scholarly journals Nitrogen and phosphorus resorption efficiency, and N : P ratios in natural populations of Typha domingensis Pers. in a coastal tropical lagoon

2013 ◽  
Vol 25 (2) ◽  
pp. 124-130
Author(s):  
Bruno dos Santos Esteves ◽  
Marina Satika Suzuki
Keyword(s):  
Aquatic Macrophytes ◽  
Natural Populations ◽  
Typha Domingensis ◽  
Resorption Efficiency ◽  
Nitrogen And Phosphorus ◽  
P Limitation ◽  
Tropical Lagoon ◽  
P Content ◽  
Different Seasons ◽  
One Year

AIM: We studied nitrogen (N) and phosphorus (P) resorption patterns in Typha domingensis Pers. in a tropical coastal lagoon during different seasons of throughout one year. METHODS: Resorption of N and P is uttered as resorption efficiency (NRE and PRE, respectively), which may be used as an indicator of a nutrient limitation. Higher resorption efficiency values might indicate limitation of a certain element for the growth of aquatic macrophytes. RESULTS: N was inferred to be less limiting than P for the growth of T. domingensis in Campelo Lagoon, since N content varied less than P content and resorption efficiency of N was lower than that of P and, concomitantly, low resorption efficiency of this element. However, T. domingensis of Campelo Lagoon frequently utilized P that was already present in its tissues, contributing to the longer residence time of this element in system. Green leaves of T. domingensis showed N : P ratio, ranging 49-96, corroborating the inference of P limitation. CONCLUSIONS: N : P ratio and resorption efficiency indicate P limitation by T. domingensis in Campelo Lagoon.

Enhanced biological phosphorus removal process implemented in membrane bioreactors to improve phosphorous recovery and recycling

2003 ◽  
Vol 48 (1) ◽  
pp. 87-94 ◽  
Author(s):  
B. Lesjean ◽  
R. Gnirss ◽  
C. Adam ◽  
M. Kraume ◽  
F. Luck
Keyword(s):  
Phosphorus Removal ◽  
Theoretical Calculations ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
P Limitation ◽  
Batch Tests ◽  
P Content ◽  
On Line ◽  
Biological Phosphorus ◽  
P Removal

The enhanced biological phosphorus removal (EBPR) process was adapted to membrane bioreactor (MBR) technology. One bench-scale plant (BSP, 200-250 L) and two pilot plants (PPs, 1,000-3,000 L each) were operated under several configurations, including pre-denitrification and post-denitrification without addition of carbon source, and two solid retention times (SRT) of 15 and 26 d. The trials showed that efficient Bio-P removal can be achieved with MBR systems, in both pre- and post-denitrification configurations. EBPR dynamics could be clearly demonstrated through batch-tests, on-line measurements, profile analyses, P-spiking trials, and mass balances. High P-removal performances were achieved even with high SRT of 26 d, as around 9 mgP/L could be reliably removed. After stabilisation, the sludge exhibited phosphorus contents of around 2.4%TS. When spiked with phosphorus (no P-limitation), P-content could increase up to 6%TS. The sludge is therefore well suited to agricultural reuse with important fertilising values. Theoretical calculations showed that increased sludge age should result in a greater P-content. This could not be clearly demonstrated by the trials. This effect should be all the more significant as the influent is low in suspended solids.

