scholarly journals Trophic state and microorganisms community of major sub-basins of the middle Rio Doce basin, southeast Brazil

2005 ◽  
Vol 48 (4) ◽  
pp. 625-633 ◽  
Author(s):  
Mauricio Mello Petrucio ◽  
Adriana Oliveira Medeiros ◽  
Carlos Augusto Rosa ◽  
Francisco Antônio Rodrigues Barbosa
Keyword(s):  
Trophic State ◽  
Heterotrophic Bacteria ◽  
Total Alkalinity ◽  
Phosphorus Concentration ◽  
Total Phosphorus Concentration ◽  
Temperature Conductivity ◽  
Total N ◽  
Southeast Brazil ◽  
Minas Gerais State ◽  
Total P

Total phosphorus concentration was used to define the trophic state of the main sub-basins of the middle Rio Doce, in Minas Gerais State (southeast Brazil) and physical, chemical, and microbiological variables of water were analyzed during 2000 to 2001. The study evaluated changes in water quality caused by seasonality and human activities. Water temperature, conductivity, pH, total alkalinity, dissolved oxygen, and concentrations of NH4-N, NO2-N, NO3-N, total-N, PO4-P, total-P, DOC, and chlorophyll-a were measured in seven rivers stretches (sampling stations). Total yeasts, faecal and total coliforms, and heterotrophic bacteria were also determined. The studied areas were considered to be under oligotrophic to eutrophic conditions. The variables that presented highest positive correlation with faecal coliforms were total-P and total-N, and heterotrophic bacteria density was identified as a good parameter to differentiate the ecosystems. These results suggested the inclusion of the trophic level and the distinct activities within a watershed as important elements when proposing conservation and restoration areas.

ASSESSMENT AND UNCERTAINTY ANALYSIS OF EUTROPHICATION FOR TE-CHI RESERVOIR, TAIWAN

1994 ◽  
Vol 30 (2) ◽  
pp. 73-80 ◽  
Author(s):  
Yu-Ming Wang ◽  
Ming-Chun Wu ◽  
Jan-Tai Kuo
Keyword(s):  
Uncertainty Analysis ◽  
Total Phosphorus ◽  
Trophic State ◽  
Load Resistance ◽  
Phosphorus Concentration ◽  
Total Phosphorus Concentration ◽  
Order Analysis ◽  
First Order ◽  
The Future ◽  
Hydrologic Conditions

This paper describes the development and application of uncertainty analysis to evaluate the risk of eutrophication for Te-Chi Reservoir, Taiwan. Two methods, probabilistic model and first-order analysis of uncertainty (FOAU), were used to quantify the expected variability of the total phosphorus concentration in the reservoir. Based on the load-resistance analysis, these two methods were applied and compared to calculate the risk of eutrophication for Te-Chi Reservoir. An approach is also proposed herein to evaluate the trophic state in the future. Since the trophic state for Te-Chi Reservoir is strongly dependent on hydrologic conditions, incorporating an annual ARM A inflow model with the empirical total phosphorus model developed in previous work, the trophic state in the future was investigated. The significant advantage of the proposed approach is that it provides a simplified and useful procedure to evaluate the risk of eutrophication for the reservoir in the future.

scholarly journals The cycle of phosphorus in the waters of the English Channel

1950 ◽  
Vol 29 (1) ◽  
pp. 145-162 ◽  
Author(s):  
F. A. J. Armstrong ◽  
H. W. Harvey
Keyword(s):  
Geographical Distribution ◽  
Total Phosphorus ◽  
Phosphorus Content ◽  
Water Mass ◽  
Phosphorus Concentration ◽  
English Channel ◽  
Total Phosphorus Concentration ◽  
Phosphorus Containing ◽  
Mean Concentration ◽  
Total P

Determinations of total phosphorus in water samples have shown areas in the western English Channel with water containing as little as 10 mg. P/m.3, and other areas with double, and more than double, this concentration.The integral mean concentration of total P in the water column, 20 miles off-shore from Plymouth, has fluctuated between 10 and 16 mg. P/m.3 since June 1947.The changes which have taken place in this integral mean concentration are attributed to different water masses, of different total phosphorus concentration, passing through the area, rather than to a seasonal change in the total phosphorus content of a water mass. No marked deposition of phosphorus-containing detritus could be found.Changes in this integral mean were not coincident with changes in salinity. The geographical distribution of total phosphorus does not coincide with the geographical distribution of salinity.

