluminum * iron Subject RIV: DA - Hydrology ; Limnology OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 4.208, year: 2016

  13. Optimizing Available Phosphorus in Calcareous Soils Fertilized with Diammonium Phosphate and Phosphoric Acid Using Freundlich Adsorption Isotherm

    Directory of Open Access Journals (Sweden)

    Asif Naeem

    2013-01-01

    Full Text Available In calcareous soils, phosphorus (P retention and immobilization take place due to precipitation and adsorption. Since soil pH is considered a major soil variable affecting the P sorption, an acidic P fertilizer could result in low P adsorption compared to alkaline one. Therefore, P adsorption from DAP and phosphoric acid (PA required to produce desired soil solution P concentration was estimated using Freundlich sorption isotherms. Two soils from Faisalabad and T. T. Singh districts were spiked with 0, 10, and 20 % for 15 days. Freundlich adsorption isotherms ( were constructed, and theoretical doses of PA and DAP to develop a desired soil solution P level (i.e., 0.20 mg L−1 were calculated. It was observed that P adsorption in soil increased with . Moreover, at all the levels of , P adsorption from PA was lower compared to that from DAP in both the soils. Consequently, lesser quantity of PA was required to produce desired solution P, 0.2 mg L−1, compared to DAP. However, extrapolating the developed relationship between soil contents and quantity of fertilizer to other similar textured soils needs confirmation.

  14. Effect of pre-calving zeolite, magnesium and phosphorus supplemention on periparturient serum mineral concentrations

    DEFF Research Database (Denmark)

    Pallesen, Anders; Pallesen, Flemming; Jørgensen, Rolf Jess

    2008-01-01

    The objective of this study was to test whether supplementing dry cow rations with phosphorus (P) and magnesium (Mg) would interfere with the beneficial effect of zeolite supplementation on the periparturient blood calcium (Ca) concentration in dairy cattle. Three groups (A-C) of 10 Danish Jersey...... cows were each given the following daily supplements from 2 weeks before the expected date of calving until actual calving: group A: zeolite, monoammonium phosphate, standard dry cow mineral and vitamin mix, containing 61g magnesium phosphate; group B: zeolite, standard mineral and vitamin mix without...... the magnesium phosphate and group C: standard mineral and vitamin mix, monoammonium phosphate. All cows in group B had an apparently less variable serum calcium concentration around calving with no cases of milk fever and no subclinical hypocalcaemia or hypomagnesaemia recorded. In contrast, a parturient drop...

  15. Phosphorus sources (P plus filter pie with or without azotofos on the available P in the soil

    Directory of Open Access Journals (Sweden)

    Maikel Abreu Jiménez

    2014-04-01

    Full Text Available The objective of the investigation was to evaluate the effect of four phosphorus sources plus filter pie with or without the biofertilizer Azotofos on the available phosphorus in the soil at different moments after the treatment. An experiment in factorial design 4(2+1 was established, being the four phosphorus sources: rock phosphate, natural phosphate, triple phosphate and Cuban phosphoric rock; two sources of the organic compound to base filter cake enriched with Azotofos microorganisms, only filter cake (without enrichment and a control treatment (without filter pie, neither Azotofos, with three repetitions. The evaluations of the tenor of available P (Bray-2 were carried out at the 30, 60, 90, 120 and 150 days after the installation of the experiment. The tenor of P (Bray-2 was influenced by the sources of P and the enrichment with biofertilizantes (factorial increasing the tenor of available P in front of the control. The triple superphosphate promoted the higher tenors in P in the soil at 60 and 90 days after its application, independently of the presence or not of the organic compound enriched with P solubilizing microorganisms, although this effect didn’t stay stable at the time.

  16. Improving phosphorus availability from Patos phosphate rock for Eucalyptus: a study with 32P radiotracer

    International Nuclear Information System (INIS)

    Villanueva, Felipe Carlos Alvarez; Muraoka, Takashi; Trevizam, Anderson Ricardo

    2006-01-01

    Eucalyptus plantation in Brazil is generally set on low fertility soils, therefore phosphorus (P) fertilization is mandatory and increases the cost of plantation operation. Using species that more efficiently uptake phosphorus from less soluble sources is an interesting option. However, little is known about eucalyptus regarding its ability of using less soluble forms of phosphorus. The use of P by eucalyptus (E. urophylla, E. grandis, and E. urophylla E. grandis) was studied in greenhouse using a loamy-textured, hipodystrophic Typic Haplustox from the Cerrado region, and 32P isotopic method. The P sources tested were triple superphosphate (TSP), phosphate rock (PR) and the triple superphosphate mixed with PR (TSP+PR). The effectiveness of P sources in terms of increasing dry matter yield was TSP = (TSP + PR) > PR, and the P uptake followed the order (TSP + PR) > TSP > PR for both species plus the hybrid. The increase in P uptake from PR due to TSP influence was 217.3% for E. urophylla, 235.7% for E. grandis, and 28.7% for E. urophylla E. grandis, indicating an enhancement effect of TSP on the effectiveness of PR. The hybrid E. urophylla E. grandis was the most efficient genotype on P soil use and E. grandis most exigent in P fertilizer. (author)

  17. Characteristics and Availability of Different Forms of Phosphorus in Animal Manures

    Directory of Open Access Journals (Sweden)

    YAN Zheng-juan

    2015-02-01

    Full Text Available The rapid development of intensive livestock industry has greatly increased the discharge of animal manure. Reasonable utilization of large amounts of phosphorus(Pin animal manure can not only save the fertilizer resource, but also avoid water pollution from manure due to direct discharge or excess application in farmland. In this study, P contents and fractionation in 76 animal manures were analyzed using Hedley P fractionation method based on the survey for 52 livestock farms, and P mobility and environmental risks in different manures were evaluated as the reference for manure P management. The results showed that there were significant differences in total P content of animal manures. The mean P contents were 22.5, 13.7, 12.9, 9.6 g P·kg-1 and 7.5 g P·kg-1, in which the proportion of organic P in total P were 33.1%, 41.5%, 66.4%, 28.1%and 36.8%in pig, chicken, duck, cattle and sheep manures, respectively. The contents of total and organic P in non-ruminant animal manure(pig, chicken and duck manureswere 1.7~3.0 times and 2.1~3.0 times greater than that in ruminant manure (cattle and sheep manuresand the proportion of organic P in total P in poultry manure was higher than that in other manures. P mineraliza-tion was easier in non-ruminant animal manure with lower C/P ratio(19~29, compared with that in ruminant manure with C/P ratio of 38~45. Manure P was sequentially extracted by deionized water(H2O-P, NaHCO3(NaHCO3-P, NaOH(NaOH-Pand HCl(HCl-P. The pro-portion of H2O-P, NaHCO3-P, NaOH-P, HCl-P and residual-P in total P in ruminant animal manure were 27.8%, 32.8%, 18.1%, 15.2%and 6.1%, respectively, while that were 24.6%, 19.4%, 12.7%, 34.4% and 8.9% in non-ruminant animal manure. The significant differences were in NaHCO3-P and HCl-P between ruminant and non-ruminant animal manures. Ruminant manure had greater proportion of liable P (H2O-P and NaHCO3-Pin total P(>60%, but the characteristics of higher mineralization rate might result in

  18. Changes in Olsen Phosphorus Concentration and Its Response to Phosphorus Balance in Black Soils under Different Long-Term Fertilization Patterns

    Science.gov (United States)

    Zhan, Xiaoying; Zhang, Li; Zhou, Baoku; Zhu, Ping; Zhang, Shuxiang; Xu, Minggang

    2015-01-01

    The Olsen phosphorus (P) concentration of a soil is a key index that can be used to evaluate the P supply capacity of the soil and to estimate the optimal P fertilization rate. A study of the relationship between the soil Olsen P concentration and the P balance (P input minus P output) and their variations among different fertilization patterns will help to provide useful information for proper management of P fertilization. In this paper, the two investigated long-term experiments were established on black soils in the northeast region of China. Six fertilization treatments were selected: (1) unfertilized (CK); (2) nitrogen only (N); (3) nitrogen and potassium (NK); (4) nitrogen and phosphorus (NP); (5) nitrogen, phosphorus, and potassium (NPK); and (6) nitrogen, phosphorus, potassium and manure (NPKM). The results showed that the average Olsen P concentrations in the black soils at Gongzhuling and Harbin (16- and 31-year study periods, respectively), decreased by 0.49 and 0.56 mg kg-1 a-1, respectively, without P addition and increased by 3.17 and 1.78 mg kg-1 a-1, respectively, with P fertilization. The changes in soil Olsen P concentrations were significantly (P<0.05) correlated with the P balances at both sites except for the NP and NPK treatments at Gongzhuling. Under an average deficit of 100 kg ha-1 P, the soil Olsen P concentration at both sites decreased by 1.36~3.35 mg kg-1 in the treatments without P addition and increased by 4.80~16.04 mg kg-1 in the treatments with 100 kg ha-1 of P accumulation. In addition, the changes in Olsen P concentrations in the soil with 100 kg ha-1of P balance were significantly correlated with the P activation coefficient (PAC, percentage of Olsen P to total P, r=0.99, P<0.01) and soil organic matter content (r=0.91, P<0.01). A low pH was related to large changes of Olsen P by 1 kg ha-1 of P balance. These results indicated that soil organic matter and pH have important effects on the change in soil Olsen P by 1 kg ha-1 of P

  19. [Response of Algae to Nitrogen and Phosphorus Concentration and Quantity of Pumping Water in Pumped Storage Reservoir].

    Science.gov (United States)

    Wan, You-peng; Yin, Kui-hao; Peng, Sheng-hua

    2015-06-01

    Taking a pumped storage reservoir located in southern China as the research object, the paper established a three-dimensional hydrodynamic and eutrophication model of the reservoir employing EFDC (environmental fluid dynamics code) model, calibrated and verified the model using long-term hydraulic and water quality data. Based on the model results, the effects of nitrogen and phosphorus concentrations on the algae growth were analyzed, and the response of algae to nitrogen and phosphorus concentration and quantity of pumping water was also calculated. The results showed that the nitrogen and phosphorus concentrations had little limit on algae growth rate in the reservoir. In the nutrients reduction scenarios, reducing phosphorus would gain greater algae biomass reduction than reducing nitrogen. When reducing 60 percent of nitrogen, the algae biomass did not decrease, while 12.4 percent of algae biomass reduction could be gained with the same reduction ratio of phosphorus. When the reduction ratio went to 90 percent, the algae biomass decreased by 17.9 percent and 35.1 percent for nitrogen and phosphorus reduction, respectively. In the pumping water quantity regulation scenarios, the algae biomass decreased with the increasing pumping water quantity when the pumping water quantity was greater than 20 percent of the current value; when it was less than 20 percent, the algae biomass increased with the increasing pumping water quantity. The algae biomass decreased by 25.7 percent when the pumping water quantity was doubled, and increased by 38.8 percent when it decreased to 20 percent. The study could play an important role in supporting eutrophication controlling in water source area.

  20. The influence of graded levels of available phosphorus on growth performance, muscle antioxidant and flesh quality of young grass carp (Ctenopharyngodon idella

    Directory of Open Access Journals (Sweden)

    Jing Wen

    2015-06-01

    Full Text Available Growth, muscle composition, meat quality characteristics and antioxidant capacity in muscle of young grass carp (Ctenopharyngodon idella (initial weight 282.9 ± 3.3 g fed graded levels of phosphorus (1.0, 2.5, 3.8, 5.6, 7.8 and 9.5 g/kg diet for 8 wk were investigated. Results indicated that percentage weight gain, feed intake, feed efficiency, serum phosphorus and alkaline phosphatase were improved with optimal phosphorus supplementations (P < 0.05. Muscle protein content and water holding capacity were significantly elevated, while moisture, lipid and ash contents were significantly decreased with dietary phosphorus to a certain level (P < 0.05. The meat shear force value and hydroxyproline content were not influenced by different levels of phosphorus. Muscle anti-hydroxyl radical, superoxide dismutase, catalase, glutathione S-transferase activities and glutathione content were significantly improved (P < 0.05. Conversely, anti-superoxide anion, glutathione reducase and glutathione peroxidase activities were decreased (P < 0.05 with dietary phosphorus to a certain level. These results indicated that suitable dietary phosphorus improved growth performance, meat quality and muscle antioxidant capacity. Dietary available phosphorus requirement of young grass carp for percentage weight gain was 4.0 g/kg diet.

  1. Disponibilidade de cádmio e chumbo para milho em solo adubado com fertilizantes fosfatados Cadmium and lead availability to corn in soil amended with phosphorus fertilizers

    Directory of Open Access Journals (Sweden)

    Eriberto Vagner de Souza Freitas

    2009-12-01

    Full Text Available Fertilizantes fosfatados são utilizados intensamente na agricultura, pois a baixa disponibilidade de P frequentemente limita o rendimento das culturas nas condições brasileiras. Esses fertilizantes, entretanto, constituem uma via de entrada de metais pesados no solo. Este trabalho objetivou avaliar o potencial de contaminação do solo por Cd e Pb adicionados por diferentes fertilizantes fosfatados, bem como a absorção destes por plantas de milho. Foram aplicadas cinco doses de diferentes fontes de P: superfosfato simples, superfosfato triplo, fosfato de Araxá, termofosfato de Yoorin e fosfato natural de Gafsa. As doses de P equivaleram a 0, 100, 300, 500 e 800 kg ha-1 de P2O5. Dois cultivos sucessivos com milho foram conduzidos no solo. O fosfato natural de Gafsa apresentou os maiores teores de Cd e Pb. Entre os fertilizantes acidulados, o superfosfato simples apresentou maior teor de Cd e Pb, e o termofosfato, maior concentração de Pb do que os acidulados. A aplicação de fosfato de Gafsa proporcionou as maiores concentrações de Pb na parte aérea do milho no primeiro cultivo. Este fosfato também foi responsável pelo maior teor de Cd nas plantas no segundo cultivo. O ácido cítrico foi mais eficiente em prever os teores disponíveis de Cd, enquanto o DTPA estimou melhor os teores de Pb.Phosphorus fertilizers are intensively used in Brazil, since the low availability of phosphorus often limits yields in tropical soils. However, these fertilizers can be a entranceway for soil contamination with heavy metals. This study was carried out to investigate heavy metal contamination caused by the application of five different phosphorus fertilizers as well as the metal uptake by corn (Zea mays plants. The fertilizers simple superphosphate, triple superphosphate, Araxá rock phosphate, Yoorin thermophosphate, and Gafsa rock phosphate were applied at rates of 0, 100, 300, 500 and 800 kg ha-1 P2O5 in two successive corn cycles. The highest Cd

  2. Estimation of the algal-available phosphorus pool in sediments of a large, shallow eutrophic lake (Taihu, China) using profiled SMT fractional analysis

    International Nuclear Information System (INIS)

    Zhu Mengyuan; Zhu Guangwei; Li Wei; Zhang Yunlin; Zhao Linlin; Gu Zhao

    2013-01-01

    Because large, shallow lakes are heavily influenced by wind–wave disturbance, it is difficult to estimate internal phosphorus load using traditional methods. To estimate the potential contribution of phosphorus from sediment to overlying water in eutrophic Lake Taihu, phosphorus fractions of surface and deep layer sediments were quantified and analyzed for algal bloom potential using a Standard Measurements and Testing (SMT) sequential extraction method and incubation experiments. Phosphorus bound to Fe, Al and Mn oxides and hydroxides (Fe–P) and organic phosphorus (OP) were to be found bioactive. The difference in Fe–P and OP contents between surface and deep layers equates to the sediment pool of potentially algal-available phosphorus. This pool was estimated at 5168 tons for the entire lake and was closely related to pollution input and algal blooms. Profiled SMT fractionation analysis is thus a potentially useful tool for estimating internal phosphorus loading in large, shallow lakes. - Highlights: ► We used profiled sediment P activity by SMT fractionation to evaluate the P release potential in large and shallow lakes. ► We built the relationship between sediment SMT fractionations of P and the P release by algal bloom degradation process. ► We discussed the supporting mechanism of sediment P release to Microcystis algal bloom in a large and shallow lake. ► We discussed the nutrient control strategy of algal bloom in shallow lakes in highly human activities disturbance catchment. - Profiled SMT fractional analysis of internal phosphorus pool in large, shallow lake.

  3. Leaf and soil nitrogen and phosphorus availability in a neotropical rain forest of nutrient-rich soil

    Directory of Open Access Journals (Sweden)

    José Luis Martínez-Sánchez

    2006-06-01

    Full Text Available The nitrogen and phosphorus supply in a lowland rain forest with a nutrient-rich soil was investigated by means of the leaf N/P quotient. It was hypothesised a high N and P supply to the forest ecosystem with a N and P rich soil. Total N and extractable P were determined in the surface (10 cm soil of three plots of the forest. Total N was analysed by the Kjeldahl method, and P was extracted with HCl and NH4F. The leaf N/P quotient was evaluated from the senesced leaves of 11 dominant tree species from the mature forest. Samples of 5 g of freshly fallen leaves were collected from three trees of each species. Nitrogen was analysed by microkjeldahl digestion with sulphuric acid and distilled with boric acid, and phosphorus was analysed by digestion with nitric acid and perchloric acid, and determined by photometry. Concentrations of total N (0.50%, n = 30 and extractable P (4.11 μg g-1, n = 30 in the soil were high. As expected, P supply was sufficient, but contrary to expected, N supply was low (N/P = 11.8, n = 11. Rev. Biol. Trop. 54(2: 357-361. Epub 2006 Jun 01.A través del cociente foliar N/P, se investigó la disponibilidad de nitrógeno y fósforo en una selva húmeda tropical con suelo fértil. Como hipótesis se esperaba encontrar una alta disponibilidad de N y P en el ecosistema debido a un suelo rico en N y P. Se determinó el N total y el P extraible en el suelo superficial (10 cm en tres sitios de la selva. El N total se analizó por el método Kjeldahl y el P por extracción con HCl y NH4F. El cociente foliar N/P se evaluó a partir de hojas seniles de 11 especies arbóreas dominantes de la selva madura. Se recolectaron muestras de 5 g de hojas recién caídas de tres árboles de cada especie. El nitrógeno se analizó por digestión microkjeldahl con ácido sulfúrico y destilación con ácido bórico, y el fósforo por digestión con ácido nítrico y ácido perclórico, y determinación con fotometría. Las concetraciones de N

  4. Physico-chemical properties of starches isolated from potato cultivars grown in soils with different phosphorus availability.

    Science.gov (United States)

    Leonel, Magali; Carmo, Ezequiel L; Fernandes, Adalton M; Franco, Célia M L; Soratto, Rogério P

    2016-04-01

    Starch is the major component of potato tubers, amounting approximately to 150-200 g kg (-1) of the tuber weight. Starch is considered to be a major factor for the functionality of the potato in food applications. This study evaluated the physical characteristics of potato starches isolated from tubers of different potato cultivars grown in soil with three levels of phosphorus (P) availability. All potatoes were growing according the same method. The starches were isolated by physical methods and the samples were analyzed for the amylose, P content, paste properties (RVA) and thermal properties of gelatinization and retrogradation (DSC). Experimental data were analyzed considering the potato cultivars and the three soil P availability. For all measured parameters significant impact of cultivar and soil P availability was determined. Phosphorus contents in potato starches ranged from 0.252 to 0.647 g kg(-1) and amylose from 27.18 to 30.8%. Starches from different potato cultivars independent of soil showed a small range of gelatinization temperature. All starches showed low resistance heating and shear stress. The results showed the influence of growing conditions (soil P availability) and also of the differences between the potato cultivars on important characteristics of applicability of starches. © 2015 Society of Chemical Industry.

  5. Maximum growth rates and possible life strategies of different bacterioplankton groups in relation to phosphorus availability in a freshwater reservoir

    Czech Academy of Sciences Publication Activity Database

    Šimek, Karel; Horňák, Karel; Jezbera, Jan; Nedoma, Jiří; Vrba, Jaroslav; Straškrábová, Viera; Macek, Miroslav; Dolan, J. R.; Hahn, M.W.

    2006-01-01

    Roč. 8, č. 9 (2006), s. 1613-1624 ISSN 1462-2912 R&D Projects: GA ČR(CZ) GA206/05/0007; GA AV ČR(CZ) 1QS600170504 Grant - others:MŠM(CZ) 60076658/01 Institutional research plan: CEZ:AV0Z60170517 Keywords : bacterioplankton community composition * growth of bacteria and flagellates * phosphorus availability * reservoir * top-down and bottom-up control Subject RIV: EE - Microbiology, Virology Impact factor: 4.630, year: 2006

  6. Effect of Phytase Superdoses and Citric Acid on Growth Performance, Plasma Phosphorus and Tibia Ash in Broilers Fed Canola Meal-Based Diets Severely Limited in Available Phosphorus

    Directory of Open Access Journals (Sweden)

    Taheri HR

    2015-06-01

    Full Text Available This experiment was conducted to investigate the effect of phytase superdoses alone or in combination with citric acid (CA in canola meal-based diets severely limited in available phosphorus (Pa on growth performance, plasma phosphorus (P, and tibia ash (TA in broilers from 22 to 42 d of age. Two hundreds and eighty 21-d-old male broilers were used in 28 pens of 10 birds per each. The experimental diets consisted of a positive control (PC diet and six negative control (NC diets which consisted of two levels of CA (0 and 20 g/Kg and three levels of phytase (0, 1000 and 4000 U/Kg in a 2 × 3 factorial arrangement. The PC diet contained 4.3 g/Kg Pa, but all NC diets contained 1.5 g/Kg Pa. Results indicated that the birds fed the PC diet had a significantly higher average daily gain (ADG, plasma P and TA, but a lower feed conversion ratio (FCR than those fed the NC diet. The ADG, FCR and plasma P values in birds fed NC diets supplemented with 4000 U/Kg phytase enzyme (with or without CA significantly reached those of birds fed the PC diet. But, addition of phytase enzyme at 1000 U/Kg only plus CA to the NC diet could significantly improve FCR and plasma P. A significant interaction was observed between phytase and CA for FCR and plasma P. Although TA values in NC + 1000 U/Kg phytase treatments (with or without CA were similar to the PC treatment, TA values of NC + 4000 U/Kg phytase treatments (with or without CA was greater than that of the PC treatment. Results of this study showed that, in severely limited Pa corn-canola meal-based diets, supplementing 4000 U/Kg phytase or also 1000 U/Kg phytase plus CA will be sufficient to obtain the comparable feed efficiency in broilers to those fed the adequate Pa diet.

  7. Water-soluble phosphorus in fresh broiler litter is dependent upon phosphorus concentration fed but not on fungal phytase supplementation.

    Science.gov (United States)

    Applegate, T J; Joern, B C; Nussbaum-Wagler, D L; Angel, R

    2003-06-01

    This experiment determined the effects of different phosphorus (P) feeding programs on total and water-soluble P excretion by broilers. Ross 308, male broilers were fed an industry (IND) diet (0.48, 0.35, 0.31, and 0.30% nonphytate P; NPP), an industry diet with reduced NPP and supplemental phytase [IND + PT; 600 phytase units (FTU)/kg; 0.36, 0.26, 0.20, and 0.19% NPP], a diet to more closely meet the birds' NPP requirements in which NPP was reduced further with supplemental phytase (REQ + P; 600 FTU/kg; 0.36, 0.26, 0.19, and 0.09% NPP), or a diet with low-phytate(lpa 1-1) corn with supplemental phytase (LPA + P; 600 FTU/kg; 0.37, 0.29, 0.19, 0.19% NPP). These diets were fed from hatch to 17 d, 17 to 31 d, 31 to 42 d, and 42 to 49 d of age, respectively. Fungal phytase was analyzed prior to diet formulation. Diets were fed to six replicate pens of 39 birds per pen. Litter samples were collected at 49 d of age and frozen prior to analyses. Diet did not significantly affect broiler performance (average BW at 49 d = 3.03 kg), tibia, or toe ash throughout the study (P > 0.05). Litter from broilers fed the IND diet was significantly higher (P litter from broilers fed IND + PT (0.84 and 0.14% of DM, respectively), REQ + P (0.78 and 0.11% of DM, respectively), or LPA + PT (0.64 and 0.12% of DM, respectively). Litter total and water-soluble P were not significantly different among broilers fed IND + PT, REQ + PT, or LPA + PT. In conclusion, phytase supplementation did not affect the solubility of P in the litter regardless of P feeding program.

  8. Roadside soils show low plant available zinc and copper concentrations

    International Nuclear Information System (INIS)

    Morse, Natalie; Walter, M. Todd; Osmond, Deanna; Hunt, William

    2016-01-01

    Vehicle combustion and component wear are a major source of metal contamination in the environment, which could be especially concerning where road ditches are actively farmed. The objective of this study was to assess how site variables, namely age, traffic (vehicles day"−"1), and percent carbon (%C) affect metal accumulation in roadside soils. A soil chronosequence was established with sites ranging from 3 to 37 years old and bioavailable, or mobile, concentrations of Zinc (Zn) and Copper (Cu) were measured along major highways in North Carolina using a Mehlich III extraction. Mobile Zn and Cu concentrations were low overall, and when results were scaled via literature values to “total metal”, the results were still generally lower than previous roadside studies. This could indicate farming on lands near roads would pose a low plant toxicity risk. Zinc and Cu were not correlated with annual average traffic count, but were positively correlated with lifetime traffic load (the product of site age and traffic count). This study shows an often overlooked variable, site age, should be included when considering roadside pollution accumulation. Zinc and Cu were more strongly associated with %C, than traffic load. Because vehicle combustion is also a carbon source, it is not obvious whether the metals and carbon are simply co-accumulating or whether the soil carbon in roadside soils may facilitate previously overlooked roles in sequestering metals on-site. - Highlights: • Low plant available zinc and copper concentrations in roadside soils of the southeast U.S. • Metals from vehicular traffic may not be adversely affecting plants in roadside environment. • Traffic volume and site age better predictor of metal pollution than traffic volume alone. - Mobile concentrations of Zn and Cu in roadside soils were below toxic levels. Zn and Cu concentrations were better correlated with lifetime vehicle load, as opposed to traffic volume.

  9. Groundwater Depth Affects Phosphorus But Not Carbon and Nitrogen Concentrations of a Desert Phreatophyte in Northwest China.

    Science.gov (United States)

    Zhang, Bo; Gao, Xiaopeng; Li, Lei; Lu, Yan; Shareef, Muhammad; Huang, Caibian; Liu, Guojun; Gui, Dongwei; Zeng, Fanjiang

    2018-01-01

    Ecological stoichiometry is an important aspect in the analysis of the changes in ecological system composition, structure, and function and understanding of plant adaptation in habitats. Leaf carbon (C), nitrogen (N), and phosphorus (P) concentrations in desert phreatophytes can be affected by different depths of groundwater through its effect on the adsorption and utilization of nutrient and plant biomass. We examined the biomass, soil organic C, available (mineral) N, and available P, and leaf C, N, and P concentrations of Alhagi sparsifolia grown at varying groundwater depths of 2.5, 4.5, and 11.0 m in 2015 and 2016 growing seasons in a desert-oasis ecotone in northwest China. The biomass of A. sparsifolia and the C, N, and P concentrations in soil and A. sparsifolia showed different responses to various groundwater depths. The leaf P concentration of A. sparsifolia was lower at 4.5 m than at 2.5 and 11.0 m likely because of a biomass dilution effect. By contrast, leaf C and N concentrations were generally unaffected by groundwater depth, thereby confirming that C and N accumulations in A. sparsifolia were predominantly determined by C fixation through the photosynthesis and biological fixation of atmospheric N 2 , respectively. Soil C, N, and P concentrations at 4.5 m were significantly lower than those at 11.0 m. Leaf P concentration was significantly and positively correlated with soil N concentration at all of the groundwater depths. The C:N and C:P mass ratios of A. sparsifolia at 4.5 m were higher than those at the other groundwater depths, suggesting a defensive life history strategy. Conversely, A. sparsifolia likely adopted a competitive strategy at 2.5 and 11.0 m as indicated by the low C:N and C:P mass ratios. To our knowledge, this study is the first to elucidate the variation in the C, N, and P stoichiometry of a desert phreatophyte at different groundwater depths in an arid ecosystem.

  10. Interaction Effect between Phosphorus and Zinc on their Availability in Soil in Relation to their Contents in Stevia (Stevia rebaudiana)

    Science.gov (United States)

    Das, Kuntal; Dang, Raman; Shivananda, T. N.; Sur, Pintu

    2005-01-01

    A greenhouse experiment was conducted at the Indian Institute of Horticultural Research (IIHR), Bangalore to study the interaction effect between phosphorus and zinc on their availability in soil in relation to their contents in stevia (Stevia rebaudiana). The results show that the amount of available P and Zn content in soil has been found to increase initially and, thereafter, the amount of the same decreased with the progress of plant growth up to 60 days irrespective of treatments. The amount of P and Zn in soils showed an increase with their separate applications either as soil or foliar spray while that of the same value significantly decreased both in soils and plants due to their combined applications, suggesting a mutual antagonistic effect between Zn and P affecting each other's availability in soil and content in the stevia plant. PMID:15980919

  11. Determining the available phosphorus release of Natuphos E 5,000 G phytase for nursery pigs.

    Science.gov (United States)

    Gourley, K M; Woodworth, J C; DeRouchey, J M; Dritz, S S; Tokach, M D; Goodband, R D

    2018-04-03

    A total of 288 pigs (PIC 327 × 1050; initially 11.1 ± 0.1 kg, and day 40 of age) were used in a 21-d growth trial to determine the available P (aP) release curve for a novel source of 6-phytase (Natuphos E 5,000 G; BASF Corporation, Florham Park, NJ). Natuphos E is a bacterial derived 6-phytase of which the phytase gene is assembled from a hybrid of phytase-producing bacteria and produced through the fermentation of Aspergillus niger. Pigs were randomly allotted to pens at weaning. From day 15 to 18 postweaning, a common corn-soybean meal diet containing 0.12% aP was fed to all pigs to acclimate them to a P-deficient diet. On day 0 of the experiment (day 19 after weaning), pens were allotted in a randomized complete block design to one of eight treatments. There were four pigs per pen and nine pens per dietary treatment. Pigs were fed a corn-soybean meal-based diet formulated to 1.25% standardized ileal digestible Lys. Experimental diets were formulated to contain 0.73% Ca and increasing aP supplied by either monocalcium P (0.12%, 0.18%, and 0.24% aP) or from increasing phytase (150, 250, 500, 750, and 1,000 phytase unit [FTU]/kg) added to the 0.12% aP diet. Analyzed phytase concentrations were 263, 397, 618, 1,100, and 1,350 FTU/kg, respectively. On day 21 of the study, one pig per pen was euthanized and the right fibula was collected for bone ash and percentage bone ash calculations. From day 0 to 21, increasing P from monocalcium P or phytase improved (linear, P ash weight and percentage bone ash increased (linear, P percentage bone ash are used as the response variables, aP release for up to 1,000 FTU/kg of Natuphos E 5,000 G phytase can be predicted by the equation: aP release = 0.000212 × FTU/kg phytase.

  12. Soil pH controls the environmental availability of phosphorus: Experimental and mechanistic modelling approaches

    International Nuclear Information System (INIS)

    Devau, Nicolas; Cadre, Edith Le; Hinsinger, Philippe; Jaillard, Benoit; Gerard, Frederic

    2009-01-01

    Inorganic P is the least mobile major nutrient in most soils and is frequently the prime limiting factor for plant growth in terrestrial ecosystems. In this study, the extraction of soil inorganic P with CaCl 2 (P-CaCl 2 ) and geochemical modelling were combined in order to unravel the processes controlling the environmentally available P (EAP) of a soil over a range of pH values (pH ∼ 4-10). Mechanistic descriptions of the adsorption of cations and anions by the soil constituents were used (1-pK Triple Plane, ion-exchange and NICA-Donnan models). These models are implemented into the geochemical code Visual MINTEQ. An additive approach was used for their application to the surface horizon of a Cambisol. The geochemical code accurately reproduced the concentration of extracted P at the different soil pH values (R 2 = 0.9, RMSE = 0.03 mg kg -1 ). Model parameters were either directly found in the literature or estimated by fitting published experimental results in single mineral systems. The strong agreement between measurements and modelling results demonstrated that adsorption processes exerted a major control on the EAP of the soil over a large range of pH values. An influence of the precipitation of P-containing mineral is discounted based on thermodynamic calculations. Modelling results indicated that the variations in P-CaCl 2 with soil pH were controlled by the deprotonation/protonation of the surface hydroxyl groups, the distribution of P surface complexes, and the adsorption of Ca and Cl from the electrolyte background. Iron-oxides and gibbsite were found to be the major P-adsorbing soil constituents at acidic and alkaline pHs, whereas P was mainly adsorbed by clay minerals at intermediate pH values. This study demonstrates the efficacy of geochemical modelling to understand soil processes, and the applicability of mechanistic adsorption models to a 'real' soil, with its mineralogical complexity and the additional contribution of soil organic matter.

  13. Soil pH controls the environmental availability of phosphorus: Experimental and mechanistic modelling approaches

    Energy Technology Data Exchange (ETDEWEB)

    Devau, Nicolas [INRA, UMR 1222 Eco and Sols - Ecologie Fonctionnelle et Biogeochimie des Sols (INRA-IRD-SupAgro), Place Viala, F-34060 Montpellier (France); Cadre, Edith Le [Supagro, UMR 1222 Eco and Sols - Ecologie Fonctionnelle et Biogeochimie des Sols (INRA-IRD-SupAgro), Place Viala, F-34060 Montpellier (France); Hinsinger, Philippe; Jaillard, Benoit [INRA, UMR 1222 Eco and Sols - Ecologie Fonctionnelle et Biogeochimie des Sols (INRA-IRD-SupAgro), Place Viala, F-34060 Montpellier (France); Gerard, Frederic, E-mail: gerard@supagro.inra.fr [INRA, UMR 1222 Eco and Sols - Ecologie Fonctionnelle et Biogeochimie des Sols (INRA-IRD-SupAgro), Place Viala, F-34060 Montpellier (France)

    2009-11-15

    Inorganic P is the least mobile major nutrient in most soils and is frequently the prime limiting factor for plant growth in terrestrial ecosystems. In this study, the extraction of soil inorganic P with CaCl{sub 2} (P-CaCl{sub 2}) and geochemical modelling were combined in order to unravel the processes controlling the environmentally available P (EAP) of a soil over a range of pH values (pH {approx} 4-10). Mechanistic descriptions of the adsorption of cations and anions by the soil constituents were used (1-pK Triple Plane, ion-exchange and NICA-Donnan models). These models are implemented into the geochemical code Visual MINTEQ. An additive approach was used for their application to the surface horizon of a Cambisol. The geochemical code accurately reproduced the concentration of extracted P at the different soil pH values (R{sup 2} = 0.9, RMSE = 0.03 mg kg{sup -1}). Model parameters were either directly found in the literature or estimated by fitting published experimental results in single mineral systems. The strong agreement between measurements and modelling results demonstrated that adsorption processes exerted a major control on the EAP of the soil over a large range of pH values. An influence of the precipitation of P-containing mineral is discounted based on thermodynamic calculations. Modelling results indicated that the variations in P-CaCl{sub 2} with soil pH were controlled by the deprotonation/protonation of the surface hydroxyl groups, the distribution of P surface complexes, and the adsorption of Ca and Cl from the electrolyte background. Iron-oxides and gibbsite were found to be the major P-adsorbing soil constituents at acidic and alkaline pHs, whereas P was mainly adsorbed by clay minerals at intermediate pH values. This study demonstrates the efficacy of geochemical modelling to understand soil processes, and the applicability of mechanistic adsorption models to a 'real' soil, with its mineralogical complexity and the additional

  14. Tomato root growth and phosphorus absorption kinetics by tomato plants as affected by phosphorus concentration in nutrient solution

    International Nuclear Information System (INIS)

    Fontes, P.C.R.; Barber, S.A.

    1984-01-01

    To evaluate the effects P concentrations in nutrient solution on root growth and on root physiological characteristics involved in P uptake by tomato Lycopersicon esculentum Mill plants, six seedlings were grown in nutrient solution at initial concentrations of 48.5, 97, 194 and 388 μMP until one day before harvest. They were then transferred to solutions with P at 20 μM and 30 μM, and the depletion curves and Michaelis-Menten parameters were determined. The conclusions were that as P supply increased and as the plant P contents are sufficient for maximum growth, the rate of P uptake tends to be lower. The results also indicate that total P uptake by tomato seedlings depends on the amount of root surface area exposed to P. (M.A.C.) [pt

  15. Effects of phosphorus availability and genetic variation of leaf terpene content and emission rate in Pinus pinaster seedlings susceptible and resistant to the pine weevil, Hylobius abietis.

    Science.gov (United States)

    Blanch, J-S; Sampedro, L; Llusià, J; Moreira, X; Zas, R; Peñuelas, J

    2012-03-01

    We studied the effects of phosphorus fertilisation on foliar terpene concentrations and foliar volatile terpene emission rates in six half-sib families of Pinus pinaster Ait. seedlings. Half of the seedlings were resistant to attack of the pine weevil Hylobius abietis L., a generalist phloem feeder, and the remaining seedlings were susceptible to this insect. We hypothesised that P stress could modify the terpene concentration in the needles and thus lead to altered terpene emission patterns relevant to plant-insect signalling. The total concentration and emission rate ranged between 5732 and 13,995 μg·g(-1) DW and between 2 and 22 μg·g(-1) DW·h(-1), respectively. Storage and emission were dominated by the isomers α- and β-pinene (77.2% and 84.2% of the total terpene amount amassed and released, respectively). In both resistant and susceptible families, P stress caused an increase of 31% in foliar terpene concentration with an associated 5-fold decrease in terpene emission rates. A higher terpene content in the leaves implies that the 'excess carbon', available under limiting growth conditions (P scarcity), is allocated to terpene production. Sensitive families showed a greater increase in terpene emission rates with increasing P concentrations, which could explain their susceptibility to H. abietis. © 2011 German Botanical Society and The Royal Botanical Society of the Netherlands.

  16. Filter Membrane Effects on Water-Extractable Phosphorus Concentrations from Soil.

    Science.gov (United States)

    Norby, Jessica; Strawn, Daniel; Brooks, Erin

    2018-03-01

    To accurately assess P concentrations in soil extracts, standard laboratory practices for monitoring P concentrations are needed. Water-extractable P is a common analytical test to determine P availability for leaching from soils, and it is used to determine best management practices. Most P analytical tests require filtration through a filter membrane with 0.45-μm pore size to distinguish between particulate and dissolved P species. However, filter membrane type is rarely specified in method protocols, and many different types of membranes are available. In this study, three common filter membrane materials (polyether sulfone, nylon, and nitrocellulose), all with 0.45-μm pore sizes, were tested for analytical differences in total P concentrations and dissolved reactive P (DRP) concentrations in water extracts from six soils sampled from two regions. Three of the extracts from the six soil samples had different total P concentrations for all three membrane types. The other three soil extracts had significantly different total P results from at least one filter membrane type. Total P concentration differences were as great as 35%. The DRP concentrations in the extracts were dependent on filter type in five of the six soil types. Results from this research show that filter membrane type is an important parameter that affects concentrations of total P and DRP from soil extracts. Thus, membrane type should be specified in soil extraction protocols. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  17. Nutritional geometry of calcium and phosphorus nutrition in broiler chicks. The effect of different dietary calcium and phosphorus concentrations and ratios on nutrient digestibility.

    Science.gov (United States)

    Wilkinson, S J; Bradbury, E J; Thomson, P C; Bedford, M R; Cowieson, A J

    2014-07-01

    A total of 600 Ross 308-day-old male broiler chicks were used in a 28 day digestibility study to investigate the interaction between dietary calcium (Ca) and non-phytate phosphorus (nPP) on the digestibility of minerals and amino acids. Diets were formulated to be nutritionally adequate except for Ca and nPP. Fifteen mash diets based on corn and soya bean meal with varying concentrations of Ca (6.4 to 12.0 g/kg) and nPP (2.4 to 7.0 g/kg) were used. Diets were clustered around total densities of Ca and nPP of 12, 13.5 or 15.0 (g/kg) and within each density, a range of five Ca : nPP ratios (1.14 : 1, 1.5 : 1, 2.0 : 1, 2.75 : 1 and 4.0 : 1) were fed. Birds had free access to feed and water throughout the study. At day 28, birds were euthanised for the determination of apparent ileal mineral and amino acid digestibility. Data were modelled in R version 2.15 using a linear mixed-effects model and interrogation of the data was performed by fitting a low order polynomial function. At high Ca concentrations, increasing nPP led to an increase in the apparent digestibility of minerals. Apparent ileal digestibility of phosphorus (P) was enhanced with increasing dietary nPP up to 5.5 g/kg beyond which no improvements were found. Maximal Ca digestibility was found in diets with >8.0 g/kg Ca with concomitant low concentrations of nPP. Diets with a broader Ca : nPP ratio improved the digestibility of Ca but were deleterious to the digestibility of P. In this study, apparent digestibility of amino acids was broadly unaffected by dietary Ca and nPP concentrations. However, interactions between Ca and nPP were observed for the digestibility of glutamine, tyrosine and methionine (all P<0.001). Nitrogen digestibility showed discrete optima around 10.0 and 5.0 g/kg nPP and Na digestibility was maximised around 8 to 9.0 g/kg Ca and 4.5 to 5.4 g/kg nPP. These data show that the ratio of Ca : nPP is more influential to mineral digestibility than the absolute dietary concentration of each

  18. Weather conditions influencing phosphorus concentration in the growing period in the large shallow Lake Peipsi (Estonia/Russia)

    OpenAIRE

    Tammeorg, Olga; Möls, Tonu; Kangur, Külli

    2014-01-01

    The impact of water temperature (T), water level (L), photosynthetically active radiation (PAR), and wind speed (V) on the total phosphorus concentration (TP) in shallow eutrophic lake Peipsi, the fourth largest lake in Europe, was studied. We used a long-term dataset (1985-2010) of TP concentrations and weather factors. A Thin Plate Spline (TPS) model was used to predict TP by year, by day of the year, and by geographical coordinates. Deviations between observed and predicted TP values (resi...

  19. Granulated wood ash to forest soils. Effects on microorganisms, phosphorus availability, and spatial relationships in the humus layer

    International Nuclear Information System (INIS)

    Clarholm, Marianne

    1999-01-01

    The report summarises effects on microorganisms, phosphorus (P) availability and spatial relationships in the humus layer of two spruce forests in south-western Sweden four to seven years after application of 3.2 tonnes (t) (Skogaby), alternatively three or six t (Torup) of granulated wood ash. There were tendencies for increases in pH and in numbers of ciliates, flagellates and small nematodes while no effects were observed for naked amoebae, the major consumers of bacteria among the protozoa. After seven years, the amount of P in microbial biomass in the humus layer in the wood ash treatment (A) in Skogaby was significantly higher than in the control (C), increased amounts of microbial nitrogen and carbon were also recorded. Observations over time indicated that the P availability in the soil first decreased after the ash addition, but later increased above that in the control. The time course was most readily seen in the microbial biomass, which contained 50% of total P in the humus layer, an amount equal to ten times the yearly uptake in trees. The microbial biomass has a much higher P concentration as compared to the needles, the component of the tree with the highest concentration. The P in micro-organisms thus form a buffer against P deficiency for the trees. A test where the 32 P uptake rate of excised mycorrhizal fine roots in the laboratory is used to establish P availability in the field, indicated an increased P availability in (A), which was in contrast to reported decreased uptake of P in trees, decreased P concentration in needles and also in roots, as compared to (C). In six treatments investigated in Skogaby 32 P uptake rates were negatively correlated to the P/C of the microbial biomass. Acid phosphatase activity was always higher in (A) as compared to treatments where soluble P had been added and at two out of five times also higher than in (C ). High phosphatase activity levels were at least partly connected to large amounts of microbial biomass

  20. Weather conditions influencing phosphorus concentration in the growing period in the large shallow Lake Peipsi (Estonia/Russia

    Directory of Open Access Journals (Sweden)

    Olga Tammeorg

    2014-01-01

    Full Text Available The impact of water temperature (T, water level (L, photosynthetically active radiation (PAR, and wind speed (V on the total phosphorus concentration (TP in shallow eutrophic lake Peipsi, the fourth largest lake in Europe, was studied. We used a long-term dataset (1985-2010 of TP concentrations and weather factors. A Thin Plate Spline (TPS model was used to predict TP by year, by day of the year, and by geographical coordinates. Deviations between observed and predicted TP values (residuals, or TP anomalies were related to the weather variables to clarify how the weather anomalies in a year might correlate with the observed fluctuations in TP dynamics. Notable seasonal variations in TP, typical for many shallow lake systems, were found: TP was two to three times higher during late summer-early autumn than during winter. Patterns of TP variability were well predicted by using geographical coordinates, year and day of the year (R2=0.69; P<0.0001. However, TP anomalies were ascribed to the effects of T, L, PAR, and V, which were proved to play a significant additional role in TP dynamics. Moreover, L had consistently negative effects over the year, whereas the effects of T and PAR on TP change were seen to be dependent on the season. TP anomalies in lake Peipsi were most sensitive to wind anomalies. V was associated with frequent switches between increasing and decreasing TP values, though it appeared mainly as a negative driver of TP anomalies in the season prior to the 180th day, and as a positive driver in the subsequent season.

  1. Phosphorus critical levels and availability in lowland soils cultivated with flooded rice

    Directory of Open Access Journals (Sweden)

    Mariano Isabela Orlando dos Santos

    2002-01-01

    Full Text Available Lowland soils present a great potential for the flooded rice crop. This work aimed to estimate critical levels of P in waterlogged soils cultivated with rice using Mehlich 1 and anion exchange resin as soil-P extractors, compare the performance of these extractors as for the evaluation of the P availability, and study the soil-P fractions involved in the P nutrition of the rice crop. Studied soils consisted of four Histosols: Low Humic Gley (GP, Aluvial (A, Humic Gley (GH and Bog Soil (O which were previously cultivated with beans. The experimental design was completely randomized, in a factorial scheme, using four soils, five P rates (75, 150, 300, 500 and 800 mg dm-3 and two liming treatments (with and without liming, with three replicates. After 60 days of flooding, soil samples were submitted to P extraction by Mehlich 1 and resin, and phosphorous fractionation. Two rice plants were cultivated in pots containing 3 dm³ of waterlogged soils. The labile P and the moderately labile P of the soils contributed for rice nutrition. The two tested extractors presented efficiency in the evaluation of P availability for the rice cultivated in lowland waterlogged soils.

  2. Influence of Stabilized Biosolids Application on Availability of Phosphorus, Copper, and Zinc

    Directory of Open Access Journals (Sweden)

    S. M. Shaheen

    2012-01-01

    Full Text Available The main aim of this study was to examine the influence of sewage sludge (SS and stabilized SS application on Olsen-P and DTPA-extractable Cu and Zn in relation to soil type, sewage source, mixing rate and incubation time. Two different SS were mixed with amendments by mixing rates 10 and 25%. These amendments include coal fly ash (CFA, bentonite (B, sugar beet factory lime (SBFL, calcium carbonate, rice straw (RS, water hyacinth (WH, and cotton stalks (CS. Treated and untreated SS had been applied to fluvial and calcareous soil with application rate 2.5% and incubated for one and two month. After incubation, soil samples were analyzed for Olsen-P and DTPA-extractable Cu and Zn. Application of SS increased significantly Olsen-P and DTPA extractable Cu and Zn compared to control. Application of stabilized SS increased significantly Olsen-P, with high increasing rate with SBFL and WH-stabilized SS. Stabilized-SS decreased significantly Cu and Zn availability compared to mono SS treatment. Bentonite-, SBFL and CFA-stabilized SS were the highest among inorganic treatments for reducing available Cu and Zn either in fluvial or calcareous soil, while WH and RS-stabilized SS treatment were the most suitable organic ones for reducing DTPA-extractable Cu and Zn.

  3. Recycling slaughterhouse waste into fertilizer: how do pyrolysis temperature and biomass additions affect phosphorus availability and chemistry?

    Science.gov (United States)

    Zwetsloot, Marie J; Lehmann, Johannes; Solomon, Dawit

    2015-01-01

    Pyrolysis of slaughterhouse waste could promote more sustainable phosphorus (P) usage through the development of alternative P fertilizers. This study investigated how pyrolysis temperature (220, 350, 550 and 750 °C), rendering before pyrolysis, and wood or corn biomass additions affect P chemistry in bone char, plant availability, and its potential as P fertilizer. Linear combination fitting of synchrotron-based X-ray absorption near edge structure spectra demonstrated that higher pyrolysis temperatures decreased the fit with organic P references, but increased the fit with a hydroxyapatite (HA) reference, used as an indicator of high calcium phosphate (CaP) crystallinity. The fit to the HA reference increased from 0% to 69% in bone with meat residue and from 20% to 95% in rendered bone. Biomass additions to the bone with meat residue reduced the fit to the HA reference by 83% for wood and 95% for corn, and additions to rendered bone by 37% for wood. No detectable aromatic P forms were generated by pyrolysis. High CaP crystallinity was correlated with low water-extractable P, but high formic acid-extractable P indicative of high plant availability. Bone char supplied available P which was only 24% lower than Triple Superphosphate fertilizer and two- to five-fold higher than rock phosphate. Pyrolysis temperature and biomass additions can be used to design P fertilizer characteristics of bone char through changing CaP crystallinity that optimize P availability to plants. © 2014 Society of Chemical Industry.

  4. Mixed models identify physic nut genotypes adapted to environments with different phosphorus availability.

    Science.gov (United States)

    Teodoro, P E; Laviola, B G; Martins, L D; Amaral, J F T; Rodrigues, W N

    2016-08-19

    The aim of this study was to screen physic nut (Jatropha curcas) genotypes that differ in their phosphorous (P) use, using mixed models. The experiment was conducted in a greenhouse located in the experimental area of the Centro de Ciências Agrárias of the Universidade Federal do Espírito Santo, in Alegre, ES, Brazil. The experiment was arranged in a randomized block design, using a 10 x 3-factorial scheme, including ten physic nut genotypes and two environments that differed in their levels of soil P availability (10 and 60 mg/dm 3 ), each with four replications. After 100 days of cultivation, we evaluated the plant height, stem diameter, root volume, root dry matter, aerial part dry matter, total dry matter, as well as the efficiency of absorption, and use. The parameters were estimated for combined selection while considering the studied parameters: stability and adaptability for both environments were obtained using the harmonic mean of the relative performance of the predicted genotypic values. High genotype by environment interactions were observed for most physic nut traits, indicating considerable influences of P availability on the phenotypic value. The genotype Paraíso simultaneously presented high adaptability and stability for aerial part dry matter, total dry matter, and P translocation efficiency. The genotype CNPAE-C2 showed a positive response to P fertilization by increasing both the total and aerial part dry matter.

  5. Selection of Green Manure Species for Efficient Absorbtion of Poorly-Available Forms of Soil Phosphorus

    Energy Technology Data Exchange (ETDEWEB)

    Franzini, V. I.; Mendes, F. L. [Brazilian Agricultural Research Corporation, EMBRAPA-Amazonia Oriental, Belem, PA, (Brazil); Muraoka, T.; Da Silva, E. C. [Center for Nuclear Energy in Agriculture, University of Sao Paulo, Piracicaba, SP (Brazil); Adu-Gyamfi, J. J. [Soil and Water Management and Crop Nutrition Laboratory, International Atomic Energy Agency, Vienna (Austria)

    2013-11-15

    Green manuring is an agronomic practice in which plants or their residues are added to the soil, improving of the soil physical, chemical and biological attributes, and increasing organic matter and fertility levels through nutrient cycling. It is estimated that green manures can increase P bioavailability. The integration of plant species in crop rotations to immobilize P is one of the most promising agronomic measures to improve the availability of P for the main crop. This study aimed to assess 21 species of green manure and a standard plant species (Lupinus albus) on their ability to absorb the available forms of P by the {sup 32}P isotopic dilution technique. It also aimed to determine if the isotopically exchangeable P, the L-values, differed when calculated with or without taking seed N into account. The results were statistically correlated and analyzed by hierarchical clustering (HCA) in order to group similar plant species. Jack bean was the most efficient species in P utilization while the Stylosanthes spp. were the most efficient in P uptake. The seed-derived P affected the P uptake efficiency evaluated by L-value technique. (author)

  6. Sedimentary deposition and reflux of phosphorus (P in the Eastern Gotland Basin and their coupling with P concentrations in the water column

    Directory of Open Access Journals (Sweden)

    Sven Hille

    2005-12-01

    Full Text Available In order to describe the role of sedimentary processes for the phosphorus (P cycle in the open Baltic Proper, P deposition and reflux were quantified for the predominately anoxic sediments of the Eastern Gotland Basin. The study is based on investigations of 53 surface sediment samples and pore water samples from 8 sediment cores. The average P deposition rate was estimated at 0.20 g ± 0.18 g -2 yr-1, the fluctuation being due to variable bulk sediment deposition rates. P refluxes were estimated by applying Fick's First Law of Diffusion. A fairly good positive correlation between sedimentary P deposition and P release was obtained. P release from sediments by diffusion exceeds net P deposition by a factor of 2. This suggests that 2/3 of the deposited gross P is recycled in the sediments and released back into the water column; only 1/3 remains in the sediment permanently. A budget calculation demonstrates that the released dissolved inorganic phosphorus (DIP accounts for the observed increase in DIP concentrations in the deep water during periods of stagnation, which is noticeable even at the surface P concentrations. Under such conditions and with the present remediation conditions it is not possible to freely manage P concentrations in the water column on short time scales.

  7. Phosphorus availability from phosphate rock and sewage sludge as influenced by the addition of water soluble phosphate fertilizer

    International Nuclear Information System (INIS)

    Zapata, F.; Zaharah, A.R.

    2002-01-01

    Phosphorus (P) inputs are required for sustainable agricultural production in most acid soils of the tropics and subtropics. Phosphate rocks (PR) and organic materials have been suggested as alternative P sources in these soils. Quantitative information on the P availability from sewage sludge (SL) is scanty. Methods to improve the effectiveness of PR such as partial acidulation and compaction with water-soluble P sources have been recommended. The objective of this greenhouse study was to evaluate the relative agronomic effectiveness (RAE) of Florida PR and sewage sludges (irradiated and non-irradiated) applied alone and in mixture with a water-soluble source (triple superphosphate, TSP) at two rates (50 and 150 mg P kg -1 soil). The 32 P isotope dilution technique was utilised to determine the proportion of P in the plant taken up from the P fertilizer treatments. Wheat was grown on an acid loamy sand Dystric Eutrocrepts and harvested 6 weeks after planting. Results on total P uptake and the RAE of the P fertilizer sources tested indicated that the addition of 50 mg P kg -1 soil as TSP was adequate in supplying P to the 6-week-old wheat plants as compared to PR and sewage sludge. Intermediate values were obtained for the mixtures. Similar responses were observed for the high P rate. For a given P rate, phosphorus uptake from PR and SL in presence of TSP was higher than P uptake from these sources alone, indicating an enhancement effect of TSP on the effectiveness of these non-readily available sources. With respect to P uptake from PR applied alone, the relative increases in P uptake from PR due to TSP influence were 52 and 67% for the low and high P rates, respectively. The relative increases in P uptake from SL due to TSP when compared to P uptake from SL alone were 102 and 59% for the low and high P rates of application. Application of a water-soluble P fertilizer together with a non-readily available P source shows an enhancement on the P uptake from the non

  8. Phosphorus availability from phosphate rock and sewage sludge as influenced by the addition of water soluble phosphate fertilizer

    Energy Technology Data Exchange (ETDEWEB)

    Zapata, F. [Soil and Water Management and Crop Nutrition Section, International Atomic Energy Agency, Vienna (Austria)]. E-mail: F.Zapata@iaea.org; Zaharah, A.R. [Department of Land Management, Universiti Putra Malaysia, Serdang, Selangor (Malaysia)

    2002-05-15

    Phosphorus (P) inputs are required for sustainable agricultural production in most acid soils of the tropics and subtropics. Phosphate rocks (PR) and organic materials have been suggested as alternative P sources in these soils. Quantitative information on the P availability from sewage sludge (SL) is scanty. Methods to improve the effectiveness of PR such as partial acidulation and compaction with water-soluble P sources have been recommended. The objective of this greenhouse study was to evaluate the relative agronomic effectiveness (RAE) of Florida PR and sewage sludges (irradiated and non-irradiated) applied alone and in mixture with a water-soluble source (triple superphosphate, TSP) at two rates (50 and 150 mg P kg{sup -1} soil). The {sup 32}P isotope dilution technique was utilised to determine the proportion of P in the plant taken up from the P fertilizer treatments. Wheat was grown on an acid loamy sand Dystric Eutrocrepts and harvested 6 weeks after planting. Results on total P uptake and the RAE of the P fertilizer sources tested indicated that the addition of 50 mg P kg{sup -1} soil as TSP was adequate in supplying P to the 6-week-old wheat plants as compared to PR and sewage sludge. Intermediate values were obtained for the mixtures. Similar responses were observed for the high P rate. For a given P rate, phosphorus uptake from PR and SL in presence of TSP was higher than P uptake from these sources alone, indicating an enhancement effect of TSP on the effectiveness of these non-readily available sources. With respect to P uptake from PR applied alone, the relative increases in P uptake from PR due to TSP influence were 52 and 67% for the low and high P rates, respectively. The relative increases in P uptake from SL due to TSP when compared to P uptake from SL alone were 102 and 59% for the low and high P rates of application. Application of a water-soluble P fertilizer together with a non-readily available P source shows an enhancement on the P

  9. Phosphorus availability in oxidic soils treated with lime and silicate applications

    Directory of Open Access Journals (Sweden)

    Aline da Silva Sandim

    2014-08-01

    Full Text Available Based on the assumption that silicate application can raise soil P availability for crops, the aim of this research was to compare the effect of silicate application on soil P desorption with that of liming, in evaluations based on two extractors and plant growth. The experiment was carried out in randomized blocks with four replications, in a 3 × 3 × 5 factorial design, in which three soil types, three P rates, and four soil acidity correctives were evaluated in 180 experimental plots. Trials were performed in a greenhouse using corn plants in 20-dm³ pots. Three P rates (0, 50 and 150 mg dm-3 were applied in the form of powder triple superphosphate and the soil was incubated for 90 days. After this period, soil samples were collected for routine chemical analysis and P content determination by the extraction methods resin, Mehlich-1 and remaining P. Based on the results, acidity correctives were applied at rates calculated for base saturation increased to 70 %, with subsequent incubation for 60 more days, when P content was determined again. The acidity correctives consisted of: dolomitic lime, steelmaking slag, ladle furnace slag, and wollastonite. Therefore, our results showed that slags raised the soil P content more than lime, suggesting a positive correlation between P and Si in soil. Silicon did not affect the extractor choice since both Mehlich-1 and resin had the same behavior regarding extracted P when silicon was applied to the soil. For all evaluated plant parameters, there was significant interaction between P rates and correctives; highest values were obtained with silicate.