Shooting and Rooting Behaviour in Relation to Season, Age and Growing Conditions of Dendrocalamus asper Backer

2020 ◽  
Vol 27 (1) ◽  
pp. 56-60
Author(s):  
Reena Joshi ◽  
Salil Tewari ◽  
Rajesh Kaushal
Keyword(s):  
Summer Monsoon ◽  
Block Design ◽  
Research Centre ◽  
Agroforestry Research ◽  
Randomized Block Design ◽  
Different Seasons ◽  
Dendrocalamus Asper ◽  
Growing Conditions ◽  
One Year ◽  
Effect Of Age

The experiment was conducted at Agroforestry Research Centre, of G. B. Pant University of Agriculture and Technology, Pantnagar to assess the effect of age (one and two year old), growing condition (intermittent misting and no misting) and different seasons (summer, monsoon, autumn and spring) on rooting and shooting of culm cuttings of Dendrocalamus asper. The experiment was laid out in factorial randomized block design with three replications. The findings indicated that in D. asper, one year old culm cuttings in the intermittent misting condition showed good results. The findings also indicated that shooting and rooting per cent of culm cuttings planted in different season showed response as Spring (March)> Summer (June)> Monsoon (August)> Autumn (October).

Study of the nutritional dynamic in olive leaves: periods of analytical stability

2017 ◽  
Vol 7 ◽  
Author(s):  
Juana Nieto ◽  
Antonio García-Fuentes ◽  
Llenalia M. García ◽  
Emilia Fernández-Ondoño
Keyword(s):  
Nutritional Deficiencies ◽  
Winter Period ◽  
Olive Leaves ◽  
Nitrogen And Phosphorus ◽  
Analytical Stability ◽  
Opposite Behavior ◽  
Zinc Concentrations ◽  
Calcium Magnesium ◽  
Olive Trees ◽  
One Year

The aim of this study was to establish the evolution curves of macro- and micro-nutrients in olive leaves and the periods of time in which they are statistically stable and can be considered suitable for a nutritional diagnosis. The study was carried out in two farms of the province of Jaén (Andalucia, Southern Spain), with olive trees of the Picual variety, under an irrigation regime and no nutritional deficiencies over the entire year. The evolution curves of each nutrient had great similarities when comparing between farms and between periods. Only in some periods the farm “Poco Humo” had higher concentrations, probably due to the most favorable edaphic characteristics of this farm. Nitrogen and phosphorus showed minimum concentrations when the leaves were young and when they were one year old, and maximum concentrations during the winter. Potassium and boron showed higher concentrations when the leaves were young, and the concentrations decreased throughout the first year of life. Concentrations of calcium, magnesium and manganese had the opposite behavior: these accumulated in leaf until reaching maximum values in winter and then remained stable, with some oscillations but without statistically significant differences. No changes were observed in the zinc concentrations in the sampled periods. Periods of at least two consecutive months without statistically significant differences were found during the winter period for all elements except nitrogen. Analytical stability was observed from the second fortnight of May till the first fortnight of August for all elements except phosphorus and boron.

Frost hardiness and winter photosynthesis of Thujapiicata and Pseudotsugamenzlesll seedlings grown at three rates of nitrogen and phosphorus supply

1995 ◽  
Vol 25 (1) ◽  
pp. 18-28 ◽  
Author(s):  
B.J. Hawkins ◽  
M. Davradou ◽  
D. Pier ◽  
R. Shortt
Keyword(s):  
Net Photosynthesis ◽  
Douglas Fir ◽  
Frost Hardiness ◽  
Nutrient Concentrations ◽  
Nitrogen And Phosphorus ◽  
Red Cedar ◽  
Air Temperatures ◽  
Foliar Nutrient ◽  
One Year ◽  
P Supply

One-year-old seedlings of western red cedar (Thujapiicata Donn ex D.Don) and Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were grown for one season in five nutrient treatments with nitrogen (N) supplied in solution at rates of 20, 100, or 250 mg•L−1 and phosphorus (P) supplied at rates of 4, 20, or 60 mg•L−1. Growth, onset of dormancy, frost hardiness on six dates, and foliar nutrient concentrations in autumn and spring were measured. Midwinter rates of net photosynthesis and transpiration were measured at air temperatures of 4, 7, and 11 °C in seedlings from all nutrient treatments. Recovery of net photosynthesis and transpiration in whole seedlings from the three N treatments was assessed at intervals for 28 days after the seedlings were frozen to −5, −15, and −25°C. Foliar N content differed significantly among nutrient treatments and was positively correlated with supply. Mitotic activity ceased earliest in plants with low N supply. Douglas-fir seedlings in the low-N treatment also ceased height growth earliest. These differences in growth had no significant correlation with frost hardiness. No consistent differences in frost hardiness among nutrient treatments were observed. Higher rates of N and P supply resulted in higher rates of winter net photosynthesis. Net photosynthesis was reduced dramatically by night frost, with greater damage occurring at lower temperatures. Net photosynthesis recovery occurred most quickly in seedlings with the midrate of N and P supply.