LAND USE TYPES AND SOIL CHARACTERISTICTS: A CASE STUDY IN HUONG VINH COMMUNE, HUONG TRA TOWN, THUA THIEN HUE PROVINCE

2017 ◽  
Vol 126 (4B) ◽  
Author(s):  
Trần Thanh Đức
Keyword(s):  
Land Use ◽  
Sweet Potato ◽  
Soil Analysis ◽  
Soil Characteristics ◽  
Low Ph ◽  
Clay Loam ◽  
Total N ◽  
Land Use Types ◽  
Total P

This research carried out in Huong Vinh commune, Huong Tra town, Thua Thien Hue province aimed to identify types of land use and soil characteristics. Results showed that five crops are found in Huong Vinh commune including rice, peanut, sweet potato, cassava and vegetable. There are two major soil orders with four soil suborders classified by FAO in Huong Vinh commune including Fluvisols (Dystric Fluvisols<em>, </em>Gleyic Fluvisols and Cambic Fluvisols) and Arenosols (Haplic Arenosols). The results from soil analysis showed that three soil suborders including Dystric Fluvisols<em>, </em>Gleyic Fluvisols and Cambic Fluvisols belonging to Fluvisols were clay loam in texture, low pH, low in OC, total N, total P<sub>2</sub>O<sub>5</sub> and total K<sub>2</sub>O. Meanwhile, the Haplic Arenosols was loamy sand in texture, poor capacity to hold OC, total N, total P<sub>2</sub>O<sub>5</sub> and total K<sub>2</sub>O

Lake Paranoá, Brasília, Brazil: Integrated Management Plan for its Restoration

1992 ◽  
Vol 27 (2) ◽  
pp. 271-286 ◽  
Author(s):  
Sonia Paulino Mattos ◽  
Irene Guimarães Altafin ◽  
Hélio José de Freitas ◽  
Cristine Gobbato Brandão Cavalcanti ◽  
Vera Regina Estuqui Alves
Keyword(s):  
Total Phosphorus ◽  
Drainage Basin ◽  
Integrated Management ◽  
Algal Growth ◽  
Nutrient Content ◽  
Management Plan ◽  
Cylindrospermopsis Raciborskii ◽  
Phosphorus Concentration ◽  
Limiting Factor ◽  
Total Phosphorus Concentration

Abstract Built in 1959, Lake Paranoá, in Brasilia, Brazil, has been undergoing an accelerated process of nutrient enrichment, due to inputs of inadequately treated raw sewage, generated by a population of 600,000 inhabitants. Consequently, it shows high nutrient content (40 µg/L of total phosphorus and 1800 µg/L of total nitrogen), low transparency (0.65 m) and high levels of chlorophyll a (65 µg/L), represented mainly by Cylindrospermopsis raciborskii and sporadic bloom of Microcystis aeruginosa, which is being combatted with copper sulphate. With the absence of seasonality and a vertical distribution which is not very evident, the horizontal pattern assumes great importance in this reservoir, in which five compartments stand out. Based on this segmentation and on the identification of the total phosphorus parameter as the limiting factor for algal growth, mathematical models were developed which demonstrate the need for advanced treatment of all the sewage produced in its drainage basin. With this, it is expected that a process of restoration will be initiated, with a decline in total phosphorus concentration to readings below 25 µg/L. Additional measures are proposed to accelerate this process.

scholarly journals Phytase-Producing Rahnella aquatilis JZ-GX1 Promotes Seed Germination and Growth in Corn (Zea mays L.)