  10. Effect of four acidifying materials added to a calcareous soil on the availability of phosphorus to ryegrass

    Energy Technology Data Exchange (ETDEWEB)

    Sen Gupta, M B; Cornfield, A H

    1964-12-01

    Ryegrass was grown in a pot test using a calcareous soil (0.36% calcium carbonate) treated with sulfur, ammonium sulfate, ferrous sulfate, and aluminium sulfate at 0.1% sulfur-equivalent, with potassium nitrate added where necessary, including the control, to equalize nitrogen supply. The sulfur treatment was the only one which significantly increased dry matter yields, total phosphorus uptake and top/root ratios in dry matter yields and total phosphorus. The ammonium sulfate, ferrous sulfate, and aluminium sulfate treatments significantly reduced top/root ratios in dry-matter yields and total phosphorus. 6 references, 1 table.

  11. Optimizing Available Phosphorus in Calcareous Soils Fertilized with Diammonium Phosphate and Phosphoric Acid Using Freundlich Adsorption Isotherm

    Science.gov (United States)

    Akhtar, Muhammad

    2013-01-01

    In calcareous soils, phosphorus (P) retention and immobilization take place due to precipitation and adsorption. Since soil pH is considered a major soil variable affecting the P sorption, an acidic P fertilizer could result in low P adsorption compared to alkaline one. Therefore, P adsorption from DAP and phosphoric acid (PA) required to produce desired soil solution P concentration was estimated using Freundlich sorption isotherms. Two soils from Faisalabad and T. T. Singh districts were spiked with 0, 10, and 20 % CaCO3 for 15 days. Freundlich adsorption isotherms (P = aC b/a) were constructed, and theoretical doses of PA and DAP to develop a desired soil solution P level (i.e., 0.20 mg L−1) were calculated. It was observed that P adsorption in soil increased with CaCO3. Moreover, at all the levels of CaCO3, P adsorption from PA was lower compared to that from DAP in both the soils. Consequently, lesser quantity of PA was required to produce desired solution P, 0.2 mg L−1, compared to DAP. However, extrapolating the developed relationship between soil CaCO3 contents and quantity of fertilizer to other similar textured soils needs confirmation. PMID:24307878

  12. Evaluation of the availability of phosphorus from decalcium phosphate and rock phosphates from Patos de Minas, Tapira and Finos de Tapira for sheep, by the isotope dilution technique

    International Nuclear Information System (INIS)

    Vitti, D.M.S.S.

    1989-01-01

    'In vitro' and 'in vivo' assays were carried out to determine the phosphorus availability from dicalcium phosphate and rock phosphates from Patos de Minas, Tapira and Finos de Tapira. Twenty four male sheep, with 40 kg live weight, were assigned to three groups of eight animals each. The animals were housed individually in metabolism cages and received a diet containing cassava meal, urea, molasses, soybean meal and mineral mixture. Phosphate sources were added to give 4 g of phosphorus per animal per day. After two weeks on the experimental diet each sheep was injected intravenously with 200 μCi of 32 P (Na 2 HPO 4 ). Blood samples were collected from the jugular vein at 24 hs intervals for 8 days. The daily fecal outputs were collected for 8 days and sampled. The specific activities of plasma and feces were determined and the fecal endogenous loss and true phosphorus absorption were calculated. For 'in vitro' assay, rumen samples were collected from a fistulated steer and aliquots were incubated with 0.1 μCi 32 P (Na 2 HPO 4 ) in a medium containing the phosphorus sources. After centrifugation microorganisms were separated and phosphorus incorporation determined. The true absorption values were 58.92; 50.85; 47.99 and 42.72% for dicalcium phosphate, Finos de Tapira, Tapira and Patos, respectively. Dicalcium phosphate showed higher availability (P [pt

  13. Water level fluctuations in a tropical reservoir: the impact of sediment drying, aquatic macrophyte dieback, and oxygen availability on phosphorus mobilization.

    Science.gov (United States)

    Keitel, Jonas; Zak, Dominik; Hupfer, Michael

    2016-04-01

    Reservoirs in semi-arid areas are subject to water level fluctuations (WLF) that alter biogeochemical processes in the sediment. We hypothesized that wet-dry cycles may cause internal eutrophication in such systems when they affect densely vegetated shallow areas. To assess the impact of WLF on phosphorus (P) mobilization and benthic P cycling of iron-rich sediments, we tested the effects of (i) sediment drying and rewetting, (ii) the impact of organic matter availability in the form of dried Brazilian Waterweed (Egeria densa), and (iii) alternating redox conditions in the surface water. In principle, drying led to increased P release after rewetting both in plant-free and in plant-amended sediments. Highest P mobilization was recorded in plant amendments under oxygen-free conditions. After re-establishment of aerobic conditions, P concentrations in surface water decreased substantially owing to P retention by sediments. In desiccated and re-inundated sediments, P retention decreased by up to 30% compared to constantly inundated sediments. We showed that WLF may trigger biochemical interactions conducive to anaerobic P release. Thereby, E. densa showed high P release and even P uptake that was redox-controlled and superimposed sedimentary P cycling. Macrophytes play an important role in the uptake of P from the water but may be also a significant source of P in wet-dry cycles. We estimated a potential for the abrupt release of soluble reactive phosphorus (SRP) by E. densa of 0.09-0.13 g SRP per m(2) after each wet-dry cycle. Released SRP may exceed critical P limits for eutrophication, provoking usage restrictions. Our results have implications for management of reservoirs in semi-arid regions affected by WLF.

  14. Long-term trends of phosphorus concentrations in an artificial lake: Socio-economic and climate drivers.

    Science.gov (United States)

    Vystavna, Yuliya; Hejzlar, Josef; Kopáček, Jiří

    2017-01-01

    European freshwater ecosystems have undergone significant human-induced and environmentally-driven variations in nutrient export from catchments throughout the past five decades, mainly in connection with changes in land-use, agricultural practice, waste water production and treatment, and climatic conditions. We analysed the relations among concentration of total phosphorus (TP) in the Slapy Reservoir (a middle reservoir of the Vltava River Cascade, Czechia), and socio-economic and climatic factors from 1963 to 2015. The study was based on a time series analysis, using conventional statistical tools, and the identification of breaking points, using a segmented regression. Results indicated clear long-term trends and seasonal patterns of TP, with annual average TP increasing up until 1991 and decreasing from 1992 to 2015. Trends in annual, winter and spring average TP concentrations reflected a shift in development of sewerage and sanitary infrastructure, agricultural application of fertilizers, and livestock production in the early 1990s that was associated with changes from the planned to the market economy. No trends were observed for average TP in autumn. The summer average TP has fluctuated with increased amplitude since 1991 in connection with recent climate warming, changes in thermal stratification stability, increased water flow irregularities, and short-circuiting of TP-rich inflow during high flow events. The climate-change-induced processes confound the generally declining trend in lake-water TP concentration and can result in eutrophication despite decreased phosphorus loads from the catchment. Our findings indicate the need of further reduction of phosphorus sources to meet ecological quality standards of the EU Water Framework Directive because the climate change may lead to a greater susceptibility of the aquatic ecosystem to the supply of nutrients.

  15. Effect of High Phytase Inclusion Rates on Performance of Broilers Fed Diets Not Severely Limited in Available Phosphorus

    Directory of Open Access Journals (Sweden)

    T. T. dos Santos

    2013-02-01

    Full Text Available Phytate is not only an unavailable source of phosphorus (P for broilers but it also acts as an anti-nutrient, reducing protein and mineral absorption, increasing endogenous losses and reducing broiler performance. The objective of this study was to investigate the anti-nutritional effects of phytate by including high levels of phytase in diets not severely limited in available P. A total of 768 male Arbor Acres broilers were distributed in six treatments of eight replicate pens of 16 birds each consisting of a positive control diet (PC, positive control with 500 FTU/kg phytase, negative control (NC diet with lower available P and calcium (Ca levels and the same NC diet with 500, 1,000 or 1,500 FTU/kg phytase. Body weight gain (BWG, feed intake (FI, feed conversion ratio (FCR and mortality were determined at 21 and 35 d of age while foot ash was determined in four birds per pen at 21 d of age. FI, FCR and foot ash where not affected by the lower mineral diets at 21 d of age nor by the enzyme inclusion but broilers fed lower Ca and available P diets had lower BWG. At 35 d of age no difference was observed between broilers fed the positive or NC diets but broilers fed 500, 1,000 and 1,500 FTU/kg on top of the NC diet had better FCR than broilers fed the positive control diet. When compared to birds fed a diet adequate in P, birds fed the same diet included with 500, 1,000 and 1,500 FTU/kg of phytase in marginally deficient available P and Ca diets had an improvement of performance. These results support the concept that hydrolysing phytate and reducing the anti-nutritional effects of phytate improves bird performance on marginally deficient diets that were not covering the P requirement of birds.

  16. Concentration and flux of total and dissolved phosphorus, total nitrogen, chloride, and total suspended solids for monitored tributaries of Lake Champlain, 1990-2012

    Science.gov (United States)

    Medalie, Laura

    2014-01-01

    Annual and daily concentrations and fluxes of total and dissolved phosphorus, total nitrogen, chloride, and total suspended solids were estimated for 18 monitored tributaries to Lake Champlain by using the Weighted Regressions on Time, Discharge, and Seasons regression model. Estimates were made for 21 or 23 years, depending on data availability, for the purpose of providing timely and accessible summary reports as stipulated in the 2010 update to the Lake Champlain “Opportunities for Action” management plan. Estimates of concentration and flux were provided for each tributary based on (1) observed daily discharges and (2) a flow-normalizing procedure, which removed the random fluctuations of climate-related variability. The flux bias statistic, an indicator of the ability of the Weighted Regressions on Time, Discharge, and Season regression models to provide accurate representations of flux, showed acceptable bias (less than ±10 percent) for 68 out of 72 models for total and dissolved phosphorus, total nitrogen, and chloride. Six out of 18 models for total suspended solids had moderate bias (between 10 and 30 percent), an expected result given the frequently nonlinear relation between total suspended solids and discharge. One model for total suspended solids with a very high bias was influenced by a single extreme value; however, removal of that value, although reducing the bias substantially, had little effect on annual fluxes.

  17. Low Soil Phosphorus Availability Increases Acid Phosphatases Activities and Affects P Partitioning in Nodules, Seeds and Rhizosphere of Phaseolus vulgaris

    Directory of Open Access Journals (Sweden)

    Jean-Jacques Drevon

    2012-06-01

    Full Text Available The effect of phosphorus (P deficiency on phosphatases activities in N2-fixing legumes has been widely studied in hydroponic culture. However, the response of acid phosphatase (APase and phytase in rhizosphere, nodules and seeds of Phaseolus vulgaris to low soil’s P-availability is not yet fully understood. In this study, six genotypes of N2-fixing P. vulgaris were grown under contrasting soil P-availabilities; i.e., low  (4.3 mg P kg−1 and sufficient (16.7 mg P kg−1 in the Haouz region of Morocco. At flowering and maturity stages, plants were harvested and analyzed for their phosphatases activities, growth and P content. Results show that, low P decreased nodulation, growth, P uptake and N accumulation in all the genotypes, but to a greater extent in the sensitive recombinant inbreed line 147. In addition, while seed P content was slightly reduced under low P soil; a higher P was noticed in the Flamingo and Contender large seeded-beans (6.15 to 7.11 mg g−1. In these latter genotypes, high APase and phytase activities in seeds and nodules were associated with a significant decline in rhizosphere’s available P. APase activity was mainly stimulated in nodules, whereas phytase activity was highly induced in seeds (77%. In conclusion, the variations of APase and phytase activities in nodules and seeds depend on genotype and can greatly influence the internal utilization of P, which might result in low P soil tolerance in N2-fixing legumes.

  18. Evaluation of plant available nitrogen in concentrated pig slurry

    International Nuclear Information System (INIS)

    Ramirez, M.; Comas, J.; Pujola, M.

    2009-01-01

    In Northeast Spin the expansion of the pig industry has brought as a result the production of vast amounts of pig slurry that exceeds field crops fertilization needs and consequently has contributed to the environmental deterioration of the region particularly ground water with NO 3 pollution. Under such circumstances, it is needed to treat and/or export pig slurry. During the last year the implantation of cogeneration plants that take advantage of the surplus of energy to produce concentrate pig slurry by water evaporation that could easily transported. (Author)

  19. Roadside soils show low plant available zinc and copper concentrations.

    Science.gov (United States)

    Morse, Natalie; Walter, M Todd; Osmond, Deanna; Hunt, William

    2016-02-01

    Vehicle combustion and component wear are a major source of metal contamination in the environment, which could be especially concerning where road ditches are actively farmed. The objective of this study was to assess how site variables, namely age, traffic (vehicles day(-1)), and percent carbon (%C) affect metal accumulation in roadside soils. A soil chronosequence was established with sites ranging from 3 to 37 years old and bioavailable, or mobile, concentrations of Zinc (Zn) and Copper (Cu) were measured along major highways in North Carolina using a Mehlich III extraction. Mobile Zn and Cu concentrations were low overall, and when results were scaled via literature values to "total metal", the results were still generally lower than previous roadside studies. This could indicate farming on lands near roads would pose a low plant toxicity risk. Zinc and Cu were not correlated with annual average traffic count, but were positively correlated with lifetime traffic load (the product of site age and traffic count). This study shows an often overlooked variable, site age, should be included when considering roadside pollution accumulation. Zinc and Cu were more strongly associated with %C, than traffic load. Because vehicle combustion is also a carbon source, it is not obvious whether the metals and carbon are simply co-accumulating or whether the soil carbon in roadside soils may facilitate previously overlooked roles in sequestering metals on-site. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Can conservation agriculture improve phosphorus (P) availability in weathered soils? Effects of tillage and residue management on soil P status after 9 years in a Kenyan Oxisol

    NARCIS (Netherlands)

    Margenot, Andrew; Paul, B.K.; Pulleman, M.M.; Parikh, Sanjai; Fonte, Steven J.

    2017-01-01

    The widespread promotion of conservation agriculture (CA) in regions with weathered soils prone to phosphorus (P) deficiency merits explicit consideration of its effect on P availability. A long-term CA field trial located on an acid, weathered soil in western Kenya was evaluated for effects of

  1. Phosphorus-loaded biochar changes soil heavy metals availability and uptake potential of maize (Zea mays L.) plants.

    Science.gov (United States)

    Ahmad, Munir; Usman, Adel R A; Al-Faraj, Abdullah S; Ahmad, Mahtab; Sallam, Abdelazeem; Al-Wabel, Mohammad I

    2018-03-01

    Biochar (BC) was produced by pyrolyzing the date palm leaf waste at 600 °C and then loaded with phosphorus (P) via sorption process. Greenhouse pot experiment was conducted to investigate the application effects of BC and P-loaded biochar (BCP) on growth and availability of P and heavy metals to maize (Zea mays L.) plants grown in contaminated mining soil. The treatments consisted of BC and BCP (at application rates of 5, 10, 20, and 30 g kg -1 of soil), recommended NK and NPK, and a control (no amendment). Sorption experiment showed that Langmuir predicted maximum P sorption capacity of BC was 13.71 mg g -1 . Applying BCP increased the soil available P, while BC and BCP significantly decreased the soil labile heavy metals compared to control. Likewise, heavy metals in exchangeable and reducible fractions were transformed to more stable fraction with BC and BCP applications. The highest application rate of BCP (3%) was most effective treatment in enhancing plant growth parameters (shoot and root lengths and dry matter) and uptake of P and heavy metals by 2-3 folds. However, based on metal uptake and phytoextraction indices, total heavy metals extraction by maize plants was very small for practical application. It could be concluded that using P-loaded biochar as a soil additive may be considered a promising tool to immobilize heavy metals in contaminated mining areas, while positive effects on the biomass growth of plants may assist the stabilization of contaminated areas affected by wind and water erosion. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Spatial variability of arsenic concentration in soils and plants, and its relationship with iron, manganese and phosphorus

    International Nuclear Information System (INIS)

    Hossain, M.B.; Jahiruddin, M.; Panaullah, G.M.; Loeppert, R.H.; Islam, M.R.; Duxbury, J.M.

    2008-01-01

    Spatial distribution of arsenic (As) concentrations of irrigation water, soil and plant (rice) in a shallow tube-well (STW) command area (8 ha), and their relationship with Fe, Mn and P were studied. Arsenic concentrations of water in the 110 m long irrigation channel clearly decreased with distance from the STW point, the range being 68-136 μg L -1 . Such decreasing trend was also noticed with Fe and P concentrations, but the trend for Mn concentrations was not remarkable. Concerning soil As, the concentration showed a decreasing tendency with distance from the pump. The NH 4 -oxalate extractable As contributed 36% of total As and this amount of As was associated with poorly crystalline Fe-oxides. Furthermore only 22% of total As was phosphate extractable so that most of the As was tightly retained by soil constituents and was not readily exchangeable by phosphate. Soil As (both total and extractable As) was significantly and positively correlated with rice grain As (0.296 ± 0.063 μg g -1 , n = 56). Next to drinking water, rice could be a potential source of As exposure of the people living in the As affected areas of Bangladesh. - Arsenic concentrations of irrigation water, soil and rice decreased with distance from STW point and it was related with iron and phosphorus concentrations

  3. Investigations of different doping concentration of phosphorus and boron into silicon substrate on the variable temperature Raman characteristics

    Science.gov (United States)

    Li, Xiaoli; Ding, Kai; Liu, Jian; Gao, Junxuan; Zhang, Weifeng

    2018-01-01

    Different doped silicon substrates have different device applications and have been used to fabricate solar panels and large scale integrated circuits. The thermal transport in silicon substrates are dominated by lattice vibrations, doping type, and doping concentration. In this paper, a variable-temperature Raman spectroscopic system is applied to record the frequency and linewidth changes of the silicon peak at 520 cm-1 in five chips of silicon substrate with different doping concentration of phosphorus and boron at the 83K to 1473K temperature range. The doping has better heat sensitive to temperature on the frequency shift over the low temperature range from 83K to 300K but on FWHM in high temperature range from 300K to 1473K. The results will be helpful for fundamental study and practical applications of silicon substrates.

  4. Processes Affecting Phosphorus and Copper Concentrations and Their Relation to Algal Growth in Two Supply Reservoirs in the Lower Coastal Plain of Virginia, 2002-2003, and Implications for Alternative Management Strategies

    Science.gov (United States)

    Speiran, Gary K.; Simon, Nancy S.; Mood-Brown, Maria L.

    2007-01-01

    because these factors affect phosphorus availability to algae. Results indicate that (1) water flows through both reservoirs in a 'plug-flow' manner; (2) little water in the lower part of Lee Hall Reservoir, into which pumped water enters, flows into the upper part of the reservoir and mixes with that water; (3) Lee Hall Reservoir generally does not stratify; and (4) Harwoods Mill Reservoir stratifies from April to June through September or October into an upper epilimnion that does not mix with water in the lower hypolimnion. The ratio of dissolved nitrogen to phosphorus concentrations (N:P) for sites in both reservoirs generally was greater than 20:1, indicating that phosphorus likely is the growth-limiting nutrient in both reservoirs. Phosphorus was present predominantly as suspended, rather than dissolved, species except in the hypolimnion of Harwoods Mill Reservoir and the natural inflow represented by Baptist Run. Because Harwoods Mill Reservoir stratified, field-measured physical and chemical characteristics and concentrations of nitrogen and phosphorus species changed sharply over short depth intervals in this reservoir. Dissolved phosphorus concentration increased from 0.015 to 0.057 milligrams per liter between a depth of 15 feet (ft) and the bottom (depth of 18 ft), indicating the release of phosphorus by the decomposition of organic material and(or) the reduction of iron oxides in bed sediment and the lower water column. Because the mixing boundary between the epilimnion and the hypolimnion likely was between depths of 6 and 10 ft, such sources in the hypolimnion would not contribute phosphorus to the growth of algae in the epilimnion from which water is withdrawn for supply until the breakdown of stratification in the fall. Furthermore, laboratory studies of samples from both reservoirs indicated that dissolved phosphorus was released from suspended particles at rates of 0.0007 to 0.0019 milligrams per liter per day. At these rates of release, particl

  5. Assessment of nitrogen and phosphorus flows in agricultural and urban systems in a small island under limited data availability

    NARCIS (Netherlands)

    Firmansyah, I.; Spiller, M.; Ruijter, De F.J.; Carsjens, G.J.; Zeeman, G.

    2017-01-01

    Nitrogen (N) and phosphorus (P) are two essential macronutrients required in agricultural production. The
    major share of this production relies on chemical fertilizer that requires energy and relies on limited resources
    (P). Since these nutrients are lost to the environment, there is a need

  6. Availability of phytate phosphorus and endogenous phytase activity in the digestive tract of laying hens 20 and 47 weeks old

    Czech Academy of Sciences Publication Activity Database

    Marounek, Milan; Skřivan, M.; Dlouhá, G.; Břeňová, Natalia

    2008-01-01

    Roč. 146, - (2008), s. 353-359 ISSN 0377-8401 R&D Projects: GA ČR GA523/07/0673 Institutional research plan: CEZ:AV0Z50450515 Keywords : phytic acid * phosphorus * laying hens Subject RIV: GH - Livestock Nutrition Impact factor: 1.882, year: 2008

  7. Effects of acidic deposition on in-lake phosphorus availability: A lesson from lakes recovering from acidification

    Czech Academy of Sciences Publication Activity Database

    Kopáček, Jiří; Hejzlar, Josef; Kaňa, Jiří; Norton, S. A.; Stuchlík, E.

    2015-01-01

    Roč. 49, č. 5 (2015), s. 2895-2903 ISSN 0013-936X R&D Projects: GA ČR(CZ) GA14-09231S Institutional support: RVO:60077344 Keywords : modelling * recovery from acid ification * nutrients * phosphorus Subject RIV: DJ - Water Pollution ; Quality Impact factor: 5.393, year: 2015

  8. Effect of phosphorus availability on the selection of species with different ploidy levels and genome sizes in a long-term grassland fertilization experiment.

    Science.gov (United States)

    Šmarda, Petr; Hejcman, Michal; Březinová, Alexandra; Horová, Lucie; Steigerová, Helena; Zedek, František; Bureš, Petr; Hejcmanová, Pavla; Schellberg, Jürgen

    2013-11-01

    Polyploidy and increased genome size are hypothesized to increase organismal nutrient demands, namely of phosphorus (P), which is an essential and abundant component of nucleic acids. Therefore, polyploids and plants with larger genomes are expected to be selectively disadvantaged in P-limited environments. However, this hypothesis has yet to be experimentally tested. We measured the somatic DNA content and ploidy level in 74 vascular plant species in a long-term fertilization experiment. The differences between the fertilizer treatments regarding the DNA content and ploidy level of the established species were tested using phylogeny-based statistics. The percentage and biomass of polyploid species clearly increased with soil P in particular fertilizer treatments, and a similar but weaker trend was observed for the DNA content. These increases were associated with the dominance of competitive life strategy (particularly advantageous in the P-treated plots) in polyploids and the enhanced competitive ability of dominant polyploid grasses at high soil P concentrations, indicating their increased P limitation. Our results verify the hypothesized effect of P availability on the selection of polyploids and plants with increased genome sizes, although the relative contribution of increased P demands vs increased competitiveness as causes of the observed pattern requires further evaluation. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  9. Concentration changeability of phosphorus, calcium and magnesium in selected partial drainage basins of the River Drwęca

    Directory of Open Access Journals (Sweden)

    Pius Bożena

    2015-12-01

    Full Text Available The paper presents the results of the research conducted between November 2008 and October 2009. The research included seasonal dynamics of the flow and runoff of phosphorus compounds (TP and P-PO43-, as well as Ca2+ and Mg2+ from 13 partial drainage basins of the River Drwęca. Water levels were registered automatically every day by recorders, and measurements of the flow were conducted once a month. Major differences were found in the water abundance as indicated by specific discharges in individual, partial drainage basins: from 1.87 dm3 s-1 km-2 (Lubianka - a lower part of the River Drwęca drainage basin to 8.22 dm3 s-1 km-2 (Gizela - an upper part of the River Drwęca drainage basin. The studied rivers were characterised by very diverse average content of total phosphorus compounds: from 0.047 mg dm-3 (Iłga to 0.816 mg dm-3 (Sandela; calcium: from 47.18 mg dm-3 (Iłga to 131.65 mg dm-3 (Trynka; and magnesium: from 9.71 mg dm-3 (Wel to 36.76 mg dm-3 (Struga Rychnowska. Analysis of variance carried out on hydrochemical properties of the studied rivers divides the rivers into two separate groups: rivers with much higher content of phosphorus, calcium and magnesium compounds (Struga Rychnowska, Trynka, Ruziec, Lubianka, Kujawka, Sandela and Gizela, and a group of rivers with low content of these compounds (Brynica, Brodniczanka, Skarlanka, Wel, Iłga.

  10. Synergistic effects and optimization of nitrogen and phosphorus concentrations on the growth and nutrient uptake of a freshwater Chlorella vulgaris.

    Science.gov (United States)

    Alketife, Ahmed M; Judd, Simon; Znad, Hussein

    2017-01-01

    The synergistic effects and optimization of nitrogen (N) and phosphorus (P) concentrations on the growth of Chlorella vulgaris (CCAP 211/11B, CS-42) and nutrient removal have been investigated under different concentrations of N (0-56 mg/L) and P (0-19 mg/L). The study showed that N/P ratio has a crucial effect on the biomass growth and nutrient removal. When N/P=10, a complete P and N removal was achieved at the end of cultivation with specific growth rate (SGR) of 1 d -1 and biomass concentration of 1.58 g/L. It was also observed that when the N content <2.5 mg/L, the SGR significantly reduced from 1.04 to 0.23 d -1 and the maximum biomass produced was decreased more than three-fold to 0.5 g/L. The Box-Behnken experimental design and response surface method were used to study the effects of the initial concentrations (P, N and C) on P and N removal efficiencies. The optimized P, N and C concentrations supporting 100% removal of both P and N at an SGR of 0.95 were 7, 55 and 10 mg/L respectively, with desirability value of 0.94. The results and analysis obtained could be very useful when applying the microalgae for efficient wastewater treatment and nutrient removal.

  11. Reducing Water Availability Impacts the Development of the Arbuscular Mycorrhizal Fungus Rhizophagus irregularis MUCL 41833 and Its Ability to Take Up and Transport Phosphorus Under in Vitro Conditions

    Directory of Open Access Journals (Sweden)

    Olivia Le Pioufle

    2018-06-01

    Full Text Available Climate change scenarios predict a higher variability in rainfall and an increased risk of water deficits during summers for the coming decades. For this reason, arbuscular mycorrhizal fungi (AMF and their mitigating effects on drought stress in plants are increasingly considered in crop management. However, the impact of a decrease in water availability on the development of AMF and their ability to take up and transport inorganic phosphorus (Pi to their hosts remain poorly explored. Here, Medicago truncatula plantlets were grown in association with Rhizophagus irregularis MUCL 41833 in bi-compartmented Petri plates. The system consisted in associating the plant and AMF in a root compartment (RC, allowing only the hyphae to extend in a root-free hyphal compartment (HC. Water availability in the HC was then lowered by increasing the concentration of polyethylene glycol-8000 (PEG-8000 from 0 to 10, 25, and 50 g L-1 (corresponding to a slight decrease in water potential of -0.024, -0.025, -0.030, and -0.056 Mpa, respectively. Hyphal growth, spore production and germination were severely impaired at the lowest water availability. The dynamics of Pi uptake by the AMF was also impacted, although total Pi uptake evaluated after 24 h stayed unchanged. The percentage of metabolically active extraradical hyphae remained above 70%. Finally, at the lowest water availability, a higher P concentration was observed in the shoots of M. truncatula. At reduced water availability, the extraradical mycelium (ERM development was impacted, potentially limiting its capacity to explore a higher volume of soil. Pi uptake was slowed down but not prevented. The sensitivity of R. irregularis MUCL 41833 to a, even small, decrease in water availability contrasted with several studies reporting tolerance of AMF to drought. This suggests a species or strain-dependent effect and support the necessity to compare the impact of water availability on morpho-anatomy, nutrient

  12. Changes in Soil Available Phosphorus, Leaf Phosphorus Content and Yield of Sword Bean (Canavalia ensiformis (L. DC. by Application of SP-36 and Phosphate Rock on Acid Upland Soil of East Lampung

    Directory of Open Access Journals (Sweden)

    Achmad Arivin Rivaie

    2015-01-01

    Full Text Available A glasshouse trial was performed to determine changes in phosphorus (P nutrition and the yield of sword bean (Canavalia ensiformis (L. DC. following the application of different rates and types of P fertilizer in an acid upland soil of East Lampung. Two different types of P fertilizer, namely SP-36 (total P = 36% and Phosphate Rock (PR (total P = 24.3%, particle size distribution = 75% <0.25 mm, 85% < 0.50 mm, 90% < 1.00 mm were used in the trial. For the treatment, each P fertilizer type consisted of four rates (0, 50, 100 and 150 mg P2O5 kg-1 soil that were arranged in a Completely Randomized Design with four replications. The results showed that the application of P fertilizers had significant effects on soil pH, soil plant-available P, the potential-P (HCl 25%, leaf N and P concentrations, the yield of sword bean. Increased rates of both forms of P fertilizer increased the soil pH values. As the soil used had low pH and very high exchangeable Al, hence, this result is most probably related to the addition of Ca2+ to the soil solution that resulted from the P fertiliser applied (liming effect, either from SP-36 (monocalcium phosphate or PR (flour apatite. There was no difference in soil available P concentration due to the different in P fertilizer types, indicating that 4 months after the fertilizer application, the relatively insoluble Phosphate Rock had the same P solubility with SP-36. Increased rates of both forms of P fertilizer increased the sword bean yield. For the application of 0 kg P2O5 ha-1, although sword bean crops had pods, but, they did not give any seed. Whereas, at the addition of P fertilizer at the rate of 50, 100, and 150 kg P2O5 ha-1 for both P fertilizer types, the crops were able to give the seeds in the pods.

  13. Seasonal Belowground Ecosystem and Eco-enzymatic Responses to Soil pH and Phosphorus Availability in Temperate Hardwood Forests

    Science.gov (United States)

    Smemo, K. A.; Deforest, J. L.; Petersen, S. L.; Burke, D.; Hewins, C.; Kluber, L. A.; Kyker, S. R.

    2013-12-01

    Atmospheric acid deposition can increase phosphorus (P) limitation in temperate hardwood forests by increasing N availability, and therefore P demand, and/or by decreasing pH and occluding inorganic P. However, only recently have studies demonstrated that P limitation can occur in temperate forests and very little is known about the temporal aspects of P dynamics in acidic forest soils and how seasonal shifts in nutrient availability and demand influence microbial investment in extracellular enzymes. The objectives of this study were to investigate how P availability and soil pH influence seasonal patterns of nutrient cycling and soil microbial activity in hardwood forests that experience chronic acid deposition. We experimentally manipulated soil pH, P, or both for three years and examined soil treatment responses in fall, winter, spring, early summer, and late summer. We found that site (glaciated versus unglaciated) and treatment had the most significant influence on nutrient pools and cycling. In general, nutrient pools were higher in glaciated soils than unglaciated for measured nutrients, including total C and N (2-3 times higher), extractable inorganic nitrogen, and readily available P. Treatment had no impact on total C and N pools in either region, but did affect other measured nutrients such as ammonium, which was greatest in the elevated pH treatment for both sites. As expected, readily available P pools were highest in the elevated P treatments (3 fold increase in both sites), but raising pH decreased available P pools in the glaciated site. Raising soil pH increased both net N mineralization rates and net P mineralization rates, regardless of site. Nitrification responses were complex, but we observed an overall significant nitrification increase under elevated pH, particularly in the growing season. Extracellular enzyme activity showed more seasonal patterns than site and treatment effects, exhibiting significant growing season activity reductions for

  14. Effect of phosphorus concentration of the nutrient solution on the volatile constituents of leaves and bracts of Origanum dictamnus.

    Science.gov (United States)

    Economakis, C; Skaltsa, Helen; Demetzos, Costas; Soković, M; Thanos, Costas A

    2002-10-23

    The chemical composition of the essential oils obtained from the leaves and bracts of hydroponically cultivated Origanum dictamnus were analyzed by GC-MS techniques. Three different concentrations of phosphorus (5, 30, and 60 mg/L) in the nutrient solution were used for the cultivation, using the nutrient film technique (NFT). A total of 46 different compounds were identified and significant differences (qualitative and quantitative) were observed between the samples. Carvacrol and p-cymene were identified as the main compounds in all samples analyzed, whereas thymoquinone was found in higher percentage in the leaves than in bracts. The essential oils were tested for their antibacterial activity against Gram-positive and Gram-negative bacteria. The oils obtained from the bracts were found to be more active. The results obtained from GC-MS analyses were submitted to chemometric analysis.

  15. Response of carbon assimilation and chlorophyll fluorescence to soybean leaf phosphorus across CO2: Alternative electron sink, nutrient efficiency and critical phosphorus concentration

    Science.gov (United States)

    To evaluate the response of CO2 assimilation (PN) and various chlorophyll fluorescence (CF) parameters to phosphorus (P) nutrition soybean plants were grown in controlled environment growth chambers with sufficient (0.50 mM) and deficient (0.10 and 0.01 mM) P supply under ambient and elevated CO2 (a...

  16. Low acetate concentrations favor polyphosphate-accumulating organisms over glycogen-accumulating organisms in enhanced biological phosphorus removal from wastewater.

    Science.gov (United States)

    Tu, Yunjie; Schuler, Andrew J

    2013-04-16

    Glycogen-accumulating organisms (GAOs) are thought to compete with polyphosphate-accumulating organisms (PAOs) in enhanced biological phosphorus removal (EBPR) wastewater treatment systems. A laboratory sequencing batch reactor (SBR) was operated for one year to test the hypothesis that PAOs have a competitive advantage at low acetate concentrations, with a focus on low pH conditions previously shown to favor GAOs. PAOs dominated the system under conventional SBR operation with rapid acetate addition (producing high in-reactor concentrations) and pH values of 7.4-8.4. GAOs dominated when the pH was decreased (6.4-7.0). Decreasing the acetate addition rate led to very low reactor acetate concentrations, and PAOs recovered, supporting the study hypothesis. When the acetate feed rate was increased, EBPR failed again. Dominant PAOs and GAOs were Candidatus Accumulibacter phosphatis and Defluviicoccus Cluster 2, respectively, according to fluorescent in situ hybridization and 454 pyrosequencing. Surprisingly, GAOs were not the immediate causes of PAO failures, based on functional and population measurements. Pyrosequencing results suggested Dechloromonas and Tetrasphaera spp. may have also been PAOs, and additional potential GAOs were also identified. Full-scale systems typically have lower in-reactor acetate concentrations than laboratory SBRs, and so, previous laboratory studies may have overestimated the practical importance of GAOs as causes of EBPR failure.

  17. Phosphorus availability due to polyphosphates additions to alfalfa plants grown on alluvial and calcareous soils using tracer techniques

    International Nuclear Information System (INIS)

    Ismail, A.S.; Massoud, M.A.; Shalil, K.M.E.

    1985-01-01

    A pot experiment was carried out to compare the effect of different sources and levels of condensed phosphates, including ring and chain structured molecules, with orthophosphate on alfalfa plants grown on alluvial and highly calcareous soils using P-32-labelled fertilizers. Data indicate that application of different sources of P-fertilizers increased both dry matter content and total-P uptake by alfalfa plants over control in both soils. The fraction of phosphorus in plants derived from added fertilizers was higher from condensed phosphates than that derived from the other sources of phosphorus. The percentages of P-fraction derived from added fertilizers (y-values) were higher in calcareous soil than those in alluvial soil

  18. Utilizing Wetlands for Phosphorus Reduction in Great Lakes Watersheds: A Review of Available Literature Examining Soil Properties and Phosphorus Removal Efficiency

    Science.gov (United States)

    2017-10-01

    term application of P as organic and inorganic fertilizers has resulted in non-point source P pollution by runoff (Daniel et al. 1998). Best...sites fertilized at rates greater than recommended. Average annual concentrations of NO3-N in drainage water from organic soils ranged from 14.8 to...soil P concentrations from long-term over fertilization and/or excessive use of organic wastes). In this paper we review research on P leaching and

  19. Optimization of the diffusive gradients in thin films (DGT) method for simultaneous assay of potassium and plant-available phosphorus in soils.

    Science.gov (United States)

    Zhang, Yulin; Mason, Sean; McNeill, Ann; McLaughlin, Michael J

    2013-09-15

    Potassium (K) and phosphorus (P) are two important macronutrients for crops, and are usually applied to soils as granular fertilizer before seeding. Therefore, accurate soil tests prior to planting to predict crop response to fertilizers are important in optimizing crop yields. Traditional methods used for testing both available K and P in soils, which are based on chemical extraction procedures, are to be soil-type dependent, and the predictive relationships across a broad range of soils are generally poor. The diffusive gradients in thin films (DGT) technique, based on diffusion theory, is extensively used to measure the diffusive supply of trace elements, metals and some nutrients in soils and water. When DGT is used to assess plant-available P in soils, a good relationship is found between crop response to P fertilizer and concentrations of P in soil measured by DGT, and therefore the DGT method provides a more precise recommendation of P fertilizer requirements. Adaptation of the DGT method to measure plant-available K in soils has already been attempted [1], but limitations were reported due to the non-uniform size of the resin gel, decreased K binding rate of the gel at long deployment times and a limited ability to measure a wide range of K concentrations. To eliminate these problems, a new resin gel has been developed by combining Amberlite and ferrihydrite. This mixed Amberlite and ferrihydrite (MAF) gel has improved properties in terms of handling and even distribution of Amberlite in the gel. The elution efficiencies of the MAF gel for K and P were 90% and 96%, respectively. The diffusion coefficient of K through the diffusive gel was 1.30 × 10(-5)cm(2)s(-1) at 22 ± 1°C and was stable through time. Since ferrihydrite is already used in DGT P testing, the ability of the MAF gel to assess available P simultaneously was also assessed. The MAF gel performed the same as the traditional ferrihydrite gel for available P assessment in a wide variety of

  20. Phosphorus and Nutrition in Chronic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Emilio González-Parra

    2012-01-01

    Full Text Available Patients with renal impairment progressively lose the ability to excrete phosphorus. Decreased glomerular filtration of phosphorus is initially compensated by decreased tubular reabsorption, regulated by PTH and FGF23, maintaining normal serum phosphorus concentrations. There is a close relationship between protein and phosphorus intake. In chronic renal disease, a low dietary protein content slows the progression of kidney disease, especially in patients with proteinuria and decreases the supply of phosphorus, which has been directly related with progression of kidney disease and with patient survival. However, not all animal proteins and vegetables have the same proportion of phosphorus in their composition. Adequate labeling of food requires showing the phosphorus-to-protein ratio. The diet in patients with advanced-stage CKD has been controversial, because a diet with too low protein content can favor malnutrition and increase morbidity and mortality. Phosphorus binders lower serum phosphorus and also FGF23 levels, without decreasing diet protein content. But the interaction between intestinal dysbacteriosis in dialysis patients, phosphate binder efficacy, and patient tolerance to the binder could reduce their efficiency.

  1. Effect of high-dose phytase and citric acid, alone or in combination, on growth performance of broilers given diets severely limited in available phosphorus.

    Science.gov (United States)

    Taheri, H R; Jabbari, Z; Adibnia, S; Shahir, M H; Hosseini, S A

    2015-01-01

    1. Two trials were conducted to evaluate the effect of high-dose phytase alone or in combination with citric acid (CA) in the diet severely limited in available phosphorus (P) on performance, plasma P and plasma Ca of broilers from 22 to 42 d of age. 2. In Trial 1, 297 21-d-old female chicks were placed into 27 pens and allocated to 9 maize-soybean meal-based dietary treatments, which were a positive control [PC, 4.23 g/kg non-phytate P (NPP)] and 8 negative control (NC, 1.35 g/kg NPP) groups consisting of two concentrations of CA (0 and 20 g/kg) and 4 concentrations of phytase (0, 1000, 2000 and 4000 U/kg) in a 2 × 4 factorial arrangement. In Trial 2, 192 21-d-old male chicks were placed into 24 pens and allocated to 6 wheat-canola meal-based dietary treatments, which were a PC (4.2 g/kg NPP), a NC (1.68 g/kg NPP) and 4 NC groups consisting of two concentrations of CA (0 and 20 g/kg) and two concentrations of phytase (2000 and 4000 U/kg) in a 2 × 2 factorial arrangement. 3. In both trials, birds fed on the PC had significantly higher average daily gain (ADG), average daily feed intake (ADFI), plasma P and lower feed conversion ratio (FCR) and plasma Ca than those of birds fed on the NC. CA supplementation significantly increased ADG and ADFI. There was a significant interaction between CA and phytase on plasma P where CA improved the effect of phytase on plasma P. In Trial 1, phytase addition improved ADG, ADFI, FCR and plasma Ca linearly. 4. Briefly, this research showed the interaction effect between CA and phytase on plasma P when broilers were fed on diets based on maize-soybean meal or wheat-canola meal. The results showed that CA supplementation lowered the concentration of phytase that is needed in low NPP diets to increase plasma P.

  2. Effect of Low Dose Gamma Radiation Upon the Concentration of Calcium and Inorganic Phosphorus in the Blood Plasma of Chickens

    International Nuclear Information System (INIS)

    Kraljevic, P.; Vilic, M.; Miljanic, S.; Simpraga, M.

    2003-01-01

    In our previous paper it has been showed that the irradiation of chickens eggs before incubation by low dose gamma irradiation effects upon growth of the chickens hatched from irradiated eggs as well as upon activity of ALT and AST, and on the concentration of total proteins, glucose and cholesterol in the blood plasma of those chickens. Therefore in this paper an attempt was made to determine the effects of irradiation of eggs by low dose of ionizing radiation on the 19th day of incubation upon the concentration of calcium (Ca) and inorganic phosphorus (P) in the blood plasma of chickens hatched from irradiated eggs. The eggs of heavy breeding chickens (Gent, line COBB 500) were irradiated by a dose of 0.15 Gy gamma radiation (6 0C o source) on the 19th day of incubation. Along with the chickens, which were hatched from irradiated eggs, there was a control group of chickens hatched from nonirradiated eggs. All other conditions were the same for both groups. After hatching, blood samples were taken on day 1, 3, 5, 7, 10, 20, 30 and 42. The concentration of Ca was determined calorimetrically using Randox optimized kits, while the concentration of P was determined by Herbos dijagnostika Sisak (Croatia) optimized kits. The concentration of Ca in the blood plasma of chickens hatched from irradiated eggs was significantly increased on the first day, while it was decreased on the day 42. The concentration of P was decreased on the first day in blood plasma of chickens hatched from irradiated eggs. The fact that the concentration of both minerals in blood plasma of chickens hatched from irradiated eggs was significantly changed on the first day proves that the irradiation of eggs by low dose of ionizing radiation on the nineteenth day of incubation had an effect on metabolism of both minerals in those chickens. (author)

  3. Influence of the calcium concentration in the presence of organic phosphorus on the physicochemical compatibility and stability of all-in-one admixtures for neonatal use

    Directory of Open Access Journals (Sweden)

    de Sousa Valeria

    2009-10-01

    Full Text Available Abstract Background Preterm infants need high amounts of calcium and phosphorus for bone mineralization, which is difficult to obtain with parenteral feeding due to the low solubility of these salts. The objective of this study was to evaluate the physicochemical compatibility of high concentrations of calcium associated with organic phosphate and its influence on the stability of AIO admixtures for neonatal use. Methods Three TPN admixture formulas were prepared in multilayered bags. The calcium content of the admixtures was adjusted to 0, 46.5 or 93 mg/100 ml in the presence of a fixed organic phosphate concentration as well as lipids, amino acids, inorganic salts, glucose, vitamins and oligoelements at pH 5.5. Each admixture was stored at 4°C, 25°C or 37°C and evaluated over a period of 7 days. The physicochemical stability parameters evaluated were visual aspect, pH, sterility, osmolality, peroxide formation, precipitation, and the size of lipid globules. Results Color alterations occurred from the first day on, and reversible lipid film formation from the third day of study for the admixtures stored at 25°C and 37°C. According to the parameters evaluated, the admixtures were stable at 4°C; and none of them presented precipitated particles due to calcium/phosphate incompatibility or lipid globules larger than 5 μm, which is the main parameter currently used to evaluate lipid emulsion stability. The admixtures maintained low peroxide levels and osmolarity was appropriate for parenteral administration. Conclusion The total calcium and calcium/phosphorus ratios studied appeared not to influence the physicochemical compatibility and stability of AIO admixtures.

  4. Leaching of Cu, Cd, Pb, and phosphorus and their availability in the phosphate-amended contaminated soils under simulated acid rain.

    Science.gov (United States)

    Cui, Hongbiao; Zhang, Shiwen; Li, Ruyan; Yi, Qitao; Zheng, Xuebo; Hu, Youbiao; Zhou, Jing

    2017-09-01

    Phosphate amendments have been used to immobilize heavy metal-contaminated soils. However, phosphate amendments contain large amounts of phosphorus, which could leach out to potentially contaminate groundwater and surface water. A laboratory column leaching experiment was designed to study the effects of simulated acid rain (SAR) on the potential release of copper (Cu), lead (Pb), cadmium (Cd), and phosphorus (P), and their availability after immobilizing with hydroxyapatite (HAP) and potassium dihydrogen phosphate (PDP). The application of HAP and PDP enhanced the leachate electrical conductivity, total organic carbon, and pH. Higher P was found in the PDP- (>4.29 mg L -1 ) and HAP-treated (>1.69 mg L -1 ) columns than that in untreated (phosphate amendments might promote the leaching of some metals while immobilizing others.

  5. Varying response of the concentration and content of soybean seed mineral elements, carbohydrates, organic acids, amino acids, protein, and oil to phosphorus starvation and CO2 enrichment

    Science.gov (United States)

    A detailed investigation of the concentration (g-1 seed weight) and content (g plant-1) of seed mineral elements and metabolic profile under phosphorus (P) starvation at ambient (aCO2) and elevated carbon dioxide (eCO2) in soybean is limited. Soybean plants were grown in a controlled environment at ...

  6. Rhizosphere organic anions play a minor role in improving crop species’ ability to take up residual phosphorus (P in agricultural soils low in P availability

    Directory of Open Access Journals (Sweden)

    Yanliang Wang

    2016-11-01

    Full Text Available Many arable lands have accumulated large reserves of residual phosphorus (P and a relatively large proportion of soil P is less available for uptake by plants. Root released organic anions are widely documented as a key physiological strategy to enhance P availability, while limited information has been generated on the contribution of rhizosphere organic anions to P utilization by crops grown in agricultural soils that are low in available P and high in extractable Ca, Al and Fe. We studied the role of rhizosphere organic anions in P uptake from residual P in four common crops Triticum aestivum, Avena sativa, Solanum tuberosum and Brassica napus in low- and high-P availability agricultural soils from long-term fertilization field trials in a mini-rhizotron experiment with four replications. Malate was generally the dominant organic anion. More rhizosphere citrate was detected in low P soils than in high P soil. Brassica napus showed 74-103% increase of malate in low P loam, compared with clay loam. Avena sativa had the greatest rhizosphere citrate concentration in all soils (5.3-15.2 mol g-1 root DW. Avena sativa also showed the highest level of root colonization by arbuscular mycorrhizal fungi (36% and 40%, the greatest root mass ratio (0.51 and 0.66 in the low-P clay loam and loam respectively, and the greatest total P uptake (5.92 mg P/mini-rhizotron in the low-P loam. Brassica napus had 15-44% more rhizosphere APase activity, ~0.1-0.4 units lower rhizosphere pH than other species, the greatest increase in rhizosphere water-soluble P in the low-P soils, and the greatest total P uptake in the low-P clay loam. Shoot P content was mainly explained by rhizosphere APase activity, water-soluble P and pH within low P soils across species. Within species, P uptake was mainly linked to rhizosphere water soluble P, APase and pH in low P soils. The effects of rhizosphere organic anions varied among species and they appeared to play minor roles in

  7. The effect of dietary protein and phosphorus on ammonia concentration and litter composition in broilers.

    Science.gov (United States)

    Ferguson, N S; Gates, R S; Taraba, J L; Cantor, A H; Pescatore, A J; Straw, M L; Ford, M J; Burnham, D J

    1998-08-01

    An experiment was conducted to determine whether broiler litter concentration of N and P and equilibrium NH3 gas concentration can be reduced by reducing dietary CP and P levels and supplementing with amino acids and phytase, respectively, without adversely affecting bird performance. Equilibrium NH3 gas concentration above the litter was measured. The experiment was divided into a starter period (1 to 21 d) and grower period (22 to 42 d), each having two different CP and P levels in a 2 x 2 factorial arrangement. The CP treatments consisted of a control with a mean CP of 204 and 202 g/kg for starter and grower periods, respectively, and a low CP diet with means of 188 and 183 g/kg, respectively, but with similar amino acid levels as the control. The P treatments comprised starter and grower control diets containing means of 6.7 and 6.3 g/kg P, respectively, and low P treatment means of 5.8 and 5.4 g/kg P supplemented with 1.0 g/kg phytase. Reducing starter diet CP by 16 g/kg reduced weight gain by 3.5% and, hence, body weight at 21 d of age, but did not affect feed intake or feed efficiency. Reducing P did not affect feed intake and weight gain, but improved feed efficiency by 2.0%. Responses in feed intake and efficiency to CP depended on the level of dietary P. For the grower period there were no significant differences in feed intake, weight gain, and feed efficiency, nor in body weight at 42 d of age, after correcting for 21-d body weight, between CP and P treatments. There were significant (P litter N and P concentrations, but not equilibrium NH3 gas concentration, moisture content, or pH, for low CP and P diets. Mean equilibrium NH3 gas concentration was 63 ppm. Litter N concentration was reduced 16.3% with the low CP diets, and litter P by 23.2% in low P treatments. The results suggest that dietary manipulation shows merit for reducing litter N and P concentrations while maintaining acceptable production performance from broilers.

  8. Rhizosphere Organic Anions Play a Minor Role in Improving Crop Species' Ability to Take Up Residual Phosphorus (P) in Agricultural Soils Low in P Availability.

    Science.gov (United States)

    Wang, Yanliang; Krogstad, Tore; Clarke, Jihong L; Hallama, Moritz; Øgaard, Anne F; Eich-Greatorex, Susanne; Kandeler, Ellen; Clarke, Nicholas

    2016-01-01

    Many arable lands have accumulated large reserves of residual phosphorus (P) and a relatively large proportion of soil P is less available for uptake by plants. Root released organic anions are widely documented as a key physiological strategy to enhance P availability, while limited information has been generated on the contribution of rhizosphere organic anions to P utilization by crops grown in agricultural soils that are low in available P and high in extractable Ca, Al, and Fe. We studied the role of rhizosphere organic anions in P uptake from residual P in four common crops Triticum aestivum, Avena sativa, Solanum tuberosum , and Brassica napus in low- and high-P availability agricultural soils from long-term fertilization field trials in a mini-rhizotron experiment with four replications. Malate was generally the dominant organic anion. More rhizosphere citrate was detected in low P soils than in high P soil. B. napus showed 74-103% increase of malate in low P loam, compared with clay loam. A. sativa had the greatest rhizosphere citrate concentration in all soils (5.3-15.2 μmol g -1 root DW). A. sativa also showed the highest level of root colonization by arbuscular mycorrhizal fungi (AMF; 36 and 40%), the greatest root mass ratio (0.51 and 0.66) in the low-P clay loam and loam respectively, and the greatest total P uptake (5.92 mg P/mini-rhizotron) in the low-P loam. B. napus had 15-44% more rhizosphere acid phosphatase (APase) activity, ~0.1-0.4 units lower rhizosphere pH than other species, the greatest increase in rhizosphere water-soluble P in the low-P soils, and the greatest total P uptake in the low-P clay loam. Shoot P content was mainly explained by rhizosphere APase activity, water-soluble P and pH within low P soils across species. Within species, P uptake was mainly linked to rhizosphere water soluble P, APase, and pH in low P soils. The effects of rhizosphere organic anions varied among species and they appeared to play minor roles in

  9. Contrasting effects of untreated textile wastewater onto the soil available nitrogen-phosphorus and enzymatic activities in aridisol.

    Science.gov (United States)

    Arif, Muhammad Saleem; Riaz, Muhammad; Shahzad, Sher Muhammad; Yasmeen, Tahira; Buttler, Alexandre; Garcıa-Gil, Juan Carlos; Roohi, Mahnaz; Rasool, Akhtar

    2016-02-01

    Water shortage and soil qualitative degradation are significant environmental problems in arid and semi-arid regions of the world. The increasing demand for water in agriculture and industry has resulted in the emergence of wastewater use as an alternative in these areas. Textile wastewater is produced in surplus amounts which poses threat to the environment as well as associated flora and fauna. A 60-day incubation study was performed to assess the effects of untreated textile wastewater at 0, 25, 50, 75, and 100% dilution levels on the physico-chemical and some microbial and enzymatic properties of an aridisol soil. The addition of textile wastewater provoked a significant change in soil pH and electrical conductivity and soil dehydrogenase and urease activities compared to the distilled-water treated control soil. Moreover, compared to the control treatment, soil phosphomonoesterase activity was significantly increased from 25 to 75% application rates, but decreased at 100% textile wastewater application rate. Total and available soil N contents increased significantly in response to application of textile wastewater. Despite significant increases in the soil total P contents after the addition of textile wastewater, soil available P content decreased with increasing concentration of wastewater. Changes in soil nutrient contents and related enzymatic activities suggested a dynamic match between substrate availability and soil N and P contents. Aridisols have high fixation and low P availability, application of textile wastewater to such soils should be considered only after careful assessment.

  10. Study of the interaction metallic cation - ligand in concentrated phosphorus acid media

    International Nuclear Information System (INIS)

    Sefiani, N.; Azzi, M.; Hlaibi, M.; Kossair, A.

    2005-01-01

    The phosphoric acid is more and more used with a high purity. The recovery of recycling element (uranium, vanadium, rare earth...) and the elimination of toxic element (cadmium, molybdenum, lead...) contained in the phosphoric acid are generally realized by extraction or precipitation. It is then very important to understand these impurities behavior in the phosphoric media in order to control their elimination. In this work, the authors considered the presence of some metallic cations (V, Al, fe, U) and fluorides ions as impurity in concentrated phosphoric acid media. (A.L.B.)

  11. Dietary phosphorus concentrations related to breaking load and chemical bone properties in heifers.

    Science.gov (United States)

    Williams, S N; Lawrence, L A; McDowell, L R; Warnick, A C; Wilkinson, N S

    1990-04-01

    Effects of dietary P on breaking load and chemical properties of bone were evaluated in growing beef heifers. Initially, 14 weaned Angus heifers received ad libitum a low P diet (.10% P dry basis) for 270 d. Heifers were subsequently randomly allotted into two groups (7 heifers/group) and received ad libitum either .12 or .20% P (dry basis). The experimental endpoint was 245 d of the treatment phase for nonpregnant and 3 wk postpartum for pregnant heifers. Results indicate that chemical and physical properties of bovine bones are sensitive to dietary P. Mineralization of rib bones was less at .12% P (dry basis). Rib bone density (g/cm3) and mineral content expressed on a per unit volume basis (mg/cm3) were the most sensitive parameters measured. Breaking load results of 12th ribs also indicated a greater amount of mineral present in heifers receiving .20% P (153.8 vs. 114.3 kg). Vertebral bone density and mineral concentrations on a per unit volume basis were also sensitive to dietary P and clearly ranked the two dietary P amounts, whereas percentage of bone ash or mineral concentration expressed on an ash basis did not.

  12. The adsorption/desorption of phosphorus in freshwater sediments from buffer zones: the effects of sediment concentration and pH.

    Science.gov (United States)

    Zhang, Liang; Du, Yun; Du, Chao; Xu, Meng; Loáiciga, Hugo A

    2016-01-01

    Riparian buffer zones adjacent to reservoirs and lakes protect aquatic ecosystems from polluted surface runoff. Sediments, collected from the buffer zones of Danjiangkou Reservoir (SR) and Honghu Lake (SL) in an ecologically fragile region in central China, were evaluated to reveal their phosphorus-adsorbing/desorbing properties and storage capacities. A nonlinear regression method was used to fit the pseudo-second-order kinetic and the modified crossover-type Langmuir isotherm models to the experimental data. It is shown that the adsorption of phosphorus onto the studied sediments followed the pseudo-second-order kinetic expression. The modified crossover-type Langmuir isotherm model was found to be a suitable method for describing adsorption/desorption processes in the experimental sediments. The maximum adsorption capacities (Q m), partitioning coefficients (K p), native adsorbed exchangeable phosphorus (NAP), and equilibrium phosphorus concentration (EPC0) were subsequently obtained for the experimental sediments. The effects of sediment concentration and pH were also investigated by batch experiments and Fourier transformation infrared and scanning electron microscopy analyses. The adsorption/desorption characteristics of different phosphate species on the sediments from reservoir and lake buffer zones were identified.

  13. Increasing phosphorus concentration in the extraradical hyphae of Rhizophagus irregularis DAOM 197198 leads to a concomitant increase in metal minerals.