scholarly journals EFFECT OF FOUR DIFFERENT PRETREATMENTS IN NITROGEN AND PHOSPHORUS FLOW AND MASS BALANCE IN EFFLUENTS OF A RECIRCULATING AQUACULTURE SYSTEM

2016 ◽  
Vol 31 (2) ◽  
pp. 21
Author(s):  
Juan P. González -Hermoso ◽  
Emilio Peña -Messina ◽  
Anselmo Miranda -Baeza ◽  
Luis R. Martínez -Córdoba ◽  
María T. Gutiérrez -Wing ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Mass Balance ◽  
Biological Degradation ◽  
Nitrogen And Phosphorus ◽  
Recirculating Aquaculture ◽  
P Content ◽  
Recirculating Aquaculture Systems ◽  
High Concentrations ◽  
Intensive Aquaculture ◽  
Phosphorus Flow

ABSTRACT. The effluents from intensive aquaculture operations such as recirculating aquaculture systems (RAS) have high concentrations of sludge that can become a source of pollution if they are not properly treated and disposed. Anaerobic digestion is commonly used for biological degradation of sludge. Pretreatments prior to anaerobic digestion can enhance sludge degradation and decrease nitrogen and phosphorus load through microbial activity. This study examines the effect of four different pretreatments (biological, chemical, mechanical and thermal) in the N and P fluxes and mass balance from a RAS effluent in a seven-month period at ambient temperature. Each month a 15-day experiment was performed. All pretreatments, except chemical, removed N (thermal 29.78%, biological 36.75%, control 42.25%, mechanical 49.46%, chemical -7.68%). All pretreatments produced phosphorus (chemical 1.96%, mechanical 16.07%, thermal 24.37%, biological 32.39%, control 58.50%). Our results showed that the mechanical pretreatment was the most effective in removing N. In contrast, none of the pretreatments reduced P content in the sludge.Efecto de cuatro pretratamientos en el flujo y balance del nitrógeno y el fósforo en efluentes de un sistema de recirculación acuícolaRESUMEN. Los efluentes de un tipo de cultivo intensivo como los Sistemas de Recirculación Acuícola (SRA) presentan altas concentraciones de lodos que pueden llegar a ser una fuente de contaminación si no son tratados y dispuestos apropiadamente. La digestión anaeróbica es usualmente empleada para llevar a cabo la degradación de los lodos. Los pretratamientos previos a la digestión anaeróbica pueden mejorar la degradación de los lodos, así como reducir la carga de nitrógeno y fósforo a través de la actividad microbiana. Este estudio examinó el efecto de cuatro pretratamientos (biológico, químico, mecánico y térmico) en el flujo y balance de masas de N y P de efluentes de un SRA durante un periodo de 7 meses a temperatura ambiente. En cada mes se llevó a cabo un experimento de 15 días. Todos los pretratamientos a excepción del químico, eliminaron nitrógeno (térmico 29.78%, biológico 36.75%, control 42.25%, mecánico 49.46%, químico -7.68%). Todos los pretratamientos produjeron fósforo (químico 1.96%, mecánico 16.07%, térmico 24.37%, biológico 32.39%, control 58.60%). Nuestros resultados indican que el pretratamiento mecánico fue el más efectivo para eliminar N. En contraste, ninguno de los pretratamientos redujo la concentración de fósforo. 