2021 ◽  
Vol 9 (8) ◽  
pp. 1647
Author(s):  
Gui-E Li ◽  
Wei-Liang Kong ◽  
Xiao-Qin Wu ◽  
Shi-Bo Ma
Keyword(s):  
Seed Germination ◽  
Plant Growth ◽  
Biomass Accumulation ◽  
Root Surface ◽  
Phosphorus Concentration ◽  
Maize Seedlings ◽  
Total Phosphorus Concentration ◽  
Rahnella Aquatilis ◽  
Maize Seeds

Phytase plays an important role in crop seed germination and plant growth. In order to fully understand the plant growth-promoting mechanism by Rahnella aquatilis JZ-GX1，the effect of this strain on germination of maize seeds was determined in vitro, and the colonization of maize root by R. aquatilis JZ-GX1 was observed by scanning electron microscope. Different inoculum concentrations and Phytate-related soil properties were applied to investigate the effect of R. aquatilis JZ-GX1 on the growth of maize seedlings. The results showed that R. aquatilis JZ-GX1 could effectively secrete indole acetic acid and had significantly promoted seed germination and root length of maize. A large number of R. aquatilis JZ-GX1 cells colonized on the root surface, root hair and the root interior of maize. When the inoculation concentration was 107 cfu/mL and the insoluble organophosphorus compound phytate existed in the soil, the net photosynthetic rate, chlorophyll content, phytase activity secreted by roots, total phosphorus concentration and biomass accumulation of maize seedlings were the highest. In contrast, no significant effect of inoculation was found when the total P content was low or when inorganic P was sufficient in the soil. R. aquatilis JZ-GX1 promotes the growth of maize directly by secreting IAA and indirectly by secreting phytase. This work provides beneficial information for the development and application of R. aquatilis JZ-GX1 as a microbial fertilizer in the future.

scholarly journals Genetic variation of seed phosphorus concentration in winter oilseed rape and development of a NIRS calibration

Euphytica ◽  
2021 ◽  
Vol 217 (4) ◽  
Author(s):  
Jakob Eifler ◽  
Jürgen Enno Wick ◽  
Bernd Steingrobe ◽  
Christian Möllers
Keyword(s):  
Genetic Variation ◽  
Field Experiments ◽  
Seed Quality ◽  
Rapeseed Meal ◽  
Quality Analysis ◽  
Phosphorus Concentration ◽  
Genotypic Differences ◽  
Organic P ◽  
P Concentration ◽  
Total P

AbstractPhytic acid is the major organic phosphorus storage compound in rapeseed. Following oil extraction, the defatted meal is used in feed mixtures for livestock. However, monogastric pigs and chickens can only poorly metabolize phytate. Hence, their excrements are rich in phosphorus (P), which when applied as manure may lead to eutrophication of surface waters. The aim of the present study was to analyze the genetic variation for total and organic P concentration (i.e. mainly phytate) in rapeseed and to compare the results with soybean. Two sets of rapeseed material were tested in field experiments in different environments with varying soil P levels and harvested seeds were used for seed quality analysis. Results revealed significant genotypic differences in total seed P concentration, which ranged from 0.47 to 0.94%. Depending on the experiment, the heritability for total P concentration ranged from 52 to 93%. The organic P portion of total P concentration was above 90% for current rapeseed hybrids. In both sets, there was a significant positive correlation between seed protein and P concentration. A NIRS calibration for total P concentration in intact seeds showed in cross validation a standard error of 0.05% and a coefficient of determination of R2 = 0.83. Total P concentration of soybean seeds and meal was between 0.55 and 0.65%, and around 1.1% for rapeseed meal. Rapeseed meal had a twofold higher ratio of total P to nitrogen concentration as compared to soybean which could be considered adverse when the meal is used for feeding livestock.