    Science.gov (United States)

    Zhang, Lin; Jiang, Caiyun; Zhou, Jiachao; Declerck, Stéphane; Tian, Changyan; Feng, Gu

    2016-11-01

    Plants associated with arbuscular mycorrhizal fungi (AMF) acquire phosphorus via roots and extraradical hyphae. How soil P level affects P accumulation within hyphae and how P in hyphae influences the accumulation of metal minerals remains little explored. A bi-compartmented in vitro cultivation system separating a root compartment (RC), containing a Ri T-DNA transformed carrot root associated to the AMF Rhizophagus irregularis DAOM 197198, from a hyphal compartment (HC), containing only the extraradical hyphae, was used. The HC contained a liquid growth medium (i.e., the modified Strullu-Romand medium containing P in the form of KH 2 PO 4 ) without (0 μM) or adjusted to 35, 100, and 700 μM of KH 2 PO 4 . The accumulation of P and metal minerals (Ca, Mg, K, Na, Fe, Cu, Mn) within extraradical hyphae and AMF-colonized roots, and the expression of the phosphate transporter gene GintPT were assessed. The expression of GintPT in the extraradical hyphae did not differ in absence of KH 2 PO 4 or in presence of 35 and 100 μM KH 2 PO 4 in the HC but was markedly reduced in presence of 700 μM KH 2 PO 4 . Hyphal P concentration was significantly lowest in absence of KH 2 PO 4 , intermediate at 35 and 100 μM KH 2 PO 4 and significantly highest in presence of 700 μM KH 2 PO 4 in the HC. The concentrations of K, Mg, and Na were positively associated with the concentration of P in the extraradical hyphae developing in the HC. Similarly, P concentration in extraradical hyphae in the HC was related to P concentration in the growth medium and influenced the concentration of K, Mg, and Na. The accumulation of the metal mineral K, Mg, and Na in the extraradical hyphae developing in the HC was possibly related to their function in neutralizing the negative charges of PolyP accumulated in the hyphae.

  14. Water-removed spectra increase the retrieval accuracy when estimating savanna grass nitrogen and phosphorus concentrations

    CSIR Research Space (South Africa)

    Ramoelo, Abel

    2011-01-01

    Full Text Available . Ritchie and H. H. T. Prins (2002). Global enviromental controls of diversity of large hervivores. Nature 415: 901-904. 26 Owen-Smith, N. and S. M. Cooper (1987). Palatabilty of woody plants to browsing ruminants in a South African savanna. In...

  15. The Effects of Arbuscular Mycorrhiza Fungi on Dry Matter and Concentrations of Nitrogen, Phosphorus and Potassium in Berseem Clover, by Cadmium stress

    Directory of Open Access Journals (Sweden)

    hashem aram

    2016-02-01

    Full Text Available Introduction: Soil contaminations with heavy metals represent a potential risk to the biosphere and leads to increased concentration in ground and surface water. Therefore metals mobility in soil has been extensively studied in the last decades. Use of agrochemicals such as synthetic fertilizers and pesticides has resulted in soil and water pollution, and loss of biodiversity. Cadmium is a heavy metal with a strong effect on crop quality. Moreover, it is a very mobile element in the environment. Plants can easily uptake cadmium and transfer it to other organs. Experiments on the effects of cadmium on the contents of macro elements in plants are scarce and therefore the mechanism of its effect has not yet been fully explained. Contaminated soil can be remediated by chemical, physical or biological techniques. Mycorrhiza is the mutualistic symbiosis (non-pathogenic association between soil-borne fungi with the roots of higher plants. Arbuscular mycorrhizal fungi (AMF are obligate biotrophs, which can form mutualistic symbioses with the roots of around 80% of plant species. Arbuscular mycorrhiza have been observed to play a vital role in metal tolerance and accumulation. Many workers have reported enhancement of phosphate uptake and growth of leguminous plants by vesicular arbuscular mycorhizal fungi (AMF. Materials and Methods: One study performed the factorial experiment based on completely randomized design (CRD with three replications in the greenhouse of Agriculture Faculty of Zanjan University. The examined factors include different levels of arbuscular mycorrhizal fungi inoculation (Glomus mosseae (with and without inoculation, and different levels of soil contamination by cadmium (0, 5, 10, 20, 40 and 80 ppm. In this study, arbuscular mycorrhizal fungi Glomus mosseae species were used. These fungi were prepared by the Plant Protection Clinic in Iran – Hamedan. The soil was prepared of arable land of depth of 0-20 cm at the University of

  16. Communities of arbuscular mycorrhizal fungi in the roots of Pyrus pyrifolia var. culta (Japanese pear) in orchards with variable amounts of soil-available phosphorus.

    Science.gov (United States)

    Yoshimura, Yuko; Ido, Akifumi; Iwase, Koji; Matsumoto, Teruyuki; Yamato, Masahide

    2013-01-01

    We examined the colonization rate and communities of arbuscular mycorrhizal fungi (AMF) in the roots of Pyrus pyrifolia var. culta (Japanese pear) in orchards to investigate the effect of phosphorus (P) fertilization on AMF. Soil cores containing the roots of Japanese pear were collected from 13 orchards in Tottori Prefecture, Japan. Soil-available P in the examined orchards was 75.7 to 1,200 mg kg(-1), showing the extreme accumulation of soil P in many orchards. The AMF colonization rate was negatively correlated with soil-available P (P soil-available P (P fungi may be adapted to high soil-available P conditions. Redundancy analysis showed the significant effects of soil pH, available P in soil, and P content in leaves of P. pyrifolia var. culta trees on AMF distribution. These results suggested that the accumulation of soil-available P affected AMF communities in the roots of Japanese pear in the orchard environment.

  17. Empirical Estimation of Total Nitrogen and Total Phosphorus Concentration of Urban Water Bodies in China Using High Resolution IKONOS Multispectral Imagery

    Directory of Open Access Journals (Sweden)

    Jiaming Liu

    2015-11-01

    Full Text Available Measuring total nitrogen (TN and total phosphorus (TP is important in managing heavy polluted urban waters in China. This study uses high spatial resolution IKONOS imagery with four multispectral bands, which roughly correspond to Landsat/TM bands 1–4, to determine TN and TP in small urban rivers and lakes in China. By using Lake Cihu and the lower reaches of Wen-Rui Tang (WRT River as examples, this paper develops both multiple linear regressions (MLR and artificial neural network (ANN models to estimate TN and TP concentrations from high spatial resolution remote sensing imagery and in situ water samples collected concurrently with overpassing satellite. The measured and estimated values of both MLR and ANN models are in good agreement (R2 > 0.85 and RMSE < 2.50. The empirical equations selected by MLR are more straightforward, whereas the estimated accuracy using ANN model is better (R2 > 0.86 and RMSE < 0.89. Results validate the potential of using high resolution IKONOS multispectral imagery to study the chemical states of small-sized urban water bodies. The spatial distribution maps of TN and TP concentrations generated by the ANN model can inform the decision makers of variations in water quality in Lake Cihu and lower reaches of WRT River. The approaches and equations developed in this study could be applied to other urban water bodies for water quality monitoring.

  18. Use of water quality surrogates to estimate total phosphorus concentrations in Iowa rivers

    Directory of Open Access Journals (Sweden)

    Keith E. Schilling

    2017-08-01

    New hydrological insights for the region: TP concentrations were highly correlated to turbidity (0.78 ± 0.20 and OP (0.69 ± 0.13 across all sites and less correlated to chlorophyll a (0.07 ± 0.15, chloride (−0.10 ± 0.24 and discharge (0.41 ± 0.23. When the regression models included OP as a variable, the mean r2 for all 43 sites was 0.90 ± 0.08 and ten of the 43 sites had r2 values greater than 0.95. When OP was excluded in the regression model, the overall mean r2 values decreased to 0.72 ± 0.14 and for six of the river sites, the r2 value decreased by 50%. Other variables (discharge, chlorophyll a, chloride were included in the regression equations on a case-by-case basis. Including OP in the regression models was critically important for rivers draining the tile-drained Des Moines Lobe region.

  19. Passivation of phosphorus diffused silicon surfaces with Al2O3: Influence of surface doping concentration and thermal activation treatments

    International Nuclear Information System (INIS)

    Richter, Armin; Benick, Jan; Kimmerle, Achim; Hermle, Martin; Glunz, Stefan W.

    2014-01-01

    Thin layers of Al 2 O 3 are well known for the excellent passivation of p-type c-Si surfaces including highly doped p + emitters, due to a high density of fixed negative charges. Recent results indicate that Al 2 O 3 can also provide a good passivation of certain phosphorus-diffused n + c-Si surfaces. In this work, we studied the recombination at Al 2 O 3 passivated n + surfaces theoretically with device simulations and experimentally for Al 2 O 3 deposited with atomic layer deposition. The simulation results indicate that there is a certain surface doping concentration, where the recombination is maximal due to depletion or weak inversion of the charge carriers at the c-Si/Al 2 O 3 interface. This pronounced maximum was also observed experimentally for n + surfaces passivated either with Al 2 O 3 single layers or stacks of Al 2 O 3 capped by SiN x , when activated with a low temperature anneal (425 °C). In contrast, for Al 2 O 3 /SiN x stacks activated with a short high-temperature firing process (800 °C) a significant lower surface recombination was observed for most n + diffusion profiles without such a pronounced maximum. Based on experimentally determined interface properties and simulation results, we attribute this superior passivation quality after firing to a better chemical surface passivation, quantified by a lower interface defect density, in combination with a lower density of negative fixed charges. These experimental results reveal that Al 2 O 3 /SiN x stacks can provide not only excellent passivation on p + surfaces but also on n + surfaces for a wide range of surface doping concentrations when activated with short high-temperature treatments

  20. Evaluating Spatial Variability in Sediment and Phosphorus Concentration-Discharge Relationships Using Bayesian Inference and Self-Organizing Maps

    Science.gov (United States)

    Underwood, Kristen L.; Rizzo, Donna M.; Schroth, Andrew W.; Dewoolkar, Mandar M.

    2017-12-01

    Given the variable biogeochemical, physical, and hydrological processes driving fluvial sediment and nutrient export, the water science and management communities need data-driven methods to identify regions prone to production and transport under variable hydrometeorological conditions. We use Bayesian analysis to segment concentration-discharge linear regression models for total suspended solids (TSS) and particulate and dissolved phosphorus (PP, DP) using 22 years of monitoring data from 18 Lake Champlain watersheds. Bayesian inference was leveraged to estimate segmented regression model parameters and identify threshold position. The identified threshold positions demonstrated a considerable range below and above the median discharge—which has been used previously as the default breakpoint in segmented regression models to discern differences between pre and post-threshold export regimes. We then applied a Self-Organizing Map (SOM), which partitioned the watersheds into clusters of TSS, PP, and DP export regimes using watershed characteristics, as well as Bayesian regression intercepts and slopes. A SOM defined two clusters of high-flux basins, one where PP flux was predominantly episodic and hydrologically driven; and another in which the sediment and nutrient sourcing and mobilization were more bimodal, resulting from both hydrologic processes at post-threshold discharges and reactive processes (e.g., nutrient cycling or lateral/vertical exchanges of fine sediment) at prethreshold discharges. A separate DP SOM defined two high-flux clusters exhibiting a bimodal concentration-discharge response, but driven by differing land use. Our novel framework shows promise as a tool with broad management application that provides insights into landscape drivers of riverine solute and sediment export.

  1. Effect of high-dose phytase supplementation in broilers from 22 to 42 days post-hatch given diets severely limited in available phosphorus.

    Science.gov (United States)

    Taheri, H R; Heidari, A; Shahir, M H

    2015-01-01

    1. Two trials were conducted from 22 to 42 d post-hatch to evaluate the effectiveness of high concentrations of supplemental phytase in maize-soya bean meal-based diets severely limited in available phosphorus (P). Growth performance, plasma P and tibia ash (TA) were measured. 2. Each trial used 220 21-d-old male broilers in 20 pens with 11 birds per pen. Dietary treatments included a positive control [PC, 4.3 g/kg nonphytate P (NPP)], negative control [NC, 2.3 g/kg NPP (Trial 1) or 1.4 g/kg NPP (Trial 2)] and NC plus 1000, 2000 or 4000 phytase U/kg of the diet. 3. Birds fed on the PC diet had higher average daily gain (ADG), gain to feed ratio (G:F), plasma P (Trials 1 and 2) and TA (Trial 2) than those fed on the NC. 4. In Trial 1, ADG and G:F values of the NC plus 1000, 2000 or 4000 phytase U/kg reached those of the PC. Plasma P values of the NC plus 2000 or 4000 phytase U/kg reached that of the PC. Although TA values of the NC, NC + 1000 or NC + 2000 reached that of the PC, TA of the NC + 4000 was more than that of the PC. 5. In Trial 2, ADG and G:F values of the NC plus 4000 phytase U/kg reached those of the PC; nevertheless, plasma P values of the NC diets did not come up to that of the PC. While TA values of the NC, NC + 1000 or NC + 2000 did not reach that of the PC, TA of the NC + 4000 was greater than that of the PC. 6. Results of this study showed that, in the diets with 2.3 and 1.4 g/kg NPP, respectively, 1000 and 4000 phytase U/kg can be sufficient to obtain a comparable performance in broilers to those given diets adequate in available P.

  2. Metallic Nanoparticle (TiO2 and Fe3O4) Application Modifies Rhizosphere Phosphorus Availability and Uptake by Lactuca sativa.

    Science.gov (United States)

    Zahra, Zahra; Arshad, Muhammad; Rafique, Rafia; Mahmood, Arshad; Habib, Amir; Qazi, Ishtiaq A; Khan, Saud A

    2015-08-12

    Application of engineered nanoparticles (NPs) with respect to nutrient uptake in plants is not yet well understood. The impacts of TiO2 and Fe3O4 NPs on the availability of naturally soil-bound inorganic phosphorus (Pi) to plants were studied along with relevant parameters. For this purpose, Lactuca sativa (lettuce) was cultivated on the soil amended with TiO2 and Fe3O4 (0, 50, 100, 150, 200, and 250 mg kg(-1)) over a period of 90 days. Different techniques, such as scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Raman, and Fourier transform infrared spectroscopy (FTIR) were used to monitor translocation and understand the possible mechanisms for phosphorus (P) uptake. The trends for P accumulation were different for roots (TiO2 > Fe3O4 > control) and shoots (Fe3O4 > TiO2 > control). Cystine and methionine were detected in the rhizosphere in Raman spectra. Affinities of NPs to adsorb phosphate ions, modifications in P speciation, and NP stress in the rhizosphere had possibly contributed to enhanced root exudation and acidification. All of these changes led to improved P availability and uptake by the plants. These promising results can help to develop an innovative strategy for using NPs for improved nutrient management to ensure food security.

  3. Benthic iron and phosphorus release from river dominated shelf sediments under varying bottom water O2 concentrations.

    Science.gov (United States)

    Ghaisas, N. A.; Maiti, K.; White, J. R.

    2017-12-01

    Phosphorus (P) cycling in coastal ocean is predominantly controlled by river discharge and biogeochemistry of the sediments. In coastal Louisiana, sediment biogeochemistry is strongly influenced by seasonally fluctuating bottom water O2, which, in turn transitions the shelf sediments from being a sink to source of P. Sediment P-fluxes were 9.73 ± 0.76 mg / m2 /d and 0.67±0.16 mg/m2/d under anaerobic and aerobic conditions respectively, indicating a 14 times higher P-efflux from oxygen deprived sediments. A high sedimentary oxygen consumption rate of 889 ± 33.6 mg/m2/d was due to organic matter re-mineralization and resulted in progressively decreasing the water column dissolved O2 , coincident with a P-flux of 7.2 ± 5.5 mg/m2/d from the sediment. Corresponding water column flux of Fe total was 19.7 ± 7.80 mg/m2/d and the sediment-TP decreased from 545 mg/Kg to 513 mg/Kg. A simultaneous increase in pore water Fe and P concentrations in tandem with a 34.6% loss in sedimentary Fe-bound P underscores the importance of O2 on coupled Fe- P biogeochemistry. This study suggests that from a 14,025 sq. km hypoxia area, Louisiana shelf sediments can supply 1.33x105 kg P/day into the water column compared to 0.094 x 105 kg P/day during the fully aerobic water column conditions.

  4. Available phosphorus levels in diets supplemented with phytase for male broilers aged 22 to 42 days kept in a high-temperature environment

    Directory of Open Access Journals (Sweden)

    Tarciso Tizziani

    2016-02-01

    Full Text Available ABSTRACT This study was conducted to evaluate the effect of reduction of the available phosphorus (avP in diets supplemented with 500 FTU/kg phytase on performance, carcass characteristics, and bone mineralization of broilers aged 22 to 42 days kept in a high-temperature environment. A total of 336 Cobb broilers with an average initial weight of 0.883±0.005 kg were distributed in a completely randomized design with six treatments - a positive control (0.354 and 0.309% avP without addition of bacterial phytase for the phases of 22 to 33 and 34 to 42 days, respectively, and another five diets with inclusion of phytase (500 FTU and reduction of the level of avP (0.354, 0.294, 0.233, 0.173, and 0.112%; and 0.309, 0.258, 0.207, 0.156, and 0.106% for the phases of 22 to 33 and 34 to 42 days, respectively - eight replicates, and seven birds per cage. The experimental diets were formulated to meet all nutritional requirements, except for avP and calcium. Birds were kept in climatic chambers at a temperature of 32.2±0.4 °C and air humidity of 65.3±5.9%. Phytase acted by making the phytate P available in diets with reduction in the levels of avP, keeping feed intake, weight gain, feed:gain, and carcass characteristics unchanged. Treatments affected ash and calcium deposition and the Ca:P ratio in the bone; the group fed the diets with 0.112 and 0.106%, from 22 to 33 and 34 to 42 days of age, respectively, obtained the lowest values, although the phosphorus deposition in the bone was not affected. Diets supplemented with 500 FTU of phytase, with available phosphorus reduced to 0.173 and 0.156%, and a fixed Ca:avP ratio of 2.1:1, meet the requirements of broilers aged 22 to 33 and 34 to 42 days, respectively, reared in a high-temperature environment.

  5. Avaliação da disponibilidade de fósforo no solo para a cultura do milho Assessment of soil phosphorus availability to corn

    Directory of Open Access Journals (Sweden)

    Gerson Roberto Miola

    1999-05-01

    Full Text Available Conduziu-se um experimento, em 1994, em casa de vegetação com seis solos do Estado do Rio Grande do Sul, com o objetivo de avaliar a disponibilidade de fósforo no solo extraído pelos métodos duplo ácido (Mehlich-1, resinas em esferas (RE, em cápsulas (RC e em membrana (RM e papéis de filtro impregnados com óxido de ferro em solo umedecido a 75% da capacidade de campo (D1 e solo saturado (D2. Os solos foram previamente incubados com quatro doses de fósforo, e cultivados com milho durante 28 dias. Os coeficientes de determinação obtidos entre o fósforo absorvido pelas plantas de milho e o fósforo extraído foram: 0,85 para o Mehlich-1; 0,82 para o RE; 0,84 para o RC; 0,89 para o RM; 0,75 para o D1 e 0,70 para o D2. As quantidades de fósforo extraídas pelos métodos das resinas foram altamente correlacionadas entre si (r=0,98 e com as extraídas pelo método D1 (r=0,89. Os resultados permitiram concluir que os métodos testados foram igualmente eficientes na extração do fósforo do solo e para avaliar a disponibilidade deste elemento para a cultura do milho.In order to evaluate soil phosphorus availability to plants, the extraction methods: Mehlich-1, exchange resins in beads (RE, encapsulated (RC and as membrane (RM and iron oxide impregnated filter papers with 75% field capacity (D1 and waterlogged conditions (D2 were studied in Rio Grande do Sul State, Brazil, in 1994, in a greenhouse experiment with six soils fertilized with four phosphate rates and cultivated with corn (Zea mays L. for 28 days. Determination coefficients between plant absorbed phosphorus and the amounts determined by the extraction methods were: 0.85 (Mehlich-1, 0.82 (RE, 0.84 (RC, 0.89 (RM, 0.75 (D1 and 0.70 (D2. Soil phosphorus contents extracted by the exchange resin methods were highly correlated (r=0.98, as well as with the amounts extracted by the D-1 method (r = 0.89. The results indicated that the studied methods are equally effective for predicting P

  6. Combined effects of nitrogen to phosphorus ratios and nitrogen speciation on cyanobacterial metabolite concentrations in eutrophic Midwestern USA reservoirs.

    NARCIS (Netherlands)

    Harris, T.D.; Smith, V.H.; Graham, J.L.; Van de Waal, D.B.; Tedesco, L.P.; Clercin, N.

    2016-01-01

    Recent studies have shown that the total nitrogen to total phosphorus (TN:TP) ratio and nitrogen oxidation state may have substantial effects on secondary metabolite (e.g., microcystins) production in cyanobacteria. We investigated the relationship between the water column TN:TP ratio and the

  7. Exploring spatiotemporal patterns of phosphorus concentrations in a coastal bay with MODIS images and machine learning models

    Science.gov (United States)

    Excessive nutrients, which may be represented as Total Nitrogen (TN) and Total Phosphorus (TP) levels, in natural water systems have proven to cause high levels of algae production. The process of phytoplankton growth which consumes the excess nutrients in a water body can also b...

  8. Effect of systemic herbicides on N2-fixing and phosphate solubilizing microorganisms in relation to availability of nitrogen and phosphorus in paddy soils of West Bengal.

    Science.gov (United States)

    Das, Amal Chandra; Debnath, Anjan

    2006-11-01

    A field experiment has been conducted with four systemic herbicides viz., butachlor [N-(butoxymethyl)-2-chloro-2',6'-diethyl-acetanilide], fluchloralin [N-(2-chloroethyl)-(2,6-dinitro-N-propyl-4-trifluoromethyl) aniline], oxadiazon [5-terbutyl-3-(2,4-dichloro-5-isopro poxyphenyl)-1,3,4-oxadiazol-2-one] and oxyfluorfen [2-chloro-1-(3-ethoxy-4-nitrophenyl)-4-(trifluoromethyl) benzene] at their recommended field rates (2.0, 1.5, 0.4 and 0.12kga.i.ha(-1), respectively) to investigate their effects on growth and activities of aerobic non-symbiotic N(2)-fixing bacteria and phosphate solubilizing microorganisms in relation to availability of nitrogen and phosphorus in the rhizosphere soils as well as yield of the rice crop (Oryza sativa L cv. IR-36). Application of herbicides, in general, highly stimulated the population and activities of the target microorganisms, which resulted in a greater amount of atmospheric nitrogen fixation and phosphate solubilization in the rhizosphere soils of the test crop. The greater microbial activities subsequently augmented the mineralization and availability of nitrogen and phosphorus in the soil solution, which in turn increased the yield of the crop. Among the herbicides, oxyfluorfen was most stimulative followed by fluchloralin and oxadiazon in augmenting the microbial activities in soil. Butachlor also accentuated the mineralization and availability of nitrogen due to higher incitement of non-symbiotic N(2)-fixing bacteria in paddy soil. The grain and straw yields of the crop were also significantly increased due to the application of oxyfluorfen (20.2% and 21%) followed by fluchloralin (13.1% and 15.4%) and butachlor (9.1% and 10.2%), respectively.

  9. Plant-availability to barley of phosphorus in ash from thermally treated animal manure in comparison to other manure based materials and commercial fertilizer

    DEFF Research Database (Denmark)

    Kuligowski, Ksawery; Poulsen, Tjalfe Gorm; Rubæk, Gitte Holton

    2010-01-01

    ), thermally gasified SS (GAs), thermally gasified poultry manure (GAp), crushed triple super phosphate (TSP) and disodium phosphate (DSP) was used as reference P fertilizer. For application of 20 kg P ha-1 mineral P fertilizer replacement value (RV) in the second year in the sandy soil was 76% and 99% for GA...... on both soils in the second year, and there was no detectable residual effect of the treatments on grass yield and P uptake. In conclusion, untreated ash and solid manures used in this study were not suitable as starter P fertilizer, but could be used to maintain the level of available P in soil......Phosphorus (P) is an essential nutrient and a limited resource, yet excess P is applied to agricultural land and can cause environmental problems in areas with intensive animal farming. In this study, the fertilizing effects of P in several animal manure-based products (including thermal treatment...

  10. Dynamics of soil available phosphorus and its impact factors under simulated climate change in typical farmland of Taihu Lake region, China.

    Science.gov (United States)

    Yu, Kaihao; Chen, Xiaomin; Pan, Genxing; Zhang, Xuhui; Chen, Can

    2016-02-01

    Global climate change affects the availability of soil nutrients, thereby influencing crop productivity. This research was conducted to investigate the effects of elevated CO2, elevated temperature, and the interaction of the elevated CO2 and temperature on the soil available phosphorus (P) of a paddy-wheat rotation in the Taihu Lake region, China. Winter wheat (Triticum aestivum L.) was cultivated during the study period from 2011 to 2014 at two CO2 levels (350 μL•L(-1) ambient and 500 μL•L(-1) elevated by 150 μL•L(-1)) and two temperatures (ambient and 2 °C above the ambient). Soil available P content increased at the first season and decreased at the last season during the three wheat growing seasons. Soil available P content showed seasonal variation, whereas dynamic changes were not significant within each growing season. Soil available P content had no obvious trends under different treatments. But for the elevated temperature, CO2, and their combination treatments, soil available P content decreased in a long time period. During the period of wheat ripening stage, significant positive correlations were found between soil available P content and saturated hydraulic conductivity (Ks) and organic matter, but significant negative correlations with soil clay content and pH value; the correlation coefficients were 0.9400 (p climate change scenario.

  11. The Effect of Calcium and Available Phosphorus Levels on Performance, Egg Quality and Bone Characteristics of Japanese Quails at End of the Egg-Production Phase

    Directory of Open Access Journals (Sweden)

    CLN Ribeiro

    Full Text Available ABSTRACT Calcium (Ca and available phosphorus (avP requirements for egg production are different between the beginning and the end of the egg-production cycle. The objective of this study was to estimate the Ca and avP requirements of Japanese quails at end of the production phase. In total, 256 Japanese quails with 48 weeks of age were randomly distributed in 2 x 2 factorial arrangement consisting of two Ca levels (29 and 38 g/kg and two avP levels (1.5 and 3.0 g/kg, totaling four treatments with eight replicates of eight hens each. The variables evaluated were feed intake (FI; egg production (EP; marketable egg production (MEP; egg weight (EW; egg mass (EM; feed conversion ratio per egg mass (FCRM; feed conversion ratio per dozen eggs (FCRD; livability (L; yolk weight (YW, albumen weight (AW, eggshell weight (SW; yolk percentage (YP, albumen percentage (AP, eggshell percentage (SP, specific egg weight (SEW; bone calcium percentage (BCa, bone phosphorus percentage (BP, bone ash weight (Bash and bone ash percentage (PBash. There was no interaction between Ca and avP levels for any of the evaluated parameters, except for SEW. Quail performance was not influenced by the treatments, except for MEP. Bone characteristics were not influenced by the tested dietary Ca and avP levels. However, SW and SP increased and AP decreased as dietary Ca level increased. The dietary supplementation of 38 g Ca/kg and 3.0 g avP/kg may increase marketable egg production and the egg quality of Japanese quails at end of the production cycle.

  12. Preparation of phosphorus targets using the compound phosphorus nitride

    International Nuclear Information System (INIS)

    Maier-Komor, P.

    1987-01-01

    Commercially available phosphorus nitride (P 3 N 5 ) shows a high oxygen content. Nevertheless, this material is attractive for use as phosphorus targets in experiments where red phosphorus would disappear due to its high vapor pressure and where a metal partner in the phosphide must be excluded due to its high atomic number. Methods are described to produce phosphorus nitride targets by vacuum evaporation condensation. (orig.)

  13. Calcium and phosphorus concentrations and the calcium/phosphorus ratio in trabecular bone from the femoral neck of healthy humans as determined by neutron activation analysis

    International Nuclear Information System (INIS)

    Zaichick, Vladimir; Tzaphlidou, Margaret

    2003-01-01

    The Ca and P concentrations as well as the Ca/P ratio were estimated in intact trabecular bone samples from the femoral neck of healthy humans, 34 women and 44 men, aged from 15 to 55 years, using instrumental neutron activation analysis. The mean values (M±SD) for the investigated parameters (on a dry-weight basis) were: 12.1±3.0%, 5.94±1.71%, 2.07±0.25 and 10.9±2.5%, 5.30±1.23%, 2.07±0.22 for females and males, respectively. A statistically significant (p≤0.05) decrease of Ca concentration with age was found only for males while the P concentration and the Ca/P ratio were not affected by age. No statistically significant sex-related differences were observed in any of the parameters. The mean values for Ca, P and the Ca/P ratio lay close to the median of the very wide range of published data. The individual variation for the Ca/P ratio in trabecular bone from the healthy human femoral neck was lower than those for Ca and P separately. This suggests that the specificity of the Ca/P ratio is better than that of Ca and P concentrations and may be more reliable for the diagnosis of bone disorders

  14. Efficiency in the avail (by Com) of zinc (65ZnCl2) and phosphorus (Na H2 PO4) ions

    International Nuclear Information System (INIS)

    Calvache, Marcelo.

    1994-01-01

    The efficiency of corn to use phosphorus and zinc ions at different growing periods was determined in two soils Udic Eutrandept and Andic Haplustoll of Pichincha Province, after adding 10 ppm zinc labelled with 65Zn (gamma emisor, 1.115 meV), 50 and 100 ppm phosphorus, and a complementary fertilization. Root, stem and leaf samples were analyzed at 15 days intervals during the growing period. Zinc efficiency use was determined by isotopic method, and phosphorus by the non-isotopic. Significant differences were found for sampling period and soil types. The efficiency of use of zinc and phosphorus fertilizer increased with the age of the crop, being higher for the soil originally containing less Zn and P. Dry matter content increased linearly with phosphorus fertilizer addition

  15. Organic resources and earthworms affect phosphorus availability to sorghum after phosphate rock addition in semi-arid West Africa

    NARCIS (Netherlands)

    Ouédraogo, E.; Brussaard, L.; Mando, A.; Stroosnijder, L.

    2005-01-01

    A field experiment was laid out in Burkina Faso (West Africa) on an Eutric Cambisol to investigate the interaction of organic resource quality and phosphate rock on crop yield and to assess the contribution of earthworms (Millsonia inermis Michaelsen) to P availability after phosphate rock

  16. Phosphorus availability to ryegrass from urban sewage sludges assessed by isotopic labeling and dilution technique, effect of irradiation

    International Nuclear Information System (INIS)

    El-Motaium, R.A.; Morel, C.

    2007-01-01

    Urban sewage sludge are widely used as alternative P input because of their high P content. Irradiation of sewage sludge is developed in Egypt to make safe spreading of sludge on agricultural fields. Five sludges were sampled from representative urban wastewater treatment plants located in Cairo, Egypt. Sub samples were irradiated using gamma radiation at 6 KGy dose. A pot experiment was conducted under plastic greenhouse using sandy P-deficient soil. The soil was homogeneously labelled with a radioactive solution of carrier-free 32 PO 4 (about 3 MBq kg / soil) to determine the contribution of the different sources of P in plant nutrition. Sludges were applied at 50 mg P/ kg soil. In addition, a control treatment was also carried out to analyze sludge P availability in comparison to a water soluble mineral fertilizer, i.e. 50 mg P/kg soil was applied as commercial monocalcium phosphate (SSP). A reference treatment was included without any P application but the radioactive solution was added. One gram of ryegrass seeds (Lolium multiflorium) was sown in each pot. The aerial parts of the ryegrass were harvested four times, every 3 weeks. Analysis of all harvests included 32 P and total P content was used to determine the respective contribution of soil and sludge to plant P nutrition and the plant available P (L value) using the isotopic dilution principle. The ratio of radioactive P to non-radioactive P, i.e. isotopic composition, was calculated. The total P content in the different urban sewage sludge was ranged from 6.2 to 13.8 g P/ kg and affected by irradiation. Because the soil was extremely P deficient (L value=0.3 mg P/ kg soil), P derived from seeds represented 99% of the P taken up when no P was applied and 87% when applying 50 mg P-SSP/ kg. After correcting the contribution of ryegrass seeds, sludge P contributed by 98% to plant nutrition and 7.2% of the applied P was recovered. The sludge type and irradiation factors did not significantly affect sludge P

  17. Genetic parameters of calcium, phosphorus, magnesium, and potassium serum concentrations during the first 8 days after calving in Holstein cows.

    Science.gov (United States)

    Tsiamadis, V; Banos, G; Panousis, N; Kritsepi-Konstantinou, M; Arsenos, G; Valergakis, G E

    2016-07-01

    Calcium, Mg, P, and K are of great importance for the health and productivity of dairy cows after calving. So far genetic studies have focused on clinical hypocalcemia, leaving the genetic parameters of these macroelements unstudied. Our objective was to estimate the genetic parameters of Ca, Mg, P, and K serum concentrations and their changes during the first 8d after calving. The study was conducted in 9 herds located in northern Greece, with 1,021 Holstein cows enrolled from November 2010 until November 2012. No herd used any kind of preventive measures for hypocalcemia. Pedigree information for all cows was available. A total of 35 cows were diagnosed and treated for periparturient paresis and, therefore, excluded from the study. The remaining 986 cows were included in genetic analysis. The distribution of cows across parities was 459 (parity 1), 234 (parity 2), 158 (parity 3), and 135 (parity ≥4). A sample of blood was taken from each cow on d1, 2, 4, and 8 after calving and serum concentrations of Ca, P, Mg, and K were measured in each sample. A final data set of 15,390 biochemical records was created consisting of 3,903 Ca, 3,902 P, 3,903Mg, and 3,682K measurements. Moreover, changes of these concentrations between d1 and 4 as well as 1 and 8 after calving were calculated and treated as different traits. Random regression models were used to analyze the data. Results showed that daily heritabilities of Ca, P, and Mg concentrations traits were moderate to high (0.20-0.43), whereas those of K were low to moderate (0.12-0.23). Regarding concentration changes, only Mg change between d1 and 8 after calving had a significant heritability of 0.18. Genetic correlations between Ca, P, Mg, and K concentrations and their concentration changes from d1 to 4 and 1 to 8 after calving were not significantly different from zero. Most phenotypic correlations among Ca, P, Mg, and K concentrations were positive and low (0.09-0.16), whereas the correlation between P and Mg was

  18. Environmental controls over methane emissions from bromeliad phytotelmata: The role of phosphorus and nitrogen availability, temperature, and water content

    Science.gov (United States)

    Kotowska, Martyna M.; Werner, Florian A.

    2013-12-01

    bromeliads are common epiphytic plants throughout neotropical forests that store significant amounts of water in phytotelmata (tanks) formed by highly modified leafs. Methanogenic archaea in these tanks have recently been identified as a significant source of atmospheric methane. We address the effects of environmental drivers (temperature, tank water content, sodium phosphate [P], and urea [N] addition) on methane production in anaerobically incubated bromeliad slurry and emissions from intact bromeliad tanks in montane Ecuador. N addition ≥ 1 mg g-1 had a significantly positive effect on headspace methane concentrations in incubation jars while P addition did not affect methane production at any dosage (≤ 1 mg g-1). Tank bromeliads (Tillandsia complanata) cultivated in situ showed significantly increased effluxes of methane in response to the addition of 26 mg N addition per tank but not to lower dosage of N or any dosage of P (≤ 5.2 mg plant-1). There was no significant interaction between N and P addition. The brevity of the stimulatory effect of N addition on plant methane effluxes (1-2 days) points at N competition by other microorganisms or bromeliads. Methane efflux from plants closely followed within-day temperature fluctuations over 24 h cycles, yet the dependency of temperature was not exponential as typical for terrestrial wetlands but instead linear. In simulated drought, methane emission from bromeliad tanks was maintained with minimum amounts of water and regained after a short lag phase of approximately 24 h. Our results suggest that methanogens in bromeliads are primarily limited by N and that direct effects of global change (increasing temperature and seasonality, remote fertilization) on bromeliad methane emissions are of moderate scale.

  19. Sargasso Sea phosphorus biogeochemistry: an important role for dissolved organic phosphorus (DOP

    Directory of Open Access Journals (Sweden)

    M. W. Lomas

    2010-02-01

    Full Text Available Inorganic phosphorus (SRP concentrations in the subtropical North Atlantic are some of the lowest in the global ocean and have been hypothesized to constrain primary production. Based upon data from several transect cruises in this region, it has been hypothesized that dissolved organic phosphorus (DOP supports a significant fraction of primary production in the subtropical North Atlantic. In this study, a time-series of phosphorus biogeochemistry is presented for the Bermuda Atlantic Time-series Study site, including rates of phosphorus export. Most parameters have a seasonal pattern, although year-over-year variability in the seasonal pattern is substantial, likely due to differences in external forcing. Suspended particulate phosphorus exhibits a seasonal maximum during the spring bloom, despite the absence of a seasonal peak in SRP. However, DOP concentrations are at an annual maximum prior to the winter/spring bloom and decline over the course of the spring bloom while whole community alkaline phosphatase activities are highest. As a result of DOP bioavailability, the growth of particles during the spring bloom occurs in Redfield proportions, though particles exported from the euphotic zone show rapid and significant remineralization of phosphorus within the first 50 m below the euphotic zone. Based upon DOP data from transect cruises in this region, the southward cross gyral flux of DOP is estimated to support ~25% of annual primary production and ~100% of phosphorus export. These estimates are consistent with other research in the subtropical North Atlantic and reinforce the hypothesis that while the subtropics may be phosphorus stressed (a physiological response to low inorganic phosphorus, utilization of the DOP pool allows production and accumulation of microbial biomass at Redfield proportions.

  20. The effects of boron supplementation of layer diets varying in calcium and phosphorus concentrations on performance, egg quality, bone strength and mineral constituents of serum, bone and faeces.

    Science.gov (United States)

    Küçükyilmaz, K; Erkek, R; Bozkurt, M

    2014-01-01

    1. A 2 × 3 factorial arrangement of treatments was used to investigate the effects of dietary calcium (Ca), phosphorus (P), and supplemental boron (B) (0, 75, and 150 mg/kg) on the performance, egg quality, bone strength, and mineral constituents in bone, serum and faeces. 2. A reduction by 18% in the dietary Ca-P concentration from the recommended levels for the hen strain reduced (P properties did not corroborate the hypothesis that B is a trace element playing an important role in mineral metabolism and bone strength through an interaction with Ca, P and Mg.

  1. VISIBE AND INFRARED SPECTRAL CHARACTERISATION OF CHINESE CABBAGE (BRASSICA RAPA L. SUBSPECIES CHINENSIS, GROWN UNDER DIFFERENT NITROGEN, POTASSIUM AND PHOSPHORUS CONCENTRATIONS

    Directory of Open Access Journals (Sweden)

    B. B. Mokoatsi

    2017-11-01

    Full Text Available There is a need to intensify research efforts on improving productivity of indigenous vegetables in South Africa. One research avenue is operationalizing remote sensing techniques to monitor crop health status. This study aimed at characterising the spectral properties of Chinese cabbage (Brassica Rapa L. subspecies Chinensis grown under varying fertilizer treatments: nitrogen (0 kg/ha, 75 kg/ha, 125 kg/ha, 175 kg/ha and 225 kg/ha, phosphorus (0 kg/ha, 9.4 kg/ha, 15.6, 21.9 kg/ha and 28.1 kg/ha and potassium (0 kg/ha, 9.4  kg/ha, 15.6 kg/ha, 21.9 kg/ha and 28.1 kg/ha. Visible and infrared spectral measurements were taken from a total of 60 samples inside the laboratory. Contiguous spectral regions were plotted to show spectral profiles of the different fertilizer treatments and then classified using gradient boosting and random forest classifiers. ANOVA revealed the potential of spectral reflectance data in discriminating different fertiliser treatments from crops. There was also a significant difference between the capabilities of the two classifiers. Gradient boost model (GBM yielded higher classification accuracies than random forest (RF. The important variables identified by each model improved the classification accuracy. Overall, the results indicate a potential for the use of spectroscopy in monitoring food quality parameters, thereby reducing the cost of traditional methods. Further research into advanced statistical analysis techniques is needed to improve the accuracy with which fertiliser concentrations in crops could be quantified. The random forest model particularly requires improvements.

  2. Regulating mineralization rates of Tithonia diversifolia and Lantana camara prunings to improve phosphorus availability in calcareous soils

    Directory of Open Access Journals (Sweden)

    Y. Nuraini

    2014-01-01

    Full Text Available The effect of mixing of Tithonia diversifolia and Lantana camara prunings to improve synchronization between P released from the prunings with crop demand for P was studied in a laboratory and in a glasshouse. Tithonia diversifolia prunings (Td, Lantana camara prunings (Lc, and farmyard manure (Pk were thoroughly mixed with the proportion (% of dry weight of; 25Td +75 Lc ; 50Td +50 Lc ; 75Td +25 Lc ; 90Lc +10 Pk ; 45Td +45 +10 Lc Pk ; 100Td and 100Lc, and then mixed with 100 g of air-dried soil with a rate equivalent to 100 kg P / ha. Results of the study showed that the pruning mixtures decomposed and mineralized faster than that of Lantana camara pruning only, but slower than that of Tithonia diversifolia pruning only. The amount of P released from the pruning mixtures increased with increasing proportion of Tithonia diversifolia pruning in the mixtures. Increasing proportion of Tithonia diversifolia pruning in the mixture applied to the soil increased the amount of P taken up by maize.

  3. Relations between total phosphorus and orthophosphorus concentrations and rainfall, surface-water discharge, and groundwater levels in Big Cypress Seminole Indian Reservation, Florida, 2014–16

    Science.gov (United States)

    McBride, W. Scott; Sifuentes, Dorothy F.

    2018-02-06

    The Seminole Tribe of Florida (the Tribe) is partnering with the U.S. Environmental Protection Agency to develop a numeric phosphorus criterion for the 52,000-acre Big Cypress Seminole Indian Reservation (BCSIR), which is located downgradient of the Everglades Agricultural Area, and of other public and private lands, in southeastern Hendry County and northwestern Broward County in southern Florida. The U.S. Geological Survey (USGS), in cooperation with the Tribe, used water-quality data collected between October 2014 and September 2016 by the Tribe and the South Florida Water Management District (SFWMD), along with data from rainfall gages, surface-water stage and discharge gages, and groundwater monitoring wells, to (1) examine the relations between local hydrology and measured total phosphorus (TP) and orthophosphorus (OP) concentrations and (2) identify explanatory variables for TP concentrations. Of particular concern were conditions when TP exceeded 10 parts per billion (ppb) (0.01 milligram per liter [mg/L]) given that the State of Florida and the Miccosukee Tribe of Indians Alligator Alley Reservation (located downstream of the BCSIR) have adopted a 10-ppb maximum TP criterion for surface waters.From October 2014 to September 2016, the Tribe collected 47–52 samples at each of nine water-quality sites for analysis of TP and OP, except at one site where 28 samples were collected. For all sites sampled, concentrations of TP (as phosphorus [P]) ranged from less than 0.002 mg/L (2 ppb) to a maximum of nearly 0.50 mg/L (500 ppb), whereas concentrations of OP (as P), the reactive form of inorganic phosphorus readily absorbed by plants and (or) abiotically absorbed, ranged from less than 0.003 mg/L (3 ppb) to a maximum of 0.24 mg/L (240 ppb). The median and interquartile ranges of concentrations of TP and OP in the samples collected in 2014–16 by the Tribe were similar to the median and interquartile ranges of concentrations in samples collected by the SFWMD at

  4. Evaluation of normal yellow dent corn and high available phosphorus corn in combination with reduced dietary phosphorus and phytase supplementation for broilers grown to market weights in litter pens.

    Science.gov (United States)

    Yan, F; Kersey, J H; Fritts, C A; Waldroup, P W; Stilborn, H L; Crum, R C; Rice, D W; Raboy, V

    2000-09-01

    A study was conducted to determine the extent fecal P levels could be reduced while maintaining performance. Various strategies were employed including the use of a high available phosphorus hybrid of corn (HAPC), supplementation with phytase enzyme, and reduced dietary P levels. The use of HAPC resulted in a 50% reduction in phytate-bound dietary P as compared with a normal yellow dent corn (YDC) diet. Dietary nonphytate P was maintained at either NRC (1994) recommendations for appropriate age periods or reduced by 0.075 or 0.15%. Portions of the diets were supplemented with 1,000 units of phytase/kg. Male chicks of a commercial strain were grown to 56 d on the test diets. Broilers fed diets with HAPC had BW, feed conversion, livability, and tibia ash that were equal to or superior to those fed diets with YDC with considerably reduced fecal P content at any dietary level of nonphytate P. Phytase supplementation enabled birds to maintain live performance at lower levels of nonphytate P, further reducing the fecal P output. One of the greatest contributions of phytase was a reduction in mortality at the lower levels of nonphytate P. Dietary P levels could be reduced by 0.075% under NRC (1994) recommendations without adversely affecting live performance; a reduction of 0.15% in conjunction with phytase supplementation maintained BW, feed conversion, and livability but reduced tibia ash. The extent to which dietary P levels can be reduced over the entire feeding program is subject to further research.

  5. Exploring the Modes of Action of Phosphorus-Based Flame Retardants in Polymeric Systems

    Directory of Open Access Journals (Sweden)

    Sebastian Rabe

    2017-04-01

    Full Text Available Phosphorus-based flame retardants were incorporated into different, easily preparable matrices, such as polymeric thermoset resins and paraffin as a proposed model for polyolefins and investigated for their flame retardancy performance. The favored mode of action of each flame retardant was identified in each respective system and at each respective concentration. Thermogravimetric analysis was used in combination with infrared spectroscopy of the evolved gas to determine the pyrolysis behavior, residue formation and the release of phosphorus species. Forced flaming tests in the cone calorimeter provided insight into burning behavior and macroscopic residue effects. The results were put into relation to the phosphorus content to reveal correlations between phosphorus concentration in the gas phase and flame inhibition performance, as well as phosphorus concentration in the residue and condensed phase activity. Total heat evolved (fire load and peak heat release rate were calculated based on changes in the effective heat of combustion and residue, and then compared with the measured values to address the modes of action of the flame retardants quantitatively. The quantification of flame inhibition, charring, and the protective layer effect measure the non-linear flame retardancy effects as functions of the phosphorus concentration. Overall, this screening approach using easily preparable polymer systems provides great insight into the effect of phosphorus in different flame retarded polymers, with regard to polymer structure, phosphorus concentration, and phosphorus species.

  6. Determination of 210Po concentration in commercially available infant formulae and assessment of daily ingestion dose

    OpenAIRE

    Prabhath, Ravi K.; Sreejith, Sathyapriya R.; Nair, Madhu G.; Rao, D.D.; Pradeepkumar, K.S.

    2015-01-01

    A study has been conducted to estimate the concentration of natural radioactive polonium in commercially available packaged infant food formulae available in Mumbai, India and the corresponding daily dose normalized based on its shelf life. Eleven most popular international brands of infant formulae were sourced from market and three aliquots from each sample were analysed for concordant results. Autodeposition method onto a silver planchet from hot dilute acid solution followed by alpha spec...

  7. The effect of dietary phosphorus level and phytase supplementation on growth performance, bone-breaking strength, and litter phosphorus concentration in broilers.

    Science.gov (United States)

    Powell, S; Johnston, S; Gaston, L; Southern, L L

    2008-05-01

    This research was conducted to determine the effects of feeding different P levels with and without phytase supplementation on broiler growth performance, bone-breaking strength (BBS), and litter P concentration. An experiment with 4 trials was conducted with 7,840 Ross x Ross straight-run broilers. For each trial, 1,960 broilers were allotted on d 0 to treatments, with 7 replications each and with 70 broilers per replication. The broilers were fed a 4-period feeding program consisting of starter (0 to 14 d), grower (14 to 32 d), finisher (32 to 41 d), and withdrawal (41 to 50 d) periods. For each trial, the same pen was used continuously for each treatment-replication combination, and the litter was not removed between trials. Broilers were fed a control diet [0.43, 0.40, 0.36, or 0.32% nonphytate P (nPP)] in the starter, grower, finisher, and withdrawal periods, respectively, a low Ca and P (LCaP) diet with a 0.05% reduction in nPP in each period, and these 2 diets supplemented with phytase at 600 phytase units/kg (nPP and Ca were reduced by 0.094% in diets with phytase). Diet did not affect (P > 0.10) broiler performance in the starter or withdrawal periods. Generally, both phytase addition and the LCaP diet decreased some aspects of growth performance during the grower and finisher periods. There was no main effect of phytase on BBS, but BBS was decreased in the broilers fed the LCaP diet with phytase addition (nPP x phytase, P broilers fed the LCaP diet. Total P, soluble P (SP), and reactive soluble P (RSP) were decreased (P litter of broilers fed the LCaP diets. Total P, SP, and RSP were decreased (P litter of broilers fed phytase. These data indicate that phytase supplementation at 600 phytase units/kg reduces growth in some periods, has no effect on BBS, and reduces total P, SP, and RSP in the litter.

  8. Effect of fire on phosphorus forms in Sphagnum moss and peat soils of ombrotrophic bogs.

    Science.gov (United States)

    Wang, Guoping; Yu, Xiaofei; Bao, Kunshan; Xing, Wei; Gao, Chuanyu; Lin, Qianxin; Lu, Xianguo

    2015-01-01

    The effect of burning Sphagnum moss and peat on phosphorus forms was studied with controlled combustion in the laboratory. Two fire treatments, a light fire (250 °C) and a severe fire (600 °C), were performed in a muffle furnace with 1-h residence time to simulate the effects of different forest fire conditions. The results showed that fire burning Sphagnum moss and peat soils resulted in losses of organic phosphorus (Po), while inorganic phosphorus (Pi) concentrations increased. Burning significantly changed detailed phosphorus composition and availability, with severe fires destroying over 90% of organic phosphorus and increasing the availability of inorganic P by more than twofold. Our study suggest that, while decomposition processes in ombrotrophic bogs occur very slowly, rapid changes in the form and availability of phosphorus in vegetation and litter may occur as the result of forest fires on peat soils. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Effect of phosphorus stress on Microcystis aeruginosa growth and phosphorus uptake.

    Directory of Open Access Journals (Sweden)

    Sajeela Ghaffar

    Full Text Available This study was designed to advance understanding of phosphorus regulation of Microcystis aeruginosa growth, phosphorus uptake and storage in changing phosphorus (P conditions as would occur in lakes. We hypothesized that Microcystis growth and nutrient uptake would fit classic models by Monod, Droop, and Michaelis-Menten in these changing conditions. Microcystis grown in luxury nutrient concentrations was transferred to treatments with phosphorus concentrations ranging from 0-256 μg P∙L-1 and luxury nitrogen. Dissolved phosphorus concentration, cell phosphorus quota, P uptake rate and cell densities were measured at day 3 and 6. Results showed little relationship to predicted models. Microcystis growth was asymptotically related to P treatment from day 0-3, fitting Monod model well, but negatively related to P treatment and cell quota from day 3-6. From day 0-3, cell quota was negatively related to P treatments at <2 μg∙L-1, but increased slightly at higher P. Cell quota decreased greatly in low P treatments from day 3-6, which may have enabled high growths in low P treatments. P uptake was positively and linearly related to P treatment during both periods. Negative uptake rates and increases in measured culture phosphorus concentrations to 5 μg∙L-1 in the lowest P treatments indicated P leaked from cells into culture medium. This leakage during early stages of the experiment may have been sufficient to stimulate metabolism and use of intracellular P stores in low P treatments for rapid growth. Our study shows P regulation of Microcystis growth can be complex as a result of changing P concentrations, and this complexity may be important for modeling Microcystis for nutrient and ecosystem management.

  10. Disponibilidade de fósforo em solos avaliada por diferentes extratores Phosphorus availability in soils, determined by different extracting procedures

    Directory of Open Access Journals (Sweden)

    Fábio Cesar da Silva

    1999-02-01

    , Bray 1 e Olsen; (d não superestima, como os extratores ácidos, a disponibilidade de P em solos tratados com fosfatos naturais; (e é o que apresenta o melhor embasamento teórico para a determinação do chamado "fator quantidade" de P em solos, que é o mais importante índice da disponibilidade do nutriente.The objective of this paper was the comparative study of the most important extractors of soil phosphorus. It presents a literature review of papers that deal with methods of extraction for the evaluation of phosphorus availability in soils. The methods considered were: anion exchange resin, Olsen, Bray 1, Bray 2, Mehlich 1, Troug, Égner, water, 0,01M CaCl2, iron hydroxide impregnated filter paper (Pi and the determinations of the E and L values. The comparison between results of soil analysis by different methods of phosphorus extraction in soils and phosphorus uptake by plants was initially made considering the coefficient of determination (r² for several extractants. The following average values and corresponding numbers of articles in which the method was considered were obtained: resin, 70% (34; E value, 68% (16; L value, 65% (8; Olsen, 54% (48; Bray 1, 50% (42; Mehlich 1, 46% (25; Égner, 44% (9; Bray 2, 42% (19; Water, 42% (15; Truog, 38% (13; CaCl2, 36% (13, and Morgan, 32% (13. The comparison of several methods, considering the pairs of results (r² obtained for the extractants, that were tested together through linear correlation and average contrasts (t student test, indicated that the resin method was statistically superior to the other methods. The resin method presents the following favorable features: (a highest values for the determinations coefficients for the correlations between P uptake by plants and soil P by the different methods, as reviewed in 72 papers; (b it can be used in both acid and alkaline soils, which is not the case for the other most commonly used methods; (c it reveals adequately the effect of liming on the increase of P

  11. Remediation of lead-contaminated sediment by biochar-supported nano-chlorapatite: Accompanied with the change of available phosphorus and organic matters.

    Science.gov (United States)

    Huang, Danlian; Deng, Rui; Wan, Jia; Zeng, Guangming; Xue, Wenjing; Wen, Xiaofeng; Zhou, Chengyun; Hu, Liang; Liu, Xigui; Xu, Piao; Guo, Xueying; Ren, Xiaoya

    2018-04-15

    Some rivers in China have been seriously contaminated due to the discharge of lead (Pb) smelting wastewater. In this study, biochar-supported nano-chlorapatite (BC-nClAP) was synthesized to immobilize Pb in contaminated sediment. The remediation effect of BC-nClAP on Pb-contaminated sediment was evaluated through batch experiments and the materials were characterized by x-ray diffraction, scanning electron microscope, Brunner-Emmet-Teller and electronic differential system. It was found that BC-nClAP can transform Pb effectively from labile fraction into stable fraction with a maximum transformation efficiency increasing to 94.1% after 30 days of treatment, and the stabilization efficiency of toxicity characteristic leaching procedure reached 100% only after 16 days of treatment. The content of available phosphorus (AP) in the sediments treated by BC-nClAP was much less than that treated by nClAP, which indicated a lower risk of eutrophication and suggested the dissolution-precipitation mechanism involved in Pb immobilization. BC-nClAP presented the best immobilization efficiency of Pb and the content of organic matters in BC-nClAP treated samples increased the most, thus the OM might play an important role during the Pb immobilization. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Nitrogen and phosphorus availabilities interact to modulate leaf trait scaling relationships across six plant functional types in a controlled-environment study.

    Science.gov (United States)

    Crous, Kristine Y; O'Sullivan, Odhran S; Zaragoza-Castells, Joana; Bloomfield, Keith J; Negrini, A Clarissa A; Meir, Patrick; Turnbull, Matthew H; Griffin, Kevin L; Atkin, Owen K

    2017-08-01

    Nitrogen (N) and phosphorus (P) have key roles in leaf metabolism, resulting in a strong coupling of chemical composition traits to metabolic rates in field-based studies. However, in such studies, it is difficult to disentangle the effects of nutrient supply per se on trait-trait relationships. Our study assessed how high and low N (5 mM and 0.4 mM, respectively) and P (1 mM and 2 μM, respectively) supply in 37 species from six plant functional types (PTFs) affected photosynthesis (A) and respiration (R) (in darkness and light) in a controlled environment. Low P supply increased scaling exponents (slopes) of area-based log-log A-N or R-N relationships when N supply was not limiting, whereas there was no P effect under low N supply. By contrast, scaling exponents of A-P and R-P relationships were altered by P and N supply. Neither R : A nor light inhibition of leaf R was affected by nutrient supply. Light inhibition was 26% across nutrient treatments; herbaceous species exhibited a lower degree of light inhibition than woody species. Because N and P supply modulates leaf trait-trait relationships, the next generation of terrestrial biosphere models may need to consider how limitations in N and P availability affect trait-trait relationships when predicting carbon exchange. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  13. Remote sensing estimation of the total phosphorus concentration in a large lake using band combinations and regional multivariate statistical modeling techniques.

    Science.gov (United States)

    Gao, Yongnian; Gao, Junfeng; Yin, Hongbin; Liu, Chuansheng; Xia, Ting; Wang, Jing; Huang, Qi

    2015-03-15

    Remote sensing has been widely used for ater quality monitoring, but most of these monitoring studies have only focused on a few water quality variables, such as chlorophyll-a, turbidity, and total suspended solids, which have typically been considered optically active variables. Remote sensing presents a challenge in estimating the phosphorus concentration in water. The total phosphorus (TP) in lakes has been estimated from remotely sensed observations, primarily using the simple individual band ratio or their natural logarithm and the statistical regression method based on the field TP data and the spectral reflectance. In this study, we investigated the possibility of establishing a spatial modeling scheme to estimate the TP concentration of a large lake from multi-spectral satellite imagery using band combinations and regional multivariate statistical modeling techniques, and we tested the applicability of the spatial modeling scheme. The results showed that HJ-1A CCD multi-spectral satellite imagery can be used to estimate the TP concentration in a lake. The correlation and regression analysis showed a highly significant positive relationship between the TP concentration and certain remotely sensed combination variables. The proposed modeling scheme had a higher accuracy for the TP concentration estimation in the large lake compared with the traditional individual band ratio method and the whole-lake scale regression-modeling scheme. The TP concentration values showed a clear spatial variability and were high in western Lake Chaohu and relatively low in eastern Lake Chaohu. The northernmost portion, the northeastern coastal zone and the southeastern portion of western Lake Chaohu had the highest TP concentrations, and the other regions had the lowest TP concentration values, except for the coastal zone of eastern Lake Chaohu. These results strongly suggested that the proposed modeling scheme, i.e., the band combinations and the regional multivariate

  14. Phosphorus and nitrogen in the eutrophication of waters

    International Nuclear Information System (INIS)

    Salonen, S.; Frisk, T.; Kaermeniemi, T.; Niemi, J.; Pitkaenen, H.; Silvo, K.; Vuoristo, H.

    1992-01-01

    This report is a summary of the contribution of nitrogen and phosphorus in the eutrophication process of inland and coastal waters. Special attention was paid to the mechanisms of these nutrients in regulating biological processes and to the methods available in estimating their effects in the eutrophication of water bodies. The report includes five chapters which are entitled: Introduction, which is a general background to the subject with special attention to the requirements of the Finnish Water Act. Phosphorus and nitrogen as factors regulating biological processes. The topics included are: definition of eutrophication, forms of phosphorus and nitrogen and their sources to inland and coastal waters, effects of these nutrients as growth factors of phytoplankton and macrophytes and consequences of eutrophication. Estimation of the effects of phosphorus and nitrogen. The topics discussed from the point of view of the tasks of the National Board of Waters and the Environment are: estimation of the effects of phosphorus and nitrogen in the planning and supervision of industry, fish farming, peat production, municipalities, agriculture and forestry. A brief state-of-the art of the research carried out in the National Board of Waters and the Environment is given. Methods of estimating the effects of phosphorus and nitrogen loading in waters. The topics are: relationships between phosphorus and nitrogen concentrations in waters, material balances, water quality models, classification of waters and different groups of organisms as indicators of water quality. Conclusions for the estimation of the effects of phosphorus and nitrogen in receiving waters

  15. Mapping watershed potential to contribute phosphorus from geologic materials to receiving streams, southeastern United States

    Science.gov (United States)

    Terziotti, Silvia; Hoos, Anne B.; Harned, Douglas; Garcia, Ana Maria

    2010-01-01

    As part of the southeastern United States SPARROW (SPAtially Referenced Regressions On Watershed attributes) water-quality model implementation, the U.S. Geological Survey created a dataset to characterize the contribution of phosphorus to streams from weathering and erosion of surficial geologic materials. SPARROW provides estimates of total nitrogen and phosphorus loads in surface waters from point and nonpoint sources. The characterization of the contribution of phosphorus from geologic materials is important to help separate the effects of natural or background sources of phosphorus from anthropogenic sources of phosphorus, such as municipal wastewater or agricultural practices. The potential of a watershed to contribute phosphorus from naturally occurring geologic materials to streams was characterized by using geochemical data from bed-sediment samples collected from first-order streams in relatively undisturbed watersheds as part of the multiyear U.S. Geological Survey National Geochemical Survey. The spatial pattern of bed-sediment phosphorus concentration is offered as a tool to represent the best available information at the regional scale. One issue may weaken the use of bed-sediment phosphorus concentration as a surrogate for the potential for geologic materials in the watershed to contribute to instream levels of phosphorus-an unknown part of the variability in bed-sediment phosphorus concentration may be due to the rates of net deposition and processing of phosphorus in the streambed rather than to variability in the potential of the watershed's geologic materials to contribute phosphorus to the stream. Two additional datasets were created to represent the potential of a watershed to contribute phosphorus from geologic materials disturbed by mining activities from active mines and inactive mines.

  16. The spatial variability of nitrogen and phosphorus concentration in a sand aquifer influenced by onsite sewage treatment and disposal systems: a case study on St. George Island, Florida.

    Science.gov (United States)

    Corbet, D Reide; Dillon, Kevin; Burnett, William; Schaefer, Geoff

    2002-01-01

    Groundwater from a shallow freshwater lens on St. George Island, a barrier island located in the Panhandle of Florida, eventually discharges into Apalachicola Bay or the Gulf of Mexico. Nutrient concentrations in groundwaters were monitored downfield from three onsite sewage treatment and disposal systems (OSTDS) on the island. Estimates of natural groundwater nutrient concentrations were obtained from an adjacent uninhabited island. Silicate, which was significantly higher in the imported drinking water relative to the surficial aquifer on St. George Island (12.2+/-1.9 mg Si l(-1) and 2.9+/-0.2 mg Si l(-1), respectively), was used as a natural conservative tracer. Our observations showed that nitrogen concentrations were attenuated to a greater extent than that of phosphorus relative to the conservative tracer. At the current setback distance (23 m), both nitrogen and phosphate concentrations are still elevated above natural levels by as much as 2 and 7 times, respectively. Increasing the setback distance to 50 m and raising the drainfields 1 m above the ground surface could reduce nutrient levels to natural concentrations (1.1+/-0.1 mg N l(-1), 0.20+/-0.02 mg P l(-1)).

  17. Effect of anaerobic digestion and liming on plant availability of phosphorus in iron- and aluminium-precipitated sewage sludge from primary wastewater treatment plants.

    Science.gov (United States)

    Alvarenga, Emilio; Øgaard, Anne Falk; Vråle, Lasse

    2017-04-01

    More efficient plant utilisation of the phosphorus (P) in sewage sludge is required because rock phosphate is a limited resource. To meet environmental legislation thresholds for P removal from wastewater (WW), primary treatment with iron (Fe) or aluminium (Al) coagulants is effective. There is also a growing trend for WW treatment plants (WWTPs) to be coupled to a biogas process, in order to co-generate energy. The sludge produced, when stabilised, is used as a soil amendment in many countries. This study examined the effects of anaerobic digestion (AD), with or without liming as a post-treatment, on P release from Fe- and Al-precipitated sludges originating from primary WWTPs. Plant uptake of P from Fe- and Al-precipitated sludge after lime treatment but without AD was also compared. Chemical characterisation with sequential extraction of P and a greenhouse experiment with barley (Hordeum vulgare) were performed to assess the treatment effects on plant-available P. Liming increased the P-labile fraction in all cases. Plant P uptake increased from 18.5 mg pot -1 to 53 mg P pot -1 with liming of Fe-precipitated sludge and to 35 mg P pot -1 with liming of the digestate, while it increased from 18.7 mg pot -1 to 39 and 29 mg P pot -1 for the Al-precipitated substrate and digestate, respectively. Thus, liming of untreated Fe-precipitated sludge and its digestate resulted in higher P uptake than liming its Al-precipitated counterparts. AD had a negative impact on P mobility for both sludges.

  18. Iodine concentration of milk-alternative drinks available in the UK in comparison with cows' milk.

    Science.gov (United States)

    Bath, Sarah C; Hill, Sarah; Infante, Heidi Goenaga; Elghul, Sarah; Nezianya, Carolina J; Rayman, Margaret P

    2017-10-01

    Iodine deficiency is present in certain groups of the UK population, notably in pregnant women; this is of concern as iodine is required for fetal brain development. UK milk is rich in iodine and is the principal dietary iodine source. UK sales of milk-alternative drinks are increasing but data are lacking on their iodine content. As consumers may replace iodine-rich milk with milk-alternative drinks, we aimed to measure the iodine concentration of those available in the UK. Using inductively coupled plasma-MS, we determined the iodine concentration of seven types of milk-alternative drink (soya, almond, coconut, oat, rice, hazelnut and hemp) by analysing forty-seven products purchased in November/December 2015. For comparison, winter samples of conventional (n 5) and organic (n 5) cows' milk were included. The median iodine concentration of all of the unfortified milk-alternative drinks (n 44) was low, at 7·3 μg/kg, just 1·7 % of our value for winter conventional cows' milk (median 438 μg/kg). One brand (not the market leader), fortified its soya, oat and rice drinks with iodine and those drinks had a higher iodine concentration than unfortified drinks, at 280, 287 and 266 μg/kg, respectively. The iodine concentration of organic milk (median 324 μg/kg) was lower than that of conventional milk. Although many milk-alternative drinks are fortified with Ca, at the time of this study, just three of forty-seven drinks were fortified with iodine. Individuals who consume milk-alternative drinks that are not fortified with iodine in place of cows' milk may be at risk of iodine deficiency unless they consume alternative dietary iodine sources.

  19. Determination of 210Po concentration in commercially available infant formulae and assessment of daily ingestion dose

    Directory of Open Access Journals (Sweden)

    Ravi K. Prabhath

    2015-07-01

    Full Text Available A study has been conducted to estimate the concentration of natural radioactive polonium in commercially available packaged infant food formulae available in Mumbai, India and the corresponding daily dose normalized based on its shelf life. Eleven most popular international brands of infant formulae were sourced from market and three aliquots from each sample were analysed for concordant results. Autodeposition method onto a silver planchet from hot dilute acid solution followed by alpha spectrometry was performed for estimation of polonium. Radiochemical recovery was ascertained by the addition of 209Po tracer. Radiochemical recovery of 209Po tracer was ranged from 14.7 to 98.1 %. The 210Po concentration in the samples was in the range of 0.08–0.23 Bq kg−1 on measured date and the corresponding daily dose, calculated on normalized date which is at mid-point of the shelf life of the sample, was ranged from 0.04 to 0.89 μSv d−1 as per the recommended daily consumption. The annual committed effective dose estimated based on the average of daily dose was found to be 150 μSv.

  20. Reduction of phosphorus concentration in mineral supplement on fertility rate, maternal ability and costs of beef cows reared in pastures of Urochloa decumbens.

    Science.gov (United States)

    Costa, Rogério Magnoli; Ponsano, Elisa Helena Giglio; de Souza, Vinícius Carneiro; Malafaia, Pedro

    2016-02-01

    Manufacturing and marketing of mineral mixtures with less than 40 g kg(-1) phosphorus (P) is prohibited under Brazilian regulations, although scientific evidence rejects this recommendation. Considering the hypothesis that P levels in commercial mineral supplements can be reduced without affecting animal performance and health, the objective of this experiment was to evaluate the effects of reducing the concentration of P in the mineral supplement (from 40 to 18 g kg(-1)) of a herd of beef cows grazing tropical pastures of signal grass (Urochloa decumbens). The experiment was carried out in the savanna region of Mato Grosso do Sul, Brazil, during the years 2011 to 2013. Variables analyzed included pregnancy rate, calving interval, weight of calves at weaning, and cost of mineral supplementation. There were no changes in the reproductive parameters of the herd and the weight at weaning of the calves. However, the cost of mineral supplementation was significantly lower when the herd was supplemented with the mineral mix containing only 18 g kg(-1) P. Phosphorus concentration of the forage was analyzed monthly during 1 year and averaged 1.9 ± 0.45 g kg(-1) DM. Thus, it appears possible to reduce P content and cost of mineral supplementation without any adverse effects on the health and productivity of beef cattle herds in the State of Mato Grosso do Sul. However, the final decision should be made based on the clinical-nutritional examination and by constant technical assistance to the farm.

  1. Phosphorus containing sintered alloys (review)

    International Nuclear Information System (INIS)

    Muchnik, S.V.

    1984-01-01

    Phosphorus additives are considered for their effect on the properties of sintered alloys of different applications: structural, antifriction, friction, magnetic, hard, superhard, heavy etc. Data are presented on compositions and properties of phosphorus-containing materials produced by the powder metallurgy method. Phosphorus is shown to be an effective activator of sintering in some cases. When its concentration in the material is optimal it imparts the material such properties as strength, viscosity, hardness, wear resistance. Problems concerning powder metallurgy of amorphous phosphorus-containing alloys are reported

  2. Changes in Soil Available Phosphorus, Leaf Phosphorus Content and Yield of Sword Bean (Canavalia Ensiformis (L.) DC.) by Application of SP-36 and Phosphate Rock on Acid Upland Soil of East Lampung

    OpenAIRE

    Achmad Arivin Rivaie

    2015-01-01

    A glasshouse trial was performed to determine changes in phosphorus (P) nutrition and the yield of sword bean (Canavalia ensiformis (L.) DC.) following the application of different rates and types of P fertilizer in an acid upland soil of East Lampung. Two different types of P fertilizer, namely SP-36 (total P = 36%) and Phosphate Rock (PR) (total P = 24.3%, particle size distribution = 75% <0.25 mm, 85% < 0.50 mm, 90% < 1.00 mm) were used in the trial. For the treatment, each P fert...

  3. Lignification in beech grown at elevated CO2 concentrations: interaction with nutrient availability and leaf maturation

    International Nuclear Information System (INIS)

    Blaschke, L; Forstreuter, M.; Sheppard, L. J.; Leith, K.; Murray, M. B.; Polle, A.

    2002-01-01

    Results of a study undertaken to investigate contradictory observations reported in the literature to the effect that growth in elevated carbon dioxide affects ontogeny, are discussed. Results of this study showed that seedlings grown at elevated carbon dioxide had nitrogen concentrations of about 15 per cent lower than seedlings grown in ambient carbon dioxide. Elevated carbon dioxide caused increased growth and biomass production in trees with a medium to high nutrient supply, but had no effect on growth of trees with a low nutrient supply rate. Because elevated carbon dioxide enhanced seedling growth in the high nutrient supply treatments, the total amount of lignin produced per seedling was higher in these treatments. Overall, the results suggest that carbon dioxide availability does not directly affect lignin concentrations, but affects them indirectly through the effects on or an interaction with nitrogen supply and growth. In seedlings, elevated carbon dioxide reduced lignin concentration on a dry mass basis, indicating diminished wood quality in a carbon dioxide-enriched atmosphere. 51 refs., 2 tabs., 5 figs

  4. Manejo da água disponível no solo e adubação fosfatada: efeito sobre a cultura do milho Management of available soil water and phosphorus fertilization: effect on corn crop

    Directory of Open Access Journals (Sweden)

    Wagner W. de A. Alves

    2002-01-01

    Full Text Available Para o presente estudo conduziu-se um ensaio em casa-de-vegetação, no Departamento de Solo e Engenharia Rural do Centro de Ciências Agrárias da Universidade Federal da Paraíba, Areia, PB, com o propósito de se avaliar quatro doses de fósforo (0, 40, 80 e 120 kg ha-1 de P2O5 e quatro níveis de água no solo (20, 40, 60 e 80% da água disponível sobre algumas características da cultura do milho (Zea mays L.. Usou-se o delineamento blocos ao acaso em esquema fatorial 4 x 4, com três repetições. A unidade experimental foi representada por um vaso plástico com 9 kg de solo coletado na profundidade de 0 a 20 cm do perfil de um Latossolo Amarelo e, segundo a análise de variância, ocorreu efeito altamente significativo (p This study was conducted under greenhouse conditions at 'Centro de Ciências Agrárias' of 'Universidade Federal da Paraíba', located in Areia, PB, Brazil. The main objective was to evaluate the effect of four doses of phosphorus (0, 40, 80 and 120 kg ha-1 of P2O5, and of four levels of available soil water (20, 40, 60 and 80% on some characteristics of corn (Zea mays L. crop. The experiment was carried out in a randomized block using a 4 x 4 factorial scheme, with three replications. The experimental unit was represented by a plastic recipient with 9 kg of soil of the superficial layer (0 - 20 cm of Oxisol. The analysis of variance showed significant effect (p < 0.01 for the phosphorus treatments as well as for the levels of the available soil water on total dry biomass of the aerial parts, evapotranspiration and the phosphorus content of the dry biomass. The necessity of a minimal value of 40% of available soil water for the corn crop was observed to obtain the response of phosphorus doses applied to soil. A significant effect (p < 0.01 of the interaction between phosphorus and available water on phosphorus content in the biomass of aerial part of the crop was also notable.

  5. Exigência de fósforo disponível para tilápia-do-nilo (35 a 100 g Available phosphorus requirement of Nile tilapia (35 to 100 g

    Directory of Open Access Journals (Sweden)

    Wilson Massamitu Furuya

    2008-06-01

    Full Text Available Objetivou-se determinar a exigência de fósforo disponível para tilápias-do-nilo. Utilizaram-se 144 peixes com peso vivo inicial de 35,33 ± 0,66 g, distribuídos em delineamento de blocos ao acaso, com quatro tratamentos e três repetições. Foram fornecidas dietas com 29,0% PB, 2.980 kcal/kg de energia digestível (ED e quatro níveis de fósforo disponível (0,25; 0,35; 0,45 ou 0,55%, obtidos pela utilização de fosfato bicálcico como fonte de fósforo. As dietas foram fornecidas aos peixes três vezes por dia, até aparente saciedade, durante 46 dias. Não foi observado efeito dos níveis de fósforo disponível na dieta sobre o índice hepatossomático, a taxa de sobrevivência e os teores de água e proteína bruta na carcaça. O aumento dos níveis de fósforo disponível na dieta promoveu aumento linear do ganho de peso médio, da excreção de fósforo e dos teores de cinza na carcaça e de cinzas, cálcio e fósforo nos ossos. Houve efeito quadrático dos níveis de fósforo disponível sobre o consumo de ração, a conversão alimentar e a taxa de eficiência protéica, que foram melhores nos níveis 0,37; 0,48 e 0,48% de fósforo disponível, respectivamente. A exigência de fósforo disponível para tilápia-do-nilo de 35 a 100 g é de 0,48% (0,53% na matéria seca.The objective of this work was to determine the available phosphorus requirement of Nile tilapia. A total of 144 fishes with initial weight 35.33 ± 0,66g LW were distributed to a completely randomized blocks design, with four treatments and three replicates. Diets with 29.0% CP and 2980 kcal/kg DE and four available phosphorus levels (0.25; 0.35; 0.45 e 0.55% were used. The dicalcium phosphate was used as phosphorus source. The diets were fed to the fishes three times a day to apparent satiation, during 46 days. No significant effect of dietary available phosphorus on hepatosomatic index, survival rate and carcass water and protein contents were observed. The

  6. Influence of integrated phosphorus supply and plant growth ...

    African Journals Online (AJOL)

    To guarantee a sufficient phosphorus supply for plants, a rapid and permanent mobilization of phosphorus from the labile phosphorus fractions is necessary, because phosphorus concentrations in soil solution are generally low. Several plant growth-promoting rhizobacteria (PGPR) have shown potential to enhance ...

  7. Effect of dietary calcium concentrations in low non-phytate phosphorus diets containing phytase on growth performance, bone mineralization, litter quality, and footpad dermatitis incidence in growing broiler chickens

    Directory of Open Access Journals (Sweden)

    Jong Hyuk Kim

    2017-07-01

    Full Text Available Objective An experiment was conducted to investigate the effect of dietary Ca concentrations in low non-phytate phosphorus (NPP diets containing phytase on growth performance, bone mineralization, litter quality, and footpad dermatitis (FPD incidence in growing broiler chickens. Methods A total of 1,800 21-day-old Ross 308 growing broiler chickens were allotted to 1 of 6 dietary treatments with 6 replicated cages. Six diets were formulated to provide increasing Ca concentrations of 4.0, 5.0, 6.0, 7.0, 8.0, or 9.0 g/kg in diets. The concentrations of NPP in all diets were maintained at 3.0 g/kg, and phytase was supplemented to all diets at the level of 1,000 fytase units (FTU/kg. At the end of the 14-d feeding trial, birds were euthanized for tibia sampling, and litter samples were collected from 3 areas in the cage. The FPD incidence was measured based on a 6-point scoring system. Results Dietary Ca concentrations had no effect on growth performance of growing broiler chickens. However, a tendency (linear, p = 0.05 for decreased feed efficiency was observed as dietary Ca concentrations were increased. The concentrations of Ca and P in the tibia of broiler chickens increased (linear and quadratic, p<0.01 with increasing Ca concentrations in low NPP diets containing phytase. Litter pH, moisture, and N contents were not affected by increasing Ca concentrations in low NPP diets containing phytase. However, a tendency (quadratic, p = 0.10 for increased FPD incidence with increasing dietary Ca concentrations was observed. Conclusion Dietary Ca concentrations from 4.0 to 9.0 g/kg in low NPP diets containing phytase have little effects on growth performance of growing broiler chickens. However, Ca and P concentrations in the tibia are decreased if dietary Ca concentrations are less than 5.0 g/kg. The FPD incidence for growing broiler chickens may be decreased if less than 9.0 g/kg of Ca is included in diets.

  8. Responses in sediment phosphorus and lanthanum concentrations and composition across 10 lakes following applications of lanthanum modified bentonite

    DEFF Research Database (Denmark)

    Dithmer, Line; Nielsen, Ulla Gro; Lürling, Miquel

    2016-01-01

    and binding forms, P adsorption capacity of discrete sediment layers, and pore water P concentrations. Lanthanum phosphate mineral phases were confirmed by solid state (31)P MAS NMR and LIII EXAFS spectroscopy. Rhabdophane (LaPO4 · nH2O) was the major phase although indications of monazite (LaPO4) formation...... conditions of P retention (with the exception of two lakes) by sediments, indicating effective control of sediment P release, i.e. between two and nine years after treatment....

  9. A representation of the phosphorus cycle for ORCHIDEE (revision 4520)

    Science.gov (United States)

    Goll, Daniel S.; Vuichard, Nicolas; Maignan, Fabienne; Jornet-Puig, Albert; Sardans, Jordi; Violette, Aurelie; Peng, Shushi; Sun, Yan; Kvakic, Marko; Guimberteau, Matthieu; Guenet, Bertrand; Zaehle, Soenke; Penuelas, Josep; Janssens, Ivan; Ciais, Philippe

    2017-10-01

    Land surface models rarely incorporate the terrestrial phosphorus cycle and its interactions with the carbon cycle, despite the extensive scientific debate about the importance of nitrogen and phosphorus supply for future land carbon uptake. We describe a representation of the terrestrial phosphorus cycle for the ORCHIDEE land surface model, and evaluate it with data from nutrient manipulation experiments along a soil formation chronosequence in Hawaii. ORCHIDEE accounts for the influence of the nutritional state of vegetation on tissue nutrient concentrations, photosynthesis, plant growth, biomass allocation, biochemical (phosphatase-mediated) mineralization, and biological nitrogen fixation. Changes in the nutrient content (quality) of litter affect the carbon use efficiency of decomposition and in return the nutrient availability to vegetation. The model explicitly accounts for root zone depletion of phosphorus as a function of root phosphorus uptake and phosphorus transport from the soil to the root surface. The model captures the observed differences in the foliage stoichiometry of vegetation between an early (300-year) and a late (4.1 Myr) stage of soil development. The contrasting sensitivities of net primary productivity to the addition of either nitrogen, phosphorus, or both among sites are in general reproduced by the model. As observed, the model simulates a preferential stimulation of leaf level productivity when nitrogen stress is alleviated, while leaf level productivity and leaf area index are stimulated equally when phosphorus stress is alleviated. The nutrient use efficiencies in the model are lower than observed primarily due to biases in the nutrient content and turnover of woody biomass. We conclude that ORCHIDEE is able to reproduce the shift from nitrogen to phosphorus limited net primary productivity along the soil development chronosequence, as well as the contrasting responses of net primary productivity to nutrient addition.

  10. Sustainable Phosphorus Measures: Strategies and Technologies for Achieving Phosphorus Security

    Directory of Open Access Journals (Sweden)

    Stuart White

    2013-01-01

    Full Text Available Phosphorus underpins the world’s food systems by ensuring soil fertility, maximising crop yields, supporting farmer livelihoods and ultimately food security. Yet increasing concerns around long-term availability and accessibility of the world’s main source of phosphorus—phosphate rock, means there is a need to investigate sustainable measures to buffer the world’s food systems against the long and short-term impacts of global phosphorus scarcity. While the timeline of phosphorus scarcity is contested, there is consensus that more efficient use and recycling of phosphorus is required. While the agricultural sector will be crucial in achieving this, sustainable phosphorus measures in sectors upstream and downstream of agriculture from mine to fork will also need to be addressed. This paper presents a comprehensive classification of all potential phosphorus supply- and demand-side measures to meet long-term phosphorus needs for food production. Examples range from increasing efficiency in the agricultural and mining sector, to technologies for recovering phosphorus from urine and food waste. Such measures are often undertaken in isolation from one another rather than linked in an integrated strategy. This integrated approach will enable scientists and policy-makers to take a systematic approach when identifying potential sustainable phosphorus measures. If a systematic approach is not taken, there is a risk of inappropriate investment in research and implementation of technologies and that will not ultimately ensure sufficient access to phosphorus to produce food in the future. The paper concludes by introducing a framework to assess and compare sustainable phosphorus measures and to determine the least cost options in a given context.

  11. A new method to measure effective soil solution concentration predicts copper availability to plants.

    Science.gov (United States)

    Zhang, H; Zhao, F J; Sun, B; Davison, W; McGrath, S P

    2001-06-15

    Risk assessments of metal contaminated soils need to address metal bioavailability. To predict the bioavailability of metals to plants, it is necessary to understand both solution and solid phase supply processes in soils. In striving to find surrogate chemical measurements, scientists have focused either on soil solution chemistry, including free ion activities, or operationally defined fractions of metals. Here we introduce the new concept of effective concentration, CE, which includes both the soil solution concentration and an additional term, expressed as a concentration, that represents metal supplied from the solid phase. CE was measured using the technique of diffusive gradients in thin films (DGT) which, like a plant, locally lowers soil solution concentrations, inducing metal supply from the solid phase, as shown by a dynamic model of the DGT-soil system. Measurements of Cu as CE, soil solution concentration, by EDTA extraction and as free Cu2+ activity in soil solution were made on 29 different soils covering a large range of copper concentrations. Theywere compared to Cu concentrations in the plant material of Lepidium heterophyllum grown on the same soils. Plant concentrations were linearly related and highly correlated with CE but were more scattered and nonlinear with respect to free Cu2+ activity, EDTA extraction, or soil solution concentrations. These results demonstrate that the dominant supply processes in these soils are diffusion and labile metal release, which the DGT-soil system mimics. The quantity CE is shown to have promise as a quantitative measure of the bioavailable metal in soils.

  12. Evaluating the use of in-situ turbidity measurements to quantify fluvial sediment and phosphorus concentrations and fluxes in agricultural streams.

    Science.gov (United States)

    Stutter, Marc; Dawson, Julian J C; Glendell, Miriam; Napier, Fiona; Potts, Jacqueline M; Sample, James; Vinten, Andrew; Watson, Helen

    2017-12-31

    Accurate quantification of suspended sediments (SS) and particulate phosphorus (PP) concentrations and loads is complex due to episodic delivery associated with storms and management activities often missed by infrequent sampling. Surrogate measurements such as turbidity can improve understanding of pollutant behaviour, providing calibrations can be made cost-effectively and with quantified uncertainties. Here, we compared fortnightly and storm intensive water quality sampling with semi-continuous turbidity monitoring calibrated against spot samples as three potential methods for determining SS and PP concentrations and loads in an agricultural catchment over two-years. In the second year of sampling we evaluated the transferability of turbidity calibration relationships to an adjacent catchment with similar soils and land cover. When data from nine storm events were pooled, both SS and PP concentrations (all in log space) were better related to turbidity than they were to discharge. Developing separate calibration relationship for the rising and falling limbs of the hydrograph provided further improvement. However, the ability to transfer calibrations between adjacent catchments was not evident as the relationships of both SS and PP with turbidity differed both in gradient and intercept on the rising limb of the hydrograph between the two catchments. We conclude that the reduced uncertainty in load estimation derived from the use of turbidity as a proxy for specific water quality parameters in long-term regulatory monitoring programmes, must be considered alongside the increased capital and maintenance costs of turbidity equipment, potentially noisy turbidity data and the need for site-specific prolonged storm calibration periods. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Effect of nanosilicon dioxide on growth performance, egg quality, liver histopathology and concentration of calcium, phosphorus and silicon in egg, liver and bone in laying quails

    Science.gov (United States)

    Faryadi, Samira; Sheikhahmadi, Ardashir

    2017-11-01

    This experiment was conducted to evaluate the effects of different levels of nanosilicon dioxide (nSiO2) on performance, egg quality, liver histopathology and concentration of calcium (Ca), phosphorus and silicon (Si) in egg, liver and bone in laying quails. The experiment was administered using 60 laying quails at 16-26 weeks of age with five treatments [0 (control), 500, 1000, 2000 and 4000 mg nSiO2 per kg of diet] and four replicates in a completely randomized design. During the experiment, the amount of feed intake was recorded weekly and performance parameters were measured. During the last 3 days of the experiment, all of the eggs in each replicate were collected and egg quality parameters were measured. At the end of 26 weeks of age, the birds were sacrificed and blood samples were collected. Liver samples from each treatment were fixed in 10% buffered formalin for histopathological assessment. The right thigh bone and a portion of liver were inserted in plastic bags and stored at - 20. The results showed that nSiO2 supplementation significantly affected egg weight and egg mass ( P 0.05) by dietary treatments. In conclusion, the results indicated that dietary supplementation of nSiO2 could improve bone density and performance without any adverse effect on the health of laying quails.

  14. The Internal Recycle Reactor Enhances Porous Calcium Silicate Hydrates to Recover Phosphorus from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Wei Guan

    2017-01-01

    Full Text Available In this experiment, the porous calcium silicate hydrates (P-CSHs were prepared via a hydrothermal method and then modified by polyethylene glycol (PEG. The modified P-CSHs combined with an internal recycle reactor could successfully recover the phosphorus from electroplating wastewater. The modified P-CSHs were characterized by X-ray diffraction (XRD, N2 adsorption-desorption isotherms, and Fourier transform infrared spectroscopy (FT-IR. After compared with different samples, the modified P-CSHs-PEG2000 sample had larger specific surface area of 87.48 m2/g and higher pore volume of 0.33 cm3/g, indicating a high capacity for phosphorus recovery. In the process of phosphorus recovery, the pH value of solution was increased to 9.5, which would enhance the recovery efficiency of phosphorus. The dissolution rate of Ca2+ from P-CSH-PEG2000 was fast, which was favorable for phosphorus precipitation and phosphorus recovery. The effects of initial concentration of phosphorus, P-CSHs-PEG2000 dosage, and stirring speed on phosphorus recovery were analyzed, so the optimal operation conditions for phosphorus recovery were obtained. The deposition was analyzed by XRD, N2 adsorption-desorption, and SEM techniques; it was indicated that the pore volume and surface area of the P-CSHs-PEG2000 were significantly reduced, and the deposition on the surface of P-CSHs-PEG2000 was hydroxyapatite.

  15. Concentration, flux, and the analysis of trends of total and dissolved phosphorus, total nitrogen, and chloride in 18 tributaries to Lake Champlain, Vermont and New York, 1990–2011

    Science.gov (United States)

    Medalie, Laura

    2013-01-01

    Annual concentration, flux, and yield for total phosphorus, dissolved phosphorus, total nitrogen, and chloride for 18 tributaries to Lake Champlain were estimated for 1990 through 2011 using a weighted regression method based on time, tributary streamflows (discharges), and seasonal factors. The weighted regression method generated two series of daily estimates of flux and concentration during the period of record: one based on observed discharges and a second based on a flow-normalization procedure that removes random variation due to year-to-year climate-driven effects. The flownormalized estimate for a given date is similar to an average estimate of concentration or flux that would be made if all of the observed discharges for that date were equally likely to have occurred. The flux bias statistic showed that 68 of the 72 flux regression models were minimally biased. Temporal trends in the concentrations and fluxes were determined by calculating percent changes in flow-normalized annual fluxes for the full period of analysis (1990 through 2010) and for the decades 1990–2000 and 2000–2010. Basinwide, flow-normalized total phosphorus flux decreased by 42 metric tons per year (t/yr) between 1990 and 2010. This net result reflects a basinwide decrease in flux of 21 metric tons (t) between 1990 and 2000, followed by a decrease of 20 t between 2000 and 2010; both results were largely influenced by flux patterns in the large tributaries on the eastern side of the basin. A comparison of results for total phosphorus for the two separate decades of analysis found that more tributaries had decreasing concentrations and flux rates in the second decade than the first. An overall reduction in dissolved phosphorus flux of 0.7 t/yr was seen in the Lake Champlain Basin during the full period of analysis. That very small net change in flux reflects substantial reductions between 1990 and 2000 from eastern tributaries, especially in Otter Creek and the LaPlatte and Winooski

  16. Study of the interaction metallic cation - ligand in concentrated phosphorus acid media; Etude de l'interaction cation metallique - ligand en milieu acide phosphorique concentre

    Energy Technology Data Exchange (ETDEWEB)

    Sefiani, N.; Azzi, M.; Hlaibi, M. [Faculte des Sciences Ain Chock, Laboratoire d' Electrochimie et Chimie de l' Environnement (LECE), Casablanca (Morocco); Kossair, A. [Centre de Recherche des Phosphates Mineraux (CERPHOS), Casablanca (Morocco)

    2005-07-01

    The phosphoric acid is more and more used with a high purity. The recovery of recycling element (uranium, vanadium, rare earth...) and the elimination of toxic element (cadmium, molybdenum, lead...) contained in the phosphoric acid are generally realized by extraction or precipitation. It is then very important to understand these impurities behavior in the phosphoric media in order to control their elimination. In this work, the authors considered the presence of some metallic cations (V, Al, fe, U) and fluorides ions as impurity in concentrated phosphoric acid media. (A.L.B.)

  17. Evaluación del fósforo disponible mediante tres métodos en distintos suelos y manejos productivos Evaluation of phosphorus available by three methods in different soils and productive managements

    Directory of Open Access Journals (Sweden)

    Carolina Fernández López

    2008-07-01

    productivos, y sugieren la existencia de una interacción tripartita que arroja diferentes resultados en el valor final del P disponible. Se concluye que, no necesariamente el método más sencillo en la evaluación de P disponible para el vegetal es el que mejor refleja la relación con la materia seca o con la concentración del P en el tejido.Phosphorus is a nutrient with low soil solubility and mobility and may present limited availability for plant growth. One way to increase phosphorus availability in soil is by fertilization. Due to the variability in the evaluation of phosphorus availability in soil, the study was carried out with the following objectives: a to compare two of the most common soil available P methods (Bray I and Olsen, and the iron oxide impregnated filter paper method (Strip; b to evaluate which of the methods is better related to some plant variables under different managements and soil conditions. The soils selected from Corrientes Province were: 1 Entisol: natural soil as a control and cultivated with Citrus, 2 Alfisol: control and cultivated with rice, 3 Vertisol: control and cultivated with pastures. Physical and chemical soil properties indicated that soils from the same order differed in the textural composition, despite having similar chemical properties, suggesting that the differences among soils can be ascribed to cultivation. In addition, a greenhouse pot trial was conducted.Six soils were fertilized with eleven levels of P (0-200 mg P kg-1 and then incubated during 25 days at 28 °C. After incubation, soil samples were analyzed for P by the Olsen, Bray I and Strip methods. Rye grass was grown in pots during 45 days and the shoot dry matter was harvested and its P content analyzed. The results obtained in this work suggest that the three studied methods of P availability in soils described adequately and significantly the relationship between extracted P and dry matter yield (R² between 0.35 for the Vertisol and 0.95, for the Entisol, % P

  18. Fatores que afetam a disponibilidade do fósforo e o manejo da adubação fosfatada em solos sob sistema plantio direto Factors affecting the phosphorus availability and the fertilization management in no-tillage system

    Directory of Open Access Journals (Sweden)

    Danilo Rheinheimer dos Santos

    2008-04-01

    fosfatados no solo sob sistema plantio direto; (c as relações entre a disponibilidade de fósforo nas camadas subsuperficiais (abaixo de 10cm, a presença de alumínio trocável e de camadas compactadas e (d o monitoramento constante das transferências de fósforo dos solos aos sistemas aquáticos.The basic phenomena of phosphorus dynamics in soil is important to define the rate and application manners of phosphates fertilizers. The forms and availability of phosphorus vary with the soil characteristics and properties. In young soils, the calcium phosphates are the main source to organisms. On the other hand, in highly weathered soils the organic phosphorus cycling assumes great importance in the maintenance of the biological bioavailability, although it is insufficient to economical crop productivity. In tropical and subtropical cultivated soils, the soil phosphorus in solution is controlled by phosphorus adsorbed at functional groups of inorganic colloids. The phosphorus diagnosis is made by soils analysis at different methodologies, each one with their advantages and limitations. The decision on adding phosphate and to the rate define is more dependent on the calibration between the value extracted with the crop yield than the extraction method. The elevation of phosphorus availability can be made in corrective or gradual addition. The corrective fertilization is more efficient, and maybe the only alternative, for phosphorus deficiency correction in deeper soil layers. The correction of phosphorus deficiency in deeper layers after the no-tillage system adoption is difficult. The superficial phosphate application in no-tillage seems not to be a good economical alternative and can become an environmental problem. The research must be intensified focusing among others: (a phosphorus fractions in soil and crop yield; (b phosphates fertilizers application in no-tillage system; (c relation of phosphorus availability with exchangeable aluminum and compacted soil layers in

  19. Effects of epiphytic algae on biomass and physiology of Myriophyllum spicatum L. with the increase of nitrogen and phosphorus availability in the water body.

    Science.gov (United States)

    Song, Yu-Zhi; Wang, Jin-Qi; Gao, Yong-Xia

    2017-04-01

    The disappearance of submerged vascular macrophytes in shallow eutrophic lakes is a common phenomenon in the world. To explore the mechanism of the decline in submerged macrophyte abundance due to the growth of epiphytic algae along a nutrient gradient in eutrophic water, a 2 × 3 factorial experiment was performed over 4 weeks with the submerged macrophyte (Myriophyllum spicatum L.) by determining the plant's biomass and some physiological indexes, such as chlorophyll (Chl) content, malondialdehyde (MDA) content, and superoxide dismutase (SOD) activity in the leaves of M. spicatum L. on days 7, 14, 21, and 28, which are based on three groups of nitrogen and phosphorus levels in the water body (N-P [mg L -1 ]: NP1 0.5-0.05, NP2 2.5-0.25, NP3 4.5-0.45) and two levels of epiphytic algae (the epiphytic algae group and the control group). Epiphytic algal biomass was also assayed. The results indicated that epiphytic algal biomass remarkably enhanced in the course of the experiment with elevated levels of nitrogen and phosphorus in the water. Under the same level of nutrient condition, plants' biomass accumulation and Chl content were higher in the control group than that in the epiphytic algae group, respectively, while MDA content and SOD activity in the former were lower than that in the latter. The influences of epiphytic algae on the biomass accumulation and Chl content and MDA content became greater and greater with elevated levels of nutrients. In general, in this experiment, water nutrients promoted the growth of both epiphytic algae and submerged plants, while the growth of epiphytic algae hindered submerged macrophytes' growth by reducing Chl content and promoting peroxidation of membrane lipids in plants.

  20. Phosphorus in agricultural soils:

    NARCIS (Netherlands)

    Ringeval, Bruno; Augusto, Laurent; Monod, Hervé; Apeldoorn, van D.F.; Bouwman, A.F.; Yang, X.; Achat, D.L.; Chini, L.P.; Oost, van K.; Guenet, Bertrand; Wang, R.; Decharme, B.; Nesme, T.; Pellerin, S.

    2017-01-01

    Phosphorus (P) availability in soils limits crop yields in many regions of the World, while excess of soil P triggers aquatic eutrophication in other regions. Numerous processes drive the global spatial distribution of P in agricultural soils, but their relative roles remain unclear. Here, we

  1. Concentration and Diversity of Availability and Use in Information Systems: A Positive Reinforcement Model.

    Science.gov (United States)

    Rousseau, Ronald

    1992-01-01

    Proposes a mathematical model to explain the observed concentration or diversity of nominal classes in information retrieval systems. The Lorenz Curve is discussed, Information Production Process (IPP) is explained, and a heuristic explanation of circumstances in which the model might be used is offered. (30 references) (LRW)

  2. Changes in water availability in the Upper Blue Nile basin under the representative concentration pathways scenario

    NARCIS (Netherlands)

    Haile, Alemseged Tamiru; Akawka, Ashenafi Lekasa; Berhanu, Beza; Rientjes, T.H.M.

    2017-01-01

    Climatic and hydrological changes will likely be intensified in the Upper Blue Nile (UBN) basin by the effects of global warming. The extent of such effects for representative concentration pathways (RCP) climate scenarios is unknown. We evaluated projected changes in rainfall and evapotranspiration

  3. Limitation On The Concentration Of Radioactive Elastothane In Building Materiel's Available In Israel

    International Nuclear Information System (INIS)

    Kovler, K.; Haquin, G.; Ne'eman, E.; Lavi, N.

    1999-01-01

    Most building materials contain naturally occurring radioactive elements the most important of which are 40 K and the members of two natural radioactive series, which can be represented by the isotopes 232 Th and 226 Ra. The presence of these radioisotopes in the building materials causes external exposure to the people that live in the house. 226 Ra can also enhance the concentration of 222 Rn and of its daughters in the house. Concentrations of natural radionuclides ( 226 Ra, 232 Th, 40 K) in the samples of building products, building binders, in lightweight aggregates, normal-weight aggregates and in industrial by-products used in construction industry of Israel were determined by gamma-ray spectrometer with a Ge-detector. A methodology was introduced to regulate the use of building materials that cause increase in indoor radiation exposure

  4. Substoichiometric determination of phosphorus

    International Nuclear Information System (INIS)

    Shigematsu, T.; Kudo, K.

    1981-01-01

    Phosphorus in orchard leaves (NBS SRM-1571) and spinach (SRM-1570) was determined by various substoichiometric analytical methods such as the direct method, Gravshchenko's method and the method of carrier amount variation. All samples were labelled with 32 P radioisotope. The data obtained by the method of carrier amount variation were also treated by the method of least squares instead of De Voe's method. Phosphorus concentration in orchard leaves was 0.206+-0.011% by the direct method, 0.219+-0.011% by Gravshchenko's method, 0.211+-0.011% by the method of carrier amount variation and 0.207+-0.007% by the method of least squares, respectively. These values agree with the value reported by NBS (0.21+-0.01%). Furthermore, these concentrations obtained by various substoichiometric methods were compared with those by radioactivation reported in a previous paper. (author)

  5. Mexico City ozone concentrations as a function of readily-available meteorological parameters

    International Nuclear Information System (INIS)

    Brown, M.J.

    1994-01-01

    Daily maximum ozone concentrations measured at four sites within the Mexico City basin during the winter months are plotted as functions of different meteorological parameters that are routinely measured at surface stations. We found that ozone concentrations are most strongly correlated to the increase in daytime temperature and the maximum daytime wind speed. We also discovered that high ozone values at the sites in the southern end of the basin occur when winds come out of the northeast. In contrast, wind direction was found to be uncorrelated with high ozone values at the northern sites. From straightforward combinations of the meteorological variables, we derived some simple rules for estimating lower and upper bounds on the ozone concentration. Scatter in the data was too long to give significance to best-fit equations and statistics. Additionally, a small rawinsonde data set was used to investigate ozone's dependence on boundary-layer height and near-surface temperature gradient. Results were inconclusive, however, due to the small size of the data set

  6. 不同种类浮萍对磷的去除及其体内磷的累积变化研究%Study of Different Kinds of Duckweed in Different Low Concentration of Orthophosphate Culture Conditions on Phosphorus Removal and Float body Phosphorus Accumulation Change

    Institute of Scientific and Technical Information of China (English)

    叶平平; 金杰; 侍远

    2012-01-01

    Taking three common duckweed in the Chaohu Lake basin--Spirodela polyrrhiza, Lemna paucico- stata and wolffia arrhiza as the objects,this article studies the phosphorus removal function the three kinds of duckweed when the water is within the surface water concentration range (0.01 mgP/L,0. 05 mgP/L,0. 1 mgP/L,0.2 mgP/L,0.5 mgP/L),and also analyzes the accumulation change of phosphorus in three kinds of duckweed. Moreover, it discusses the treatment of phosphorus wastewater system on remove phosphorus way, and provides theoretical basis for duckweed in Chaohu Lake basin dephosphorization ecological restora- tion. The experimental results show that the plant body on phosphorus direct absorption is one of the main mechanisms for clean--up effect; three kinds of duckweed respectviely have high removal efficiency, and phosphorus removal rate is Spirodela polyrrhiza 〉 Lemna paucicostata 〉 wolffia arrhiza, and three float right utilization rate increase as the concentration reduce;the phosphorus removal rate of Spirodela polyrrhiza is 60% -48.9%,Lemna paucicostata is 90% - 47.2%,wolffia arrhiza is 90% - 34.2%. The phosphorus absorption of three duckweed basically account for more than 70% of the remove function. And there are differences among different varieties and different phosphorus concentration.%以巢湖流域常见的3种浮萍——紫背浮萍(以下称紫萍)、稀脉浮萍萍和芜萍为对象,研究了三种浮萍对地表水浓度范围内(0.01mgP/L,0.05mgP/L,0.1mgP/L,0.2mgP/L,0.5mgP/L)的磷的去除作用,以及磷在三种浮萍体内的积累变化和三种浮萍对磷的吸收作用占总去除作用。探讨了浮萍处理含磷污水系统的去除磷途径。实验表明:植物体对磷的直接吸收是其净化作用的主要机制之一。三种浮萍对磷都有较高的去除效率。并且磷去除率紫萍〉稀脉浮萍〉芜萍,并且随浓度的降低而增加。三种浮萍对磷的利用

  7. Effect of Different Fertilization Systems (Chemical, Biological and Integrated( on Nitrogen and Phosphorus Concentration, Biochemical Attributes and Sepals Dry Weight of Roselle (Hibiscus sabdariffa L.

    Directory of Open Access Journals (Sweden)

    roghayeh mohammadpour vashvaei

    2017-12-01

    Full Text Available Introduction Roselle (Hibiscus sabdariffa L. is a subtropical medicinal plant belongs to the Malvaceae family. Roselle sepals are valuable due to its therapeutic properties and culinary uses. During past decades rising cost of chemical inputs and overusing them in conventional farming have caused various environmental issues such as soil and water resources contamination, reduction in food quality production, decreasing soil fertility and biological imbalance in the soil that they impose irreparable damage to ecosystems. Sustainable agriculture which is based on the use of bio-fertilizers with the aim of eliminating or considerably reducing the use of chemical inputs is the optimal solution to overcome these problems. Abo-Baker and Gehan (2011 in their study on the effect of bio-fertilizers in combination with different rates of chemical fertilizers on growth characters, yield component and chemical constituents of roselle demonstrated that the inoculation with the mixture of bio-fertilizers combined with 50 or 100% chemical fertilizers improved, in most cases, growth characters and increased sepal yield or at least did not differ significantly from the control (full recommended dose of NPK alone. These researchers stated that applying 50% of the recommended dose of NPK plus the mixture of bio-fertilizer can save half of the quantity of chemical fertilizers, decrease the production cost and obtain high quality product. The present study was designed to investigate the effect of bio-fertilizers in combination with different doses of chemical fertilizers on the element concentrations, biochemical properties and yield of roselle to find the appropriate integration of them. Material and Methods This experiment was conducted based on a randomized complete block design with three replications, at the Research Station, University of Zabol, during growing season of 2011-2012 and 2012-2013. Experimental treatments were plant nutrition with NPK (220, 130

  8. COMPARISON OF DIFFERENT EXTRACTION METHODS REPRESENTING AVAILABLE AND TOTAL CONCENTRATIONS OF Cd, Cu, Fe, Mn and Zn IN SOIL

    Directory of Open Access Journals (Sweden)

    Vladimir Ivezić

    2013-06-01

    Full Text Available Various extraction methods are used to predict plant uptake of trace metals. Most commonly it is total concentration that is used for risk assessment and evaluation of trace metal availability. However, recent studies showed that total concentration is a poor indicator of availability while concentrations in soil solution show good correlation with plant uptake. Present study was conducted on magricultural soils with low levels of trace metals where 45 soil samples were collected from different soil types. The main objective was to compare four different extraction methods and examine how total and reactive (EDTA trace metal concentrations correlate ,with soil solution concentration (in this study determined by water extraction. The samples were analyzed by four extraction methods: strong acid extraction (ultra-pure HNO3 extraction and aqua regia, weak acid extraction by EDTA and the most available fraction, fraction in soil solution, were represented by water extraction (weakest extractant. Five elements were investigated (Cd, Cu, Fe, Mn and Zn. Water extraction significantly correlated with EDTA extraction for Cu, Fe and Mn, while total extraction (HNO3 extraction and aqua regia correlated significantly with water extraction only for Cu. No correlation between water extraction and total extraction confirmed poor role of total concentration as an indicator of availability. EDTA extraction can be used to represent reactive pool of trace metals in soil but it should be also taken with caution when using it to describe available fraction.

  9. Growth and nutrient efficiency of Betula alnoides clones in response to phosphorus supply

    Directory of Open Access Journals (Sweden)

    Lin Chen

    2016-12-01

    Full Text Available As phosphorus deficiency limits the productivity of many plantation forests in Asia, there is considerable interest in developing phosphorus-efficient clones for the region through targeted breeding programs. Therefore, we determined growth, nutrient concentrations and nutrient absorption and utility efficiencies of four Betula alnoides clones (C5, C6, 1-202 and BY1 in response to six phosphorus levels of 0, 17, 52, 70, 140 and 209 mg P plant-1 coded as P1 to P6, respectively. Maximum growth occurred in the P4, P5 and P6 plants since they had the largest height, biomass, leaf area and branch number. Phosphorus application increased the phosphorus concentrations of all clones. Nutrient loading was achieved with the P6 treatment because growth and biomass were not significantly higher, but root, stem and leaf phosphorus concentrations were approximately twice those of P4 plants. Clone BY1 had the highest phosphorus-efficiency, and is recommended for field application due to its maximum root collar diameter, biomass, root/shoot ratio, leaf area, nutrient absorption and utility efficiency among the four clones. The findings will help to improve the nutrient efficiency of this species in plantation forestry in Asia.

  10. Phosphorus fractions and its potential release in the sediments of Koycegiz Lake, Turkey

    Directory of Open Access Journals (Sweden)

    Yalçın Şahin

    2012-12-01

    Full Text Available This study was conducted to find out the seasonal and spatial patterns of the phosphorus in the littoral sediment and its potential release into the Koycegiz Lake, south west Turkey, between November 2011 and March 2012 at two months intervals. The scanning electron microscopy was used for elemental compositions of the sediment. The amounts and forms of phosphorus (P in surface sediments of Koycegiz Lake were examined using a not sequential chemical extraction procedure. Four fractions of sedimentary P, including organic bound phosphorus fraction (Org≈P, calcium bound phosphorus fraction (Ca≈P, iron+aluminium bound phosphorus fraction (Fe+Al≈P and carbonate bound phosphorus fraction (CO3≈P were separately quantified. The results indicated that the contents of different phosphorus fractions in the sediments varied greatly. The proportion of phosphorus fractions was estimated as Org≈P (90.20 %, this fraction was followed by Ca≈P (9.06 %, Fe+Al≈P (0.47 % and CO3≈P (0.27 % in this study. The level of phosphorus release from the sediment to the lake is calculated as low. The sediment phosphorus release fluctuated between -6.647–75.883 μg/m2.d-1 and the total phosphorus (TP concentrations of the sediment samples were changed between 980.39 μg/gDW (Dry Weight - 1990.81 μg/gDW. The results show that it can be evaluation as eutrophic for Koycegiz Lake.

  11. Associations of Socioeconomic Status and Processed Food Intake with Serum Phosphorus in Community-Living Adults: the Multi-Ethnic Study of Atherosclerosis (MESA)

    Science.gov (United States)

    Gutiérrez, Orlando M.; Katz, Ronit; Peralta, Carmen A.; de Boer, Ian H.; Siscovick, David; Wolf, Myles; Roux, Ana Diez; Kestenbaum, Bryan; Nettleton, Jennifer A.; Ix, Joachim H.

    2011-01-01

    Objective Higher serum phosphorus concentrations are associated with cardiovascular disease events and mortality. Low socioeconomic status is linked with higher serum phosphorus, but the reasons are unclear. Poor individuals disproportionately consume inexpensive processed foods commonly enriched with phosphorus-based food preservatives. Accordingly, we hypothesized that excess intake of these foods accounts for a relationship between lower socioeconomic status and higher serum phosphorus. Design Cross-sectional analysis. Setting and Participants We examined a random cohort of 2,664 participants with available phosphorus measurements in the Multi-Ethnic Study of Atherosclerosis, a community-based sample of individuals free of clinically apparent cardiovascular disease from across the United States. Predictor Variables Socioeconomic status, the intake of foods commonly enriched with phosphorus additives (processed meats, sodas) and frequency of fast food consumption. Outcomes Fasting morning serum phosphorus concentrations. Results In unadjusted analyses, lower income and lower educational achievement categories were associated with modestly higher serum phosphorus (by 0.02 to 0.10 mg/dL, P fast-food consumption with serum phosphorus in multivariable-adjusted analyses. In contrast, each serving per day higher soda intake was associated with 0.02 mg/dl lower serum phosphorus (95% confidence interval, −0.04, −0.01). Conclusions Greater intake of foods commonly enriched with phosphorus additives was not associated with higher serum phosphorus in a community-living sample with largely preserved kidney function. These results suggest that excess intake of processed and fast foods may not impact fasting serum phosphorus concentrations among individuals without kidney disease. PMID:22217539

  12. Phosphorus Dynamics along River Continuum during Typhoon Storm Events

    Directory of Open Access Journals (Sweden)

    Ming Fai Chow

    2017-07-01

    Full Text Available Information on riverine phosphorus (P dynamics during typhoon storm events remains scarce in subtropical regions. Thus, this study investigates the spatial and temporal dynamics of riverine phosphorus in a headwater catchment during three typhoon events. Continuous sampling (3 h intervals of stormwater samples and discharge data were conducted at five locations, which represent the upstream, transitional zone, and downstream areas of the main inflow river. The results revealed that the average event mean concentrations (EMCs for total dissolved phosphorus (TDP and particulate phosphorus (PP in the upstream catchment of Fei-Tsui reservoir were 15.66 μg/L and 11.94 μg/L, respectively. There was at least a 1.3-fold increase in flow-weighted concentrations of TDP and PP from the upper to lower reaches of the main stream. PP and TDP were transported either in clockwise or anticlockwise directions, depending on storm intensity and source. The transport of TDP was primarily regulated by the subsurface flow during the storm event. Soluble reactive phosphorus (SRP contributes more than 50% of the TDP load in moderate storms, while extreme storms supply a greater dissolved organic phosphorus (DOP load into the stream. TDP accounted for approximately 50% of TP load during typhoon storms. Mobilization of all P forms was observed from upstream to downstream of the river, except for DOP. A decrease of DOP load on passing downstream may reflect the change in phosphorus form along the river continuum. Peak discharge and antecedent dry days are correlated positively with P fluxes, indicating that river bank erosion and re-suspension of within-channel sediment are the dominant pathways of P during typhoon storm periods.

  13. Temporal changes in nitrogen and phosphorus concentrations with comparisons to conservation practices and agricultural activities in the Lower Grand River, Missouri and Iowa, and selected watersheds, 1969–2015

    Science.gov (United States)

    Krempa, Heather M.; Flickinger, Allison K.

    2017-08-01

    This report presents the results of a cooperative study by the U.S. Geological Survey and Missouri Department of Natural Resources to estimate total nitrogen (TN) and total phosphorus (TP) concentrations at monitoring sites within and near the Lower Grand River hydrological unit. The primary objectives of the study were to quantify temporal changes in TN and TP concentrations and compare those concentrations to conservation practices and agricultural activities. Despite increases in funding during 2011–15 for conservation practices in the Lower Grand River from the Mississippi River Basin Healthy Watersheds Initiative, decreases in flow-normalized TN and TP concentrations during this time at the long-term Grand River site were less than at other long-term sites, which did not receive funding from the Mississippi River Basin Healthy Watersheds Initiative. The relative differences in the magnitude of flow-normalized TN and TP concentrations among long-term sites are directly related to the amount of agricultural land use within the watershed. Significant relations were determined between nitrogen from cattle manure and flow-normalized TN concentrations at selected long-term sites, indicating livestock manure may be a substantial source of nitrogen within the selected long-term site watersheds. Relations between flow-normalized TN and TP concentrations with Conservation Reserve Program acres and with nitrogen and phosphorus from commercial fertilizer indicate that changes in these factors alone did not have a substantial effect on stream TN and TP concentrations; other landscape activities, runoff, within-bank nutrients that are suspended during higher streamflows, or a combination of these have had a greater effect on stream TN and TP concentrations; or there is a lag time that is obscuring relations. Temporal changes in flow-adjusted TN and TP concentrations were not substantial at Lower Grand River Mississippi River Basin Healthy Watersheds Initiative sites

  14. Weather, landscape, and management effects on nitrate and soluble phosphorus concentrations in subsurface drainage discharge in the western Lake Erie basin

    Science.gov (United States)

    Subsurface drainage, while an important and necessary agricultural production practice in the Midwest, contributes nitrate (NO3) and soluble phosphorus (P) to surface waters. Eutrophication (i.e., excessive enrichment of waters by NO3 and soluble P) supports harmful algal blooms (HABs) in receiving ...

  15. Concentrations and biological availability of 238U and 230Th in the environs of a uranium milling operation

    International Nuclear Information System (INIS)

    Ibrahim, S.; Flot, S.; Whicker, F.W.

    1982-01-01

    This paper reports on a study whose objectives were to determine 238 U and 230 Th concentrations in soil and native plants from various sites around a conventional acid leach uranium milling operation in the Western US, and to estimate plant/soil concentration factors. Soil and vegetation samples were collected from exposed, weathered tailings; near the edge of a tailings pond; from a reclamation area; and at several native range background (control) locations. The results indicate that mean plant/soil concentration factors varied significantly among sites and between radionuclides, but no significant differences between plant groups were found. Concentration factors for 230 Th were greater than for 238 U for plants growing at the edge of the tailings pond. It is speculated that the lower concentration factors for uranium relative to thorium at this site may be due to the proportion of their contents in soil that is biologically available for plant uptake

  16. Fluid availability of sports drinks differing in carbohydrate type and concentration

    International Nuclear Information System (INIS)

    Davis, J.M.; Burgess, W.A.; Slentz, C.A.; Bartoli, W.P.

    1990-01-01

    Plasma D2O-accumulation profiles (qualitative indices of fluid-absorption rates) were determined in eight subjects after ingestion of 275 mL of five D2O-labeled beverages: a water placebo (W), 6% maltodextrin (6% M), and three solutions containing a 6%, 8%, and 10% glucose-fructose mix (6% GF, 8% GF, and 10% GF). Except for W all beverages contained 20 mmol sodium/L and 3 mmol potassium/L. No differences in plasma D2O accumulation were found. Plasma glucose increased at 20 and 30 min after ingestion of the carbohydrate drinks and returned to baseline (6% GF and 6% M) or below (8% GF and 10% GF) by 60 min. Insulin responded similarly and, except for a slightly lower value at 30 min for 6% GF, no differences were detected. It appears that fluids in drinks containing less than or equal to 8-10% carbohydrate (simple sugars or maltodextrins) are made available for dilution in body fluids at similar rates and should be similar in replenishing body fluids lost in sweat during exercise

  17. Characteristics of Phosphorus Runoff Losses from Typical Paddy Fields in Guangdong Province, China

    Directory of Open Access Journals (Sweden)

    NING Jian-feng

    2018-03-01

    Full Text Available Three experimental paddy fields located in the city of Zengcheng, Qingyuan and Gaozhou in Guangdong Province were selected to monitor the runoff losses of phosphorus from the year of 2008 to 2012. The results showed that runoff event in paddy field occurred mainly in the early rice season. The runoff concentration of total phosphorus(TP under conventional fertilization treatment was in the range of 0.02~1.56 mg·L-1. It was recorded that TP concentration in 11%~18% of the total runoff samples exceeded the grade Ⅴ of the national surface water environmental quality(0.4 mg·L-1. Peak concentration of different phosphorus forms[TP, dissolved total P(DTP and particulate P(PP] were observed within 14 days after fertilization, which indicated the high environmental pollution risk of phosphorus during this period. Application of phosphorus fertilizer increased runoff load of DTP in paddy field and showed no effect on that of PP and TP. The annual runoff loads of 0.63~4.05, 0.33~2.91 kg·hm-2 and 1.10~6.68 kg·hm-2 for DTP, PP and TP, respectively, were recorded under conventional fertilizer model. Runoff load of phosphorus exhibited wide spatial and temporal variation during experimental period. Runoff coefficient of 0.06%~6.81% of phosphorus was recorded. It was observed that DTP dominated the phosphorus runoff load. Phosphorus runoff losses from paddy field was affected by a variety of natural and human factors, and fertilization, precipitation and runoff volume were identified as the main factors.