Influence of phosphorus scavenging by iron in contrasting dimictic lakes

2013 ◽  
Vol 70 (7) ◽  
pp. 941-952 ◽  
Author(s):  
Adam R. Hoffman ◽  
David E. Armstrong ◽  
Richard C. Lathrop
Keyword(s):  
Primary Production ◽  
Trophic State ◽  
Internal Loading ◽  
Molar Ratios ◽  
Regulatory Controls ◽  
Total P ◽  
P Removal

Internal regulatory controls of phosphorus (P) via iron (Fe) scavenging were quantified in four contrasting dimictic Wisconsin lakes: Mendota (eutrophic, calcareous), Fish (mesotrophic, calcareous), Devil’s (mesotrophic, noncalcareous), and Sparkling (oligotrophic, noncalcareous). Hypolimnetic enrichment of P was highest in Mendota and Devil’s and least in Fish and Sparkling. This enrichment was attributed mainly to internal loading in the noncalcareous lakes and regeneration of sedimenting epilimnetic P in the calcareous lakes. Differences in Fe scavenging efficiencies at fall turnover were related to hypolimnetic Fe:P molar ratios as well as Fe availability and its control by sulfate–sulfide chemistries. In the noncalcareous lakes with high hypolimnetic Fe enrichment (Fe:P > 2), 45% of whole-lake total P was removed. P removal was low (<20%) in the two calcareous lakes with minimal Fe enrichment (Fe:P < 2). These differences in hypolimnetic P enrichment and subsequent Fe scavenging at fall turnover help to explain the differences in the amount of P available for subsequent spring and summer primary production as well as the differences in trophic state of the four lakes.

High prevalence of intestinal infections and ectoparasites in dogs, Minas Gerais State (southeast Brazil)

2012 ◽  
Vol 111 (5) ◽  
pp. 1913-1921 ◽  
Author(s):  
Jörg Heukelbach ◽  
Raphael Frank ◽  
Liana Ariza ◽  
Íris de Sousa Lopes ◽  
Alcides de Assis e Silva ◽  
...  
Keyword(s):  
Minas Gerais ◽  
Southeast Brazil ◽  
Intestinal Infections ◽  
High Prevalence ◽  
Minas Gerais State

scholarly journals Diurnal and spatial (vertical) dynamics of nutrients (N, P, Si) in four sampling days (summer, fall, winter, and spring) in a tropical shallow reservoir and their relationships with the phytoplankton community

2005 ◽  
Vol 65 (1) ◽  
pp. 141-157 ◽  
Author(s):  
J. J. Ramírez ◽  
C. E. M. Bicudo
Keyword(s):  
Phytoplankton Community ◽  
Southeastern Brazil ◽  
Nitrogen And Phosphorus ◽  
Vertical Variation ◽  
Total N ◽  
Phosphorus Forms ◽  
Reactive Silica ◽  
Photosynthetic Assimilation ◽  
The City ◽  
Total P

The vertical and diurnal variation of nitrogen and phosphorus forms, as well as that of soluble reactive silica (SRS), were studied in four sampling days at Garças reservoir, a shallow tropical one located in the city of São Paulo, in southeastern Brazil. Except for N-NH4, all other inorganic forms of nitrogen (N-NO2, N-NO3, and total N) demonstrated decreased concentrations toward the bottom of reservoir. Similarly, all showed significant diurnal differences on every sampling day, with increased values during the night due to absence of photosynthetic assimilation during that period. In the sampling days, these forms decreased on the spring sampling day due to the bloom of Microcystis registered during this period of the year. All three forms of phosphorus (SRP, particulate P, and total P) showed significant vertical variation, except on the fall sampling day. On the summer sampling day there was an increase of both total P and particulate P, the latter because it constitutes more than 70% of the total P during all sampling days. Hourly phosphorus variation was significant during all sampling days, except for the summer one. The SRS vertical variation was significant during all sampling days, except for that in the spring. It was also different hourly on sampling days.

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