  18. Níveis de fósforo disponível em dietas para codornas japonesas de 45 a 57 semanas de idade Available phosphorus levels for Japanese quail diets from 45 to 57 weeks of age

    Directory of Open Access Journals (Sweden)

    Carlos Henrique Rocha Costa

    2011-10-01

    Full Text Available Conduziu-se um experimento com o objetivo de verificar o efeito de níveis de fósforo disponível (Pd na dieta sobre o desempenho, a qualidade dos ovos, o tecido ósseo e as porcentagens de fósforo (P, cálcio (Ca e magnésio (Mg nas excretas produzidas por codornas durante o terço final de postura. Foram utilizadas 300 codornas japonesas com 313 dias de idade, distribuídas em 30 unidades experimentais de dez aves. O delineamento foi inteiramente casualizado, composto de cinco níveis de Pd (0,15; 0,25; 0,35; 0,45 e 0,55%, com seis repetições por tratamento. As dietas experimentais foram isoproteicas (20,0% PB, isocalóricas (2.900 kcal EM/kg, isocálcicas (3,0% Ca e isoaminoacídicas. O aumento dos níveis de Pd na dieta aumentou linearmente os teores de Ca e Mg na tíbia, entretanto reduziu linearmente a altura dos ovos analisados. Observou-se efeito quadrático sobre o peso específico, o peso e a porcentagem de casca, a porcentagem de cálcio na casca e de fósforo na tíbia, cujos pontos de máxima foram atingidos com a utilização de 0,43; 0,41; 0,42; 0,27 e 0,42% Pd, respectivamente. Efeitos quadráticos também foram observados para excreção de Ca, cinzas e P, cujos valores máximos foram obtidos com a utilização de 0,34; 0,30 e 0,43% Pd na dieta, respectivamente. Nos demais parâmetros avaliados, não houve efeito dos níveis de Pd. Dietas contendo 0,15% Pd atendem satisfatoriamente às exigências para desempenho e manutenção da integridade física do ovo, além de reduzir a excreção de fósforo sem provocar perda de ovos por problemas de casca nem ocorrência de fadiga de gaiola por enfraquecimento do sistema ósseo, embora seja observada redução na mineralização da casca e do tecido ósseo de codornas japonesas no terço final do ciclo de produção (45 a 57 semanas de idade.An experiment was conducted aiming to verify the effect of different levels of available phosphorus (AP in the diet on performance, egg

  19. Longitudinal Gradients in Phosphorus Characteristics in the Minnesota-Upper Mississippi River System

    National Research Council Canada - National Science Library

    James, William

    2002-01-01

    This technical note describes longitudinal patterns in soluble phosphorus and biologically available particulate phosphorus and equilibrium characteristics for suspended sediment collected at stations...

  20. Removing Phosphorus from Aqueous Solutions Using Lanthanum Modified Pine Needles.

    Directory of Open Access Journals (Sweden)

    Xianze Wang

    Full Text Available The renewable pine needles was used as an adsorbent to remove phosphorus from aqueous solutions. Using batch experiments, pine needles pretreated with alkali-isopropanol (AI failed to effectively remove phosphorus, while pine needles modified with lanthanum hydroxide (LH showed relatively high removal efficiency. LH pine needles were effective at a wide pH ranges, with the highest removal efficiency reaching approximately 85% at a pH of 3. The removal efficiency was kept above 65% using 10 mg/L phosphorus solutions at desired pH values. There was no apparent significant competitive behavior between co-existing anions of sulfate, nitrate, and chloride (SO4(2-, NO3(- and Cl(-; however, CO3(2- exhibited increased interfering behavior as concentrations increased. An intraparticle diffusion model showed that the adsorption process occurred in three phases, suggesting that a boundary layer adsorption phenomena slightly affected the adsorption process, and that intraparticle diffusion was dominant. The adsorption process was thermodynamically unfavorable and non-spontaneous; temperature increases improved phosphorus removal. Total organic carbon (TOC assays indicated that chemical modification reduced the release of soluble organic compounds from 135.6 mg/L to 7.76 mg/L. This new information about adsorption performances provides valuable information, and can inform future technological applications designed to remove phosphorus from aqueous solutions.

  1. Phosphorus Uptake and Partitioning in Maize as Affected by Tillage ...

    African Journals Online (AJOL)

    Higher phosphorus concentrations were found in the ears than in the shoots and leaves at physiological maturity. Tillage x phospho-rus interactions influenced phosphorus partitioning in the ears and the leaves on the Dystric Cam-bisol but not on the Ferric Acrisol. PUE in the plant parts were significantly higher under ...

  2. Lysimeter experiments to determine the ability of soil to reduce concentrations of BOD, available P and inorganic N in dirty water.

    Science.gov (United States)

    Brookman, S K E; Chadwick; Retter, A R

    2005-11-01

    Lysimeter experiments were conducted to determine the ability of different soils to reduce levels of biochemical oxygen demand (BOD) and concentrations of molybdate reactive phosphorus (MRP) and ammonium-N (NH4(+)-N) in dirty water and the impact of applications on nitrate leaching. An additional experiment investigated the effect of dirty water components on leaching quality. This information is required to assess the potential risk of dirty water applications on polluting groundwater and to assess the use of such soils in the development of treatment systems for dirty water. Intact and disturbed soil lysimeters, 0.5 and 1m deep were constructed from four soils; a coarse free-draining sandy loam, a sandy loam over soft sandstone, a calcareous silty clay over chalk and a sandy loam over granite. For the coarse free-draining sandy loam, lysimeters were also constructed from disturbed soil with and without the addition of lime, to assess if this could increase phosphorus immobilisation. Levels of BOD and concentrations of MRP, NH4(+)-N and nitrate (NO3(-)-N) of leachates were measured following dirty water applications at 2 and 8 mm day(-1) under laboratory conditions. Under the daily 2mm application, all soils were effective at treating dirty water, reducing concentrations of BOD, MRP and NH4(+)- N by > or = 98% but NO3(-)-N concentrations increased up to 80 mg l(-1) from the 0.5 m deep lysimeters of the sandy loam over granite. Soils were less effective at reducing levels of BOD, MRP and NH4(+)- N at the 8 mm daily rate of application, with maximum NO3(-)-N concentrations of leachates of 200 mg l(-1) from disturbed soils.

  3. Granulated wood ash to forest soils. Effects on microorganisms, phosphorus availability, and spatial relationships in the humus layer; Granulerad vedaska till skog paa fastmark. Paaverkan paa fosfortillgaang, mikroorganismer och rumsliga variationsmoenster

    Energy Technology Data Exchange (ETDEWEB)

    Clarholm, Marianne [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Mycology and Pathology

    1999-07-01

    The report summarises effects on microorganisms, phosphorus (P) availability and spatial relationships in the humus layer of two spruce forests in south-western Sweden four to seven years after application of 3.2 tonnes (t) (Skogaby), alternatively three or six t (Torup) of granulated wood ash. There were tendencies for increases in pH and in numbers of ciliates, flagellates and small nematodes while no effects were observed for naked amoebae, the major consumers of bacteria among the protozoa. After seven years, the amount of P in microbial biomass in the humus layer in the wood ash treatment (A) in Skogaby was significantly higher than in the control (C), increased amounts of microbial nitrogen and carbon were also recorded. Observations over time indicated that the P availability in the soil first decreased after the ash addition, but later increased above that in the control. The time course was most readily seen in the microbial biomass, which contained 50% of total P in the humus layer, an amount equal to ten times the yearly uptake in trees. The microbial biomass has a much higher P concentration as compared to the needles, the component of the tree with the highest concentration. The P in micro-organisms thus form a buffer against P deficiency for the trees. A test where the {sup 32}P uptake rate of excised mycorrhizal fine roots in the laboratory is used to establish P availability in the field, indicated an increased P availability in (A), which was in contrast to reported decreased uptake of P in trees, decreased P concentration in needles and also in roots, as compared to (C). In six treatments investigated in Skogaby {sup 32}P uptake rates were negatively correlated to the P/C of the microbial biomass. Acid phosphatase activity was always higher in (A) as compared to treatments where soluble P had been added and at two out of five times also higher than in (C ). High phosphatase activity levels were at least partly connected to large amounts of

  4. The efficacy of Aspergillus niger phytase in rendering phytate phosphorus available for absorption in pigs is influenced by pig physiological status

    NARCIS (Netherlands)

    Kemme, P.A.; Jongbloed, A.W.; Mroz, Z.; Beynen, A.C.

    1997-01-01

    We performed an experiment with 112 piglets, 32 growing-finishing pigs, and 12 sows during pregnancy and lactation to test the hypotheses that apparent total tract digestibilities of P and Ca as well as the efficacy of Aspergillus niger phytase in rendering phytate P available in pigs depend on pig

  5. Estimation of phosphorus flux in rivers during flooding.

    Science.gov (United States)

    Chen, Yen-Chang; Liu, Jih-Hung; Kuo, Jan-Tai; Lin, Cheng-Fang

    2013-07-01

    Reservoirs in Taiwan are inundated with nutrients that result in algal growth, and thus also reservoir eutrophication. Controlling the phosphorus load has always been the most crucial issue for maintaining reservoir water quality. Numerous agricultural activities, especially the production of tea in riparian areas, are conducted in watersheds in Taiwan. Nutrients from such activities, including phosphorus, are typically flushed into rivers during flooding, when over 90% of the yearly total amount of phosphorous enters reservoirs. Excessive or enhanced soil erosion from rainstorms can dramatically increase the river sediment load and the amount of particulate phosphorus flushed into rivers. When flow rates are high, particulate phosphorus is the dominant form of phosphorus, but sediment and discharge measurements are difficult during flooding, which makes estimating phosphorus flux in rivers difficult. This study determines total amounts of phosphorus transport by measuring flood discharge and phosphorous levels during flooding. Changes in particulate phosphorus, dissolved phosphorus, and their adsorption behavior during a 24-h period are analyzed owing to the fact that the time for particulate phosphorus adsorption and desorption approaching equilibrium is about 16 h. Erosion of the reservoir watershed was caused by adsorption and desorption of suspended solids in the river, a process which can be summarily described using the Lagmuir isotherm. A method for estimating the phosphorus flux in the Daiyujay Creek during Typhoon Bilis in 2006 is presented in this study. Both sediment and phosphorus are affected by the drastic discharge during flooding. Water quality data were collected during two flood events, flood in June 9, 2006 and Typhoon Bilis, to show the concentrations of suspended solids and total phosphorus during floods are much higher than normal stages. Therefore, the drastic changes of total phosphorus, particulate phosphorus, and dissolved phosphorus in

  6. A representation of the phosphorus cycle for ORCHIDEE (revision 4520

    Directory of Open Access Journals (Sweden)

    D. S. Goll

    2017-10-01

    Full Text Available Land surface models rarely incorporate the terrestrial phosphorus cycle and its interactions with the carbon cycle, despite the extensive scientific debate about the importance of nitrogen and phosphorus supply for future land carbon uptake. We describe a representation of the terrestrial phosphorus cycle for the ORCHIDEE land surface model, and evaluate it with data from nutrient manipulation experiments along a soil formation chronosequence in Hawaii. ORCHIDEE accounts for the influence of the nutritional state of vegetation on tissue nutrient concentrations, photosynthesis, plant growth, biomass allocation, biochemical (phosphatase-mediated mineralization, and biological nitrogen fixation. Changes in the nutrient content (quality of litter affect the carbon use efficiency of decomposition and in return the nutrient availability to vegetation. The model explicitly accounts for root zone depletion of phosphorus as a function of root phosphorus uptake and phosphorus transport from the soil to the root surface. The model captures the observed differences in the foliage stoichiometry of vegetation between an early (300-year and a late (4.1 Myr stage of soil development. The contrasting sensitivities of net primary productivity to the addition of either nitrogen, phosphorus, or both among sites are in general reproduced by the model. As observed, the model simulates a preferential stimulation of leaf level productivity when nitrogen stress is alleviated, while leaf level productivity and leaf area index are stimulated equally when phosphorus stress is alleviated. The nutrient use efficiencies in the model are lower than observed primarily due to biases in the nutrient content and turnover of woody biomass. We conclude that ORCHIDEE is able to reproduce the shift from nitrogen to phosphorus limited net primary productivity along the soil development chronosequence, as well as the contrasting responses of net primary productivity to nutrient

  7. Total and available heavy metal concentrations in soils of the Thriassio plain (Greece) and assessment of soil pollution indexes.

    Science.gov (United States)

    Massas, Ioannis; Kalivas, Dionisios; Ehaliotis, Constantions; Gasparatos, Dionisios

    2013-08-01

    The Thriassio plain is located 25 km west of Athens city, the capital of Greece. Two major towns (Elefsina and Aspropyrgos), heavy industry plants, medium to large-scale manufacturing, logistics plants, and agriculture comprise the main land uses of the studied area. The aim of the present study was to measure the total and available concentrations of Cr, Zn, Ni, Pb, Co, Mn, Ba, Cu, and Fe in the top soils of the plain, and to asses soil contamination by these metals by using the geoaccumulation index (I geo), the enrichment factor (EF), and the availability ratio (AR) as soil pollution indexes. Soil samples were collected from 90 sampling sites, and aqua regia and DTPA extractions were carried out to determine total and available metal forms, respectively. Median total Cr, Zn, Ni, Pb, Co, Mn, Ba, Cu, and Fe concentrations were 78, 155, 81, 112, 24, 321, 834, 38, and 16 × 10(3) mg kg(-1), respectively. The available fractions showed much lower values with medians of 0.4, 5.6, 1.7, 6.9, 0.8, 5.7, 19.8, 2.1, and 2.9 mg kg(-1). Though median total metal concentrations are not considered as particularly high, the I geo and the EF values indicate moderate to heavy soil enrichment. For certain metals such as Cr, Ni, Cu, and Ba, the different distribution patterns between the EFs and the ARs suggest different origin of the total and the available metal forms. The evaluation of the EF and AR data sets for the soils of the two towns further supports the argument that the EFs can well demonstrate the long-term history of soil pollution and that the ARs can adequately portray the recent history of soil pollution.

  8. Evaluation of two commercially available ELISA kits for the determination of melatonin concentrations in amniotic fluid throughout pregnancy.

    Science.gov (United States)

    Bagci, Soyhan; Altuntas, Özlem; Katzer, David; Berg, Christoph; Willruth, Arne; Reutter, Heiko; Bartmann, Peter; Müller, Andreas; Zur, Berndt

    2017-01-01

    Background The aim of the present study is to evaluate the utility of extraction versus non-extraction-based commercial melatonin ELISA kits for determining the melatonin concentration in amniotic fluid obtained in early and late pregnancy. Methods Pregnancy duration less than 28 weeks was defined as early and from 28 weeks until delivery as late gestation. Nine samples were obtained in early and 18 in late pregnancy. Two commercially available melatonin ELISA kits (melatonin ELISA RE54021, including methanol-based extraction and direct saliva melatonin ELISA RE 54041, not including an extraction step, both from IBL-International, Germany) were used to determine melatonin concentrations in amniotic fluid. Results The mean melatonin concentration in ELISAs assayed by the non-extraction was significantly lower than those assayed after extraction. Subgroup analysis showed that there was no significant difference between melatonin concentration measured by non-extraction versus extraction ELISA in early pregnancy (11.2 ± 7.4 vs. 12.2 ± 7.7, respectively, P = 0.463) but that the mean melatonin concentration in late pregnancy was significantly lower when assayed by non-extraction ELISA than when assayed by extraction ELISA (14.8 ± 9.3 vs. 145.1 ± 179.3, respectively; P pregnancy was rather poor (r 2  = 0.271, P = 0.022), as opposed to the good correlation found in early pregnancy (r 2  = 0.929, P melatonin assay without an extraction step, such as direct saliva ELISA, does not seem to be a valid method to determine the melatonin concentration of amniotic fluid, especially in late gestation.

  9. Factors affecting phosphorus transport at a conventionally-farmed site in Lancaster County, Pennsylvania, 1992-95

    Science.gov (United States)

    Galeone, Daniel G.

    1996-01-01

    equilibrium processes.Physical characteristics, such as particle-size distributions in soil, the suspended sediment and particle-size distribution in surface runoff, and surface topography, were quantified. Hydrologic characteristics, such as precipitation intensity and duration, volumes of surface runoff, and infiltration rates of soil, were also monitored during the study period. Volumes of surface runoff differed by plot.Volumes of surface runoff measured during the study period from plots 1 (0.43 acres), 2 (0.23 acres), and 3 (0.28 acres) were 350,000, 350,000, and 750,000 liters per acre, respectively. About 90 percent of the volume of surface runoff occurred after October 1993 because of the lack of intense precipitation from March 30, 1993, through November 30, 1993. For any one precipitation amount, volumes of surface runoff increased with an increase in the maximum intensity of precipitation and decreased with an increase in storm duration. The significantly higher volume of surface runoff for plot 3 relative to plots 1 and 2 was probably caused by lower infiltration rates on plot 3.Soil concentrations of plant-available phosphorus (PAP) for each study plot were high (31-60 parts per million) to excessive (greater than 60 parts per million) for each depth interval (0-6, 6-12, and 12- 24 inches) and sampling period except for some samples collected at depths of 12-24 inches. The high levels of PAP before manure applications made it difficult to detect any changes in the concentration of soil PAP caused by manure applications. Manure applications to the study area prior to this study resulted in relatively high concentrations of soil PAP; however, the manure applications to plot 3 during the study period did cause an increase in the soil concentration of PAP after the second manure application. The percentages of total phosphorus in plant-available and inorganic forms were about 5 and 80 percent, respectively, in the 0-24--inch depth interval of soil on the study plots

  10. Phosphorus and Calcium Metabolism in Postmenopausal Women with Diabetes Mellitus: Effects of the Type and Duration of the Disease, Time of Menopause and Body Mass

    Directory of Open Access Journals (Sweden)

    M.L. Kyryliuk

    2016-02-01

    Full Text Available The article deals with the impact of diabetes mellitus (DM on the phosphorus and calcium metabolism in postmenopausal women, depending on the type and duration of the disease, duration of menopause, body mass and type of hypoglycemic therapy. The state of phosphorus and calcium metabolism in 86 women with type 1 DM (13 patients and type 2 DM (73 patients was studied. In all patients, the concentration of calcium and phosphorus in the blood was within normal limits. It was found that the concentration of ionized calcium, total calcium and inorganic phosphorus in the blood can not be the main criterion for the state of bone mineral density in postmenopausal women with DM. Sulfonylureas and insulin in combination with biguanides have no effect on the status of phosphorus and calcium metabolism in postmenopausal women with type 2 DM.

  11. Available phosphorus and sulphur, exchangeable aluminum and remaining phosphorus in rhodic eutrudox submitted to gypsum cultivated with wheat and soybean Fósforo e enxofre disponível, alumínio trocável e fósforo remanescente em latossolo vermelho submetido ao gesso cultivado com trigo e soja

    Directory of Open Access Journals (Sweden)

    Leandro Rampim

    2013-09-01

    Full Text Available The response to gypsum as a supplier of nutrients in the subsurface provides better root distribution for annual crops plants and thus provides use of larger volume of soil increasing the uptake of water and nutrients and therefore increased productivity, especially with evidence of interference of gypsum in phosphorus available in the soil. In this study evaluated the use of gypsum (CaSO4.2H2O the levels of available phosphorus and sulfur, exchangeable aluminum and interference in the remaining phosphorus in the soil at 0-0.10, 0.10-0.20; 0.20-0.40 m of deep in Rhodic Eutrudox in no tillage and crop yields of wheat and soybean. We conducted sampling of soil at six and 12 months after surface application of 1000, 2000, 3000, 4000 and 5000 kg ha-1 gypsum and treatment without application of gypsum. The use of gypsum increased linearly the S content is available in layers from 0-0,10, 0,10-0,20 and 0,20 to 0,40 m deep, with the minimum content of available P at a dose of 2200 kg ha-1 and exchangeable Al with a dose of 3000 kg ha-1 layers evaluated, however, did not influence the values of remaining P. The use of gypsum increased linearly the S content available at depths of 0-0.10, 0.10-0.20 and 0.20-0.40 m, minimum P content available at the dose of 3166 kg ha-1 and exchangeable Al minimum point at the dose of 3300 kg ha-1 at a depth of 0.20-0.40 m however, did not affect the remaining P values. The use of gypsum increased the productivity of wheat, but did not influence soybean yield. A resposta ao gesso agrícola como fornecedor de nutrientes na subsuperfície proporciona melhor distribuição de raízes para culturas anuais e assim propicia às plantas explorar maior volume de solo aumentando a absorção de água e nutrientes e consequentemente incrementar a produtividade, com indícios da interferência do gesso no teor de fósforo disponível no solo. Neste trabalho o objetivo foi avaliar o uso do gesso agrícola (CaSO4.2H2O nos teores de f

  12. Fertilizer phosphorus in some Finnish soils

    Directory of Open Access Journals (Sweden)

    Armi Kaila

    1961-01-01

    Full Text Available In the present paper it is tried to trace the fate of fertilizer phosphorus in soil by comparing the analyses of soils from treated and untreated plots of field trials. This indirect approach cannot be expected to provide exact values, but it is likely to give an approximate answer. The results reported above do not in any marked degree change our present conception of the forms in which fertilizer phosphorus accumulates in soils. In the acid soils studied (pH 4—6.4 in 0.02 N CaCl2 superphosphate tended to increase the fractions which were extracted by NH4F or NaOH. Hyperphosphate phosphorus was mostly found in the acid-soluble fraction. During a longer period of dressing with phosphate an increase in the organic phosphorus content of a peat soil could be detected. In the incubation experiments the mineralization of organic phosphorus occurred at a higher rate in the samples from the plots treated with superphosphate than in those from the untreated one. It might be supposed that the organic phosphorus mineralized mainly originated from the plant residues. It seems that the fractionation method developed by CHANG and JACKSON (4 for the estimation of discrete forms of soil phosphorus is not quite satisfactory for tracing the fertilizer phosphorus in soils recently dressed with phosphates. In particular, it may be fallacious to conclude that the fraction extracted by NH4F would only represent phosphorus bound to aluminium and its compounds. At least in the absence of soil, a large part of phosphorus in dicalcium phosphate dihydrate falls into this fraction, and also a small amount of hyperphosphate phosphorus may be found in it. The test values for »available» phosphorus showed the effect of fertilizers in accordance with previous observations (9, 13. Acetic acid soluble P revealed the treatment with hyperphosphate, but only slightly the application of superphosphate. The test value for the sorbed P of BRAY and KURTZ (2, or phosphorus

  13. Estimation of Fluoride Concentration of Various Citrus and Non-Citrus Fruits Commonly Consumed and Commercially Available in Mathura City

    Directory of Open Access Journals (Sweden)

    Navin Anand Ingle

    2013-01-01

    Full Text Available Background: Since fluoride is available from various sources, the total ingestion of fluoride by a person should be estimated taking into consideration the fluoride consumed from all the sources including fruits. There are very few epidemiological studies carried out associated with fluoride estimation in fruit samplesand especially in the Indian scenario Objective: To estimate and compare the fluoride concentration of different commercially available citrus and non-citrus fruits in Mathura city. Materials & Method: Fifteen different types of fruits commercially available and consumed by people ofMathura City were collected. Out of the 15 fruit samples 5 were citrus fruits and 10 were non-citrus fruits. The fluoride estimation of fruit samples was done at Central Laboratory,Lucknow. Juices of all 15 fruit samples were prepared, from each sample 10 ml of juice was measured and fluoride testing of each sample was carried out by using Orion 4 star -ion electrode analyzer. The collected data was analyzed using the statistical software program SPSS, version 17. Results: The fluoride concentration in citrus fruits ranged from 0.04ppm (Orange to 0.08 ppm (Tomato while in non-citrus fruits it ranged from 0.04ppm (chikoo to 0.18 ppm (Guava. No significant difference was observed between the mean fluoride concentration of citrus and non citrus fruits. Conclusions: Both citrus and non citrus fruits have fluorides. Guava was found to have the maximumamount of fluoridecontent (0.18 ppm among both the citrus and non citrus fruits.

  14. Substoichiometric extraction of phosphorus

    International Nuclear Information System (INIS)

    Shigematsu, T.; Kudo, K.

    1981-01-01

    A study of the substoichiometric extraction of phosphorus is described. Phosphorus was extracted in the form of ternary compounds such as ammonium phosphomolybdate, 8-hydroxyquinolinium phosphomolybdate, tetraphenylarsonium phosphomolybdate and tri-n-octylamine phosphomolybdate. Consequently, phosphorus was extracted substoichiometrically by the addition of a substoichiometric amount of molybdenum for the four phosphomolybdate compounds. On the other hand, phosphorus could be separated substoichiometrically with a substoichiometric amount of tetraphenylarsonium chloride or tri-n-octylamine. Stoichiometric ratios of these ternary compounds obtained substoichiometrically were 1:12:3 for phosphorus, molybdenum and organic reagent. The applicability of these compounds to phosphorus determination is also discussed. (author)

  15. Accumulation of phosphorus in coastal marine sediments: relationship to benthic and diffusive fluxes

    Directory of Open Access Journals (Sweden)

    Rocio Ponce

    2010-11-01

    Full Text Available Sedimentary phosphorus was characterized in sediment cores from 3 coastal ecosystems of the Gulf of Cadiz. High spatial variability was observed in total phosphorus (from 445 to 20291 μg g.sed-1 and in the other phosphorus phases studied. This variability correlates with the proximity of the 10 sampling stations to sources of urban and/or industrial effluent in the zone. The benthic and diffusive fluxes were measured concurrently with sediment collection at these stations. The measured values of benthic fluxes range between –14 and 6 mmol m-2 d-1. Generally, stations that showed increased interstitial phosphate concentrations with increasing depth were characterized by positive values in phosphate benthic fluxes and by high percentages of reactive forms of sedimentary phosphorus. Negative benthic fluxes were associated with stations receiving more anthropogenic matter, which showed progressively decreasing phosphate concentrations in the interstitial water with depth. In these anthropogenic areas, the non-reactive forms of phosphorus (those associated with ferric oxyhydroxide and authigenic carbonate fluorapatite are abundant, and reach values exceeding 75% of total phosphorus in sediment.

  16. Influence of bread crust-derived Maillard reaction products on phosphorus balance in rats.

    Science.gov (United States)

    Roncero-Ramos, Irene; Delgado-Andrade, Cristina; Alonso-Olalla, Rebeca; Navarro, María Pilar

    2012-10-01

    Maillard reaction products (MRP) improve food palatability and are linked to some positive biological actions. However, diverse negative consequences, some related to protein damage and mineral availability, have been established. We investigated the effects of MRP, from a bread crust diet, on phosphorus bioavailability and tissue distribution in rats to determine whether these effects are related to the molecular weight of browning products. During a study period of 88 days, rats were fed either a control diet or one of the following: with bread crust as a source of MRP, or one with its soluble high molecular weight, soluble low molecular weight or insoluble fraction (bread crust, HMW, LMW and insoluble diets, respectively). In the final week, a phosphorus balance was performed, after which the animals were sacrificed and some organs removed to analyse phosphorus content. A second balance was carried out throughout the experimental period to calculate phosphorus retention. Phosphorus balance in the last week was unchanged. However, considering the whole experimental period, a trend towards improved bioavailability, significant in the HMW group, was observed. Higher phosphorus concentrations were measured in the small intestine and bone. The consumption of MRP derived from bread did not alter phosphorus retention, due to increased bioavailability, especially concerning HMW compounds. The overall phosphorus body content remained unchanged and there were no changes in the bone, its principal metabolic destination. However, MRP consumption markedly raised phosphorus levels at the digestive level, especially when consumed as isolate fractions. The slower rate of stomach emptying is assumed to be related to this effect.

  17. Twelve Years of Monitoring Phosphorus and Suspended-Solids Concentrations and Yields in the North Fork Ninnescah River above Cheney Reservoir, South-Central Kansas 1997-2008

    Science.gov (United States)

    Stone, Mandy L.; Graham, Jennifer L.; Ziegler, Andrew C.

    2009-01-01

    Cheney Reservoir, located on the North Fork Ninnescah River in south-central Kansas, is the primary water supply for the city of Wichita and an important recreational resource. Concerns about taste-and-odor occurrences in Cheney Reservoir have drawn attention to potential pollutants, including total phosphorus (TP) and total suspended solids (TSS). July 2009 was the 15th anniversary of the establishment of the Cheney Reservoir Watershed pollution management plan. The U.S. Geological Survey (USGS), in cooperation with the city of Wichita, has collected water-quality data in the basin since 1996, and has monitored water quality continuously on the North Fork Ninnescah River since 1998. This fact sheet describes 12 years (1997-2008) of computed TP and TSS data and compares these data with water-quality goals for the North Fork Ninnescah River, the main tributary to Cheney Reservoir.

  18. AnalysisThe Availability of Using Concentrated Solar Power (CSP as Electricity Source in Al-Hilla City

    Directory of Open Access Journals (Sweden)

    Wisam Shamkhi Jaber

    2017-03-01

    Full Text Available The needing of using clean energy increases every year because of the negative impact of emissions from electricity power plant and to reduce the costs of generating power by using natural energies like solar, wind, and other sources. The availability of using solar energy as source of producing electricity in Al-Hilla city by using Concentrating Solar Power (CSP was investigated in this research. The major parameters in this study were the city position, and the annually amount of solar received, also, number of charts related to solar parameters for the management of CSP were derived and showed in this research. The using of CSP as electricity power can be important solution to force the problem of high cost of electricity power fuel needed and the lack of power produced because of increasing of power consumed specially in summer season.

  19. Phosphorus blood test

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003478.htm Phosphorus blood test To use the sharing features on this page, please enable JavaScript. The phosphorus blood test measures the amount of phosphate in the blood. ...

  20. Origin, concentration, availability and fate of dissolved organic carbon in coastal lagoons of the Rio de Janeiro State

    Directory of Open Access Journals (Sweden)

    Albert Luiz Suhett

    Full Text Available The coastal lagoons in the northern Rio de Janeiro State (Brazil present a wide gradient of dissolved organic carbon (DOC and water color, with the highest DOC concentrations reported in the literature for aquatic ecosystems. Thus, they represent a peculiar set of ecosystems for the study of the origin, processing and fate of DOC in inland waters. We reviewed data from 2 decades of studies on the carbon cycle in these coastal lagoons and discussed the fluctuations in the concentration and quality of DOC, factors affecting DOC microbial and photochemical degradation, CO2 emission, as well as the role of humic and non-humic carbon to the energy flow through the trophic chains. We show that DOC quality, not its quantity, determines the rates of photochemical and microbial degradation both seasonally (within system and spatially (among systems, with the exception of DOC photo-oxidation among lagoons, which is partially explained by DOC concentration at regional scale. In humic lagoons, there is a fairly predictable pattern of seasonal variation in DOC concentration associated to rainfall-induced inputs of allochthonous C. However, little is known about the exact timing of these allochthonous inputs and how they relate to the seasonal variation of DOC chemical properties (i.e. its quality. Depth-integrated photo-oxidation rates were less representative in highly humic lagoons, due to strong light attenuation in the water column. Nevertheless, the potential contribution of photo-oxidation and bacterial respiration to total CO2 efflux (~11% did not differ significantly when all lagoons were pooled together. Contrary to prevailing paradigms for humic waters, microalgae seem to be the main C source in humic lagoons, sustaining pelagic food webs through zooplankton, in spite of some contribution of allochthonous C. Thus, the predominant role of the microbial loop in the DOC recovery to food webs in such systems is to be questioned.

  1. On the use of 31P NMR for the quantification of hydrosoluble phosphorus-containing compounds in coral host tissues and cultured zooxanthellae

    Science.gov (United States)

    Godinot, Claire; Gaysinski, Marc; Thomas, Olivier P.; Ferrier-Pagès, Christine; Grover, Renaud

    2016-02-01

    31P Nuclear Magnetic Resonance (NMR) was assessed to investigate the phosphorus-containing compounds present in the tissues of the scleractinian coral Stylophora pistillata as well as of cultured zooxanthellae (CZ). Results showed that phosphorus-containing compounds observed in CZ were mainly phosphate and phosphate esters. Phosphate accounted for 19 ± 2% of the total phosphorus compounds observed in CZ maintained under low P-levels (0.02 μM). Adding 5 mM of dissolved inorganic phosphorus (KH2PO4) to the CZ culture medium led to a 3.1-fold increase in intracellular phosphate, while adding 5 mM of dissolved organic phosphorus led to a reduction in the concentration of phosphorus compounds, including a 2.5-fold intracellular phosphate decrease. In sharp contrast to zooxanthellae, the host mainly contained phosphonates, and to a lesser extent, phosphate esters and phosphate. Two-months of host starvation decreased the phosphate content by 2.4 fold, while bleaching of fed corals did not modify this content. Based on 31P NMR analyses, this study highlights the importance of phosphonates in the composition of coral host tissues, and illustrates the impact of phosphorus availability on the phosphorus composition of host tissues and CZ, both through feeding of the host and inorganic phosphorus enrichment of the CZ.

  2. Study on Growth of Duckweed and Its Removal Efficiency of Phosphorus under Different P- concentrations%不同磷浓度下浮萍生长和去除磷效率研究

    Institute of Scientific and Technical Information of China (English)

    张震; 辛静; 蔡树美; 钱晓晴

    2011-01-01

    以少根紫萍、稀脉浮萍和紫萍为供试材料,以霍格兰氏营养液为培养液,考察了夏季气象条件下3种浮萍在培养液中鲜重的增加和去除磷效率的情况.结果表明:浮萍在磷浓度为0.1 ~46.5 mg,/L的水体中均可生长.浮萍生长的最适磷浓度范围为0.1~15.5 mg/L,其中磷浓度在3.1 m/L左右的情况下,浮萍长势最佳.相对于稀脉浮萍和少根紫萍,紫萍表现出一定的磷去除优势,尤其是在高磷浓度条件下紫萍磷去除的优势更为明显.%Taking Lemna perpusilla, Spirodela oligorrhiza and Spirodela polyrrhiza as the tested materials, the fresh weight gam and phosphorus removal efficiency of different duckweed cultivars in Hoagland nutrient solution under the summer meteorological condition were investigated. The results showed that duckweed could grow in the water body containing 0.1 ~46. 5 mg/L P, the optimum P - concentration range for the growth of duckweed was 0.1 ~ 15.5 mg/L, and the duckweed grew best when the concentration of P was about 3. 1 mg/L. Spirodela polyrrhiza had better phosphorus removal efficiency than Spirodela oligorrhiza and Lemna perpusilla, especially under the condition of high P - concentration.

  3. Glacial-interglacial variability in ocean oxygen and phosphorus in a global biogeochemical model

    Directory of Open Access Journals (Sweden)

    V Palastanga

    2013-02-01

    Full Text Available Increased transfer of particulate matter from continental shelves to the open ocean during glacials may have had a major impact on the biogeochemistry of the ocean. Here, we assess the response of the coupled oceanic cycles of oxygen, carbon, phosphorus, and iron to the input of particulate organic carbon and reactive phosphorus from shelves. We use a biogeochemical ocean model and specifically focus on the Last Glacial Maximum (LGM. When compared to an interglacial reference run, our glacial scenario with shelf input shows major increases in ocean productivity and phosphorus burial, while mean deep-water oxygen concentrations decline. There is a downward expansion of the oxygen minimum zones (OMZs in the Atlantic and Indian Ocean, while the extension of the OMZ in the Pacific is slightly reduced. Oxygen concentrations below 2000 m also decline but bottom waters do not become anoxic. The model simulations show when shelf input of particulate organic matter and particulate reactive P is considered, low oxygen areas in the glacial ocean expand, but concentrations are not low enough to generate wide scale changes in sediment biogeochemistry and sedimentary phosphorus recycling. Increased reactive phosphorus burial in the open ocean during the LGM in the model is related to dust input, notably over the southwest Atlantic and northwest Pacific, whereas input of material from shelves explains higher burial fluxes in continental slope and rise regions. Our model results are in qualitative agreement with available data and reproduce the strong spatial differences in the response of phosphorus burial to glacial-interglacial change. Our model results also highlight the need for additional sediment core records from all ocean basins to allow further insight into changes in phosphorus, carbon and oxygen dynamics in the ocean on glacial-interglacial timescales.

  4. Concentração de nitrogênio, fósforo e potásiio na parte aérea do feijoeiro em resposta à irrigação, fertirrigação e micronutrientes Concentration of nitrogen, phosphorus and potassium in drybean shoots in response to irrigation, fertirrigation and micronutrients

    Directory of Open Access Journals (Sweden)

    Eder João Pozzebon

    1996-08-01

    Full Text Available Este experimento teve como objetivo avaliar a concentração de nitrogênio, fósforo e potássio na parte aérea do feijoeiro em resposta à irrigação, fertirrigação com nitrogênio parcelado e aplicação de micronutrientes via semente. O experimento foi conduzido a campo em solo Podzólico Vermelho-Amarelo, de textura média, em Santa Maria, RS. Os tratamentos consistiram de combinações do uso de irrigação por aspersão, micronutrientes via semente e modo de aplicação de nitrogênio em cobertura. Os tratamentos com adubação de cobertura convencional receberam o nitrogênio (85kg N ha-1 na forma de uréia granulada aos 12 dias após a emergência. Na fertirrigação usou-se o parcelamento do nitrogênio aos 12, 24 e 30 dias após a emergência. Os micronutrientes foram aplicados numa dosagem de 3,5 g kg ha-1 de sementes de uma formulação de 38% de zinco, 9% de molibdênio, 2% de boro e 0,5% de cobalto. As concentrações de nitrogênio, fósforo e potássio foram determinadas nas folhas, talos e sementes aos 49 e 71 dias após a emergência. A irrigação promoveu maior concentração de nitrogênio, fósforo e potássio nas folhas aos 49 dias após a emergência. Aos 71 dias após a emergência, ocorreram menores concentrações de nitrogênio e fósforo nas folhas e talos para os tratamentos irrigados e nas sementes houve maior concentração de nitrogênio, fósforo e potássio para os tratamentos não irrigados. Não houve efeito do parcelamento do nitrogênio via fertirrigação e aplicação de micronutrientes às sementes sobre a concentração de nitrogênio, fósforo e potássio na parte aérea das plantas.The objective of this study was to evaluate the concentration of nitrogen, phosphorus and potassium in drybean shoots in response to irrigation, fertirrigation with nitrogen and seed micronutrient application. The experiment was conducted on a loam Podzolic soil, in Santa Maria, RS. Treatments with conventional

  5. The relationship between silicon availability, and growth and silicon concentration of the salt marsh halophyte Spartina anglica

    NARCIS (Netherlands)

    De Bakker, N.; Hemminga, M.A.; Van Soelen, J.

    1999-01-01

    Analysis of silicon concentrations of various halophytes from salt marshes in the S.W. Netherlands shows that the silicon concentration of Spartina anglica (Gramineae) is relatively high. To study the influence of dissolved Si concentrations on growth and plant tissue concentrations of S. anglica,

  6. Use of Phosphorus Isotopes for Improving Phosphorus Management in Agricultural Systems

    International Nuclear Information System (INIS)

    2016-10-01

    Phosphorus is an essential element in plant, human and animal nutrition. Soils with low levels of phosphorus are widespread in many regions of the world, and the deficiency limits plant growth and reduces crop production and food quality. This publication provides comprehensive and up to date information on several topics related to phosphorus in soil–plant systems, in agricultural systems and in the environment. It presents the theoretical background as well as practical information on how to use nuclear and radioisotope tracer techniques in both laboratory and greenhouse experiments to assess soil phosphorus forms and plant-available soil phosphorus pools, and to understand the cycling processes in soil–plant systems. The publication focuses on practical applications of radiotracer techniques and can serve as resource material for research projects on improving sustainable phosphorus management in agricultural systems and as practical guidance on the use of phosphate isotopes in soil–plant research

  7. Estimates of long-term water total phosphorus (TP) concentrations in three large shallow lakes in the Yangtze River basin, China.

    Science.gov (United States)

    Wu, Pan; Qin, Boqiang; Yu, Ge

    2016-03-01

    The shallow lakes in the eastern China developed on alluvial plains with high-nutrient sediments, and most overflow into the Yangtze River with short hydraulic residence times, whereas they become eutrophic over long time periods. Assuming strong responses to hydrogeological changes in the basin, we attempted to determine the dynamic eutrophication history of these lakes. Although evaluation models for internal total phosphorus (TP) loading are widely used for deep lakes in Europe and North America, the accuracy of these models for shallow lakes that have smaller water volumes controlled by the geometrical morphology and greater basin area of alluvial plains is unknown. To describe the magnitude of changes in velocity of trophic state for the studied shallow lakes, we first evaluated the P retention model in relation to the major forces driving lake morphology, basin climate, and external discharge and then used the model to estimate changes in TP in three large shallow lakes (Taihu, Chao, and Poyang) over 60 years (1950-2009 AD). The observed levels of TP were verified against the relative error of the three lakes (Yangtze River basin. This work will contribute to the development of an internal P loading model for further evaluating trophic states.

  8. Linking development and determinacy with organic acid efflux from proteoid roots of white lupin grown with low phosphorus and ambient or elevated atmospheric CO{sub 2} concentration

    Energy Technology Data Exchange (ETDEWEB)

    Watt, M.; Evans, J.R.

    1999-07-01

    White lupin (Lupinus albus L.) was grown in hydroponic culture with 1 {micro}M phosphorus to enable the development of proteoid roots to be observed in conjunction with organic acid exudation. Discrete regions of closely spaced, determinate secondary laterals emerged in near synchrony on the same plant. One day after reaching their final length, citrate exudation occurred over a 3-d pulse. The rate of exudation varied diurnally, with maximal rates during the photoperiod. At the onset of citrate efflux, rootlets had exhausted their apical meristems and had differentiated root hairs and vascular tissues along their lengths. Neither in vitro phosphoenolpyruvate carboxylase nor citrate synthase activity was correlated with the rate of citrate exudation. The authors suggest that an unidentified transport process, presumably at the plasma membrane, regulates citrate efflux. Growth with elevated atmospheric [CO{sub 2}] promoted earlier onset of rootlet determinacy by 1 d, resulting in shorter rootlets and citrate export beginning 1 d earlier as a 2-d diurnal pulse. Citrate was the dominant organic acid exported, and neither the rate of exudation per unit length of root nor the composition of exudate was altered by atmospheric [CO{sub 2}].

  9. Total and Available Heavy Metal Concentrations and Assessment of Soil Pollution Indices in Selected Soils of Zanjan

    Directory of Open Access Journals (Sweden)

    M. Taheri

    2017-01-01

    Full Text Available Introduction: Soil is a hardly renewable natural resource. Although soil degradation, caused by either human activities and natural processes is a relatively slow procedure, but its effects are long lasting and most often, irreversible in the time scale of man's life. Among the most significant soil contaminants resulting from both natural and human sources, heavy metals are more important due to their long- term toxicity effects. For evaluating soil's enrichment rate by heavy metals, a wide and full study of soils background values, including total and available fractions of heavy metal contents should be done. Zanjan province has some great mines and concentrating industries of lead and zinc especially in Angoran, Mahneshan. Unfortunately produced waste materials of these industries spread over the adjacent areas. Investigations showed that accumulation of some heavy metals in vegetables and crops planted in this region had occurred. Therefore, performing some investigations in these polluted areas and assessing pollution rate and heavy metals distribution in arable lands had prime importance. Our goals were: 1 determining the total and available amounts of Cu, Pb, Zn and Cd in the soils of arable lands in polluted areas of Zanjan city, 2 producing the distribution map for the metals mentioned above and 3 calculating pollution indices in the soils. Materials and Methods: The study area was in south west of Zanjan city. For soil sampling, a 1 Km by 1 Km grid defined in ArcGIS software on landuse layer and totally 144 points that placed on agricultural lands, due to our goals, were sampled. For sampling, in a 5m radius around the point we collected some subsamples from depth of 0 - 15 cm, and after mixing the subsamples, finally a 1Kg soil sample prepared and sent to the laboratory. Sampled soils were air dried and were passed through a 2mm sieve. Soils organic matter (OM content and texture were determined by Walkely-Black and Bouyoucos

  10. Selection of Common Bean Lines, Recombinant Inbred Lines and Commercial Genotypes Tolerant to Low Phosphorus Availability in an Acrisol Soil on the Basis of Root Traits and Grain Yield

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, A.; Gomez, L. A.; Morales, A. [Instituto de Suelos, MINAG (Cuba); others, and

    2013-11-15

    Common bean (Phaseolus vulgaris L.) is the most important food legume for human consumption worldwide and especially in Latin America and Africa, but low soil phosphorus (P) availability limits grain production in these areas. For these reason eighty five recombinant inbred lines (RILs) of BAT 477 x DOR 364 and twenty commercial bean genotypes were sown in plots in an Acrisol soil with low P availability to evaluate nine root traits and grain yield. The study was carried out in Pinar del Rio province in Cuba between November 2006 and February 2009. The plots received basal fertilization (N and K) and P fertilization between 15 and 90 kg P{sub 2}O{sub 5} ha{sup -1}. Ten plants were sampled from each plot at R{sub 6} pod fill to evaluate root traits and shoot biomass, and at R{sub 9} physiological maturity to estimate grain yield. The 85 RILs showed great variability for root traits, grain yield and P stress tolerance calculated as relative grain yield. The commercial bean lines also showed large diversity in yield parameters. Principal Component Analysis showed that there were high and significant correlations between root traits (basal root number, primary root depth, adventitious root length and adventitious root number) and grain yield parameters (grain yield at 15 P level and relative grain yields). Adventitious root traits showed the greatest correlation with yield under low P. Promising RILs included 75.1.1, 60.1.1, 38.1.1, 14.1.1 and 38.1.1 and promising commercial bean lines included ICA Pijao, BAT 482, ICA 23, BAT 24 and BAT 832. (author)

  11. Effect of continuous intravenous administration of a 50% dextrose solution on phosphorus homeostasis in dairy cows.

    Science.gov (United States)

    Grünberg, Walter; Morin, Dawn E; Drackley, James K; Barger, Anne M; Constable, Peter D

    2006-08-01

    To determine the effect of continuous IV administration of 50% dextrose solution on phosphorus homeostasis in lactating dairy cows. Clinical trial. 4 multiparous Jersey cows. Cows were administered 50% dextrose solution IV (0.3 g/kg/h [0.14 g/lb/h]) for 5 days. Plasma concentrations of glucose, immune-reactive insulin (IRI), and phosphorus were determined before, during, and for 72 hours after dextrose infusion. Phosphorus intake and losses of phosphorus in urine, feces, and milk were determined. Each cow received a sham treatment that included instrumentation and sampling but not administration of dextrose. Plasma glucose, IRI, and phosphorus concentrations were stable during sham treatment. Plasma phosphorus concentration decreased rapidly after onset of dextrose infusion, reaching a nadir in 24 hours and remaining less than baseline value for 36 hours. Plasma phosphorus concentration increased after dextrose infusion was stopped, peaking in 6 hours. Urinary phosphorus excretion did not change during dextrose infusion, but phosphorus intake decreased because of reduced feed intake, followed by decreased fecal phosphorus loss and milk yield. Rapid changes in plasma phosphorus concentration at the start and end of dextrose infusion were temporally associated with changes in plasma glucose and IRI concentrations and most likely caused by compartmental shifts of phosphorus. Hypophosphatemia developed in response to hyperglycemia or hyperinsulinemia in dairy cows administered dextrose via continuous IV infusion. Veterinarians should monitor plasma phosphorus concentration when administering dextrose in this manner, particularly in cows with decreased appetite or preexisting hypophosphatemia.

  12. Concentrations and Fractionation of Carbon, Iron, Sulfur, Nitrogen and Phosphorus in Mangrove Sediments Along an Intertidal Gradient (Semi-Arid Climate, New Caledonia

    Directory of Open Access Journals (Sweden)

    Jonathan Deborde

    2015-02-01

    Full Text Available In mangrove ecosystems, strong reciprocal interactions exist between plant and substrate. Under semi-arid climate, Rhizophora spp. are usually predominant, colonizing the seashore, and Avicennia marina develops at the edge of salt-flats, which is the highest zone in the intertidal range. Along this zonation, distribution and speciation of C, Fe, S, N, and P in sediments and pore-waters were investigated. From the land-side to the sea-side of the mangrove, sediments were characterized by I/ increase in: (i water content; (ii TOC; (iii mangrove-derived OM; II/ and decrease in: (i salinity; (ii redox; (iii pH; (iv solid Fe and solid P. Beneath Avicennia and Rhizophora, TS accumulated at depth, probably as a result of reduction of iron oxides and sulfate. The loss of total Fe observed towards the sea-side may be related to sulfur oxidation and to more intense tidal flushing of dissolved components. Except the organic forms, dissolved N and P concentrations were very low beneath Avicennia and Rhizophora stands, probably as a result of their uptake by the root systems. However, in the unvegetated salt-flat, NH4+ can accumulate in organic rich and anoxic layers. This study shows: (i the evolution of mangrove sediment biogeochemistry along the intertidal zone as a result of the different duration of tidal inundation and organic enrichment; and (ii the strong links between the distribution and speciation of the different elements.

  13. Simulating the effects of phosphorus limitation in the Mississippi and Atchafalaya River plumes

    Directory of Open Access Journals (Sweden)

    A. Laurent

    2012-11-01

    Full Text Available The continental shelf of the northern Gulf of Mexico receives high dissolved inorganic nitrogen and phosphorus loads from the Mississippi and Atchafalaya rivers. The nutrient load results in high primary production in the river plumes and contributes to the development of hypoxia on the Louisiana shelf in summer. While phytoplankton growth is considered to be typically nitrogen-limited in marine waters, phosphorus limitation has been observed in this region during periods of peak river discharge in spring and early summer. Here we investigate the presence, spatio-temporal distribution and implications of phosphorus limitation in the plume region using a circulation model of the northern Gulf of Mexico coupled to a multi-nutrient ecosystem model. Results from a 7-yr simulation (2001–2007 compare well with several sources of observations and suggest that phosphorus limitation develops every year between the Mississippi and Atchafalaya deltas. Model simulations show that phosphorus limitation results in a delay and westward shift of a fraction of river-stimulated primary production. The consequence is a reduced flux of particulate organic matter to the sediment near the Mississippi delta, but slightly enhanced fluxes west of Atchafalaya Bay. Simulations with altered river phosphate concentrations (±50% show that significant variation in the spatial extent of phosphorus limitation (±40% in July results from changes in phosphate load.

  14. Application of contact stabilization activated sludge for enhancing biological phosphorus removal (EBPR in domestic wastewater

    Directory of Open Access Journals (Sweden)

    Ehab M. Rashed

    2014-04-01

    Full Text Available The experiment has been performed in order to investigate the effect of using contact stabilization activated sludge as an application of enhancing biological phosphorous removal (EBPR by using contact tank as a phosphorus uptake zone and using thickening tank as a phosphorus release zone. The study involved the construction of a pilot plant which was setup in Quhafa waste water treatment plant (WWTP that included contact, final sedimentation, stabilization and thickening tanks, respectively with two returns sludge in this system one of them to contact tank and another to stabilization tank. Then observation of the uptake and release of total phosphorus by achievement through two batch test using sludge samples from thickener and final sedimentations. Results showed the removal efficiencies of COD, BOD and TP for this pilot plant with the range of 94%, 85.44% and 80.54%, respectively. On the other hand the results of batch tests showed that the reason of high ability of phosphorus removal for this pilot plant related to the high performance of microorganisms for phosphorus accumulating. Finally the mechanism of this pilot plant depends on the removal of the phosphorus from the domestic waste water as a concentrated TP solution from the supernatant above the thickening zone not through waste sludge like traditional systems.

  15. Characteristic of wet method of phosphorus recovery from polish sewage sludge ash with nitric acid

    Directory of Open Access Journals (Sweden)

    Gorazda Katarzyna

    2016-01-01

    Full Text Available Sewage Sludge Ash (SSA is a concentrated source of phosphorus and can be successfully recycled via a number of different routes. This paper presents research results on phosphorus recovery from differently combusted sewage sludge with the use of nitric acid extraction. Different SSA forms from Polish thermal utilization stations were compared. It was revealed that sewage treatment technology as well as combustion technology influence many physical and chemical parameters of ashes that are crucial for further phosphorus recovery from such waste according to the proposed method. Presented research defines extraction efficiency, characterized extracts composition and verifies the possibility of using SSA as cheaper and alternative sources of phosphorus compounds. Gdynia, Kielce and Kraków SSA have the best properties for the proposed technology of phosphorus recovery with high extraction efficiency greater than 86%. Unsuitable results were obtained for Bydgoszcz, Szczecin Slag and Warszawa SSA. Extraction process for Łódź and Szczecin Dust SSA need to be improved for a higher phosphorus extraction efficiency greater than 80%.

  16. Characterization of phosphorus leaching from phosphate waste rock in the Xiangxi River watershed, Three Gorges Reservoir, China.

    Science.gov (United States)

    Jiang, Li-Guo; Liang, Bing; Xue, Qiang; Yin, Cheng-Wei

    2016-05-01

    Phosphate mining waste rocks dumped in the Xiangxi River (XXR) bay, which is the largest backwater zone of the Three Gorges Reservoir (TGR), are treated as Type I industry solid wastes by the Chinese government. To evaluate the potential pollution risk of phosphorus leaching from phosphate waste rocks, the phosphorus leaching behaviors of six phosphate waste rock samples with different weathering degrees under both neutral and acidic conditions were investigated using a series of column leaching experiments, following the Method 1314 standard of the US EPA. The results indicate that the phosphorus release mechanism is solubility-controlled. Phosphorus release from waste rocks increases as pH decreases. The phosphorus leaching concentration and cumulative phosphorus released in acidic leaching conditions were found to be one order of magnitude greater than that in neutral leaching conditions. In addition, the phosphorus was released faster during the period when environmental pH turned from weak alkalinity to slight acidity, with this accelerated release period appearing when L/S was in the range of 0.5-2.0 mL/g. In both neutral and acidic conditions, the average values of Total Phosphorus (TP), including orthophosphates, polyphosphates and organic phosphate, leaching concentration exceed the availability by regulatory (0.5 mg/L) in the whole L/S range, suggesting that the phosphate waste rocks stacked within the XXR watershed should be considered as Type II industry solid wastes. Therefore, the phosphate waste rocks deposited within the study area should be considered as phosphorus point pollution sources, which could threaten the adjacent surface-water environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Quantifying phosphorus levels in soils, plants, surface water, and shallow groundwater associated with bahiagrass-based pastures.

    Science.gov (United States)

    Sigua, Gilbert C; Hubbard, Robert K; Coleman, Samuel W

    2010-01-01

    Recent assessments of water quality status have identified eutrophication as one of the major causes of water quality 'impairment' not only in the USA but also around the world. In most cases, eutrophication has accelerated by increased inputs of phosphorus due to intensification of crop and animal production systems since the early 1990 s. Despite substantial measurements using both laboratory and field techniques, little is known about the spatial and temporal variability of phosphorus dynamics across landscapes, especially in agricultural landscapes with cow-calf operations. Critical to determining environmental balance and accountability is an understanding of phosphorus excreted by animals, phosphorus removal by plants, acceptable losses of phosphorus within the manure management and crop production systems into soil and waters, and export of phosphorus off-farm. Further research effort on optimizing forage-based cow-calf operations to improve pasture sustainability and protect water quality is therefore warranted. We hypothesized that properly managed cow-calf operations in subtropical agroecosystem would not be major contributors to excess loads of phosphorus in surface and ground water. To verify our hypothesis, we examined the comparative concentrations of total phosphorus among soils, forage, surface water, and groundwater beneath bahiagrass-based pastures with cow-calf operations in central Florida, USA. Soil samples were collected at 0-20; 20-40, 40-60, and 60-100 cm across the landscape (top slope, middle slope, and bottom slope) of 8 ha pasture in the fall and spring of 2004 to 2006. Forage availability and phosphorus uptake of bahiagrass were also measured from the top slope, middle slope, and bottom slope. Bi-weekly (2004-2006) groundwater and surface water samples were taken from wells located at top slope, middle slope, and bottom slope, and from the runoff/seepage area. Concentrations of phosphorus in soils, forage, surface water, and shallow

  18. Effect of phosphorus level on nitrogen accumulation and yield in soybean

    International Nuclear Information System (INIS)

    You Yubo; Wu Dongmei; Gong Zhenping; Ma Chunmei

    2012-01-01

    In this paper, the 15 N labeling with sand culture was conducted to study effects of phosphorus level on nitrogen accumulation, nodule nitrogen fixation and yield of soybean plants. Results showed that nitrogen accumulation, fixation and yield of soybean plants all presented a single peak curve with improvement of phosphorus nutrition level, with the peak value of phosphorus concentration in nutrient solution of 31 mg/L. When phosphorus concentration of nutrient solution was 11 mg/L, no obvious promotion was found on the ratio of nodule nitrogen fixation when increasing phosphorus concentration again, However, when phosphorus concentration of nutrient solution was 21 mg/L, increasing phosphorus concentration again had no obvious promotion on soybean plant nitrogen accumulation, nodule nitrogen fixation accumulation and yield, indicating that effect of phosphorus nutrition level on nitrogen fixation was lower than that on yield formation level. (authors)

  19. Assessment of conservation easements, total phosphorus, and total suspended solids in West Fork Beaver Creek, Minnesota, 1999-2012

    Science.gov (United States)

    Christensen, Victoria G.; Kieta, Kristen A.

    2014-01-01

    in 2009 were affected by outlier concentrations documented in March 2009. Agricultural land-retirement data only were available through 2008; therefore, it was not possible to compare total phosphorus and total suspended solids concentrations to agricultural land-retirement data for 2009–11. A downward trend in annual flow-weighted mean total-phosphorus concentrations was related significantly to annual land retirement for 1999–2008. The relation between annual flow-weighted mean total suspended solids concentration and annual land retirement was not statistically significant for 1999–2008. If land-retirement data had been available for 2009–11, it is possible that the relation between total phosphorus and land retirement would no longer be evident because of the marked increase in flow-weighted concentrations during 2009. Alternatively, the increase in annual flow-weighted mean total-phosphorus concentrations during 2009–11 may be because of other factors, including industrial discharges, increases in drain tile installation, changes in land use including decreases in agricultural land retirement after 2008, increases in erosion, increases in phosphorus applications to fields, or unknown causes. Inclusion of land-retirement effects in agency planning along with other factors adds perspective with regard to the broader picture of interdependent systems and allows agencies to make informed decisions on the benefits of perpetual easements compared to limited duration easements.

  20. Comparison of the Level of Boron Concentrations in Black Teas with Fruit Teas Available on the Polish Market

    Directory of Open Access Journals (Sweden)

    Anetta Zioła-Frankowska

    2014-01-01

    Full Text Available The determination of boron by inductively coupled plasma-atomic emission spectrometry has been carried in water-soluble and acid soluble (total content fractions of 36 samples of traditional black tea and fruit brew. The estimation of the impact of the type of tea on the concentration of boron in water-soluble and acid extracts and potential human health risk from the daily intake of boron was carried out in this study. The levels of boron differed significantly in black and fruit tea types. The mean total content of boron ranged from 8.31 to 18.40 mg/kg in black teas, from 12.85 to 15.13 mg/kg in black tea with fruit flavor, and from 12.09 to 22.77 mg/kg in fruit brews. The degree of extraction of boron in black tea ranged from 8% to 27% and for fruit tea from 17% to 69%. In addition, the values below 25% were of black teas with fruit flavors. The daily intake of B from tea infusions (three cups/day is still within the average daily intake except for some of the fruit brews which exceed acceptable regulations of the daily intake of total boron by humans. Hence, it may not produce any health risks for human consumption, if other sources of metal contaminated food are not taken at the same time.

  1. Phosphorus determination by various substoichiometric methods

    International Nuclear Information System (INIS)

    Shigematsu, Toshio; Kudo, Kiyoshi

    1981-01-01

    Various substoichiometric methods have been classified from a view point of the substoichiometric separation. Based upon the substoichiometric separation, phosphorus was determined substoichiometrically by a direct method, a method of carrier amount variation and a comparison method for the irradiated sample. The direct method was applied to the determination of phosphorus in orchard leaves (SRM-1571). The analytical value was 0.23 +- 0.01%. Phosphorus in orchard leaves and spinach (SRM-1570) was determined by an ordinary method which devided the sample into equal parts in the method of carrier amount variation. Analytical values of orchard leaves and spinach were 0.22 +- 0.02% and 0.56 +- 0.04%, respectively. Moreover, a new modification of the method of carrier amount variation was studied by the use of various standard samples such as red phosphorus, spinach and orchard leaves. These standard samples were also employed for the determination of phosphorus in orchard leaves and 0.21 +- 0.01% was obtained. All these results are in good agreement with the value reported by NBS. The comparison method was applied to the determination of phosphorus in a semiconductor silicon single crystal. As a result of the correction of 32 P activity induced by the secondary nuclear reaction of 30 Si, 7.9 ppb and 3.1 ppb were obtained for the phosphorus concentrations in the single crystal silicon. (author)

  2. Screening crops for efficient phosphorus acquisition in a low phosphorus soil using radiotracer technique

    International Nuclear Information System (INIS)

    Meena, S.; Malarvizhi, P.; Rajeswari, R.

    2017-01-01

    Deficiency of phosphorus (P) is the major limitation to agricultural production. Identification of cultivars with greater capacity to grow in soils having low P availability (phosphorus efficiency) will help in P management in a sustainable way. Green house experiment with maize (CO 6) and cotton (MCU 13) as test crops with four levels of phosphorus (0, 3.75, 7.50 and 15 mg P kg -1 soil) was conducted in a P deficient soil (7.2 kg ha -1 ) to study the phosphorus acquisition characteristics and to select efficient crop using 32 P radiotracer technique. Carrier free 32 P obtained as orthophosphoric acid in dilute hydrochloric acid medium from the Board of Radiation and Isotope Technology, Mumbai was used for labeling the soil @ 3200 kBq pot -1 . After 60 days the crops were harvested and the radioactivity was measured in the plant samples using Liquid scintillation counter (PerkinElmer - Tricarb 2810 TR). Different values of specific radioactivity and Isotopically Exchangeable Phosphorus for maize and cotton indicated that chemically different pools of soil P were utilized and maize accessing a larger pool than cotton. Maize having recorded high Phosphorus Use Efficiency, Phosphorus Efficiency and low Phosphorus Stress Factor values, it is a better choice for P deficient soils. Higher Phosphorus Acquisition Efficiency of maize (59 %) than cotton (48%) can be related to the ability of maize to take up P from insoluble inorganic P forms. (author)

  3. Impacts of dietary calcium, phytate, and nonphytate phosphorus concentrations in the presence or absence of phytase on inositol hexakisphosphate (IP6) degradation in different segments of broilers digestive tract

    Science.gov (United States)

    Li, W.; Angel, R.; Kim, S.-W.; Brady, K.; Yu, S.; Plumstead, P. W.

    2016-01-01

    A total of 1,440 straight-run Heritage 56M × fast-feathering Cobb 500F broiler birds were fed from 11 to 13 d of age to determine the impacts of calcium (Ca), phytate phosphorus (PP), nonphytate P (nPP) and phytase concentrations on the myo-inositol hexakisphosphate (IP6) flow through the different parts of gastrointestinal tract (GIT). The experiment was a 2×2×2×3 randomized block design with 2 Ca (0.7 and 1.0%), 2 PP (0.23 and 0.34%), 2 nPP (0.28 and 0.45%) and 3 phytase (0-, 500-, and 1,000-phytase unit (FTU)/kg) concentrations. The experiment was replicated twice (block) with 3 replicates per treatment (Trt) of 10 birds per block. Concentration of IP6 in crop, proventriculus (Prov) plus (+) gizzard (Giz) and distal ileum digesta as well as the ileal IP6 disappearance was determined at 13 d of age. In crop, higher IP6 concentration was seen with increased Ca (P phytase, higher dietary PP led to greater IP6 concentration (P phytase were also seen in Prov+Giz and ileum (P phytase improved IP6 degradation but the degree of impact was dependent on nPP and PP (P phytase inclusion significantly reduced IP6 concentration and IP6 disappearance in distal ileum regardless of GIT segments or diet composition, but impacts of dietary Ca, nPP, and PP differed depending on GIT segment examined. PMID:26740131

  4. Effect of dietary calcium concentrations in low non-phytate phosphorus diets containing phytase on growth performance, bone mineralization, litter quality, and footpad dermatitis incidence in growing broiler chickens.

    Science.gov (United States)

    Kim, Jong Hyuk; Jung, Hyunjung; Pitargue, Franco Martinez; Han, Gi Ppeum; Choi, Hyeon Seok; Kil, Dong Yong

    2017-07-01

    An experiment was conducted to investigate the effect of dietary Ca concentrations in low non-phytate phosphorus (NPP) diets containing phytase on growth performance, bone mineralization, litter quality, and footpad dermatitis (FPD) incidence in growing broiler chickens. A total of 1,800 21-day-old Ross 308 growing broiler chickens were allotted to 1 of 6 dietary treatments with 6 replicated cages. Six diets were formulated to provide increasing Ca concentrations of 4.0, 5.0, 6.0, 7.0, 8.0, or 9.0 g/kg in diets. The concentrations of NPP in all diets were maintained at 3.0 g/kg, and phytase was supplemented to all diets at the level of 1,000 fytase units (FTU)/kg. At the end of the 14-d feeding trial, birds were euthanized for tibia sampling, and litter samples were collected from 3 areas in the cage. The FPD incidence was measured based on a 6-point scoring system. Dietary Ca concentrations had no effect on growth performance of growing broiler chickens. However, a tendency (linear, p = 0.05) for decreased feed efficiency was observed as dietary Ca concentrations were increased. The concentrations of Ca and P in the tibia of broiler chickens increased (linear and quadratic, pLitter pH, moisture, and N contents were not affected by increasing Ca concentrations in low NPP diets containing phytase. However, a tendency (quadratic, p = 0.10) for increased FPD incidence with increasing dietary Ca concentrations was observed. Dietary Ca concentrations from 4.0 to 9.0 g/kg in low NPP diets containing phytase have little effects on growth performance of growing broiler chickens. However, Ca and P concentrations in the tibia are decreased if dietary Ca concentrations are less than 5.0 g/kg. The FPD incidence for growing broiler chickens may be decreased if less than 9.0 g/kg of Ca is included in diets.

  5. Biological phosphorus cycling in dryland regions

    Science.gov (United States)

    Belnap, Jayne; Bunemann, Else; Oberson, Astrid; Frossard, Emmanuel

    2011-01-01

    The relatively few studies done on phosphorus (P) cycling in arid and semiarid lands (drylands) show many factors that distinguish P cycling in drylands from that in more mesic regions. In drylands, most biologically relevant P inputs and losses are from the deposition and loss of dust. Horizontal and vertical redistribution of P is an important process. P is concentrated at the soil surface and thus vulnerable to loss via erosion. High pH and CaCO3 limit P bioavailability, and low rainfall limits microbe and plant ability to free abiotically bound P via exudates, thus making it available for uptake. Many invasive plants are able to access recalcitrant P more effectively than are native plants. As P availability depends on soil moisture and temperature, climate change is expected to have large impacts on P cycling

  6. Phosphorus poisoning in waterfowl

    Science.gov (United States)

    Coburn, D.R.; DeWitt, J.B.; Derby, J.V.; Ediger, E.

    1950-01-01

    Black ducks and mallards were found to be highly susceptible to phosphorus poisoning. 3 mg. of white phosphorus per kg. of body weight given in a single dose resulted in death of a black duck in 6 hours. Pathologic changes in both acute and chronic poisoning were studied. Data are presented showing that diagnosis can be made accurately by chemical analysis of stored tissues in cases of phosphorus poisoning.

  7. 75 FR 76336 - Notice of Data Availability Regarding Two Studies of Ambient Lead Concentrations Near a General...

    Science.gov (United States)

    2010-12-08

    ... studies are located in Docket ID No. EPA-HQ-OAR-2006-0735. II. How does this information relate to the.... Modeling results show aircraft engine run-up is the most important source contribution to the maximum lead concentration. Sensitivity analysis shows that engine run-up time, lead concentration in aviation gasoline, and...

  8. Phosphorus Characteristics with Controlled Nitrogen in Fertile Soils in Protected Vegetable Field

    Directory of Open Access Journals (Sweden)

    WANG Heng

    2014-06-01

    Full Text Available There is an unreasonable phenomenon of fertilization in vegetable facility cultivation, with the serious imbalance of soil nutrient. In purpose of understanding the absorption characteristics of phosphorus from nitrogen-rich soil, a long-term nitrogen-controlled experiment was carried from the year 2004 to 2007, and a split plot experiment of leaching was carried in winter-spring season of 2007. The results showed that the content of phosphorus varied with different nitrogen control. The TP was decreased with nitrogen supply of none(NN 、organic manure(MN 、organic manure and straw(MN+S, and the decreased range was NN>MN>MN+S, meanwhile the increase range of TP was traditional-nitrogen(CN >traditional-nitrogen+straw(CN+S >optimized-nitrogen+straw(SN+S >optimized-nitrogen(SN. The available P with CN and CN+S reached to 213.7 mg· kg -1 、225.4 mg·kg -1, which increased by 17.1 percent and 23.5 percent, which declared the phosphorus was accumulated; The available P with other nitrogen controlled decreased with the range of NN>MN>MN+S>SN+S>SN跃CN>CN+S, which showed that the supply reduction of nitrogen could slowdown the phosphorus accumulated and promote the utilization ratio of phosphorus. The organophosphorus was increased except NN, with obvious increase with CN、CN+S(308.4 mg·kg -1 、331.4 mg·kg -1 by 28.5 percent and 38.2 percent. The absorption coefficient of phosphorus with SN+S(P 2 O 5,mg· 100 g -1 reached to 1 571, increased by 143.6 percent; Otherwise the absorption coefficient of phosphorus with CN、CN+S showed negative growth, the CN dipped to 416(P 2 O 5,mg·100 g -1 by 35.5 percent. Adding wheat straw could greatly improved the capacity of absorption of phosphorus and slow down the accumulation of available phosphorus to some extent. The concentrations of total phosphorus in the filtrate with SN+S were less than SN, contrary to the concentration of organophosphorus, thus the straw returning had a certain effect on

  9. Peak Phosphorus: Clarifying the Key Issues of a Vigorous Debate about Long-Term Phosphorus Security

    Directory of Open Access Journals (Sweden)

    Stuart White

    2011-10-01

    Full Text Available This paper reviews the latest information and perspectives on global phosphorus scarcity. Phosphorus is essential for food production and modern agriculture currently sources phosphorus fertilizers from finite phosphate rock. The 2008 food and phosphate fertilizer price spikes triggered increased concerns regarding the depletion timeline of phosphate rock reserves. While estimates range from 30 to 300 years and are shrouded by lack of publicly available data and substantial uncertainty, there is a general consensus that the quality and accessibility of remaining reserves are decreasing and costs will increase. This paper clarifies common sources of misunderstandings about phosphorus scarcity and identifies areas of consensus. It then asks, despite some persistent uncertainty, what would it take to achieve global phosphorus security? What would a ‘hard-landing’ response look like and how could preferred ‘soft-landing’ responses be achieved?

  10. Phosphorus vertical migration in aquic brown soil and light chernozem under different phosphorous application rate: a soil column leaching experiment.

    Science.gov (United States)

    Zhao, Muqiu; Chen, Xin; Shi, Yi; Zhou, Quanlai; Lu, Caiyan

    2009-01-01

    A soil column leaching experiment was conducted to study the vertical migration of phosphorus in aquic brown soil and light chernozem under different phosphorus fertilization rates. The results showed that total dissolved phosphorus concentration in the leachates from the two soils was nearly the same, but dissolved inorganic phosphorus concentration was obviously different. In all fertilization treatments, aquic brown soil had a higher content of phosphorus in calcium chloride extracts compared with light chernozem. But Olsen phosphorus content was higher at the soil depth beneath 0-20 cm, and increased with increasing phosphorus application rate.

  11. Glyphosate sorption and desorption in soils with distinct phosphorus levels

    Directory of Open Access Journals (Sweden)

    Prata Fábio

    2003-01-01

    Full Text Available The sorption of glyphosate by soils occurs due to the inner sphere complex formation with metals of soil oxides, which are related to the soil phosphate adsorption capacity. The aim of this study was to evaluate the effects of increasing rates of phosphorus on sorption and desorption of glyphosate in three soils with different mineralogical attributes. Soils were a Rhodic Kandiudalf, an Anionic Acrudox and a Typic Humaquept. Soil samples were amended with KH2PO4 at equivalent rates of 0; 1,000; 5,000; 20,000 and 50,000 kg ha-1 of P2O5, which are high from the agricultural point of view, but necessary in order to perform sorption and desorption studies. The experimental design consisted of a completely randomized factorial: 2 soils x 5 phosphorus rates and 3 replicates. For the sorption experiments, five glyphosate solutions were employed (0.42; 0.84; 1.68; 3.36 and 6.72 mg L-1, with a 14C radioactivity of 0.233 kBq mL-1. Four steps of the desorption procedure with CaCl2 0.01 mol L-1 and one extraction with Mehlich 3 were performed only at one concentration (0.84 mol L-1. Soil samples were afterwards biologically oxidized to establish the radioactive balance. Glyphosate competes with phosphorus for specific sorption sites, but this competition becomes important when phosphorus is present at rates higher than 1,000 mg dm-3. Moreover, a small amount of applied glyphosate was extracted (<10%, and the extraction increased with increasing soil phosphorus content.

  12. Increasing Dietary Phosphorus Intake from Food Additives: Potential for Negative Impact on Bone Health123

    OpenAIRE

    Takeda, Eiji; Yamamoto, Hironori; Yamanaka-Okumura, Hisami; Taketani, Yutaka

    2014-01-01

    It is important to consider whether habitual high phosphorus intake adversely affects bone health, because phosphorus intake has been increasing, whereas calcium intake has been decreasing in dietary patterns. A higher total habitual dietary phosphorus intake has been associated with higher serum parathyroid hormone (PTH) and lower serum calcium concentrations in healthy individuals. Higher serum PTH concentrations have been shown in those who consume foods with phosphorus additives. These fi...

  13. A new model of tail diffusion of phosphorus and boron in silicon

    International Nuclear Information System (INIS)

    Morehead, F.F.; Lever, R.F.

    1986-01-01

    It is well known that high surface concentration phosphorus diffusion leads to deeply penetrating tails in its concentration profile. At 700 0 C the tail diffusivity exceeds that of low concentration phosphorus by a factor of a thousand. Less spectacular, but very significant tailing also affects boron, making the conventional models contained in commonly available process simulation programs quite inaccurate for boron diffusions with high surface concentrations. The authors show that the observed tailing can be accounted for by a model whose central assumption is the local equality of dopant and oppositely directed defect fluxes. As predicted by the model, the effect is greatest for normal processing at low temperatures for high surface concentrations. It is minimal for the high temperatures of rapid thermal annealing and unrelated to transient effects

  14. Phytoextraction of excess soil phosphorus

    International Nuclear Information System (INIS)

    Sharma, Nilesh C.; Starnes, Daniel L.; Sahi, Shivendra V.

    2007-01-01

    In the search for a suitable plant to be used in P phytoremediation, several species belonging to legume, vegetable and herb crops were grown in P-enriched soils, and screened for P accumulation potentials. A large variation in P concentrations of different plant species was observed. Some vegetable species such as cucumber (Cucumis sativus) and yellow squash (Cucurbita pepo var. melopepo) were identified as potential P accumulators with >1% (dry weight) P in their shoots. These plants also displayed a satisfactory biomass accumulation while growing on a high concentration of soil P. The elevated activities of phosphomonoesterase and phytase were observed when plants were grown in P-enriched soils, this possibly contributing to high P acquisition in these species. Sunflower plants also demonstrated an increased shoot P accumulation. This study shows that the phytoextraction of phosphorus can be effective using appropriate plant species. - Crop plants such as cucumber, squash and sunflower accumulate phosphorus and thus can be used in the phytoextraction of excess phosphorus from soils

  15. Phytoextraction of excess soil phosphorus

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Nilesh C. [Department of Biology, Western Kentucky University, 1906 College Heights Boulevard 11080, Bowling Green, KY 42101-1080 (United States); Starnes, Daniel L. [Department of Biology, Western Kentucky University, 1906 College Heights Boulevard 11080, Bowling Green, KY 42101-1080 (United States); Sahi, Shivendra V. [Department of Biology, Western Kentucky University, 1906 College Heights Boulevard 11080, Bowling Green, KY 42101-1080 (United States)]. E-mail: shiv.sahi@wku.edu

    2007-03-15

    In the search for a suitable plant to be used in P phytoremediation, several species belonging to legume, vegetable and herb crops were grown in P-enriched soils, and screened for P accumulation potentials. A large variation in P concentrations of different plant species was observed. Some vegetable species such as cucumber (Cucumis sativus) and yellow squash (Cucurbita pepo var. melopepo) were identified as potential P accumulators with >1% (dry weight) P in their shoots. These plants also displayed a satisfactory biomass accumulation while growing on a high concentration of soil P. The elevated activities of phosphomonoesterase and phytase were observed when plants were grown in P-enriched soils, this possibly contributing to high P acquisition in these species. Sunflower plants also demonstrated an increased shoot P accumulation. This study shows that the phytoextraction of phosphorus can be effective using appropriate plant species. - Crop plants such as cucumber, squash and sunflower accumulate phosphorus and thus can be used in the phytoextraction of excess phosphorus from soils.

  16. Phosphorus recycling from an unexplored source by polyphosphate accumulating microalgae and cyanobacteria – a step to phosphorus security in agriculture

    Directory of Open Access Journals (Sweden)

    Chandan eMukherjee

    2015-12-01

    Full Text Available Phosphorus (P, an essential element required for crop growth has no substitute. The global food security depends on phosphorus availability in soil for crop production. World phosphorus reserves are fast depleting and with an annual increase of 2.3% in phosphorus demand, the current reserves will be exhausted in coming 50-100 years. India and other Western countries are forced to import phosphorus fertilizers at high costs to meet their agricultural demands due to uneven distribution of phosphate rocks on earth. The present study from India, aims to draw attention to an unnoticed source of phosphorus being wasted as parboiled rice mill effluent and subsequent bio-recovery of the valuable element from this unconventional source. The research was conducted in West Bengal, India, a state with the highest number of parboiled rice mills where its effluent carries on an average ~40 mg/L of soluble phosphorus. Technology to recover and recycle this wastewater P in India in a simple, inexpensive mode is yet to be optimized. Our strategy to use microalgae, Chlorella sp. and cyanobacteria, Cyanobacterium sp., Lyngbya sp. and Anabaena sp. to sequester the excess phosphorus from the effluent as polyphosphate inclusions and its subsequent recycling as slow and moderate release phosphorus biofertilizers to aid plant growth, preventing phosphorus loss and pollution, is a contemporary venture to meet the need of the hour. These polyphosphate accumulating microorganisms play a dual role of remediation and recovery of phosphorus, preliminarily validated in laboratory scale.

  17. Molecular Design of Nanofiltration Membranes for the Recovery of Phosphorus from Sewage Sludge

    KAUST Repository

    Thong, Zhiwei

    2016-08-24

    With the rapid depletion of mineral phosphorus, the recovery of phosphorus from sewage sludge becomes increasingly important. However, the presence of various contaminants such as heavy metals in sewage sludge complicates the issue. One must separate phosphorus from the heavy metals in order to produce fertilizers of high quality. Among various available methods, nanofiltration (NF) has been demonstrated to be a feasible and promising option when the sewage sludge undergoes acidic dissolution and the operating pH is around 2. Because the performance of commercially available thin film composite (TFC) NF membranes reported thus far has great room for improvement, the development of highly permeable positively charged NF membranes is recommended. To this aim, a NF membrane that is desirable for phosphorus recovery was fabricated via interfacial polymerization of polyethylenimine (PEI) and trimesoyl chloride (TMC) on a porous poly(ether sulfone) (PES) membrane substrate. Through an optimization of the interfacial polymerization process, which involves varying the molecular weight of PEI and the concentration of TMC, the resultant membrane displays a low molecular weight cutoff (MWCO) of 170 Da with a reasonably high pure water permeability (A) of 6.4 LMH/bar. The newly developed NF membrane can effectively reject a wide variety of heavy metal ions such as Cu, Zn, Pb and Ni (>93%) while demonstrating a low phosphorus rejection of 19.6% at 10 bar using a feed solution of pH 2. Thus, up to 90% of the feed phosphorus may be recovered using this newly developed NF membrane at a permeate recovery of 90%. This is a highly competitive value for the recovery of phosphorus. © 2016 American Chemical Society.

  18. Improving phosphorus availability from Patos phosphate rock for Eucalyptus: a study with 32P radiotracer; Melhorando a disponibilidade de fosforo da rocha fosforica de Patos para eucalipto: um estudo com radiotracador 32P

    Energy Technology Data Exchange (ETDEWEB)

    Villanueva, Felipe Carlos Alvarez [Instituto de Investigaciones Fundamentales en Agriculturea Tropical (INIFAT), Santiago de las Vegas, La Habana (Cuba)]. E-mail: falvarez@cena.usp.br; Muraoka, Takashi; Trevizam, Anderson Ricardo [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Fertilidade do Solo; Franzini, Vinicius Ide [Sao Paulo Univ., Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz. Programa de Pos-graduacao em Solos e Nutricao de Plantas; Rocha, Alexandre Prado [Escola de Engenharia de Piracicaba, SP (Brazil)

    2006-01-15

    Eucalyptus plantation in Brazil is generally set on low fertility soils, therefore phosphorus (P) fertilization is mandatory and increases the cost of plantation operation. Using species that more efficiently uptake phosphorus from less soluble sources is an interesting option. However, little is known about eucalyptus regarding its ability of using less soluble forms of phosphorus. The use of P by eucalyptus (E. urophylla, E. grandis, and E. urophylla E. grandis) was studied in greenhouse using a loamy-textured, hipodystrophic Typic Haplustox from the Cerrado region, and 32P isotopic method. The P sources tested were triple superphosphate (TSP), phosphate rock (PR) and the triple superphosphate mixed with PR (TSP+PR). The effectiveness of P sources in terms of increasing dry matter yield was TSP = (TSP + PR) > PR, and the P uptake followed the order (TSP + PR) > TSP > PR for both species plus the hybrid. The increase in P uptake from PR due to TSP influence was 217.3% for E. urophylla, 235.7% for E. grandis, and 28.7% for E. urophylla E. grandis, indicating an enhancement effect of TSP on the effectiveness of PR. The hybrid E. urophylla E. grandis was the most efficient genotype on P soil use and E. grandis most exigent in P fertilizer. (author)

  19. Phosphorus vacancy cluster model for phosphorus diffusion gettering of metals in Si

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Renyu; Trzynadlowski, Bart; Dunham, Scott T. [Department of Electrical Engineering, University of Washington, Seattle, Washington 98195 (United States)

    2014-02-07

    In this work, we develop models for the gettering of metals in silicon by high phosphorus concentration. We first performed ab initio calculations to determine favorable configurations of complexes involving phosphorus and transition metals (Fe, Cu, Cr, Ni, Ti, Mo, and W). Our ab initio calculations found that the P{sub 4}V cluster, a vacancy surrounded by 4 nearest-neighbor phosphorus atoms, which is the most favorable inactive P species in heavily doped Si, strongly binds metals such as Cu, Cr, Ni, and Fe. Based on the calculated binding energies, we build continuum models to describe the P deactivation and Fe gettering processes with model parameters calibrated against experimental data. In contrast to previous models assuming metal-P{sub 1}V or metal-P{sub 2}V as the gettered species, the binding of metals to P{sub 4}V satisfactorily explains the experimentally observed strong gettering behavior at high phosphorus concentrations.

  20. Phosphorus and phytase levels for layer hens

    OpenAIRE

    Juliana Cristina Ramos Rezende; Antonio Carlos de Laurentiz; Rosemeire da Silva Filardi; Vitor Barbosa Fascina; Daniella Aparecida Berto; Sérgio Turra Sobrane Filho

    2013-01-01

    The objective of this research was to evaluate the performance and bone quality of laying hens after peak production fed diets containing phosphorus levels and phytase. An experiment was conducted with 384 Hy-line distributed in a completely randomized in a factorial 4 x 3 with 4 levels of available phosphorus and 3 levels of phytase. The experimental period was divided into four periods of 28 days, at the end of each cycle were determined experimental feed intake, egg production, egg weight,...

  1. Further developments and field deployment of phosphorus functionalized polymeric scale inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Todd, Malcolm J.; Thornton, Alex R.; Wylde, Jonathan J.; Strachan, Catherine J.; Moir, Gordon [Clariant Oil Services, Muttenz (Switzerland); Goulding, John [John Goulding Consultancy, York (United Kingdom)

    2012-07-01

    As the oil and gas industry strives to replace ageing, environmentally undesirable scale inhibitors there is an ever increasing use of polymeric inhibitors. The incorporation of phosphorous functionality into a polymer backbone has been shown to improve inhibition efficiency, enhance adsorption characteristics and allow the polymer concentration to be analyzed by elemental phosphorus. It is known that some phosphorus tagged polymers can be problematic to analyze in oil field brines as they typically have a low phosphorus content which is difficult to determine from the background. The development of novel phosphorus functionalized polymeric scale inhibitors was previously described (IBP3530-10). This paper follows the development of the inhibitor class. Utilizing extensive laboratory testing the interactive nature of the scale inhibitors and reservoir lithology was studied. These novel phosphorus functionalized inhibitors were compared to a number of other available scale inhibitors. The incorporation of phosphorus functionality into polymeric inhibitors can be expensive utilizing traditional methods as the phosphorus containing monomers are the financially limiting factor. These are typically vinyl phosphonic acid (VPA), or vinyl diphosphonic acid (VDPA). The novel phosphorus functionalized monomers utilized herein are simpler to manufacture allowing higher phosphorus content within the polymer backbone. The addition of phosphorus into a polymer backbone has previously been known to exacerbate analysis issues in some commercially available scale inhibitors. This is due to incomplete polymerization reactions leaving free and/or inorganic phosphorus containing moieties which can interfere with the analysis, or low levels of phosphorus within end-capped polymers can make it difficult to determine the active concentration accurately within field brines which contain many impuritie. Polymeric inhibitors are known to contain a range of molecular weights with varying

  2. Global patterns of foliar nitrogen isotopes and their relationships with climate, mycorrhizal fungi, foliar nutrient concentrations, and nitrogen availability

    Science.gov (United States)

    Joseph M. Craine; Andrew J. Elmore; Marcos P. M. Aidar; Mercedes Bustamante; Todd E. Dawson; Erik A. Hobbie; Ansgar Kahmen; Michelle C. Mack; Kendra K. McLauchlan; Anders Michelsen; Gabriela Nardoto; Linda H. Pardo; Josep Penuelas; Peter B. Reich; Edward A.G. Schuur; William D. Stock; Pamela H. Templer; Ross A. Virginia; Jeffrey M. Welker; Ian J. Wright

    2009-01-01

    Ratios of nitrogen (N) isotopes in leaves could elucidate underlying patterns of N cycling across ecological gradients. To better understand global-scale patterns of N cycling, we compiled data on foliar N isotope ratios, foliar N concentrations, mycorrhizal type and climate for over 11 000 plants worldwide. Global-scale comparisons of other components of the N cycle...

  3. US Subseabed Disposal Program radioecological data base: summaries of available radionuclide concentration factors and biological half-lives

    International Nuclear Information System (INIS)

    Gomez, L.S.; Marietta, M.G.; Jackson, D.W.

    1984-01-01

    The US Subseabed Disposal Program has compiled an extensive objective concentration factor and biological half-life data base from the international marine radioecological literature. A microcomputer-based data management system has been implemented to provide statistical and graphical summaries of these data. The data base is constructed in a manner which allows subsets to be sorted using a number of inter-study variables such as organism category, tissue/organ category, geographic location (for in situ studies), and several laboratory-related conditions (e.g., exposure time and exposure concentration). We discuss concentration factor data summaries for many elements. We also discuss summary material for biological half-life data. We discuss the results of our review with the estimates of mean concentration factors provided by the IAEA. It is proposed that this presentation scheme will enable those concerned with predictive assessment of radiation dose in the marine environment to make a more judicious selection of data for a given application. 7 references

  4. Global patterns of foliar nitrogen isotopes and their relationships with climate, mycorrhizal fungi, foliar nutrient concentrations, and nitrogen availability

    DEFF Research Database (Denmark)

    Craine, J M; Elmore, A J; Aidar, M P M

    2009-01-01

    Ratios of nitrogen (N) isotopes in leaves could elucidate underlying patterns of N cycling across ecological gradients. To better understand global-scale patterns of N cycling, we compiled data on foliar N isotope ratios (d15N), foliar N concentrations, mycorrhizal type and climate for over 11 00...

  5. Sewage-effluent phosphorus: A greater risk to river eutrophication than agricultural phosphorus?

    International Nuclear Information System (INIS)

    Jarvie, Helen P.; Neal, Colin; Withers, Paul J.A.

    2006-01-01

    Phosphorus (P) concentrations from water quality monitoring at 54 UK river sites across seven major lowland catchment systems are examined in relation to eutrophication risk and to the relative importance of point and diffuse sources. The over-riding evidence indicates that point (effluent) rather than diffuse (agricultural) sources of phosphorus provide the most significant risk for river eutrophication, even in rural areas with high agricultural phosphorus losses. Traditionally, the relative importance of point and diffuse sources has been assessed from annual P flux budgets, which are often dominated by diffuse inputs in storm runoff from intensively managed agricultural land. However, the ecological risk associated with nuisance algal growth in rivers is largely linked to soluble reactive phosphorus (SRP) concentrations during times of ecological sensitivity (spring/summer low-flow periods), when biological activity is at its highest. The relationships between SRP and total phosphorus (TP; total dissolved P + suspended particulate P) concentrations within UK rivers are evaluated in relation to flow and boron (B; a tracer of sewage effluent). SRP is the dominant P fraction (average 67% of TP) in all of the rivers monitored, with higher percentages at low flows. In most of the rivers the highest SRP concentrations occur under low-flow conditions and SRP concentrations are diluted as flows increase, which is indicative of point, rather than diffuse, sources. Strong positive correlations between SRP and B (also TP and B) across all the 54 river monitoring sites also confirm the primary importance of point source controls of phosphorus concentrations in these rivers, particularly during spring and summer low flows, which are times of greatest eutrophication risk. Particulate phosphorus (PP) may form a significant proportion of the phosphorus load to rivers, particularly during winter storm events, but this is of questionable relevance for river eutrophication

  6. Effect of Nitrogen Form and pH of Nutrient Solution on the Shoot Concentration of Phosphorus, Nitrate, and Nitrogen of Spinach in Hydroponic Culture

    OpenAIRE

    N. Najafi; M. Parsazadeh

    2010-01-01

    In order to study the effect of nitrogen form and pH of nutrient solution on the shoot concentration of P, nitrate, organic N + inorganic ammonium, and total N of spinach, a factorial experiment was conducted with two factors including pH of nutrient solution in three levels (4.5, 6.5 and 8.0) and nitrate to ammonium ratio of nutrient solution in five levels (100:0, 75:25, 50:50, 25:75 and 0:100). This factorial experiment was carried out in a completely randomized design with four replicatio...

  7. A new model of anomalous phosphorus diffusion in silicon

    International Nuclear Information System (INIS)

    Budil, M.; Poetzl, H.; Stingeder, G.; Grasserbauer, M.

    1989-01-01

    A model is presented to describe the 'kink and tail' diffusion of phosphorus. The diffusion behaviour of phosphorus is expplained by the motion of phosphorus-interstitial and phosphorus-vacancy pairs in different charge states. The model yields the enhancement of diffusion in the tail region depending on surface concentration. Furthermore it yields the same selfdiffusion coefficient for interstitials as the gold diffusion experiments. A transformation of the diffusion equation was found to reduce the number of simulation equations. (author) 7 refs., 5 figs

  8. Avaliação de métodos para estimativa da disponibilidade de fósforo para arroz em solos de Várzea do Rio Grande do Sul Estimation methods of phosphorus availability for rice in flooded soils in Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Leandro Souza da Silva

    2008-02-01

    Full Text Available A eficácia da análise de solo depende de quanto o valor obtido pelo método está correlacionado com a quantidade do nutriente absorvida pela planta, em solos de uma determinada região de utilização do sistema de recomendação de adubação. O objetivo deste trabalho foi avaliar a correlação entre o teor de P no solo avaliado por diferentes métodos de extração e a quantidade de P absorvida por plantas de arroz irrigado por inundação. Foram coletadas amostras na camada superficial (0-20 cm de solos de várzea em 16 locais do Rio Grande do Sul (RS, com ampla faixa de variação de características químicas e físicas. Os solos receberam três níveis de P: P0 (sem P, P1 (1/2 de P2 e P2 (quantidade para atingir 0,2 mg L-1 na solução do solo, com base na capacidade máxima de adsorção de P de cada solo. As unidades experimentais constaram de quatro quilogramas de solo em vasos com capacidade de 8 L, cultivados com arroz irrigado em casa de vegetação, com três repetições e dispostos inteiramente ao acaso. Cultivou-se o arroz durante 45 dias, quando foi colhida a parte aérea das plantas e quantificado o P absorvido. Amostras dos solos foram submetidas a diferentes métodos de análise de P: Mehlich-1, Mehlich-2, Mehlich-3, Resina de troca de ânions (RTA em lâminas, RTA em esferas, Bray-1, Bray-2, Olsen, Morgan, Lactato de Ca, Texas, Oxalato, EDTA, H2SO4 e NaOH. Realizaram-se análises de correlação entre os teores de P no solo e as quantidades absorvidas pelas plantas. Dentre os métodos testados, H2SO4, Texas, Lactato de Ca, EDTA, Olsen e RTA foram os que se destacaram, mas apresentaram eficácia semelhante à do extrator Mehlich-1.The reliability of soil analysis depends on the correlation of nutrient concentration in the soil obtained by a given method with the plant nutrient uptake. The objective of this study was to evaluate the correlations between phosphorus content estimated by different methods and phosphorus

  9. Performance of fertigation technique for phosphorus application in cotton

    Directory of Open Access Journals (Sweden)

    M. Aslam

    2009-05-01

    Full Text Available Low native soil phosphorus availability coupled with poor utilization of added phosphorus is one of the major constraints limiting the productivity of the crops. With a view of addressing this issue, field studies were conducted to compare the relative efficacy of broadcast and fertigation techniques for phosphorus application during 2005-2006 using cotton as a test crop. Two methods of phosphorus application i.e. broadcast and fertigation were evaluated using five levels of P2O5 (0, 30, 45, 60 and 75 kg P2O5 ha -1. Fertigation showed an edge over broadcast method at all levels of phosphorus application. The highest seed cotton yield was recorded with 75 kg P2O5 ha-1. Fertilizer phosphorus applied at the rate of 60 kg ha-1 through fertigation produced 3.4 tons ha-1 of seed cotton yield, which was statistically identical to 3.3 tons recorded with 75 kg ha-1 of broadcast phosphorus. Agronomic performance of phosphorus was influenced considerably by either method of fertilizer application. The seed cotton yield per kg of fertigation phosphorus was 48% higher than the corresponding broadcast application. The results of these studies showed that fertigation was the most efficient method of phosphorus application compared with the conventional broadcast application of fertilizers.

  10. Numerical Simulation of the Interaction between Phosphorus and Sediment Based on the Modified Langmuir Equation

    Directory of Open Access Journals (Sweden)

    Pengjie Hu

    2018-06-01

    Full Text Available Phosphorus is the primary factor that limits eutrophication of surface waters in aquatic environments. Sediment particles have a strong affinity to phosphorus due to the high specific surface areas and surface active sites. In this paper, a numerical model containing hydrodynamics, sediment, and phosphorus module based on improved Langmuir equation is established, where the processes of adsorption and desorption are considered. Through the statistical analysis of the physical experiment data, the fitting formulas of two important parameters in the Langmuir equation are obtained, which are the adsorption coefficient, ka, and the ratio k between the adsorption coefficient and the desorption coefficient. In order to simulate the experimental flume and get a constant and uniform water flow, a periodical numerical flume is built by adding a streamwise body force, Fx. The adsorbed phosphorus by sediment and the dissolved phosphorus in the water are separately added into the Advection Diffusion equation as a source term to simulate the interaction between them. The result of the numerical model turns out to be well matched with that of the physical experiment and can thus provide the basis for further analysis. With the application of the numerical model to some new and relative cases, the conclusion will be drawn through an afterwards analysis. The concentration of dissolved phosphorus proves to be unevenly distributed along the depth and the maximum value approximately appears in the 3/4 water depth because both the high velocity in the top layer and the high turbulence intensity in the bottom layer can promote sediment adsorption on phosphorus.

  11. Experimental studies on correlation between accumulation of radionuclides by fish, availability of bottom sediments, and concentration of microelements in water

    Energy Technology Data Exchange (ETDEWEB)

    Katkov, A E

    1979-07-01

    There are revealed peculiarities of accumulation of radionuclides desorbed from the ground by hydrobionts as compared with the accumulation of radionuclides appearing in the basin for the first time. The results of the experimental investigations on the dependence of nuclide accumulation coefficients (AC) on their concentration in water are summarized. The experiments have been performed on adult (6-8 years) golden crucian carp Carassius carassius in a basin with fresh water with /sup 51/Cr, /sup 54/Mn, /sup 59/Fe, /sup 60/Co, /sup 90/Sr, /sup 95/Zr, /sup 106/Ru, /sup 125/Sb, /sup 131/I, /sup 137/Cs, /sup 144/Ce, /sup 210/Po. The radionuclide group (/sup 54/Mn, /sup 144/Ce, /sup 210/Po) has been found out. The ground has contributed to its accumulation. For another group (/sup 60/Co, /sup 137/Cs, /sup 51/Cr) it has been found an indistinctly expressed influence only of silt containing ground on AC. The third group comprises the radionuclides (/sup 90/Sr, /sup 95/Zr, /sup 106/Ru, /sup 125/Sb, /sup 131/I) accumulation of which in fish has been prevented by the ground. An inverse correlation between the nuclide AC changes in fishes (..delta..K) and changes in the concentration of their isotope carried (..delta..C) in water has been observed. The results of the mathematical processing of the summarized experimental data according to the ..delta..Kx ..delta..C=1 criterion are described by the dependence close to ACxC..-->.. const., cor. responding to the law of tendency to constancy preservation in the microelement concentration tissues. In the course of investigation of the relationship between the AC and the change of the radionuclide aggregate state in water no common dependence has been established.

  12. Nutrient uptake dynamics across a gradient of nutrient concentrations and ratios at the landscape scale

    Science.gov (United States)

    Gibson, Catherine A.; O'Reilly, Catherine M.; Conine, Andrea L.; Lipshutz, Sondra M.

    2015-02-01

    Understanding interactions between nutrient cycles is essential for recognizing and remediating human impacts on water quality, yet multielemental approaches to studying nutrient cycling in streams are currently rare. Here we utilized a relatively new approach (tracer additions for spiraling curve characterization) to examine uptake dynamics for three essential nutrients across a landscape that varied in absolute and relative nutrient availability. We measured nutrient uptake for soluble reactive phosphorous, ammonium-nitrogen, and nitrate-nitrogen in 16 headwater streams in the Catskill Mountains, New York. Across the landscape, ammonium-nitrogen and soluble reactive phosphorus had shorter uptake lengths and higher uptake velocities than nitrate-nitrogen. Ammonium-nitrogen and soluble reactive phosphorus uptake velocities were tightly correlated, and the slope of the relationship did not differ from one, suggesting strong demand for both nutrients despite the high ambient water column dissolved inorganic nitrogen: soluble reactive phosphorus ratios. Ammonium-nitrogen appeared to be the preferred form of nitrogen despite much higher nitrate-nitrogen concentrations. The uptake rate of nitrate-nitrogen was positively correlated with ambient soluble reactive phosphorus concentration and soluble reactive phosphorus areal uptake rate, suggesting that higher soluble reactive phosphorus concentrations alleviate phosphorus limitation and facilitate nitrate-nitrogen uptake. In addition, these streams retained a large proportion of soluble reactive phosphorus, ammonium-nitrogen, and nitrate-nitrogen supplied by the watershed, demonstrating that these streams are important landscape filters for nutrients. Together, these results (1) indicated phosphorus limitation across the landscape but similarly high demand for ammonium-nitrogen and (2) suggested that nitrate-nitrogen uptake was influenced by variability in soluble reactive phosphorus availability and preference for

  13. Phosphorus dendrimers for nanomedicine.

    Science.gov (United States)

    Caminade, Anne-Marie

    2017-08-31

    From biomaterials to imaging, and from drug delivery to drugs by themselves, phosphorus-containing dendrimers offer a large palette of biological properties, depending essentially on their types of terminal functions. The most salient examples of phosphorus dendrimers used for the elaboration of bio-chips and of supports for cell cultures, for imaging biological events, and for carrying and delivering drugs or biomacromolecules are presented in this feature article. Several phosphorus dendrimers can be considered also as drugs per se (by themselves) in particular to fight against cancers, neurodegenerative diseases, and inflammation, both in vitro and in vivo. Toxicity assays are also reported.

  14. A Comprehensive Look at Nitrogen and Phosphorus Use Efficiency in Saffron (Crocus Sativus L.

    Directory of Open Access Journals (Sweden)

    Alireza Koocheki

    2016-08-01

    Full Text Available Saffron (Crocus sativus L. is an annual plant from a biological aspect, but it has a perennial cycle in the field conditions. Cytological impairments such as triploid and self-incompatibility mechanisms are considered as the most important reasons for male-sterility in saffron. Therefore, saffron reproduction is made by meristems tissues and establishment of new daughter corms which are produced by the mother corms. During the growing season, mother corms deteriorate gradually with increasing daughter corms growth. Each daughter corm is considered as a mother corm for replanting in the next growing season. Duo to the life cycle of saffron as a perennial plant in the field conditions, the gradual deterioration of mother corms during the growing season and also the remobilization of nitrogen and phosphorus from aerial part to daughter corms at the end of each growing season, the study of acquisition and use efficiency of nitrogen and phosphorus in saffron is more complicated than other annual or biannual plants. Firstly, the objective of this review article is to describe the nitrogen and phosphorus concentration in aerial parts and daughter corms in saffron. In addition, relevant literature related to the most important strategies for improving nitrogen and phosphorus use efficiency is reviewed. Secondly, the relationship between nitrogen and phosphorus use efficiency in saffron is discussed.

  15. Determination of Phosphorus Adsorption Using Various Forms of Isotherms in Soils of Adıyaman Çamgazi Plain

    OpenAIRE

    AĞCA, Necat

    2014-01-01

    Samples from 8 widespread soil series from Adıyaman Çamgazi Plain were equilibriated at a constant temperature with 16 different solutions containing 0 to 50 mg/ml phosphorus in batch-type experiments. The phosphorus concentrations of the equilibrium solutions and the amounts of phosphorus adsorbed by the soils at these concentrations were determined. These phosphorus-adsorption data were evaluated statistically for their suitability for adsorption isotherms in various concentration ranges.

  16. Optimization of induced crystallization reaction in a novel process of nutrients removal coupled with phosphorus recovery from domestic wastewater

    Directory of Open Access Journals (Sweden)

    Zou Haiming

    2017-12-01

    Full Text Available Phosphorus removal and recovery from domestic wastewater is urgent nowadays. A novel process of nutrients removal coupled with phosphorus recovery from domestic sewage was proposed and optimization of induced crystallization reaction was performed in this study. The results showed that 92.3% of phosphorus recovery via induced Hydroxyapatite crystallization was achieved at the optimum process parameters: reaction time of 80 min, seed crystal loads of 60 g/L, pH of 8.5, Ca/P mole ratio of 2.0 and 4.0 L/min aeration rate when the PO43--P concentration was 10 mg/L in the influent, displaying an excellent phosphorus recovery performance. Importantly, it was found that the effect of reaction temperature on induced Hydroxyapatite crystallization was slight, thus favoring practical application of phosphorus recovery method described in this study. From these results, the proposed method of induced HAP crystallization to recover phosphorus combined with nutrients removal can be an economical and effective technology, probably favoring the water pollution control and phosphate rock recycle.

  17. Metabolism of nonparticulate phosphorus in an acid bog lake

    International Nuclear Information System (INIS)

    Koenings, J.P.

    1977-01-01

    In North Gate Lake, an acid bog lake located on the northern Michigan-Wisconsin border, U.S.A., the algal nutrient inorganic phosphate (FRP) is not detectable by chemical means. Organic phosphorus (FUP) represents 100% of the detectable filterable phosphorus. The availability and cycling of this organic fraction are of considerable interest in regard to the primary productivity of this system. To clarify these relationships, the cycling of nonparticulate forms of phosphorus found in the epilimnion of this lake was studied

  18. Metabolism of nonparticulate phosphorus in an acid bog lake

    Energy Technology Data Exchange (ETDEWEB)

    Koenings, J. P.

    1977-01-01

    In North Gate Lake, an acid bog lake located on the northern Michigan-Wisconsin border, U.S.A., the algal nutrient inorganic phosphate (FRP) is not detectable by chemical means. Organic phosphorus (FUP) represents 100% of the detectable filterable phosphorus. The availability and cycling of this organic fraction are of considerable interest in regard to the primary productivity of this system. To clarify these relationships, the cycling of nonparticulate forms of phosphorus found in the epilimnion of this lake was studied.

  19. Isotopically exchangeable phosphorus

    International Nuclear Information System (INIS)

    Barbaro, N.O.

    1984-01-01

    A critique revision of isotope dilution is presented. The concepts and use of exchangeable phosphorus, the phosphate adsorption, the kinetics of isotopic exchange and the equilibrium time in soils are discussed. (M.A.C.) [pt

  20. Probing Phosphorus Efficient Low Phytic Acid Content Soybean Genotypes with Phosphorus Starvation in Hydroponics Growth System.

    Science.gov (United States)

    Kumar, Varun; Singh, Tiratha Raj; Hada, Alkesh; Jolly, Monica; Ganapathi, Andy; Sachdev, Archana

    2015-10-01

    Phosphorus is an essential nutrient required for soybean growth but is bound in phytic acid which causes negative effects on both the environment as well as the animal nutrition. Lowering of phytic acid levels is associated with reduced agronomic characteristics, and relatively little information is available on the response of soybean plants to phosphorus (P) starvation. In this study, we evaluated the effects of different P starvation concentrations on the phytic acid content, growth, and yield of seven mutant genotypes along with the unirradiated control, JS-335, in a hydroponics growth system. The low phytic acid containing mutant genotypes, IR-JS-101, IR-DS-118, and IR-V-101, showed a relatively high growth rate in low P concentration containing nutrient solution (2 μM), whereas the high P concentration (50 μM) favored the growth of IR-DS-111 and IR-DS-115 mutant genotypes containing moderate phytate levels. The mutant genotypes with high phytic acid content, IR-DS-122, IR-DS-114, and JS-335, responded well under P starvation and did not have any significant effect on the growth and yield of plants. Moreover, the reduction of P concentration in nutrient solution from 50 to 2 μM also reduced the phytic acid content in the seeds of all the soybean genotypes under study. The desirable agronomic performance of low phytic acid containing mutant genotype IR-DS-118 reported in this study suggested it to be a P-efficient genotype which could be considered for agricultural practices under P limiting soils.

  1. Cyanobacteria and cyanotoxins: the influence of nitrogen versus phosphorus.

    Directory of Open Access Journals (Sweden)

    Andrew M Dolman

    Full Text Available The importance of nitrogen (N versus phosphorus (P in explaining total cyanobacterial biovolume, the biovolume of specific cyanobacterial taxa, and the incidence of cyanotoxins was determined for 102 north German lakes, using methods to separate the effects of joint variation in N and P concentration from those of differential variation in N versus P. While the positive relationship between total cyanobacteria biovolume and P concentration disappeared at high P concentrations, cyanobacteria biovolume increased continually with N concentration, indicating potential N limitation in highly P enriched lakes. The biovolumes of all cyanobacterial taxa were higher in lakes with above average joint NP concentrations, although the relative biovolumes of some Nostocales were higher in less enriched lakes. Taxa were found to have diverse responses to differential N versus P concentration, and the differences between taxa were not consistent with the hypothesis that potentially N(2-fixing Nostocales taxa would be favoured in low N relative to P conditions. In particular Aphanizomenon gracile and the subtropical invasive species Cylindrospermopsis raciborskii often reached their highest biovolumes in lakes with high nitrogen relative to phosphorus concentration. Concentrations of all cyanotoxin groups increased with increasing TP and TN, congruent with the biovolumes of their likely producers. Microcystin concentration was strongly correlated with the biovolume of Planktothrix agardhii but concentrations of anatoxin, cylindrospermopsin and paralytic shellfish poison were not strongly related to any individual taxa. Cyanobacteria should not be treated as a single group when considering the potential effects of changes in nutrient loading on phytoplankton community structure and neither should the N(2-fixing Nostocales. This is of particular importance when considering the occurrence of cyanotoxins, as the two most abundant potentially toxin producing

  2. Dynamical Analysis of a Nitrogen-Phosphorus-Phytoplankton Model

    Directory of Open Access Journals (Sweden)

    Yunli Deng

    2015-01-01

    Full Text Available This paper presents a nitrogen-phosphorus-phytoplankton model in a water ecosystem. The main aim of this research is to analyze the global system dynamics and to study the existence and stability of equilibria. It is shown that the phytoplankton-eradication equilibrium is globally asymptotically stable if the input nitrogen concentration is less than a certain threshold. However, the coexistence equilibrium is globally asymptotically stable as long as it exists. The system is uniformly persistent within threshold values of certain key parameters. Finally, to verify the results, numerical simulations are provided.

  3. Visualizing alternative phosphorus scenarios for future food security

    Directory of Open Access Journals (Sweden)

    Tina-Simone Neset

    2016-10-01

    Full Text Available The impact of global phosphorus scarcity on food security has increasingly been the focus of scientific studies over the past decade. However, systematic analyses of alternative futures for phosphorus supply and demand throughout the food system are still rare and provide limited inclusion of key stakeholders. Addressing global phosphorus scarcity requires an integrated approach exploring potential demand reduction as well as recycling opportunities. This implies recovering phosphorus from multiple sources, such as food waste, manure and excreta, as well as exploring novel opportunities to reduce the long-term demand for phosphorus in food production such as changing diets. Presently, there is a lack of stakeholder and scientific consensus around priority measures. To therefore enable exploration of multiple pathways and facilitate a stakeholder dialogue on the technical, behavioral and institutional changes required to meet long-term future phosphorus demand, this paper introduces an interactive web-based tool, designed for visualizing global phosphorus scenarios in real-time. The interactive global phosphorus scenario tool builds on several demand and supply side measures that can be selected and manipulated interactively by the user. It provides a platform to facilitate stakeholder dialogue to plan for a soft landing and identify a suite of concrete priority options, such as investing in agricultural phosphorus use efficiency, or renewable fertilizers derived from phosphorus recovered from wastewater and food waste, to determine how phosphorus demand to meet future food security could be attained on a global scale in 2040 and 2070. This paper presents four example scenarios, including (1 the potential of full recovery of human excreta, (2 the challenge of a potential increase in non-food phosphorus demand, (3 the potential of a decreased animal product consumption, and (4 the potential decrease in phosphorus demand from increased efficiency

  4. Soil Phosphorus Storage Capacity for Environmental Risk Assessment

    Directory of Open Access Journals (Sweden)

    Vimala D. Nair

    2014-01-01

    Full Text Available Reliable techniques must be developed to predict phosphorus (P storage and release from soils of uplands, ditches, streams, and wetlands in order to better understand the natural, anthropogenic, and legacy sources of P and their impact on water quality at a field/plot as well as larger scales. A concept called the “safe” soil phosphorus storage capacity (SPSC that is based on a threshold phosphorus saturation ratio (PSR has been developed; the PSR is the molar ratio of P to Fe and Al, and SPSC is a PSR-based calculation of the remaining soil P storage capacity that captures risks arising from previous loading as well as inherently low P sorption capacity of a soil. Zero SPSC amounts to a threshold value below which P runoff or leaching risk increases precipitously. In addition to the use of the PSR/SPSC concept for P risk assessment and management, and its ability to predict isotherm parameters such as the Langmuir strength of bonding, KL, and the equilibrium P concentration, EPC0, this simple, cost-effective, and quantitative approach has the potential to be used as an agronomic tool for more precise application of P for plant uptake.

  5. Effects of P-efficient Transgenic Rice OsPT4 on Inorganic Phosphorus Fractions in Red Soil

    Directory of Open Access Journals (Sweden)

    WEI Lin-lin

    2017-08-01

    Full Text Available In a rhizobox experiment with phosphorus(P fertilizer application and P-deficiency, planting wild-type rice(Nipp, P-efficient mutant rice(PHO2, P-efficient transgenic rice(OsPT4 were chosen to evaluate effects of phosphorus efficient transgenic rice on inorganic phosphorus in the rhizosphere and non-rhizosphere soil. The obtained results were summarized as follows:(1Significant higer dry weight and P accumulation were observed in OsPT4 and PHO2 than in Nipp, but lower total P and inorganic phosphorus observed in OsPT4 and PHO2 than in Nipp;(2The concentrations of inorganic phosphorus fractions in the rhizosphere and non-rhizosphere soil were sorted as follows:O-P > Fe-P > Al-P > Ca-P, and the order of inorganic phosphorus fractions adapted to three rice materials;(3When added phosphorus fertilizer, the concents of rhizospheric Al-P, Fe-P and non-rhizospheric Ca-P in three rice materials had no significant difference. The concents of rhizospheric soil O-P and Ca-P in OsPT4 and PHO2 were significantly inferior to Nipp, and their concents of non-rhizospheric soil Al-P, Fe-P and O-P were significantly lower than Nipp. When added no phosphorus fertilizer, the concents of rhizospheric Al-P, O-P, Ca-P and non-rhizosphere Al-P, Ca-P in three rice materials had no significant difference, and the concents of rhizosphere Fe-P and non-rhizosphere soil Fe-P, O-P in OsPT4 and PHO2 were significantly lower than Nipp, but rhizosphere Ca-P was significantly higher than Nipp.

  6. Total phosphorus recovery in flowback fluids after gelled hydrocarbon fracturing fluid treatments

    Energy Technology Data Exchange (ETDEWEB)

    Fyten, G.; Houle, P.; Taylor, R.S. [Halliburton Energy Services, Calgary, AB (Canada); Stemler, P.S. [Petro-Canada Oil and Gas Inc., Calgary, AB (Canada); Lemieux, A. [Omnicon Consultants Inc., Calgary, AB (Canada)

    2006-07-01

    Carbon dioxide miscible hydrocarbon fracturing fluids are used in unconventional gas reservoirs such as tight gas, shale gas, and coalbed methane. These fracturing fluids address phase trapping concerns by using oil-based fracturing fluid technology for use in reservoirs that are water sensitive. This paper addressed the problem of refinery tower fouling caused by volatile phosphorous components found in phosphate ester oil gellants. In order to address costly unplanned refinery shutdowns, a maximum 0.5 ppm volatile phosphorus in crude specification has been proposed. However, this specification is based on average concentrations of phosphorus added to the oil to gel it. The specification also falsely assumes that the oil is phosphorus free to begin with. The authors noted that refinery tower fouling is actually the result of total phosphorus throughput rather than peak concentrations at any one point. This paper focused on the total phosphorus recovery in addition to peak concentrations. It also examined what percentage of the total recovered phosphorus is in fact volatile, since this is the material that plugs the trays. The total per cent recovery of phosphorus originally added as phosphorus based gellant was examined along with the total percent recovery of volatile phosphorus as a function of total phosphorus. The phosphorus concentrations in both new and reused fracturing fluids before addition of gellants was also examined along with the potential explanations for phosphorus concentrations higher than those originally added. It was shown that the first 50 per cent of a hydraulic fracturing fluid flowback can result in recovery of greater than or less than the amount of phosphorus added to that portion of the fracturing fluid. The initial high concentrations of total and volatile phosphorus are greater than the phosphorus concentrations inherent in the system. Therefore, as flowback continues, there would be a rapid decline in the concentration of phosphorus

  7. Advances in understanding phosphorus cycling in inland waters - Their significance for South African limnology

    CSIR Research Space (South Africa)

    Twinch, AJ

    1980-02-01

    Full Text Available The definitions of the different phosphorus compound fractions present in inland waters are reviewed and the limitations of the definitions discussed. The development of models of phosphorus cycling is summarized. Attempts to establish...

  8. Bioaccumulation of heavy metals in the earthworms Lumbricus rubellus and Aporrectodea caliginosa in relation to total and available metal concentrations in field soils

    International Nuclear Information System (INIS)

    Hobbelen, P.H.F.; Koolhaas, J.E.; Gestel, C.A.M. van

    2006-01-01

    The aim of this study was to determine important metal pools for bioaccumulation by the earthworms Lumbricus rubellus and Aporrectodea caliginosa in soils with high binding capacity. Cd, Cu and Zn concentrations in soil, pore water and CaCl 2 extracts of soil, in leaves of the plant species Urtica dioica and in earthworms were determined at 15 field sites constituting a gradient in metal pollution. Variations in the Cu and Cd concentrations in L. rubellus and Cu concentrations in A. caliginosa were best explained by total soil concentrations, while variation in Cd concentration in A. caliginosa was best explained by pore water concentrations. Zn concentrations in L. rubellus and A. caliginosa were not significantly correlated to any determined variable. It is concluded that despite low availability, earthworms in floodplain soils contain elevated concentrations of Cu and Cd, suggesting that uptake takes place not only from the soluble metal concentrations. - Earthworms in floodplain soils not only accumulate heavy metals from soluble metal pools

  9. Bioaccumulation of heavy metals in the earthworms Lumbricus rubellus and Aporrectodea caliginosa in relation to total and available metal concentrations in field soils

    Energy Technology Data Exchange (ETDEWEB)

    Hobbelen, P.H.F. [Department of Animal Ecology, Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands)]. E-mail: phobbelen@usgs.gov; Koolhaas, J.E. [Department of Animal Ecology, Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands); Gestel, C.A.M. van [Department of Animal Ecology, Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands)

    2006-11-15

    The aim of this study was to determine important metal pools for bioaccumulation by the earthworms Lumbricus rubellus and Aporrectodea caliginosa in soils with high binding capacity. Cd, Cu and Zn concentrations in soil, pore water and CaCl{sub 2} extracts of soil, in leaves of the plant species Urtica dioica and in earthworms were determined at 15 field sites constituting a gradient in metal pollution. Variations in the Cu and Cd concentrations in L. rubellus and Cu concentrations in A. caliginosa were best explained by total soil concentrations, while variation in Cd concentration in A. caliginosa was best explained by pore water concentrations. Zn concentrations in L. rubellus and A. caliginosa were not significantly correlated to any determined variable. It is concluded that despite low availability, earthworms in floodplain soils contain elevated concentrations of Cu and Cd, suggesting that uptake takes place not only from the soluble metal concentrations. - Earthworms in floodplain soils not only accumulate heavy metals from soluble metal pools.

  10. Changes in water quality of the River Frome (UK) from 1965 to 2009: Is phosphorus mitigation finally working?

    Energy Technology Data Exchange (ETDEWEB)

    Bowes, M.J., E-mail: mibo@ceh.ac.uk [Centre for Ecology and Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, Oxfordshire, OX10 8BB (United Kingdom); Smith, J.T. [School of Earth and Environmental Sciences, Burnaby Building, University of Portsmouth, Portsmouth PO1 3QL (United Kingdom); Neal, C. [Centre for Ecology and Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, Oxfordshire, OX10 8BB (United Kingdom); Leach, D.V. [formally Centre for Ecology and Hydrology, Winfrith Technology Centre, Dorchester, Dorset, DT2 8ZD (United Kingdom); Scarlett, P.M.; Wickham, H.D.; Harman, S.A.; Armstrong, L.K. [Centre for Ecology and Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, Oxfordshire, OX10 8BB (United Kingdom); Davy-Bowker, J. [Freshwater Biological Association, River Laboratory, East Stoke, Wareham, Dorset, BH20 6BB (United Kingdom); Haft, M. [Freshwater Biological Association, Ferry Landing, Far Sawrey, Ambleside, Cumbria, LA22 0LP (United Kingdom); Davies, C.E. [Centre for Ecology and Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, Oxfordshire, OX10 8BB (United Kingdom)

    2011-08-15

    The water quality of the River Frome, Dorset, southern England, was monitored at weekly intervals from 1965 until 2009. Determinands included phosphorus, nitrogen, silicon, potassium, calcium, sodium, magnesium, pH, alkalinity and temperature. Nitrate-N concentrations increased from an annual average of 2.4 mg l{sup -1} in the mid to late 1960s to 6.0 mg l{sup -1} in 2008-2009, but the rate of increase was beginning to slow. Annual soluble reactive phosphorus (SRP) concentrations increased from 101 {mu}g l{sup -1} in the mid 1960s to a maximum of 190 {mu}g l{sup -1} in 1989. In 2002, there was a step reduction in SRP concentration (average = 88 {mu}g l{sup -1} in 2002-2005), with further improvement in 2007-2009 (average = 49 {mu}g l{sup -1}), due to the introduction of phosphorus stripping at sewage treatment works. Phosphorus and nitrate concentrations showed clear annual cycles, related to the timing of inputs from the catchment, and within-stream bioaccumulation and release. Annual depressions in silicon concentration each spring (due to diatom proliferation) reached a maximum between 1980 and 1991, (the period of maximum SRP concentration) indicating that algal biomass had increased within the river. The timing of these silicon depressions was closely related to temperature. Excess carbon dioxide partial pressures (EpCO{sub 2}) of 60 times atmospheric CO{sub 2} were also observed through the winter periods from 1980 to 1992, when phosphorus concentration was greatest, indicating very high respiration rates due to microbial decomposition of this enhanced biomass. Declining phosphorus concentrations since 2002 reduced productivity and algal biomass in the summer, and EpCO{sub 2} through the winter, indicating that sewage treatment improvements had improved riverine ecology. Algal blooms were limited by phosphorus, rather than silicon concentration. The value of long-term water quality data sets is discussed. The data from this monitoring programme are made

  11. Total phosphorus, phytate phosphorus contents and the correlation of phytates with amylose in selected edible beans in Sri Lanka

    Directory of Open Access Journals (Sweden)

    Keerthana Sivakumaran

    2018-02-01

    Full Text Available Phytate a major anti nutritional factors in legumes and it accounts for larger portion of the total phosphorus, while limiting the bioavailablity of certain divalent cations to the human body. Legumes of eleven varieties cultivated in Sri Lanka, Mung bean (MI5, MI6, Cowpea (Waruni, MICP1, Bombay, Dhawala, ANKCP1, Soybean (MISB1, Pb1 and Horse gram (ANKBlack, ANKBrown were analyzed for phosphorus content and phytate content. Total phosphorus content was quantified by dry ashing followed by spectrophotometrical measurement of the blue colour intensity of acid soluble phosphate with sodium molybdate in the presence of ascorbic acid while phytate phosphorus using anion exchange chromatographic technique followed by spectrometrical measurement of the digested organic phosphorus and amylose content by Simple Iodine-Colourimetric method. Where the least value for phosphorus was observed 275.04 ±1.44 mg.100g-1 in ANKBlack (Horse gram and the highest in MISB1 (Soyabean with 654.94 ±0.05 mg.100g-1. The phytate phosphorus content (which is a ratio of phyate to total phosphorus was highest in Dhawala (Cowpea. The phytate phosphorus (which is a ratio of phyate to total phosphorus was highest in Dhawala with 67.42% and least in Bombay (Cowpea with 24.87%. The amylose content of the legumes was least in Pb1 with 8.71 ±0.13 mg.100mg-1 and the highest in MI6 22.58 ±0.71 mg.100mg-1. The correlation between phyate and total phosphorus was significant (p <0.05 and positive (r = 0.62. Similarly the correlation coefficient for phytate phosphorus and total phosphorus was significant (p <0.05 and positive (r = 0.63. Amylose content of legumes was significantly correlated negatively (p <0.05 with the total phytates content (r = -0.82.

  12. Evaluation of five commercially available assays and measurement of serum total protein concentration via refractometry for the diagnosis of failure of passive transfer of immunity in foals.

    Science.gov (United States)

    Davis, Rachel; Giguère, Steeve

    2005-11-15

    To determine and compare sensitivity, specificity, accuracy, and predictive values of measurement of serum total protein concentration by refractometry as well as 5 commercially available kits for the diagnosis of failure of passive transfer (FPT) of immunity in foals. Prospective study. 65 foals with various medical problems and 35 clinically normal foals. IgG concentration in serum was assessed by use of zinc sulfate turbidity (assay C), glutaraldehyde coagulation (assay D), 2 semiquantitative immunoassays (assays F and G), and a quantitative immunoassay (assay H). Serum total protein concentration was assessed by refractometry. Radial immunodiffusion (assays A and B) was used as the reference method. For detection of IgG or = 6.0 g/dL indicated adequate IgG concentrations. Most assays were adequate as initial screening tests. However, their use as a definitive test would result in unnecessary treatment of foals with adequate IgG concentrations.

  13. Analysis of Canadian and Irish forage, oats and commercially available equine concentrate feed for pathogenic fungi and mycotoxins

    Directory of Open Access Journals (Sweden)

    Buckley Thomas

    2007-04-01

    Full Text Available Abstract Respiratory infections, recurrent airway obstruction (RAO and exercise induced pulmonary haemorrhage (EIPH are major causes of poor performance in horses. Fungi and mycotoxins are now recognised as a major cause of these conditions. The most notable fungi are Aspergillus and Fusarium. Fungal spores can originate from forage, bedding and feed and, in turn, these fungal spores can produce a series of mycotoxins as secondary metabolites. This study set out to ascertain the degree of fungal and mycotoxin contamination in feed and fodder used in Irish racing yards over a one-year period. Weather conditions in forage producing areas were sampled by Met Eireann and the Canadian Meteorological Service. Fifty per cent of Irish hay, 37% of haylage and 13% of Canadian hay contained pathogenic fungi. Of the mycotoxins, T2 and zearalenone were most prominent. Twenty-one per cent of Irish hay and 16% of pelleted feed contained zearalenone. Forty per cent of oats and 54% of pelleted feed contained T2 toxins.

  14. The effects of phosphorus limitation on carbon metabolism in diatoms.

    Science.gov (United States)

    Brembu, Tore; Mühlroth, Alice; Alipanah, Leila; Bones, Atle M

    2017-09-05

    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'. © 2017 The Authors.

  15. Phosphorus distribution in sandy soil profile under drip irrigation system

    International Nuclear Information System (INIS)

    El-Gendy, R.W.; Rizk, M.A.; Abd El Moniem, M.; Abdel-Aziz, H.A.; Fahmi, A.E.

    2009-01-01

    This work aims at to studying the impact of irrigation water applied using drip irrigation system in sandy soil with snap bean on phosphorus distribution. This experiment was carried out in soils and water research department farm, nuclear research center, atomic energy authority, cairo, Egypt. Snap bean was cultivated in sandy soil and irrigated with 50,37.5 and 25 cm water in three water treatments represented 100, 75 and 50% ETc. Phosphorus distribution and direction of soil water movement had been detected in three sites on the dripper line (S1,S2 and S3 at 0,12.5 and 25 cm distance from dripper). Phosphorus fertilizer (super phosphate, 15.5% P 2 O 5 in rate 300 kg/fed)was added before cultivation. Neutron probe was used to detect the water distribution and movement at the three site along soil profile. Soil samples were collected before p-addition, at end developing, mid, and late growth stages to determine residual available phosphorus. The obtained data showed that using 50 cm water for irrigation caused an increase in P-concentration till 75 cm depth in the three sites of 100% etc treatment, and covered P-requirements of snap bean for all growth stages. As for 37.5 and 25 cm irrigation water cannot cover all growth stages for P-requirements of snap bean. It could be concluded that applied irrigation water could drive the residual P-levels till 75 cm depth in the three sites. Yield of the crop had been taken as an indicator as an indicator profile. Yield showed good response according to water quantities and P-transportation within the soil profile

  16. Experiments on accumulation of phosphorus in the plants Myosotis palustris, Glyceria maxima and Nasturtium officinale

    Directory of Open Access Journals (Sweden)

    O. Prokopchuk

    2016-10-01

    Full Text Available The problem of availability of quality water is highly relevant today, so the technologies of prediction and prevention of water pollution and purification are very important. Biological methods of cleaning, in paticular cleaning water by the so-called method of biosorption, have been increasingly used in the last decade. This method means the removal of dangerous substances and improvement of water condition by using aquatic organisms, in particular plants. Therefore, in view of the rich experience of research conducted in the biosorption sphere, we decided to predict the effectiveness of this method by using the cumulative ability of higher water plants to absorb phosphorus compounds. For this purpose, we selected water and plant samples (Glyceria maxima (C. Hartm. Holmb., Nasturtium officinale R. Br., Myosotis palustris (L. L. from the river Seret (Ternopil, Ukraine. The plants were placed into sterilized glass jars filled with 3 liters of water from the river Seret (control samples and still tap water with addition of sodium phosphate with phosphorus concentration of 3.5 mg/dm³ (research sample, which were cultured in laboratory conditions for four months. We determined the content of phosphates, permanganate and dichromate oxidation in the water and the total content of phosphorus in the plants. We traced the dynamic of organic substances and the content of phosphates in the water, the accumulation of phosphorus in plants and the rate of accumulation of phosphorus in the plants and in the water. We calculated correlation coefficients to detect the dependence between phosphorus indicators in the aquatic plants and the concentration of phosphate ions in the water. We found that M. palustris had the greatest capacity to accumulate phosphorus and the highest rate of phosphorus accumulation from water, which allows us to consider it the most effective aquatic plant for absorption of elements and decreasing water pollution. We also established

  17. The effects of increased phosphorus application on shoot dry matter ...

    African Journals Online (AJOL)

    The effects of increased phosphorus application on shoot dry matter, shoot P and Zn concentrations in wheat ( Triticum durum L.) and maize ( Zea mays L.)wheat ( Triticum durum L.) and maize ( Zea mays L.) grown in a calcareous soil.

  18. Effect of phosphorus sources on phosphorus and nitrogen utilization by three sweet potato cultivars

    International Nuclear Information System (INIS)

    Montanez, A.; Zapata, F.; Kumarasinghe, K.S.

    1996-01-01

    A greenhouse experiment was conducted at the FAO/IAEA Agriculture and Biotechnology Laboratory in Seibersdorf, Austria using three sweet potato cultivars, TIS 2, TIS 3053 and TIS 1487. The three sweet potato cultivars were grown at two levels of phosphorus (0 kg P/kg soil and 60 kg P/kg soil). The fertilizer treatments consisted of two sources of phosphorus, Gafza rock Phosphate and triple super phosphate with 14.19 and 19.76% total phosphorus, respectively. 15 N labelled urea was used to study the nitrogen recovery in tubers from the applied nitrogen fertilizer. The results from these preliminary studies indicate that there is considerable genotypic variation among cultivars in the efficiency with which phosphorus and nitrogen are taken up and used to produce biomass. Their response to different sources of phosphorus are also variable. TIS-2 and TIS-1487 have a greater ability to absorb phosphorus from Gafza rock phosphate and produce higher tube yields indicating their greater potential for using alternative sources of natural phosphate fertilizers more effectively. Gafza rock phosphate also increased accumulation of nitrogen in TIS-1487, a characteristic which will place this cultivar at an advantage when growing in soils low in nitrogen. On an overall basis taking into account tuber yield, phosphorus use efficiency, and nitrogen use efficiency, TIS-2 may be considered the better candidate for introduction into soils poor in resources particularly phosphorus. This study was conducted with a limited number of cultivars due to limitation in the availability of germplasma. In spite of this, the differences in their abilities for phosphorus and nitrogen uptake and use are clearly visible which justifies large scale screening experiments using a broader germplasm base, in the future. (author). 14 refs, 1 fig., 3 tabs

  19. Effect of phosphorus sources on phosphorus and nitrogen utilization by three sweet potato cultivars

    Energy Technology Data Exchange (ETDEWEB)

    Montanez, A; Zapata, F [FAO/IAEA Agriculture and Biotechnology Lab., Seibersdorf (Austria). Soils Science Unit; Kumarasinghe, K S [Joint FAO/IAEA Div. of Nuclear Techniques in Food and Agriculture, Vienna (Austria). Soil Fertility, Irrigation and Crop Production Section

    1996-07-01

    A greenhouse experiment was conducted at the FAO/IAEA Agriculture and Biotechnology Laboratory in Seibersdorf, Austria using three sweet potato cultivars, TIS 2, TIS 3053 and TIS 1487. The three sweet potato cultivars were grown at two levels of phosphorus (0 kg P/kg soil and 60 kg P/kg soil). The fertilizer treatments consisted of two sources of phosphorus, Gafza rock Phosphate and triple super phosphate with 14.19 and 19.76% total phosphorus, respectively. {sup 15}N labelled urea was used to study the nitrogen recovery in tubers from the applied nitrogen fertilizer. The results from these preliminary studies indicate that there is considerable genotypic variation among cultivars in the efficiency with which phosphorus and nitrogen are taken up and used to produce biomass. Their response to different sources of phosphorus are also variable. TIS-2 and TIS-1487 have a greater ability to absorb phosphorus from Gafza rock phosphate and produce higher tube yields indicating their greater potential for using alternative sources of natural phosphate fertilizers more effectively. Gafza rock phosphate also increased accumulation of nitrogen in TIS-1487, a characteristic which will place this cultivar at an advantage when growing in soils low in nitrogen. On an overall basis taking into account tuber yield, phosphorus use efficiency, and nitrogen use efficiency, TIS-2 may be considered the better candidate for introduction into soils poor in resources particularly phosphorus. This study was conducted with a limited number of cultivars due to limitation in the availability of germplasma. In spite of this, the differences in their abilities for phosphorus and nitrogen uptake and use are clearly visible which justifies large scale screening experiments using a broader germplasm base, in the future. (author). 14 refs, 1 fig., 3 tabs.

  20. Effect of exposure to sunlight and phosphorus-limitation on bacterial degradation of coloured dissolved organic matter (CDOM) in freshwater.

    Science.gov (United States)

    Kragh, Theis; Søndergaard, Morten; Tranvik, Lars

    2008-05-01

    This study reports on the interacting effect of photochemical conditioning of dissolved organic matter and inorganic phosphorus on the metabolic activity of bacteria in freshwater. Batch cultures with lake-water bacteria and dissolved organic carbon (DOC) extracted from a humic boreal river were arranged in an experimental matrix of three levels of exposure to simulated sunlight and three levels of phosphorus concentration. We measured an increase in bacterial biomass, a decrease in DOC and bacterial respiration as CO(2) production and O(2) consumption over 450 h. These measurements were used to calculate bacterial growth efficiency (BGE). Bacterial degradation of DOC increased with increasing exposure to simulated sunlight and availability of phosphorus and no detectable growth occurred on DOC that was not pre-exposed to simulated sunlight. The outcome of photochemical degradation of DOC changed with increasing availability of phosphorus, resulting in an increase in BGE from about 5% to 30%. Thus, the availability of phosphorus has major implications for the quantitative transfer of carbon in microbial food webs.

  1. Organic chemistry of elemental phosphorus

    International Nuclear Information System (INIS)

    Milyukov, V A; Budnikova, Yulia H; Sinyashin, Oleg G

    2005-01-01

    The principal achievements and the modern trends in the development of the chemistry of elemental phosphorus are analysed, described systematically and generalised. The possibilities and advantages of the preparation of organophosphorus compounds directly from white phosphorus are demonstrated. Attention is focused on the activation and transformation of elemental phosphorus in the coordination sphere of transition metal complexes. The mechanisms of the reactions of white phosphorus with nucleophilic and electrophilic reagents are discussed. Electrochemical approaches to the synthesis of organic phosphorus derivatives based on white phosphorus are considered.

  2. The influence of excess vacancy generation on the diffusion of ion implanted phosphorus into silicon

    International Nuclear Information System (INIS)

    Bakowski, A.

    1985-01-01

    The diffusion of ion implanted phosphorus in silicon has been studied. It was found that the diffusion coefficient is not only dependent on the phosphorus surface concentration (the concentration effect) but also on the conditions at the silicon surface (the surface effect). The phosphorus diffusion coefficient is considerably lower when the silicon surface during annealing is covered with a CVD oxide layer. It is suggested that excess vacancies generated at the surface are reponsible for both the concentration and surface effects. Enhanced phosphorus diffusion is attributed to the disturbance of thermodynamic equilibrium in the crystal through phosphorus-vacancy part formation by vacancies introduced into silicon at the surface. On the basis of the data presented, it can be concluded that two mechanisms for excess vacancy generation are involved. Assuming that phosphorus diffuses via E-centers, calculations of the concentration profiles and the diffusion coefficient were performed for different concentrations and surface conditions. (orig.)

  3. Biological nitrogen and phosphorus removal by filamentous bacteria ...

    African Journals Online (AJOL)

    The availability of excess nutrients (phosphorus (P) and nitrogen (N)) in wastewater systems causes many water quality problems. These problems include eutrophication whereby algae grow excessively and lead to depletion of oxygen, death of the aquatic life and bad odours. Biological phosphorus removal has gained ...

  4. Evaluation of phosphorus sorption characteristics of soils from the ...

    African Journals Online (AJOL)

    The evaluation of phosphorus sorption characteristics of soils and their relation to soil properties from the Bambouto sequence of Baranka 1, Baranka 2, Femock 1 and Femock 2 has been studied. Phosphorus, an essential plant nutrient, is often not readily available to plants and this deficiency tends to limit plant growth.

  5. Contributions to total phosphorus intake: all sources considered.

    Science.gov (United States)

    Calvo, Mona S; Uribarri, Jaime

    2013-01-01

    High serum phosphorus is linked to poor health outcome and mortality in chronic kidney disease (CKD) patients before or after the initiation of dialysis. Dietary intake of phosphorus, a major determinant of serum phosphorus, seems to be systematically underestimated using the available software tools and generalized nutrient content databases. Several sources of dietary phosphorus including the addition of phosphorus ingredients in food processing, and phosphorus content of vitamin and mineral supplements and commonly used over-the-counter or prescription medications are not fully accounted for by the nutrient content databases and software programs in current clinical use or used in large population studies. In this review, we explore the many unknown sources of phosphorus in the food supply to identify all possible contributors to total phosphorus intake of Americans that have escaped inclusion in past intake estimates. Our goal is to help delineate areas for future interventions that will enable tighter control of dietary phosphorus intake, a critical factor to maintaining health and quality of life in CKD and dialysis patients. © 2012 Wiley Periodicals, Inc.

  6. III. Quantitative aspects of phosphorus excretionin ruminants

    OpenAIRE

    Bravo , David; Sauvant , Daniel; Bogaert , Catherine; Meschy , François

    2003-01-01

    International audience; Ruminant phosphorus excretion and metabolism were studied through a database. Faecal endogenous phosphorus is the main pathway of phosphorus excretion and averages 0.85 of total faecal phosphorus. The remaining 0.15 is unabsorbed dietary phosphorus. Faecal endogenous phosphorus is mainly unabsorbed phosphorus, with saliva being the major source, and is correlated to factors influencing saliva secretion (DM intake, physical dietary characteristics and dietary phosphorus...

  7. The study of Phosphorus distribution at Putrajaya Wetland

    Science.gov (United States)

    Mubin Zahari, Nazirul; Malek, Nur Farzana Fasiha Abdul; Fai, Chow Ming; Humaira Haron, Siti; Hafiz Zawawi, Mohd; Nazmi Ismail, Iszmir; Mohamad, Daud; Syamsir, Agusril; Sidek, Lariyah Mohd; Zakwan Ramli, Mohd; Ismail, Norfariza; Zubir Sapian, Ahmad; Noordin, Normaliza; Rahaman, Nurliyana Abdul; Muhamad, Yahzam; Mat Saman, Jarina

    2018-04-01

    This study is concerning phosphorus distribution in Putrajaya Wetland. Phosphorus is one of the important component in nutrients for living things be it aquatic or non – aquatic organisms. Total phosphorus (TP) results will give some information on the trophic status of surface water in water bodies. The focus of this study is to determine the total phosphorus concentration in Putrajaya Wetland which is in the inlet of the wetland then outlet of the wetland (Central Wetland Lake). The water sample is taken from Putrajaya Wetland and the test was conducted in the laboratory. The result from this study shows the results for total phosphorus according to month, sampling station and cells. Lowest total phosphate at the Central Wetland compare with all the wetland arms cells.

  8. Influence of phosphorus on point defects in an austenitic alloy

    International Nuclear Information System (INIS)

    Boulanger, L.

    1988-06-01

    The influence of phosphorus on points defects clusters has been studied in an austenitic alloy (Fe/19% at. Cr/13% at. Ni). Clusters are observed by transmission electron microscopy. After quenching and annealing, five types of clusters produced by vacancies or phosphorus-vacancies complexes are observed whose presence depends on cooling-speed. Vacancy concentration (with 3.6 10 -3 at. P) in clusters is about 10 -5 and apparent vacancy migration is 2 ± 0.1 eV. These observations suggest the formation of metastable small clusters during cooling which dissociate during annealing and migrate to create the observed clusters. With phosphorus, the unfrequent formation of vacancy loops has been observed during electron irradiation. Ions irradiations show that phosphorus does not favour nucleation of interstitial loops but slowers their growth. It reduces swelling by decreasing voids diameter. Phosphorus forms vacancy complexes whose role is to increase the recombination rate and to slow vacancy migration [fr

  9. Neutron activation analysis for calibration of phosphorus implantation dose

    International Nuclear Information System (INIS)

    Paul, Rick L.; Simons, David S.

    2001-01-01

    A feasibility study was undertaken to determine if radiochemical neutron activation analysis (RNAA) can be used to certify the retained dose of phosphorus implanted in silicon, with the goal of producing a phosphorus SRM. Six pieces of silicon, implanted with a nominal phosphorus dose of 8.5x10 14 atoms·cm -2 were irradiated at a neutron flux of 1.05x10 14 cm -2 ·s -1 . The samples were mixed with carrier, dissolved in acid, the phosphorus isolated by chemical separation, and 32 P measured using a beta proportional counter. A mean phosphorus concentration of (8.35±0.20)x10 14 atoms·cm -2 (uncertainty=1 standard deviation) was determined for the six samples, in agreement with the nominal implanted dose

  10. Occurrence of phosphorus in groundwater and surface water of northwestern Mississippi

    Science.gov (United States)

    Welch, Heather L.; Kingsbury, James A.; Coupe, Richard H.

    2010-01-01

    Previous localized studies of groundwater samples from the Mississippi River Valley alluvial (MRVA) aquifer have demonstrated that dissolved phosphorus concentrations in the aquifer are much higher than the national background concentration of 0.03 milligram per liter (mg/L) found in 400 shallow wells across the country. Forty-six wells screened in the MRVA aquifer in northwestern Mississippi were sampled from June to October 2010 to characterize the occurrence of phosphorus in the aquifer, as well as the factors that might contribute to high dissolved phosphorus concentrations in groundwater. Dissolved phosphorus concentrations ranged from 0.12 to 1.2 mg/L with a median concentration of 0.62 mg/L. The predominant subunit of the MRVA aquifer in northwestern Mississippi is the Holocene alluvium in which median dissolved phosphorus concentrations were higher than the Pleistocene valley trains deposits subunit. Highest phosphorus concentrations occurred in water from wells located along the Mississippi River. A general association between elevated phosphorus concentrations and dissolved iron concentrations suggests that reducing conditions that mobilize iron in the MRVA aquifer also might facilitate transport of phosphorus. Using baseflow separation to estimate the contribution of baseflow to total streamflow, the estimated contribution to the total phosphorus load associated with baseflow at the Tensas River at Tendal, LA, and at the Bogue Phalia near Leland, MS, was 23 percent and 8 percent, respectively. This analysis indicates that elevated concentrations of dissolved phosphorus in the MRVA aquifer could be a possible source of phosphorus to streams during baseflow conditions. However, the fate of phosphorus in groundwater discharge and irrigation return flow to streams is not well understood.

  11. Large Constructed Wetlands for Phosphorus Control: A Review

    Directory of Open Access Journals (Sweden)

    Robert H. Kadlec

    2016-06-01

    Full Text Available This paper reviews aspects of the performance of large (>40 ha constructed treatment wetlands intended for phosphorus control. Thirty-seven such wetlands have been built and have good data records, with a median size of 754 ha. All are successfully removing phosphorus from a variety of waters. Period of record median concentration reductions were 71%, load reductions 0.77 gP·m−2·year−1, and rate coefficients 12.5 m·year−1. Large wetlands have a narrower performance spectrum than the larger group of all sizes. Some systems display startup trends, ranging to several years, likely resulting from antecedent soil and vegetation conditions. There are internal longitudinal gradients in concentration, which vary with lateral position and flow conditions. Accretion in inlet zones may require attention. Concentrations are reduced to plateau values, in the range of about 10–50 mgP·m−3. Vegetation type has an effect upon performance measures, and its presence facilitates performance. Trends in the performance measures over the history of individual systems display only small changes, with both increases and decreases occurring. Such trends remove little of the variance in behavior. Seasonality is typically weak for steady flow systems, and most variability appears to be stochastic. Stormwater systems display differences between wet and dry season behavior, which appear to be flow-driven. Several models of system performance have been developed, both steady and dynamic.

  12. Traps for phosphorus adsorption

    International Nuclear Information System (INIS)

    Montoya, Nawer D; Villegas, Wilson E; Rodriguez, Lino M; Taborda, Nelson; Montes de C, Consuelo

    2001-01-01

    Several AL 2 O 3 supported oxides such as: NiO, CuO, Co 2 O 3 BaO, CeO 2 and ZnO were investigated for phosphorus adsorption. Zno/y-Al 2 O 3 exhibited the highest phosphorus adsorption capacity. However, since it diminishes the activity of to the reaction mixture it should be located upstream of the NoX catalyst, i.e. 0,3% Pd-H-MOR, in order to protect it against p poisoning. The treatment procedure with citric acid was effective for the removal of more than 70% phosphorus from the adsorbent, ZnO/y-Al 2 O 3

  13. Effect of mycorrhiza on growth criteria and phosphorus nutrition of lettuce (Lactuca sativa L. under different phosphorus application rates

    Directory of Open Access Journals (Sweden)

    S. Fatih Ergin

    2016-10-01

    Full Text Available In this study, effect of mycorrhiza on growth criteria and phosphorus nutrition of lettuce (Lactuca sativa L. under different phosphorus fertilization rates were investigated. Phosphorus were added into growing media as 0, 50, 100 and 200 mg P2O5/kg with and without mycorrhiza applications. Phosphorus applications significantly increased yield criteria of lettuce according to the control treatment statistically. Mycorrhiza application also significantly increased plant diameter, plant dry weight and phosphor uptake by plant. The highest phosphorus uptakes by plants were determined in 200 mg P2O5/kg treatments as 88.8 mg P/pot with mycorrhiza and 83.1 mg P/pot without mycorrhiza application. In the control at 0 doses of phosphorus with mycorrhiza treatment, phosphorus uptake (69.9 mg P/pot, edible weight (84.36 g, dry weight (8.64 g and leaf number (28 of lettuce were higher than that (47.7 mg P/pot, 59.33 g, 6.75 g and 20, respectively in the control without mycorrhiza application. It was determined that mycorrhiza had positive effect on growth criteria and phosphorus nutrition by lettuce plant, and this effect decreased at higher phosphorus application rates.

  14. Chromatography of phosphorus oxoacids

    International Nuclear Information System (INIS)

    Ohashi, S.

    1975-01-01

    The present state of studies on the chromatographic separation of phosphorus oxoacids is surveyed. In this paper, chromatographic techniques are divided into four groups, i.e. paper and thin-layer chromatography, paper electrophoresis, ion-exchange chromatography, and gel chromatography. The separation mechanisms and characteristics for these chromatographic methods are discussed and some examples for the separation of phosphorus oxoacids are described. As examples of the application of ion-exchange and gel chromatography, studies on the hot atom chemistry of 32 P in solid inorganic phosphates and those on the substitution reactions between diphosphonate (diphosphite) and polyphosphates are reported. (author)

  15. Microbial Phosphorus Solubilization and Its Potential for Use in Sustainable Agriculture

    Directory of Open Access Journals (Sweden)

    Elizabeth T. Alori

    2017-06-01

    Full Text Available The use of excess conventional Phosphorus (P fertilizers to improve agricultural productivity, in order to meet constantly increasing global food demand, potentially causes surface and ground water pollution, waterway eutrophication, soil fertility depletion, and accumulation of toxic elements such as high concentration of selenium (Se, arsenic (As in the soil. Quite a number of soil microorganisms are capable of solubilizing/mineralizing insoluble soil phosphate to release soluble P and making it available to plants. These microorganisms improve the growth and yield of a wide variety of crops. Thus, inoculating seeds/crops/soil with Phosphate Solubilizing Microorganisms (PSM is a promising strategy to improve world food production without causing any environmental hazard. Despite their great significance in soil fertility improvement, phosphorus-solubilizing microorganisms have yet to replace conventional chemical fertilizers in commercial agriculture. A better understanding of recent developments in PSM functional diversity, colonizing ability, mode of actions and judicious application should facilitate their use as reliable components of sustainable agricultural systems. In this review, we discussed various soil microorganisms that have the ability to solubilize phosphorus and hence have the potential to be used as bio fertilizers. The mechanisms of inorganic phosphate solubilization by PSM and the mechanisms of organic phosphorus mineralization are highlighted together with some factors that determine the success of this technology. Finally we provide some indications that the use of PSM will promote sustainable agriculture and conclude that this technology is ready for commercial exploitation in various regions worldwide.

  16. Selenium and phosphorus interaction in pea (pisum sativum L.)

    International Nuclear Information System (INIS)

    Singh, Mahendra; Bhandari, D.K.

    1975-01-01

    The interaction of selenium and phosphorus on the dry matter yield and concentration and uptake of phosphorus, sulfur and selenium was studied in pea (Pisum sativnum) var. T 163. The fertilizer was tagged with P 32 . It was observed that increased concentration of applied selenium in soil decreased the dry matter yield and increased the concentration and uptake of total P, soil P and selenium in pea plants. Increased concentration of P alone increased dry matter yield, concentration and uptake of total, soil and fertilizer P and selenium which was beyond safe limits, and decreased concentration and uptake of sulphur. Selenium and phosphorus showed strong synergetic relationship by increasing the concentration of each other in plants while both showed antagonistic effect on the concentration of sulphur. Phosphorus compensated the toxic effect of selenium and improved the growth and dry matter yield of pea plants. The highest selenium concentration of 22.4 ppm was observed in 100 ppm phosphorus with 5 ppm selenium treated pots while lowest (0.10 ppm) in control. (author)

  17. Phosphorus solubility in an acid forest soil as influenced by form of applied phosphorus and liming

    International Nuclear Information System (INIS)

    Fransson, Ann-Mari; Bergkvist, Bo; Tyler, Germund

    1999-01-01

    Sedimentary phosphorus, superphosphate, and wood-ash, as well as either sedimentary phosphorus. superphosphate or ash combined with lime, were distributed in selected plots in an 80-yr-old Norway spruce forest [Picea abies (L.) Karst]. After 2 yrs, the sedimentary phosphorus had increased the oxalate/oxalic acid-extractable P in the O-horizon, and the superphosphate had increased the oxalate/oxalic acid-extractable P in the E-horizon. At first, the percolation water from the superphosphate treatment showed high P concentrations. It soon returned to control levels, however. The percolation water from the sedimentary phosphorus treatment gradually showed increased phosphate concentrations. The wood-ash increased neither the amount of extractable P nor the P concentration in the percolation water. The oxalate/oxalic acid-extractable P from the sedimentary P treatment was reduced by liming. The P concentration in the percolation water also tended to be reduced. This was perhaps due to formation of Ca phosphates in the vicinity of the lime particles. In addition, if the solubility rate was similar to the uptake rate, it could account for the decreased P concentration

  18. Phosphorus in Agriculture : 100 % Zero

    NARCIS (Netherlands)

    Schnug, Ewald; De Kok, Luit J.

    2016-01-01

    Phosphorus is essential for all living organisms, reserves in geogenic deposits are finite, and phosphorus nutrient mining and oversupply are common phenomenons on agricultural soils. Only if the agricultural phosphorus cycle can be closed and the fertilized nutrient been utilized completely,

  19. Effect of low ambient mineral concentrations on the accumulation of calcium, magnesium and phosphorus by early life stages of the air-breathing armoured catfish Megalechis personata (Siluriformes; Callichthyidae)

    NARCIS (Netherlands)

    Mol, J.H.; Atsma, W.; Flik, G.; Bouwmeester, H.; Osse, J.W.M.

    1999-01-01

    he accumulation of calcium, magnesium and phosphorus was measured during an 8-week period in the early life stages of the air-breathing armoured catfish Megalechis personata acclimated to low-mineral fresh water (0.073 mmol l-1 calcium, 0.015 mmol l-1 magnesium, <0.001 mmol l-1 phosphate) and

  20. Absorption spectrum of neutral phosphorus (P I) in the range 7700-8256 A

    International Nuclear Information System (INIS)

    Deng Lunhua; Li Chuanliang; Zhang Junli; Yang Xiaohua; Chen Yangqin

    2010-01-01

    The absorption spectrum of neutral phosphorus was recorded in the range 7700-8256 A using optical heterodyne magnetic rotation concentration modulation spectroscopy with a tunable Ti:sapphire laser as the light source. Phosphorus atoms were excited by discharging the mixed gases of phosphorus vapor and neon gas. The phosphorus vapor was prepared by heating white phosphorus chips placed on a cylindrical copper electrode during discharge. In total, 234 lines of P I were observed, of which 127 were assigned. The transition frequencies were obtained with an uncertainty of 0.007 cm -1 . Empirical line intensities were provided covering four orders of magnitude.

  1. Absorption spectrum of neutral phosphorus (P I) in the range 7700-8256 Å

    Science.gov (United States)

    Deng, Lunhua; Li, Chuanliang; Zhang, Junli; Yang, Xiaohua; Chen, Yangqin

    2010-12-01

    The absorption spectrum of neutral phosphorus was recorded in the range 7700-8256 Å using optical heterodyne magnetic rotation concentration modulation spectroscopy with a tunable Ti:sapphire laser as the light source. Phosphorus atoms were excited by discharging the mixed gases of phosphorus vapor and neon gas. The phosphorus vapor was prepared by heating white phosphorus chips placed on a cylindrical copper electrode during discharge. In total, 234 lines of P I were observed, of which 127 were assigned. The transition frequencies were obtained with an uncertainty of 0.007 cm-1. Empirical line intensities were provided covering four orders of magnitude.

  2. Biochar as phosphorus transporter to support the closure of the phosphorus cycle

    Science.gov (United States)

    Soja, Gerhard; Jagerhofer, Reinhard; Fristak, Vladimir; Pfeifer, Christoph

    2017-04-01

    Waste materials rich in phosphorus could partly substitute rock phosphate-based mineral fertilizers. As rock phosphate is listed as critical raw material, measures for increasing the recovery rate of phosphorus and for closing the phosphorus cycle are required. However, direct use of the waste materials as fertilizers are frequently not possible because of legal constraints, adverse side effects because of co-occurring contaminants or hygienic concerns. So this study had the objective to test the appropriateness of carbonizing P-rich residues that can be used as secondary P resources for producing P fertilizers. The resulting biochar or hydrochar products should be tested for the bioavailability of P for plant uptake. Feedstock materials tested as secondary P resources were chicken manure, animal bone flour, sewage sludge, and digestates. These materials were either pyrolyzed at different temperatures, partly with different chemical modifications, or hydrothermally carbonized. The biochar and hydrochar products were analyzed for their total and available P concentrations, and the plant bioavailability was determined with a standardized plant growth test with rye (Neubauer-test). The results showed that biochar produced from a mixture of chicken manure and saw dust was equivalent to a standard phosphate fertilizer (superphosphate) with respect to P available for plant uptake. For most materials, a pyrolysis temperature of 400 °C was slightly more beneficial for P availability than 500 °C. Pyrolytic carbonization mostly was more supportive for plant growth than hydrothermal carbonization of the tested feedstocks. For some feedstocks the addition of sodium carbonate improved the P uptake of the plants without affecting the biomass production. The results show that P-rich waste materials used as secondary resources for carbonization can effectively contribute to increased P recovery, savings in the use of mineral phosphate fertilizers and reduced P loads to non

  3. Identification of cowpea cultivars for low phosphorus soils of Nigeria

    International Nuclear Information System (INIS)

    Afolabi, N.O.; Ogunbodede, B.A.; Adediran, J.A.

    1996-01-01

    Twenty cultivars of cowpea, Vigna unguiculata, adapted to the Nigerian ecologies were screened to identify cultivars which can give high and sustainable yields when grown on soils with low available phosphorus in a sub-humid climate. Some cultivars including TVX3236, AFB1757, Ogunfowokan and K-28 gave three to four times higher grain yields than the other cultivars at zero phosphorus supply. While phosphorus application reduced grain yield in most of the cultivars with marked reduction in the higher yielding cultivars, low yielding cultivars tended to show some yield increase. Phosphorus use efficiency of the roots, stem or leaves was not significantly correlated with grain yield when 60 KgP/ha was applied. Reduction in yield due to phosphorus application might be due to induced Zn deficiency as Zn supply in these soils has been found to be inherently low. High grain yielding capacity without fertilizer phosphorus application was generally positively correlated with high vegetative shoot dry matter production. However, no clear relationship could be found between grain yield and root dry matter at maturity. It is concluded that selection for phosphorus efficiency in cowpea can substantially contribute to higher cowpea productivity and the farmers income on soils low in available phosphorus in the sub-humid areas of Nigeria. (author). 5 refs, 2 figs, 2 tabs

  4. Identification of cowpea cultivars for low phosphorus soils of Nigeria

    Energy Technology Data Exchange (ETDEWEB)

    Afolabi, N O; Ogunbodede, B A; Adediran, J A [Obafemi Awolowo Univ., Ibadan (Nigeria). Inst. of Agricultural Research and Training

    1996-07-01

    Twenty cultivars of cowpea, Vigna unguiculata, adapted to the Nigerian ecologies were screened to identify cultivars which can give high and sustainable yields when grown on soils with low available phosphorus in a sub-humid climate. Some cultivars including TVX3236, AFB1757, Ogunfowokan and K-28 gave three to four times higher grain yields than the other cultivars at zero phosphorus supply. While phosphorus application reduced grain yield in most of the cultivars with marked reduction in the higher yielding cultivars, low yielding cultivars tended to show some yield increase. Phosphorus use efficiency of the roots, stem or leaves was not significantly correlated with grain yield when 60 KgP/ha was applied. Reduction in yield due to phosphorus application might be due to induced Zn deficiency as Zn supply in these soils has been found to be inherently low. High grain yielding capacity without fertilizer phosphorus application was generally positively correlated with high vegetative shoot dry matter production. However, no clear relationship could be found between grain yield and root dry matter at maturity. It is concluded that selection for phosphorus efficiency in cowpea can substantially contribute to higher cowpea productivity and the farmers income on soils low in available phosphorus in the sub-humid areas of Nigeria. (author). 5 refs, 2 figs, 2 tabs.

  5. Colorimetric Chemical Differentiation and Detection of Phosphorus in Eutrophic and High Particulate Waters: Advantages of a New Monitoring Approach

    Directory of Open Access Journals (Sweden)

    Lisa Felgentreu

    2018-06-01

    Full Text Available Phosphorus (P is a key factor forcing eutrophication in limnic and marine systems, and all monitoring programs for water quality accordingly include P determinations. However, traditional monitoring does not allow an analysis of the different components involved in the P cycle taking place in the water column. Nonetheless, the implementation of measures addressing eutrophication requires a full understanding of the processes involved in the transformation and transport of P, in all its chemical forms. In this study, the P categories present in a river and its estuary in northern Germany, which discharge into the Baltic Sea, were characterized. Using the molybdenum blue method we found that the classification of P into the traditional fractions (DIP, DOP, POP applied in the ocean cannot be applied to turbid waters such as rivers because interferences between the fractions seems to occur. Therefore a new nomenclature has been introduced. In addition to total phosphorus (TP and dissolved molybdate-reactive phosphorus (DRP; previously referred to as inorganic phosphorus, dissolved non-molybdate-reactive phosphorus (DNP, particulate molybdatereactive phosphorus (PRP, and particulate non-molybdate-reactive phosphorus (PNP were distinguished. The high spatial and temporal variations in the proportions of these forms with respect to the TP concentration well-demonstrate the complexity of the P cycle and the involved P fractions and emphasize the need for expanded monitoring approach. The potential of eutrophication could be underestimated if not all P categories were considered. With the new operational nomenclature the common and standardized molybdenum blue reaction could be used to implement the analysis of various P components into regular monitoring programs.

  6. Digestible phosphorus levels for barrows from 50 to 80 kg

    Directory of Open Access Journals (Sweden)

    Viviane Maria Oliveira dos Santos Nieto

    2016-05-01

    Full Text Available ABSTRACT This study was carried out to evaluate the levels of digestible phosphorus in diets for barrows with a high potential for lean meat deposition from 50 to 80 kg. Eighty barrows, with an initial weight of 47.93±3.43 kg, were distributed in completely randomized blocks, with each group given five levels of digestible phosphorus (1.86, 2.23, 2.61, 2.99, and 3.36 g kg−1. There were eight replicates, and two animals per experimental unit. Phosphorus levels did not significantly influence feed intake, weight gain, or feed conversion ratio. Daily digestible phosphorus intake increased linearly as levels of phosphorus in the diet were increased. Phosphorus levels did not significantly influence muscle depth, loin eye area, backfat thickness, or the percentage and quantity of lean meat in the carcass. A linear increase was observed for feeding cost as the levels of digestible phosphorus in the diet were increased, and the level of 1.86 g kg−1 cost 29.4% less when compared with the level of 2.61 g kg−1. The dry matter, natural matter, the coefficient of the residue, and volatile solids of the waste were not significantly influenced by phosphorus levels. Conversely, it was possible to observe an increasing linear effect for total solids, total phosphorus, and total nitrogen in the waste of animals receiving diets with increased levels of digestible phosphorus. The level of 1.86 g kg−1, which corresponded to a daily intake of 4.77 g−1 of digestible phosphorus, meets the requirements of barrows weighing 50 to 80 kg.

  7. Patient education for phosphorus management in chronic kidney disease

    Directory of Open Access Journals (Sweden)

    Kalantar-Zadeh K

    2013-05-01

    Full Text Available Kamyar Kalantar-ZadehHarold Simmons Center for Kidney Disease Research and Epidemiology, Division of Nephrology and Hypertension, University of California Irvine’s School of Medicine, Irvine, CA, USAObjectives: This review explores the challenges and solutions in educating patients with chronic kidney disease (CKD to lower serum phosphorus while avoiding protein insufficiency and hypercalcemia.Methods: A literature search including terms “hyperphosphatemia,” “patient education,” “food fatigue,” “hypercalcemia,” and “phosphorus–protein ratio” was undertaken using PubMed.Results: Hyperphosphatemia is a strong predictor of mortality in advanced CKD and is remediated via diet, phosphorus binders, and dialysis. Dietary counseling should encourage the consumption of foods with the least amount of inorganic or absorbable phosphorus, low phosphorus-to-protein ratios, and adequate protein content, and discourage excessive calcium intake in high-risk patients. Emerging educational initiatives include food labeling using a “traffic light” scheme, motivational interviewing techniques, and the Phosphate Education Program – whereby patients no longer have to memorize the phosphorus content of each individual food component, but only a “phosphorus unit” value for a limited number of food groups. Phosphorus binders are associated with a clear survival advantage in CKD patients, overcome the limitations associated with dietary phosphorus restriction, and permit a more flexible approach to achieving normalization of phosphorus levels.Conclusion: Patient education on phosphorus and calcium management can improve concordance and adherence and empower patients to collaborate actively for optimal control of mineral metabolism.Keywords: hyperphosphatemia, renal diet, phosphorus binders, educational programs, food fatigue, concordance

  8. Study of Concentrations of Available Cations and Anions in PM2.5 in the Air of Twelfth Region of Tehran City

    Directory of Open Access Journals (Sweden)

    Hossean Arfaeinia

    2017-04-01

    Full Text Available Background: In the last few decades, the city's air quality has become a major concern; especially there is strong evidence about health effects of particulate matter in urban communities.In addition to suspended particles concentration, the ionic part of suspended particles is also very important, So that some studies  ions like Sulfate is the reson of increasing the respiratory diseases.So the aim of this study was to study of concentration of PM2.5 particles and their ionic componentsincluding major anions and cations in twelfth region of Tehran city in 2013. Materials & Methods: This cross - sectional study was conducted in the air of twelfth region of Tehran. PM2.5 concentration was calculated with sampling by frmOMNITMAmbient Air Sampler with PTFE filter with a diameter of 47 mm and through the weight measurement.Concentration of anions and cations which had associated with PM2.5 particles was read after collected sample preparation and injection to device Ion Chromatography (IC Metrohm 850 model. Correlation matrix was calculated between anions and cations. Data analysis was carried out by Excel and SPSS version 18 and One-Way ANOVA test. Results: The mean daily concentration of PM2.5 particles was 19.41 µg/m3 during the study. One-Way ANOVA test showed a significant difference at the 0.05 level between PM2.5 concentrations on different days of the week. Concentrations for sodium, potassium, ammonium, calcium, magnesium, sulfate, nitrate, chloride were obtained 0.28, 0.06, 0.49, 0.87, 0.63, 56.3, 1.43 and 0.71 µg/m3, respectively, and no value was detected for fluoride and nitrite. Balance between anions and cations were calculated and the correlation coefficient (R2 were obtained 0.972 between the anions and cations. Conclusion The mean concentrations of PM2.5 was higher than the air standards in Iran and WHO guidelines (25 µg/m3 and EPA standards (35 µg/m3. In a study reported that the One-Way ANOVA test between particle

  9. [Effects of tobacco garlic crop rotation and intercropping on tobacco yield and rhizosphere soil phosphorus fractions].

    Science.gov (United States)

    Tang, Biao; Zhang, Xi-zhou; Yang, Xian-bin

    2015-07-01

    A field plot experiment was conducted to investigate the tobacco yield and different forms of soil phosphorus under tobacco garlic crop rotation and intercropping patterns. The results showed that compared with tobacco monoculture, the tobacco yield and proportion of middle/high class of tobacco leaves to total leaves were significantly increased in tobacco garlic crop rotation and intercropping, and the rhizosphere soil available phosphorus contents were 1.3 and 1.7 times as high as that of tobacco monoculture at mature stage of lower leaf. For the inorganic phosphorus in rhizosphere and non-rhizosphere soil in different treatments, the contents of O-P and Fe-P were the highest, followed by Ca2-P and Al-P, and Ca8-P and Ca10-P were the lowest. Compared with tobacco monoculture and tobacco garlic crop intercropping, the Ca2-P concentration in rhizosphere soil under tobacco garlic crop rotation at mature stage of upper leaf, the Ca8-P concentration at mature stage of lower leaf, and the Ca10-P concentration at mature stage of middle leaf were lowest. The Al-P concentrations under tobacco garlic crop rotation and intercropping were 1.6 and 1.9 times, and 1.2 and 1.9 times as much as that under tobacco monoculture in rhizosphere soil at mature stages of lower leaf and middle leaf, respectively. The O-P concentrations in rhizosphere soil under tobacco garlic crop rotation and intercropping were significantly lower than that under tobacco monoculture. Compared with tobacco garlic crop intercropping, the tobacco garlic crop rotation could better improve tobacco yield and the proportion of high and middle class leaf by activating O-P, Ca10-P and resistant organic phosphorus in soil.

  10. Phosphorus Fluxes from Three Coastal Watersheds under Varied Agriculture Intensities to the Northern Gulf of Mexico

    Directory of Open Access Journals (Sweden)

    Songjie He

    2018-06-01

    Full Text Available This study aims to evaluate recent total phosphorus (TP and dissolved inorganic phosphorus (DIP transport from three coastal rivers—the Calcasieu, Mermentau, and Vermilion Rivers—that drain watersheds with varied agriculture intensities (21%, 67%, and 61%, respectively into the northern Gulf of Mexico, one of the world’s largest summer hypoxic zones. The study also examined the spatial trends of TP and DIP from freshwater to saltwater along an 88-km estuarine reach with salinity increasing from 0.02 to 29.50. The results showed that from 1990–2009 to 2010–2017, the TP fluxes for one of the agriculture-intensive rivers increased while no significant change was found for the other two rivers. Change in river discharge was the main reason for this TP flux trend. The two more agriculture-intensive river basins showed consistently higher TP and DIP concentrations and fluxes, as well as higher DIP:TP ratios than the river draining less agriculture-intensive land, confirming the strong effect of land uses on phosphorus input and speciation. Longitudinal profiles of DIP along the salinity gradient of the estuarine reach displayed characteristic input behavior. Desorption of DIP from suspended solids and river bed sediments, urban inputs, as well as stronger calcium carbonate and phosphorus co-precipitation at the marine endmember could be the reasons for such mixing dynamics.

  11. STOCHASTIC MODELING OF COMPRESSIVE STRENGTH OF PHOSPHORUS SLAG CONTENT CEMENT

    Directory of Open Access Journals (Sweden)

    Ali Allahverdi

    2016-07-01

    Full Text Available One of the common methods for quick determination of compressive strength as one of the most important properties for assessment of cement quality is to apply various modeling approaches. This study is aimed at finding a model for estimating the compressive strength of phosphorus slag content cements. For this purpose, the compressive strengths of chemically activated high phosphorus slag content cement prepared from phosphorus slag (80 wt.%, Portland cement (14 wt.% and a compound chemical activator containing sodium sulfate and anhydrite (6 wt.% were measured at various Blaine finenesses and curing times. Based on the obtained results, a primary stochastic model in terms of curing time and Blaine fineness has been developed. Then, another different dataset was used to incorporate composition variable including weight fractions of phosphorus slag, cement, and activator in the model. This model can be effectively used to predict the compressive strength of phosphorus slag content cements at various Blaine finenesses, curing times, and compositions.

  12. Black Phosphorus: Critical Review and Potential for Water Splitting Photocatalyst

    Directory of Open Access Journals (Sweden)

    Tae Hyung Lee

    2016-10-01

    Full Text Available A century after its first synthesis in 1914, black phosphorus has been attracting significant attention as a promising two-dimensional material in recent years due to its unique properties. Nowadays, with the development of its exfoliation method, there are extensive applications of black phosphorus in transistors, batteries and optoelectronics. Though, because of its hardship in mass production and stability problems, the potential of the black phosphorus in various fields is left unexplored. Here, we provide a comprehensive review of crystal structure, electronic, optical properties and synthesis of black phosphorus. Recent research works about the applications of black phosphorus is summarized. Among them, the possibility of black phosphorous as a solar water splitting photocatalyst is mainly discussed and the feasible novel structure of photocatalysts based on black phosphorous is proposed.

  13. Recovery of phosphorus compounds from thermally-processed wastes

    Science.gov (United States)

    Czechowska-Kosacka, A.; Pawłowski, L.; Niedbala, G.; Cel, W.

    2018-05-01

    Depletion of phosphorus deposits is one of the most serious global problems, which may soon lead to a crisis in food production. It is estimated that if the current living standard is maintained, the available reserves will be depleted in 130 years. Considering the principle of sustainable development, searching for alternative phosphorus sources is extremely important. The work presented the results of the research on the possibility of utilizing wastes as a source of phosphorus. The studies were conducted on poultry manure. The physicochemical properties of phosporus-rich wastes were determined as well. The fertilizing properties of ashes from poultry manure combustion – obtained from different systems, i.e. caged and barn production. The assimilability of phosphorus from the obtained ashes was determined. Potential applications of phosphorus-rich ashes were proposed as well.

  14. Dietary phosphorus restriction in dialysis patients: potential impact of processed meat, poultry, and fish products as protein sources.

    Science.gov (United States)

    Sherman, Richard A; Mehta, Ojas

    2009-07-01

    Dietary intake of phosphorus is derived largely from protein sources and is a critical determinant of phosphorus balance in patients with chronic kidney disease. Information about the phosphorus content of prepared foods generally is unavailable, but it is believed to contribute significantly to the phosphorus burden of patients with chronic kidney disease. Analysis of dietary components. We measured the phosphorus content of 44 food products, including 30 refrigerated or frozen precooked meat, poultry, and fish items, generally national brands. Measured and reported phosphorus content of foods. Phosphorus by using Association of Analytical Communities official method 984.27; protein by using Association of Analytical Communities official method 990.03. We found that the ratio of phosphorus to protein content in these items ranged from 6.1 to 21.5 mg of phosphorus per 1 g of protein. The mean ratio in the 19 food products with a label listing phosphorus as an additive was 14.6 mg/g compared with 9.0 mg/g in the 11 items without listed phosphorus. The phosphorus content of only 1 precooked food product was available in a widely used dietary database. Results cannot be extrapolated to other products. Manufacturers also may alter the phosphorus content of foods at any time. Protein content was not directly measured for all foods. Better reporting of phosphorus content of foods by manufacturers could result in improved dietary phosphorus control without risk of protein malnutrition.

  15. Do invasive mussels restrict offshore phosphorus transport in Lake Huron?

    Science.gov (United States)

    Cha, Yoonkyung; Stow, Craig A; Nalepa, Thomas F; Reckhow, Kenneth H

    2011-09-01

    Dreissenid mussels were first documented in the Laurentian Great Lakes in the late 1980s. Zebra mussels (Dreissena polymorpha) spread quickly into shallow, hard-substrate areas; quagga mussels (Dreissena rostriformis bugensis) spread more slowly and are currently colonizing deep, offshore areas. These mussels occur at high densities, filter large water volumes while feeding on suspended materials, and deposit particulate waste on the lake bottom. This filtering activity has been hypothesized to sequester tributary phosphorus in nearshore regions reducing offshore primary productivity. We used a mass balance model to estimate the phosphorus sedimentation rate in Saginaw Bay, a shallow embayment of Lake Huron, before and after the mussel invasion. Our results indicate that the proportion of tributary phosphorus retained in Saginaw Bay increased from approximately 46-70% when dreissenids appeared, reducing phosphorus export to the main body of Lake Huron. The combined effects of increased phosphorus retention and decreased phosphorus loading have caused an approximate 60% decrease in phosphorus export from Saginaw Bay to Lake Huron. Our results support the hypothesis that the ongoing decline of preyfish and secondary producers including diporeia (Diporeia spp.) in Lake Huron is a bottom-up phenomenon associated with decreased phosphorus availability in the offshore to support primary production.

  16. The bioaccumulation factor for phosphorus-32 in edible fish tissue. Final report 1 Aug 77-15 Oct 79

    International Nuclear Information System (INIS)

    Kaho, B.; Turgeon, K.

    1980-03-01

    Information used to derive the bioaccumulation factor for P-32 in edible portions of fish from water was reviewed to evaluate the currently recommended values of 100,000 in fresh water and 29,000 in sea water that are applied in generic calculations of radiation doses to persons from nuclear power reactor effluents. A phosphorus bioaccumulation factor of 70,000 was calculated for larger rivers and estuarine waters on the basis of geometric mean phosphorus concentrations of 2 mg/g wet weight in fish muscle and 0.03 mg/1 dissolved in water. A bioaccumulation factor for P-32 of 3,000 was computed by multiplying the phosphorus bioaccumulation factor by the ratio of the biological to the effective turnover rate in fish muscle. A biological turnover rate in muscle of 0.2 percent per day was estimated from phosphorus balances as a long-term average for large fish, although more rapid turnovers have been observed for brief periods. Large deviations from these selected generic bioaccumulation factors occur because of differences in phosphorus concentrations and turnover rates. Bioaccumulation of this magnitude is due to P-32 concentration at lowest trophic levels in the food web, not by concentration in fish, hence the availability of concentrating organisms determines whether this bioaccumulation factor is reached. Several other conditions that affect the P-32 bioaccumulation factor have not been quantified but are suggested for study. Measurement programs are recommended to determine site-specific P-32 bioaccumulation factors and enlarge the data base for the generic values

  17. Dietary phosphorus requirement of pejerrey fingerlings (Odontesthes bonariensis

    Directory of Open Access Journals (Sweden)

    Cleber Bastos Rocha

    2014-02-01

    Full Text Available To determine the available phosphorus requirement of pejerrey fish, four semi-purified diets were formulated to contain increasing available phosphorus levels (0.90, 2.7, 5.7 and 8.3 g/kg. Each diet was assigned to groups of 10 fish with average weight of 1.26±0.17 g, distributed into a completely randomized design with four treatments and four replications. Fish were fed at a rate of 10% total biomass four times a day for 60 days. The parameters productive performance, body chemical composition and mineral composition of bones and scales were evaluated. The best productive performance of fingerlings was obtained with the diet containing 4.3 g/kg available phosphorus. The average level of 6.3 g/kg available phosphorus promotes better mineralization of bones and scales in pejerrey fish.

  18. A Hierarchical Phosphorus Nanobarbed Nanowire Hybrid: Its Structure and Electrochemical Properties.

    Science.gov (United States)

    Zhao, Dan; Li, Beibei; Zhang, Jinying; Li, Xin; Xiao, Dingbin; Fu, Chengcheng; Zhang, Lihui; Li, Zhihui; Li, Jun; Cao, Daxian; Niu, Chunming

    2017-06-14

    Nanostructured phosphorus-carbon composites are promising materials for Li-ion and Na-ion battery anodes. A hierarchical phosphorus hybrid, SiC@graphene@P, has been synthesized by the chemical vapor deposition of phosphorus on the surfaces of barbed nanowires, where the barbs are vertically grown graphene nanosheets and the cores are SiC nanowires. A temperature-gradient vaporization-condensation method has been used to remove the unhybridized phosphorus particles formed by homogeneous nucleation. The vertically grown barb shaped graphene nanosheets and a high concentration of edge carbon atoms induced a fibrous red phosphorus (f-RP) growth with its {001} planes in parallel to {002} planes of nanographene sheets and led to a strong interpenetrated interface interaction between phosphorus and the surfaces of graphene nanosheets. This hybridization has been demonstrated to significantly enhance the electrochemical performances of phosphorus.

  19. Concentration of heavy metals n available fish species (bain, mastacembelus armatus; taki, channa punctatus and bele, glossogobius giuris) in the turag river, bangladesh

    International Nuclear Information System (INIS)

    Afrin, R.; Younus, M.D.

    2015-01-01

    This study was conducted to assess the concentration level of heavy metals in three available fish species (Bain, Mastacembelus armatus; Taki, Channa punctatus and Bele, Glossogobius giuris) of the Turag river, Bangladesh during the months from January to March, 2014. In case of bio-concentration of heavy metals in fish, the levels of Pb, Cd, Cr, Cu and Fe ranged from 0.01-0.13 mg/kg, 0.001-0.02 mg/kg, 0.17-0.48 mg/kg, 0.30-0.74 mg/kg and 4.05-46.86 mg/kg, respectively while Hg was below detection level. These values indicate that the heavy metals were concentrated in fish flesh at a higher level than water. The highest values of Pb, Cd and Cr were found in Bain fish, Fe was found in Taki fish and Cu was found in Bele fish. Most of the heavy metals have crossed the permissible limits in fish, especially for the values of Cr, Cu and Fe. From the results of the present investigation, it can be concluded that the available fish species are harmful for their consumers. (author)

  20. Initial amino acid intake influences phosphorus and calcium homeostasis in preterm infants--it is time to change the composition of the early parenteral nutrition.

    Directory of Open Access Journals (Sweden)

    Francesco Bonsante

    Full Text Available Early aggressive parenteral nutrition (PN, consisting of caloric and nitrogen intake soon after birth, is currently proposed for the premature baby. Some electrolyte disturbances, such as hypophosphatemia and hypercalcemia, considered unusual in early life, were recently described while using this PN approach. We hypothesize that, due to its impact on cell metabolism, the initial amino acid (AA amount may specifically influence the metabolism of phosphorus, and consequently of calcium. We aim to evaluate the influence of AA intake on calcium-phosphorus metabolism, and to create a calculation tool to estimate phosphorus needs.Prospective observational study. Phosphate and calcium plasma concentrations and calcium balance were evaluated daily during the first week of life in very preterm infants, and their relationship with nutrition was studied. For this purpose, infants were divided into three groups: high, medium and low AA intake (HAA, MAA, LAA. A calculation formula to assess phosphorus needs was elaborated, with a theoretical model based on AA and calcium intake, and the cumulative deficit of phosphate intake was estimated.154 infants were included. Hypophosphatemia (12.5% and hypercalcemia (9.8% were more frequent in the HAA than in the MAA (4.6% and 4.8% and in the LAA group (0% and 1.9%; both p<0.001.Calcium-phosphorus homeostasis was influenced by the early AA intake. We propose to consider phosphorus and calcium imbalances as being part of a syndrome, related to incomplete provision of nutrients after the abrupt discontinuation of the placental nutrition at birth (PI-ReFeeding syndrome. We provide a simple tool to calculate the optimal phosphate intake. The early introduction of AA in the PN soon after birth might be completed by an early intake of phosphorus, since AA and phosphorus are (along with potassium the main determinants of cellular growth.

  1. Phosphorus Transport in Rivers.

    Science.gov (United States)

    1978-11-01

    be attributed to excessive nutrient inputs to the lake. These nutrients sti- mulate the phytoplankton (algae) growth which yields excess growth. The...phosphorus in relation to the restoration of Lake Erie. The various computational techniques presented herein aid in the understanding of total...as caused by the absorption on clay materials and by assimilation by periphyton . Other investigators have found correlations between flow and other

  2. Aluminum-Based Water Treatment Residue Reuse for Phosphorus Removal

    Directory of Open Access Journals (Sweden)

    Lai Yoke Lee

    2015-04-01

    Full Text Available Aluminum-based water treatment residue (Al-WTR generated during the drinking water treatment process is a readily available recycled material with high phosphorus (P adsorption capacity. The P adsorption capacity of Al-WTR generated from Singapore’s water treatment plant was evaluated with reference to particle size range, adsorption pH and temperature. Column tests, with WTR amendments in sand with and without compost, were used to simulate the bioretention systems. The adsorption rate decreased with increasing WTR sizes. Highest P adsorption capacity, 15.57 mg PO43−-P/g WTR, was achieved using fine WTR particles (>50% particles at less than 0.30 mm. At pH 4, the contact time required to reduce effluent P concentration to below the detectable range was half compared with pH 7 and 9. The adsorption rate observed at 40 ± 2 °C was 21% higher compared with that at 30 ± 2 °C. Soil mixes amended with 10% WTR and compost were able to maintain consistently high (90% total phosphorus (TP removal efficiency at a TP load up to 6.45 g/m3. In contrast, TP removal efficiencies associated with columns without WTR amendment decreased to less than 45% as the TP load increased beyond 4.5 g/m3. The results showed that WTR application is beneficial for enhanced TP removal in bioretention systems.

  3. to Phosphorus Fertilization, Crop Sequence and Tillage Management

    Directory of Open Access Journals (Sweden)

    Xiaopeng Gao

    2012-01-01

    Full Text Available Field experiments were conducted at two locations in Manitoba, Canada, to determine the effect of crop rotation, phosphorus (P fertilization and tillage on grain yield and grain concentrations of Cd and Zn in durum wheat (Triticum durum L.. Compared to conventional tillage (CT, reduced tillage (RT management decreased grain Cd and increased grain yield and grain Zn in half of the site-years. The type of preceding crops of spring wheat-flax or canola-flax had little influence. Rate and timing of P application had little effect on grain Cd, but increasing P rate tended to decrease grain Zn. No interactive effect was detected among tested factors. Grain Zn was not related to grain Cd, but positively to other nutrients such as Fe, Mn, P, Ca, K, and Mg. Both grain Zn and Fe correlated positively with grain protein content, suggesting protein may represent a sink for micronutrients. The study suggested that the tillage management may have beneficial effects on both grain yield and quality. Phosphorus fertilizer can remain available for subsequent crops and high annual inputs in the crop sequence may decrease crop grain Zn. Understanding the environment is important in determining the impact of agricultural management on agronomic and nutrient traits.

  4. Phosphorus and phytase levels for layer hens

    Directory of Open Access Journals (Sweden)

    Juliana Cristina Ramos Rezende

    2013-02-01

    Full Text Available The objective of this research was to evaluate the performance and bone quality of laying hens after peak production fed diets containing phosphorus levels and phytase. An experiment was conducted with 384 Hy-line distributed in a completely randomized in a factorial 4 x 3 with 4 levels of available phosphorus and 3 levels of phytase. The experimental period was divided into four periods of 28 days, at the end of each cycle were determined experimental feed intake, egg production, egg weight, feed conversion, mortality, and average egg weight, shell thickness, Haugh units and specific gravity. At the end of the experimental period were determined amounts of calcium and phosphorus excreted by the method of total excreta collection and a fowl per experimental unit was sacrificed for collection of bones and evaluation of width, length and level of robustness from femur and tibia. There was interaction between phosphorus levels and phytase on feed intake, feed conversion and percentage of posture. For inclusion levels of phytase all egg quality variables showed no significant differences. The treatments did not affect bone characteristics of laying hens.

  5. Quantitative autoradiography of semiconductor materials by means of diffused phosphorus standards

    International Nuclear Information System (INIS)

    Treutler, H.C.; Freyer, K.

    1983-01-01

    A suitable standard sample was developed and tested on the basis of phosphorus for the quantitative autoradiography of elements of interest in semiconductor technology. By the aid of silicon disks with a phosphorus concentration of 6x10 17 atomsxcm - 2 the error of the quantitative autoradiogprahic method is determined. The relative mean error of the density measurement is at best +-4%; the relative mean error of the determination of phosphorus concentration by use of an error-free standard sample is about +-15%. The method will be extended to other elements by use of this standard sample of phosphorus. (author)

  6. Phosphorus metabolism and estimation of phosphorus requirements for sheep

    International Nuclear Information System (INIS)

    Louvandini, H.; Vitti, D.M.S.S.

    1996-01-01

    The main objective of the present work was to determine the effects of different dietary phosphorus (P) levels on endogenous faecal loss and to estimate the minimum daily requirement of P for sheep. The study was conducted with 24 Suffolk sheep which received a basic diet consisting of a hay-concentrate mixture. The treatment consisted of different amounts of bone meal, added to the basic diet, so as to obtain supplementary P levels of 0, 2 and 3 g/day. Twenty-one days after the introduction of the experimental diet, 7.4 MBq radioactive P ( 32 P) was injected in the left jugular vein of each sheep and blood, feces and urine were collected daily for 8 days at 24-hour intervals. The samples were analysed for inorganic P and for radioactive specific activities. Mean endogenous faecal losses of P were 10.00, 31.79, 39.35 and 38.06 mg/kg live weight (LW) per day in sheep supplemented with 0, 1, 2 and 3 g respectively. A positive linear relation ship was observed between endogenous faecal loss and consumed P, indicating that this loss was linked to dietary P. Total P excretion in the faeces, as well as P absorption, retention urinary excretion and salivary secretion were also directly related to P intake, as part of the mechanism of homeostatic control of organism animal. The minimum endogenous faecal loss for zero P intake, calculated by interpolation, was 8.27 mg/kg LW per day, and for zero balance, the calculated phosphorus consumption was 21.36 mg/kg LW per day. (author)

  7. Pervasive phosphorus limitation of tree species but not communities in tropical forests

    Science.gov (United States)

    Turner, Benjamin L.; Brenes-Arguedas, Tania; Condit, Richard

    2018-03-01

    Phosphorus availability is widely assumed to limit primary productivity in tropical forests, but support for this paradigm is equivocal. Although biogeochemical theory predicts that phosphorus limitation should be prevalent on old, strongly weathered soils, experimental manipulations have failed to detect a consistent response to phosphorus addition in species-rich lowland tropical forests. Here we show, by quantifying the growth of 541 tropical tree species across a steep natural phosphorus gradient in Panama, that phosphorus limitation is widespread at the level of individual species and strengthens markedly below a threshold of two parts per million exchangeable soil phosphate. However, this pervasive species-specific phosphorus limitation does not translate into a community-wide response, because some species grow rapidly on infertile soils despite extremely low phosphorus availability. These results redefine our understanding of nutrient limitation in diverse plant communities and have important implications for attempts to predict the response of tropical forests to environmental change.

  8. Using modified multiple phosphorus sensitivity indices for mitigation and management of phosphorus loads on a catchment level

    CSIR Research Space (South Africa)

    Oberholster, Paul J

    2013-01-01

    Full Text Available The relationships between river and lake phosphorus sensitivity, environmental drivers and catchment characteristics within the upper Olifants River and Lake Loskop were studied over a period of four years to come up with mitigation and management...

  9. Concentration levels of rare-earth elements and thorium on plants from the Morro de Ferro environment as an indicator for the biological availability of transuranium elements

    International Nuclear Information System (INIS)

    Miekeley, N.; Casartelli, E.A.; Dotto, R.M.

    1994-01-01

    Plants and soils from a natural thorium and rare-earth element occurrence (Morro do Ferro, Brazil) were analyzed by alpha spectrometry (Th) and ICP-AES (REE), after pre-concentration of the elements by solvent extraction, co-precipitation and ion exchange procedures. Leaching experiments with humic acid solutions and different soils were performed to estimate the fraction of elements biologically available. High concentrations of the light rare-earth elements (LREE) and of Th, reaching some hundreds of μg/g-ash, were measured in plant leaves from the areas of the highest concentration of these elements in soil and in near-surface waters. Chondrite normalized REE plots of plant leaves and corresponding soils are very similar, suggesting that there is no significant fractionation between the REE during uptake from the soil solution and incorporation into the leaves. However, Ce-depletion was observed for some plant species, increasing for Solanum ciliatum in the sequence: leaves -3 to 10 -2 . Leaching experiments confirmed the importance of humic acid complexation for the bio-uptake of Th and REE and further showed that only a very small fraction of these elements in soil is leachable. The implications of these results on the calculated CR's will be discussed. (author) 26 refs.; 5 figs.; 5 tabs

  10. Fotossíntese, relações hídricas e crescimento de cafeeiros jovens em relação à disponibilidade de fósforo Photosynthesis, water relations and growth of young coffee plants according to phosphorus availability

    Directory of Open Access Journals (Sweden)

    Leandro da Silva

    2010-09-01

    Full Text Available O objetivo deste trabalho foi avaliar de que maneira a alta disponibilidade de fósforo no solo afeta a fotossíntese e o crescimento de mudas de cafeeiro arábica (Coffea arabica. Mudas da cultivar Ouro Verde com aproximadamente quatro meses de idade, cultivadas com boa disponibilidade hídrica, foram submetidas a três tratamentos quanto à disponibilidade de fósforo: quantidade recomendada de P, na literatura (PA; duas vezes a dosagem utilizada em PA (P+; e sem adição de P ao solo (P-. Após 70 dias da aplicação dos tratamentos, foram avaliados: as trocas gasosas, a atividade fotoquímica, o potencial de água da folha, a condutância hidráulica da planta (K L, a partição de matéria seca na planta, os teores de pigmentos e carboidratos, e a composição química das folhas. O tratamento P- influenciou negativamente a fotossíntese, e levou à restrição do crescimento das plantas. As plantas do tratamento P+ apresentaram maior teor foliar de P (~1,9 g kg-1, com incrementos na assimilação de CO2, na eficiência instantânea de carboxilação e na atividade fotoquímica - maior eficiência do fotossistema II e maior transporte aparente de elétrons - em relação às plantas do tratamento PA. Houve aumento em K L, maior teor de carboidratos foliares e maior teor de clorofila nas plantas que receberam o dobro da dose recomendada de P, as quais apresentaram maior produção de matéria seca em relação às de PA e P-.The objective of this work was to evaluate how high soil phosphorus (P availability affects the photosynthesis and growth of young coffee arabica plants (Coffea arabica. Four months old coffee seedlings of the Ouro Verde cultivar, cultivated in good hydric conditions, were exposed to three P availability treatments: P dosage recommended in the literature (RP; two times the recommended dosage (P+; and without P (P-. Seventy days after treatment application, evaluations of leaf gas exchange, photochemical activity, leaf

  11. Mycorrhizal Dependency of Alcaparro (Senna pistaciifolia Kunth at Three Concentrations of Soil Solution Phosphorus / Dependencia Micorrizal de la Alcaparra (Senna pistaciifolia Kunth bajo Tres Concentraciones de Fósforo en la Solución del Suelo

    Directory of Open Access Journals (Sweden)

    Jorge Alberto Sierra Escoba

    2014-12-01

    Full Text Available Abstract. A greenhouse bioassay was carried out to determine themycorrhizal dependency of alcaparro (Senna pistaciifolia Kunth. Arandomized complete experimental design was employed, with sixtreatments in a factorial arrangement 3x2; the treatments consistedof three levels in soil solution phosphorus (P (0.002, 0.02, and0.2 mg L-1 combined with two levels of mycorrhizal inoculationeither uninoculated or inoculated with Glomus agreggatum. Thevariables studied were leaf P content as a function of time, shootdry matter, shoot P content, mycorrhizal colonization of roots, andthe mycorrhizal dependency (MD. The results indicate that the leafP content increased significantly with the mycorrhizal inoculationin alcaparro to 0.02 mg L-1 after the second sampling days, butnot in the other soil P levels. Likewise, shoot dry weight increasedsignificantly at 0.02 mg L-1. On the other hand, the total plant Pcontent increase at all levels of soil available P. The mycorrhizalcolonization in alcaparro roots was 11, 23, and 0% at 0.02, 0.002and 0.2 mg of P L-1, respectively. The MD for alcaparro was 32%,which allow classify this specie as moderately dependent on themycorrhizal association. /  Resumen. Se realizó un bioensayo en invernadero para determinar la dependencia micorrizal de alcaparro (Senna pistaciifolia Kunth. Se utilizó un diseño experimental completamente randomizado. Los tratamientos se arreglaron en un factorial 3x2, estos consistieron en la combinación de tres niveles de P en la solución del suelo (0.002, 0.02 y 0.2 mg L-1 y 2 niveles de inoculación micorrizal (inoculado y no inoculado con el hongo Glomus agreggatum. Se emplearon como variables respuesta el contenido de P foliar en función del tiempo; al momento de la cosecha, se determinaron la masa seca aérea, el P total en la parte aérea y la colonización micorrizal. Los resultados indican que el contenido de P foliar a 0.02 mg L-1 en el segundo muestreo aumentó significativamente

  12. Phosphorus and the dairy cow

    OpenAIRE

    Ekelund, Adrienne

    2003-01-01

    The general aim of the present work was to investigate phosphorus balance in the dairy cow, with reference to the amount and source of phosphorus. Furthermore, biochemical bone markers were used to study the bone turnover during the lactation and dry period. Phosphorus is located in every cell of the body and has more known functions than any other mineral element in the animal body. Phosphorus is also an important constituent of milk, and is therefore required in large amounts in a high yiel...

  13. Assessment of Non-Point Source Total Phosphorus Pollution from Different Land Use and Soil Types in a Mid-High Latitude Region of China

    Directory of Open Access Journals (Sweden)

    Zhiwei Wang

    2016-11-01

    Full Text Available The transport characteristics of phosphorus in soil and the assessment of its environmental risk have become hot topics in the environmental and agricultural fields. The Sanjiang Plain is an important grain production base in China, and it is characterised by serious land use change caused by large-scale agricultural exploitation. Agricultural inputs and tillage management have destroyed the soil nutrient balance formed over long-term conditions. There are few studies on non-point source phosphorus pollution in the Sanjiang Plain, which is the largest swampy low plain in a mid-high-latitude region in China. Most studies have focused on the water quality of rivers in marsh areas, or the export mechanism of phosphorus from specific land uses. They were conducted using experimental methods or empirical models, and need further development towards mechanism models and the macro-scale. The question is how to find a way to couple processes in phosphorus cycling and a distributed hydrological model considering local hydrological features. In this study, we report an attempt to use a distributed phosphorus transport model to analyse non-point source total phosphorus pollution from different land uses and soil types on the Sanjiang Plain. The total phosphorus concentration generally shows an annually increasing trend in the study area. The total phosphorus load intensity is heterogeneous in different land use types and different soil types. The average total phosphorus load intensity of different land use types can be ranked in descending order from paddy field, dry land, wetlands, grassland, and forestland. The average total phosphorus load intensity of different soil types can be ranked in descending order: paddy soil, bog soil, planosol, meadow soil, black soil, and dark brown earth. The dry land and paddy fields account for the majority of total phosphorus load in the study area. This is mainly caused by extensive use of phosphate fertilizer on the

  14. Biologic phosphorus elimination - influencing parameters, boundary conditions, process optimation

    International Nuclear Information System (INIS)

    Dai Xiaohu.

    1992-01-01

    This paper first presents a systematic study of the basic process of biologic phosphorus elimination as employed by the original 'Phoredox (Main Stream) Process'. The conditions governing the process and the factors influencing its performance were determined by trial operation. A stationary model was developed for the purpose of modelling biologic phosphorus elimination in such a main stream process and optimising the dimensioning. The validity of the model was confirmed by operational data given in the literature and by operational data from the authors' own semitechnical-scale experimental plant. The model permits simulation of the values to be expected for effluent phosphorus and phosphate concentrations for given influent data and boundary conditions. It is thus possible to dimension a plant for accomodation of the original Phoredox (Main Stream) Process or any similar phosphorus eliminating plant that is to work according to the principle of the main stream process. (orig./EF) [de

  15. Phosphorus Processing—Potentials for Higher Efficiency

    Directory of Open Access Journals (Sweden)

    Ludwig Hermann

    2018-05-01

    Full Text Available In the aftermath of the adoption of the Sustainable Development Goals (SDGs and the Paris Agreement (COP21 by virtually all United Nations, producing more with less is imperative. In this context, phosphorus processing, despite its high efficiency compared to other steps in the value chain, needs to be revisited by science and industry. During processing, phosphorus is lost to phosphogypsum, disposed of in stacks globally piling up to 3–4 billion tons and growing by about 200 million tons per year, or directly discharged to the sea. Eutrophication, acidification, and long-term pollution are the environmental impacts of both practices. Economic and regulatory framework conditions determine whether the industry continues wasting phosphorus, pursues efficiency improvements or stops operations altogether. While reviewing current industrial practice and potentials for increasing processing efficiency with lower impact, the article addresses potentially conflicting goals of low energy and material use as well as Life Cycle Assessment (LCA as a tool for evaluating the relative impacts of improvement strategies. Finally, options by which corporations could pro-actively and credibly demonstrate phosphorus stewardship as well as options by which policy makers could enforce improvement without impairing business locations are discussed.

  16. Phosphorus kinetics in ovine fed with different phosphorus sources, using the isotopic dilution technique

    International Nuclear Information System (INIS)

    Vitti, D.M.S.S.; Abdalla, A.L.; Meirelles, C.F.

    1992-01-01

    Phosphorus kinetics in fluids and tissues of sheep was studied. Sixteen castrated sheep were kept in metabolism cages, receiving a semipuried diet containing as phosphorus sources dicalcium phosphate (BIC), monoammonium phosphate (MAP), superphosphate (SPT) and Tapita phosphate (TAP) 200 μCi P-32 was intravenously injected in each sheep and blood and feces were collected for eight days. From the specific activities in feces and plasma the endogenous phosphorus and the absorption coefficient were calculated. plasma P-32 half-life was determined. Nine days after injection the animals were killed and liver, kidney and muscle and bone samples were collected. P-32 retention and specific activities in tissues were determined. Endogenous phosphorus and absorption coefficient values were 54.44 ± 15.31 mh/kg live weight and 0.60; 47.98 ± 12.44 and 0.56; 39.70 ± 7.29 and 0.49; 59.11 ± 17.12 and 0.58 respectively bor BIC, MAP, TAP and SPT. P-32 retention by tissues was 0.29 ± 0.09; 0.27 ± 0.06; 0.16 ± 0.04 and 0.08 ± 0.03 dose/g fresh matter, respectively for bone, liver, kidney and muscle. It was concluded that animals which received TAP showed differences in absorption, distribution and P-32 retention by fluids and tissues. Phosphorus availability was lower for this source. (author)

  17. Phosphorus fertilizer and grazing management effects on phosphorus in runoff from dairy pastures.

    Science.gov (United States)

    Dougherty, Warwick J; Nicholls, Paul J; Milham, Paul J; Havilah, Euie J; Lawrie, Roy A

    2008-01-01

    Fertilizer phosphorus (P) and grazing-related factors can influence runoff P concentrations from grazed pastures. To investigate these effects, we monitored the concentrations of P in surface runoff from grazed dairy pasture plots (50 x 25 m) treated with four fertilizer P rates (0, 20, 40, and 80 kg ha(-1) yr(-1)) for 3.5 yr at Camden, New South Wales. Total P concentrations in runoff were high (0.86-11.13 mg L(-1)) even from the control plot (average 1.94 mg L(-1)). Phosphorus fertilizer significantly (P pasture biomass (P dairy pastures should be the maintenance of soil P at or near the agronomic optimum by the use of appropriate rates of P fertilizer.

  18. Carbon and phosphorus regulating bacterial metabolism in oligotrophic boreal lakes

    DEFF Research Database (Denmark)

    Vidal, L. O.; Graneli, W.; Daniel, C. B.

    2011-01-01

    This study focused on how phosphorus and carbon control pelagic bacteria in lakes over a gradient of dissolved organic carbon (DOC from 6.7 to 29.5 mg C L(-1)) and phosphorus (P-tot from 5 to 19 mu g L(-1)). Five oligotrophic lakes in southern Sweden were sampled in late autumn. Phosphate...... carbon mineralization in this kind of system during autumn is conditioned by the combined availability of labile carbon and phosphorus, with the assimilated carbon mainly transformed to inorganic carbon in respiration, contributing to CO(2) supersaturation in these systems....

  19. Sensitivity of soil phosphorus tests in predicting the potential risk of phosphorus loss from pasture soil

    Directory of Open Access Journals (Sweden)

    H. SOINNE

    2008-12-01

    Full Text Available The objective of this study was to examine the effects of urine and dung additions on the phosphorus (P chemistry of pasture land and to compare the sensitivity of two soil extraction methods in assessing the P-loading risk. In a field experiment, urine and dung were added to soil in amounts corresponding to single excrement portions and the soil samples, taken at certain intervals, were analysed for pHH2O, acid ammonium acetate extractable P (PAc and water extractable total P (TPw, and molybdate reactive P (MRPw. Urine additions immediately increased soil pH and MRPw, but no such response was observed in PAc extraction due to the low pH (4.65 of the extractant enhancing the resorption of P. The PAc responded to the dunginduced increase in soil total P similarly as did Pw, which suggests that both tests can serve to detect areas of high P concentration. However, water extraction was a more sensitive method for estimating short-term changes in P solubility. In pasture soils, the risk of P loss increases as a result of the interaction of urination and high P concentration in the topsoil resulting from continuous dung excretion.;

  20. Effects of nitrate addition on phosphorus retention in an eutrophic reservoir : laboratory experiments

    International Nuclear Information System (INIS)

    Yamada, T.; Janke, H.; Colzato, M.; Beraldo, D.; Mozeto, A.; Botta, C.; Nascimento, M.

    2010-01-01

    The Ibrite reservoir in southeast Brazil is polluted with effluents from an oil refinery as well as domestic untreated sewage from cities in the region. In this study, calcium nitrate was used as a sediment remediation technology in order to reduce phosphorus availability. Experiments were conducted in microcosms incubated for up to 135 days. Ceriodaphnia silvestrii and Vibrio fisheri were used to conduct an acute toxicity assessment of the water column and pore water of the sediments. Chironomus xanthus was used to assess bulk sediments. Results of the chemical analyses showed that high values of acid volatile sulfide in the sediments decreased by 99 per cent after 135 days of incubation. Approximately 50 per cent of the soluble reactive phosphorus was removed from the water column. The toxicity of the tested organisms was attributed to high nitrate concentrations in pore water sediments. Results indicated that calcium nitrate is not suitable as a sediment remediation technology.

  1. Negative effects of excessive soil phosphorus on floristic quality in Ohio wetlands.

    Science.gov (United States)

    Stapanian, Martin A; Schumacher, William; Gara, Brian; Monteith, Steven E

    2016-05-01

    Excessive soil nutrients, often from agricultural runoff, have been shown to negatively impact some aspects of wetland plant communities. We measured plant-available phosphorus (Mehlich-3: MeP) in soil samples, and assessed the vascular plant community and habitat degradation at 27 emergent and 13 forested wetlands in Ohio, USA. We tested two hypotheses: (1) that an index of vegetation biological integrity based on floristic quality was lower in wetlands with higher concentrations of MeP in the soil, and (2) that higher concentrations of MeP occurred in wetlands with more habitat degradation (i.e., lower quality), as estimated by a rapid assessment method. Hypothesis (1) was supported for emergent, but not for forested wetlands. Hypothesis (2) was marginally supported (P=0.09) for emergent, but not supported for forested wetlands. The results indicate that the effect of concentration of phosphorus in wetland soils and the quality of plant species assemblages in wetlands is more complex than shown in site-specific studies and may depend in part on degree of disturbance in the surrounding watershed and dominant wetland vegetation type. Woody plants in forested wetlands are typically longer lived than herbaceous species in the understory and emergent wetlands, and may persist despite high inputs of phosphorus. Further, the forested wetlands were typically surrounded by a wide band of forest vegetation, which may provide a barrier against sedimentation and the associated phosphorus inputs to the wetland interior. Our results indicate that inferences about soil nutrient conditions made from rapid assessment methods for assessing wetland habitat condition may not be reliable. Copyright © 2016. Published by Elsevier B.V.

  2. The challenge of controlling phosphorus in chronic kidney disease.

    Science.gov (United States)

    Cannata-Andía, Jorge B; Martin, Kevin J

    2016-04-01

    The pathogenesis and management of chronic kidney disease-mineral bone disorders (CKD-MBD) has experienced major changes, but the control of serum phosphorus at all stages of CKD still seems to be a key factor to improve clinical outcomes. High serum phosphorus is the most important uremia-related, non-traditional risk factor associated with vascular calcification in CKD patients and in the general population. Phosphorus may also be one of the key elements linking vascular calcification with low bone turnover. The main hormones and factors that contribute to the kidney regulation of phosphorus and calcium include parathyroid hormone, FGF-23, klotho and 1,25-dihydroxyvitamin D (1,25(OH)2D). Serum phosphorus did not start rising until CKD 3b in contrast with the earlier changes observed with fibroblast growth factor-23 (FGF-23), Klotho, calcitriol and parathyroid hormone (PTH). Despite FGF-23 and PTH having synergic effects regarding phosphorus removal, they have opposite effects on 1,25(OH)2D3. At the same stages of CKD in which phosphorus retention appears to occur, calcium retention also occurs. As phosphorus accumulation is associated with poor outcomes, an important question without a clear answer is at which level-range should serum phosphorus be maintained at different stages of CKD to improve clinical outcomes. There are four main strategies to manage phosphate homeostasis; phosphorus dietary intake, administration of phosphate binder agents, effective control of hyperparathyroidism and to ensure in the CKD 5D setting, an adequate scheme of dialysis. Despite all the available strategies, and the introduction of new phosphate binder agents in the market, controlling serum phosphorus remains challenging, and hyperphosphatemia continues to be extremely common in CKD 5 patients. Furthermore, despite phosphate binding agents having proved to be effective in reducing serum phosphorus, their ultimate effects on clinical outcomes remain controversial. Thus, we still

  3. Phosphorus, sulfur and pyridine

    OpenAIRE

    Schönberger, Stefanie

    2013-01-01

    The synthesis of distinct neutral or anionic P,S compounds in solution provides a great challenge for chemists. Due to the similarity in the energies of the P–P, P–S and S–S bonds nearly solely a mixture of compounds with different composition and charge is obtained. Our interest focuses on the system consisting of phosphorus, sulfur and pyridine, with the aim of a greater selectivity of P,S compounds in solution. The combination of these three components offers the opportunity...

  4. The Spatial-temperal Distribution of Phosphorus Species and the Main Factors Influencing on Phosphorus Transportation in Middle Reaches of the Yarlung Zangbo River, China

    Science.gov (United States)

    Pu, X.; An, R.; Li, R.; Huang, W.; Li, J.

    2017-12-01

    The objectives of the current study are to investigate the spatial, temperal variation of phisphorus (P) fraction in middle reaches of the Yarlung Zangbo River of China. Samples were collected in April (dry season), August (wet season), and Octber (normal season) along with the middle reaches from Lazi site to Nuxia sitewhich which is about 1000km long. Sequential extraction were applied to determine the forms of phosphorus in suspended particles and to assess the potential bioavailability of particulate P. The results indicated that the distribution of suspended particle size inflenced not only the total phosphorus concentration, but also the proportions of different forms of phosphorus. The exchangeable phosphorus (Ex-P), Fe-bound-P, Ca-bound-P were the most aboundant forms and the highest proportions of total P. The total P concentrations were closely relative to the concentration of suspended particles. According to the characteristics of suspended particles in the Yarlung Zangbo River, the relationship between the suspended particles size and species of phosphorus was established though statistical analysis. The Ex-P increased with the decreasing of suspended particulate size. The content of bioavailable particulate phosphorus varied greatly with the proportions of particulate size. In genral, the higher the proportion of smaller particle size, the higher the content of bioavailable phosphorus. The main factors which affect the phosphorus transportation in Yarlung Zangbo River had also been discussed.

  5. Habitual Intakes, Food Sources and Excretions of Phosphorus and Calcium in Three German Study Collectives

    Directory of Open Access Journals (Sweden)

    Ulrike Trautvetter

    2018-02-01

    Full Text Available Phosphorus intake in Europe is far above recommendations. We present baseline data from three human intervention studies between 2006 and 2014 regarding intake and excretion of phosphorus and calcium. All subjects documented their nutritional habits in weighed dietary records. Fasting blood samples were drawn, and feces and urine were quantitatively collected. Dietary phosphorus intake was estimated based on weighed dietary records and urine phosphorus excretions. Food sources were identified by allocation to defined food product groups. Average phosphorus consumption was 1338 mg/day and did not change from 2006 to 2014, while calcium intake decreased during this period (1150 to 895 mg/day. The main sources for phosphorus intake were bread/cereal products, milk/milk products and meat/meat products/sausage products and the main sources of calcium intake included milk/milk products/cheese, bread/cereal products and beverages. There was no difference between estimated phosphorus intake from the weighed dietary records and urine phosphorus excretion. In conclusion, we demonstrated constant phosphorus intakes far above the recommendations and decreasing calcium intakes below the recommendations in three German collectives from 2006 to 2014. Furthermore, we could show in case of usual intakes that an estimated phosphorus intake from urine phosphorus excretion is similar to the calculated intake from weighed dietary records.

  6. Towards a closed phosphorus cycle

    NARCIS (Netherlands)

    Keyzer, M.A.

    2010-01-01

    Summary: This paper stresses the need to address upcoming scarcity of phosphorus, a mineral nutrient that is essential for all life on Earth. Agricultural crops obtain phosphorus from the pool in the soil that can be replenished by recycling of organic material, or by application of inorganic

  7. Phosphorus sorption-desorption and effects of temperature, pH and salinity on phosphorus sorption in marsh soils from coastal wetlands with different flooding conditions.

    Science.gov (United States)

    Bai, Junhong; Ye, Xiaofei; Jia, Jia; Zhang, Guangliang; Zhao, Qingqing; Cui, Baoshan; Liu, Xinhui

    2017-12-01

    Wetland soils act as a sink or source of phosphorus (P) to the overlaying water due to phosphorus sorption-desorption processes. Litter information is available on sorption and desorption behaviors of phosphorus in coastal wetlands with different flooding conditions. Laboratory experiments were conducted to investigate phosphorus sorption-desorption processes, fractions of adsorbed phosphorus, and the effects of salinity, pH and temperature on phosphorus sorption on soils in tidal-flooding wetlands (TW), freshwater-flooding wetlands (FW) and seasonal-flooding wetlands (SW) in the Yellow River Delta. Our results showed that the freshly adsorbed phosphorus dominantly exists in Occluded-P and Fe/AlP and their percentages increased with increasing phosphorus adsorbed. Phosphorus sorption isotherms could be better described by the modified Langmuir model than by the modified Freundlich model. A binomial equation could be properly used to describe the effects of salinity, pH, and temperature on phosphorus sorption. Phosphorus sorption generally increased with increasing salinity, pH, and temperature at lower ranges, while decreased in excess of some threshold values. The maximum phosphorus sorption capacity (Q max ) was larger for FW soils (256 mg/kg) compared with TW (218 mg/kg) and SW soils (235 mg/kg) (p < 0.05). The percentage of phosphorus desorption (P des ) in the FW soils (7.5-63.5%) was much lower than those in TW (27.7-124.9%) and SW soils (19.2-108.5%). The initial soil organic matter, pH and the exchangeable Al, Fe and Cd contents were important factors influencing P sorption and desorption. The findings of this study indicate that freshwater restoration can contribute to controlling the eutrophication status of water bodies through increasing P sorption. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Nitrogen deposition increases the acquisition of phosphorus and potassium by heather Calluna vulgaris

    International Nuclear Information System (INIS)

    Rowe, Edwin C.; Smart, Simon M.; Kennedy, Valerie H.; Emmett, Bridget A.; Evans, Christopher D.

    2008-01-01

    Increased plant productivity due to nitrogen pollution increases the strength of the global carbon sink, but is implicated in plant diversity loss. However, modelling and experimental studies have suggested that these effects are constrained by availability of other nutrients. In a survey of element concentrations in Calluna vulgaris across an N deposition gradient in the UK, shoot concentrations of N and more surprisingly phosphorus and potassium were positively correlated with N deposition; tissue N/P ratio even decreased with N deposition. Elevated P and K concentrations possibly resulted from improved acquisition due to additional enzyme production or mycorrhizal activity. Heather occurs on organic soils where nutrient limitations are likely due to availability constraints rather than small stocks. However, if this effect extends to other plant and soil types, effects of N deposition on C sinks and plant competition may not be as constrained by availability of other nutrients as previously proposed. - Heather tissue phosphorus and potassium concentrations increased across a nitrogen deposition gradient, implying that nitrogen limited acquisition of other plant nutrients

  9. Phosphorus conditions at various depths in some mineral soils

    Directory of Open Access Journals (Sweden)

    Armi Kaila

    1963-05-01

    Full Text Available The fractionation method of CHANG and JACKSON (2 was used for the analysing of the distribution of inorganic phosphorus in the topsoil and subsoil of twelve virgin and twelve cultivated soils from various parts of the country; two virgin soils and twenty cultivated soils were studied down to the depths of 60 cm or 70 cm, one even to 2 m. In the more intensively podsolized virgin soils the surface layers, particularly the A2-horizon, are very poor in all the forms of inorganic phosphorus while the enrichment layer will contain fairly high amounts of iron and aluminium bound phosphorus. The application of fertilizers and the other cultivation managements tend to accumulate aluminium and iron bound phosphorus in the plough layer. In some soils the minimum content of calcium bound phosphorus occurs in the layer below the plough layer, but an increase with the depth seems to be typical to it in all the non-Litorina soils, while the first two fractions usually decrease with the depth. In the Litorina soils the iron bound phosphorus is dominant in all the layers studied, but the content of reductant soluble phosphorus is low in these soils, and their content of calcium bound phosphorus is higher than the content of phosphorus bound by aluminium. The predominance of calcium phosphate in the subsoil and the rather low content of reductant soluble and occluded fractions indicate that the chemical weathering in most of our soils is not yet at an advanced stage. The test values determined were in accordance with the results of the fractionation and the estimation of ammonium oxalate soluble aluminium and iron.

  10. Evaluation of Uncertainties in the Determination of Phosphorus by RNAA

    International Nuclear Information System (INIS)

    Rick L. Paul

    2000-01-01

    A radiochemical neutron activation analysis (RNAA) procedure for the determination of phosphorus in metals and other materials has been developed and critically evaluated. Uncertainties evaluated as type A include those arising from measurement replication, yield determination, neutron self-shielding, irradiation geometry, measurement of the quantity for concentration normalization (sample mass, area, etc.), and analysis of standards. Uncertainties evaluated as type B include those arising from beta contamination corrections, beta decay curve fitting, and beta self-absorption corrections. The evaluation of uncertainties in the determination of phosphorus is illustrated for three different materials in Table I. The metal standard reference materials (SRMs) 2175 and 861 were analyzed for value assignment of phosphorus; implanted silicon was analyzed to evaluate the technique for certification of phosphorus. The most significant difference in the error evaluation of the three materials lies in the type B uncertainties. The relatively uncomplicated matrix of the high-purity silicon allows virtually complete purification of phosphorus from other beta emitters; hence, minimal contamination correction is needed. Furthermore, because the chemistry is less rigorous, the carrier yield is more reproducible, and self-absorption corrections are less significant. Improvements in the chemical purification procedures for phosphorus in complex matrices will decrease the type B uncertainties for all samples. Uncertainties in the determination of carrier yield, the most significant type A error in the analysis of the silicon, also need to be evaluated more rigorously and minimized in the future

  11. Toxicity of acid mine pit lake water remediated with limestone and phosphorus

    Energy Technology Data Exchange (ETDEWEB)

    Neil, L.L.; McCullough, C.D.; Lund, M.A.; Evans, L.H.; Tsvetnenko, Y. [Edith Cowan University, Joondalup, WA (Australia)

    2009-11-15

    Pit lakes are increasingly common worldwide and have potential to provide many benefits. However, lake water toxicity may require remediation before beneficial end uses can be realised. Three treatments to remediate AMD (pH similar to 4.8) pit lake water containing elevated concentrations of Al and Zn from Collie, Western Australia were tested in mesocosms. Treatments were: (a) limestone neutralisation (L), (b) phosphorus amendment (P), and c) combined limestone neutralisation and phosphorus amendment (L+P). Laboratory bioassays with Ceriodaphnia cf. dubia, Chlorella protothecoides and Tetrahymena thermophila assessed remediation. Limestone neutralisation increased pH and reduced heavy metal concentrations by 98% (Al) to 14% (Mg), removing toxicity to the three test species within 2 months. Phosphorus amendment removed toxicity after 6 months of treatment. However, phosphorus amendment to prior limestone neutralisation failed to reduce toxicity more than limestone neutralisation alone. Low concentrations of both phosphorus and nitrogen appear to limit phytoplankton population growth in all treatments.

  12. Toxicity of acid mine pit lake water remediated with limestone and phosphorus.

    Science.gov (United States)

    Neil, Luke L; McCullough, Clint D; Lund, Mark A; Evans, Louis H; Tsvetnenko, Yuri

    2009-11-01

    Pit lakes are increasingly common worldwide and have potential to provide many benefits. However, lake water toxicity may require remediation before beneficial end uses can be realised. Three treatments to remediate AMD (pH approximately 4.8) pit lake water containing elevated concentrations of Al and Zn from Collie, Western Australia were tested in mesocosms. Treatments were: (a) limestone neutralisation (L), (b) phosphorus amendment (P), and (c) combined limestone neutralisation and phosphorus amendment (L+P). Laboratory bioassays with Ceriodaphnia cf. dubia, Chlorella protothecoides and Tetrahymena thermophila assessed remediation. Limestone neutralisation increased pH and reduced heavy metal concentrations by 98% (Al) to 14% (Mg), removing toxicity to the three test species within 2 months. Phosphorus amendment removed toxicity after 6 months of treatment. However, phosphorus amendment to prior limestone neutralisation failed to reduce toxicity more than limestone neutralisation alone. Low concentrations of both phosphorus and nitrogen appear to limit phytoplankton population growth in all treatments.

  13. Concentração plasmática de cortisol, uréia, cálcio e fósforo em vacas de corte mantidas a pasto suplementadas com levedura de cromo durante a estação de monta Cortisol, urea, calcium and phosphorus plasma concentration in grazing beef cows supplemented with high chromium yeast during breeding season

    Directory of Open Access Journals (Sweden)

    Eduardo Fabian Aragón Vásquez

    2003-08-01

    Full Text Available Foi pesquisada a influência da suplementação com cromo (Cr sobre a concentração plasmática de cortisol, uréia, cálcio e fósforo em vacas zebu mantidas a pasto e numa situação de estresse calórico durante a estação de monta. Foram utilizadas trinta vacas primíparas com peso entre 380 e 385kg. Os animais foram divididos em grupos de 15 vacas, formando o tratamento suplementado com Cr e o tratamento não suplementado (controle. As vacas pastorearam em piquetes formados por Brachiaria brizanta cv. Marandu. A fonte de Cr foi levedura enriquecida (1g Cr kg-1 de produto comercial e foi adicionado à mistura mineral aportando 0,017% de Cr. Amostras de sangue foram tomadas em três períodos através de venipunção jugular e coletadas em tubos contendo heparina. As amostras de plasma foram analisadas para fósforo, cálcio, uréia e cortisol. Os dados foram analisados como um desenho de blocos ao acaso. O consumo médio diário de mistura mineral foi de 72,92g no grupo suplementado com Cr (12,40mg Cr/cabeça/dia e 77,84g no grupo controle (0,78mg Cr/cabeça/dia. A concentração plasmática de cortisol, no grupo suplementado com Cr, foi menor que no tratamento controle (2,11mg dl-1 vs. 3,29mg dl-1. As concentrações plasmáticas de fósforo (6,36mg dl-1 vs 3,56mg dl-1 e de cálcio (12,87mg dl-1 vs 9,02mg dl-1 foram maiores no grupo suplementado com Cr durante o primeiro período, mas não existiram diferenças no segundo e terceiro períodos de colheita. Os níveis plasmáticos de uréia (17,13mg dl-1 vs. 17,70mg dl-1 não foram diferentes entre os grupos experimentais.The influence of supplemental chromium (Cr on plasma cortisol, urea, calcium and phosphorus concentration were investigated in grazing cattle in caloric stress situation during the breeding season. Thirty primiparous zebu cows with 380 to 385kg of body weight were assigned to the following treatments: 15 cows fed supplemental Cr and 15 cows without supplemental Cr (Control

  14. Effect of Free Nitrous Acid on Nitrous Oxide Production and Denitrifying Phosphorus Removal by Polyphosphorus-Accumulating Organisms in Wastewater Treatment

    Directory of Open Access Journals (Sweden)

    Zhijia Miao

    2018-01-01

    Full Text Available The inhibition of free nitrous acid (FNA on denitrifying phosphorus removal has been widely reported for enhanced biological phosphorus removal; however, few studies focus on the nitrous oxide (N2O production involved in this process. In this study, the effects of FNA on N2O production and anoxic phosphorus metabolism were investigated using phosphorus-accumulating organisms (PAOs culture highly enriched (91±4% in Candidatus Accumulibacter phosphatis. Results show that the FNA concentration notably inhibited anoxic phosphorus metabolism and phosphorus uptake. Poly-β-hydroxyalkanoate (PHA degradation was completely inhibited when the FNA concentration was approximately 0.0923 mgHNO2-N/L. Higher initial FNA concentrations (0.00035 to 0.0103 mgHNO2-N/L led to more PHA consumption/TN (0.444 to 0.916 mmol-C/(mmol-N·gVSS. Moreover, it was found that FNA, rather than nitrite and pH, was likely the true inhibitor of N2O production. The highest proportion of N2O to TN was 78.42% at 0.0031 mgHNO2-N/L (equivalent to 42.44 mgNO2-N/L at pH 7.5, due to the simultaneous effects of FNA on the subsequent conversion of NO2 into N2O and then into N2. The traditional nitrite knee point can only indicate the exhaustion of nitrite, instead of the complete removal of TN.

  15. Comparison of inductively coupled plasma mass spectrometry and colorimetric determination of total and extractable phosphorus in soils

    International Nuclear Information System (INIS)

    Ivanov, Krasimir; Zaprjanova, Penka; Petkova, Milena; Stefanova, Violeta; Kmetov, Veselin; Georgieva, Deyana; Angelova, Violina

    2012-01-01

    The most widely used method for determination of total phosphorus in soils is perchloric acid digestion, followed by a colorimetric assay to measure the concentration of P in solution. The first part of this study compares an alternative digestion method, using aqua regia (ISO 11466 and EPA Method 3052), with perchloric acid digestion procedure, and also compares inductively coupled plasma mass spectroscopy (ICP-MS) with colorimetry for the measurement of P on the basis of five internationally certified standard soils and 20 real-life soils with widely different extractability of phosphorus. The phosphorus concentration was determined by means of the reduced phosphomolybdenum blue and ICP-MS. The relationship between methods has been examined statistically. Good agreement of the results from colorimetry and ICP-MS was established for all certified soils. The microwave-assisted digestion with aqua regia was comparable, both in precision and accuracy, with the hot plate aqua regia method. The phosphorus concentration found with the HF + HClO 4 digestion method was in good agreement with the certified mean values, while the superiority in extracting phosphorus, when compared to other methods, was obvious. Soil testing for plant-available phosphorus in Bulgaria and many European countries is most commonly conducted using acid Ca-lactate extraction (Egner–Riehm test) and alkaline sodium bicarbonate extraction (BDS ISO 11263:2002), based on Olsen test, followed by a colorimetric assay to measure the concentration of P in solution. The second part of this study reports the differences between Egner–Riehm test and BDS ISO 11263:2002 measured colorimetrically and by ICP-MS. Fifty soils were selected from South Bulgaria to represent a wide range of soil properties. It was established that ICP-MS consistently yielded significantly higher P concentrations than the colorimetric method in both extraction tests, and the relative differences were greatest in soils with lower P

  16. Comparison of inductively coupled plasma mass spectrometry and colorimetric determination of total and extractable phosphorus in soils

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, Krasimir, E-mail: kivanov1@abv.bg [Department of Chemistry, University of Agriculture, Plovdiv (Bulgaria); Zaprjanova, Penka [Tobacco and Tobacco Products Institute, Plovdiv (Bulgaria); Petkova, Milena [Department of Chemistry, University of Agriculture, Plovdiv (Bulgaria); Stefanova, Violeta; Kmetov, Veselin; Georgieva, Deyana [Department of Analytical Chemistry, Plovdiv University ' Paisii Hilendarski,' Plovdiv (Bulgaria); Angelova, Violina [Department of Chemistry, University of Agriculture, Plovdiv (Bulgaria)

    2012-05-15

    The most widely used method for determination of total phosphorus in soils is perchloric acid digestion, followed by a colorimetric assay to measure the concentration of P in solution. The first part of this study compares an alternative digestion method, using aqua regia (ISO 11466 and EPA Method 3052), with perchloric acid digestion procedure, and also compares inductively coupled plasma mass spectroscopy (ICP-MS) with colorimetry for the measurement of P on the basis of five internationally certified standard soils and 20 real-life soils with widely different extractability of phosphorus. The phosphorus concentration was determined by means of the reduced phosphomolybdenum blue and ICP-MS. The relationship between methods has been examined statistically. Good agreement of the results from colorimetry and ICP-MS was established for all certified soils. The microwave-assisted digestion with aqua regia was comparable, both in precision and accuracy, with the hot plate aqua regia method. The phosphorus concentration found with the HF + HClO{sub 4} digestion method was in good agreement with the certified mean values, while the superiority in extracting phosphorus, when compared to other methods, was obvious. Soil testing for plant-available phosphorus in Bulgaria and many European countries is most commonly conducted using acid Ca-lactate extraction (Egner-Riehm test) and alkaline sodium bicarbonate extraction (BDS ISO 11263:2002), based on Olsen test, followed by a colorimetric assay to measure the concentration of P in solution. The second part of this study reports the differences between Egner-Riehm test and BDS ISO 11263:2002 measured colorimetrically and by ICP-MS. Fifty soils were selected from South Bulgaria to represent a wide range of soil properties. It was established that ICP-MS consistently yielded significantly higher P concentrations than the colorimetric method in both extraction tests, and the relative differences were greatest in soils with lower

  17. Nutrient concentrations in a Littorella uniflora community at higher CO2 concentrations and reduced light intensities

    DEFF Research Database (Denmark)

    Andersen, T.; Pedersen, O.; Andersen, F. Ø.

    2005-01-01

    laboratory experiments with isoetid vegetation (Littorella uniflora) where water column CO2 and light could be manipulated in order to test whether (i) light and CO2 availability affect nutrient concentrations in isoetid vegetation, and (ii) if changes in light and CO2 climate affect fluxes of inorganic...... nitrogen (N) and phosphorus (P) from sediment to water column, which potentially could result in increased growth of epiphytic algae. 3. The results showed that the standing stocks of phosphorus and nitrogen in the L. uniflora vegetation were significantly influenced by CO2 concentration and light...... intensity. Both standing stocks of P and N were significantly higher in the mesocosm treatments with high CO2 concentration than in those at low CO2 concentration. Similarly, standing stocks of P and N enhanced with increasing light intensity. 4. Measurements of nutrient fluxes both in the field...

  18. Levels of available phosphorus and calcium for broilers from 8 to 35 days of age fed rations containing phytase Níveis de fósforo disponível e de cálcio para frangos de corte de 8 a 35 dias de idade alimentados com rações contendo fitase

    Directory of Open Access Journals (Sweden)

    Adimar Cardoso Júnior

    2010-06-01

    Full Text Available Two experiments using Cobb broiler chicks from 8 to 35 days of age were carried out to evaluate the effect of reducing levels of calcium and available phosphorus in diets supplemented with 500 ftu phytase/kg on the performance of the birds, the content of ashes in the tibia, the metabolizable energy of the diet, and the metabolizability of the dry matter and crude protein. It was used 1,404 broiler chicks in the experiment 1 to evaluate feed intake, weight gain, food conversion and percentage of the ashes in the tibia. In the experiment 2, simultaneously carried out with experiment 1, a total of 390 birds were transferred to a metabolism room to determine the metabolizable energy and metabolizability of the dry matter and crude protein. It was used in the two experiments, a complete random design in a 3 × 4 + 1 factorial scheme with three levels of available phosphorus (0.375; 0.325; and 0.275% and four levels of calcium (0.85; 0.75; 0.65 and 0.55% in the diets, supplemented with phytase. It was also used a control diet without phytase, based on corn and soybean bran, formulated with 0.425% of available phosphorus and 0.85% of calcium. In the experiment 1, the reduction of levels of calcium and phosphorus did not cause a significant difference on the performance and percentage of bone ashes. The levels of calcium and available phosphorus used in the experiment 2 can be reduced down to 0.65 and 0.325%, respectively, because the effects are similar to those obtained with the currently suggested levels.Dois experimentos com pintos de corte da linhagem Cobb no período de 8 a 35 dias de idade foram realizados para avaliar o efeito da redução dos níveis de cálcio e fósforo disponível (Pdisp em rações suplementadas com 500 ftu de fitase/kg sobre o desempenho das aves, o teor de cinzas na tíbia, a energia metabolizável (EMAn da dieta e a metabolizabilidade da matéria seca (MS e da proteína bruta (PB. No experimento 1, foram utilizados 1

  19. Phosphorus cycles of forest and upland grassland ecosystems and some effects of land management practices.

    Science.gov (United States)

    Harrison, A F

    The distribution of phosphorus capital and net annual transfers of phosphorus between the major components of two unfertilized phosphorus-deficient UK ecosystems, an oak--ash woodland in the Lake District and an Agrostis-Festuca grassland in Snowdonia (both on acid brown-earth soils), have been estimted in terms of kg P ha--1. In both ecosystems less than 3% of the phosphorus, totalling 1890 kg P ha--1 and 3040 kg P ha--1 for the woodland and grassland, respectively, is contained in the living biomass and half that is below ground level. Nearly all the phosphorus is in the soil matrix. Although the biomass phosphorus is mostly in the vegetation, the soil fauna and vegetation is slower (25%) than in the grassland vegetatation (208%)