scholarly journals EFFECTS OF NITROGEN AND PHOSPHORUS ON THE YIELD AND CHEMICAL COMPOSITION OF MEADOW FOXTAIL

1975 ◽  
Vol 55 (4) ◽  
pp. 949-954 ◽  
Author(s):  
M. C. J. VAN ADRICHEM ◽  
J. N. TINGLE
Keyword(s):  
Chemical Composition ◽  
Crude Protein ◽  
Dry Matter ◽  
Nitrogen And Phosphorus ◽  
N Application ◽  
Dry Matter Digestibility ◽  
P Content ◽  
Mn Content ◽  
N Rates

The effects of spring-applied nitrogen (0, 56, 112 and 224 kg/ha) and phosphorus (0 and 27.4 kg/ha) on the dry matter (DM) yield and forage quality of successive harvests of meadow foxtail (Alopecurus pratensis L.) were investigated. Nitrogen increased DM yield, crude protein, Cu, K and Zn contents and decreased P, Ca, Mg and Mn contents. Application of P in combination with N increased K content in the first cut and arrested the decline of P content due to N application in all cuts. The levels of dry matter digestibility and Cu declined in successive cuts whereas Mn content increased. At low N rates, Ca and Mg contents increased as the season advanced.

scholarly journals Vegetation responses to season of fire in an aseasonal, fire-prone fynbos shrubland

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3591 ◽  
Author(s):  
Tineke Kraaij ◽  
Richard M. Cowling ◽  
Brian W. van Wilgen ◽  
Diba R. Rikhotso ◽  
Mark Difford
Keyword(s):  
Floristic Composition ◽  
Fire Season ◽  
Summer Drought ◽  
Winter Rainfall ◽  
Recruitment Success ◽  
Floral Diversity ◽  
Four Seasons ◽  
Different Seasons ◽  
Varied Response ◽  
One Year

Season of fire has marked effects on floristic composition in fire-prone Mediterranean-climate shrublands. In these winter-rainfall systems, summer-autumn fires lead to optimal recruitment of overstorey proteoid shrubs (non-sprouting, slow-maturing, serotinous Proteaceae) which are important to the conservation of floral diversity. We explored whether fire season has similar effects on early establishment of five proteoid species in the eastern coastal part of the Cape Floral Kingdom (South Africa) where rainfall occurs year-round and where weather conducive to fire and the actual incidence of fire are largely aseasonal. We surveyed recruitment success (ratio of post-fire recruits to pre-fire parents) of proteoids after fires in different seasons. We also planted proteoid seeds into exclosures, designed to prevent predation by small mammals and birds, in cleared (intended to simulate fire) fynbos shrublands at different sites in each of four seasons and monitored their germination and survival to one year post-planting (hereafter termed ‘recruitment’). Factors (in decreasing order of importance) affecting recruitment success in the post-fire surveys were species, pre-fire parent density, post-fire age of the vegetation at the time of assessment, and fire season, whereas rainfall (for six months post-fire) and fire return interval (>7 years) had little effect. In the seed-planting experiment, germination occurred during the cooler months and mostly within two months of planting, except for summer-plantings, which took 2–3 months longer to germinate. Although recruitment success differed significantly among planting seasons, sites and species, significant interactions occurred among the experimental factors. In both the post-fire surveys and seed planting experiment, recruitment success in relation to fire- or planting season varied greatly within and among species and sites. Results of these two datasets were furthermore inconsistent, suggesting that proteoid recruitment responses are not related to the season of fire. Germination appeared less rainfall-dependent than in winter-rainfall shrublands, suggesting that summer drought-avoiding dormancy is limited and has less influence on variation in recruitment success among fire seasons. The varied response of proteoid recruitment to fire season (or its simulation) implies that burning does not have to be restricted to particular seasons in eastern coastal fynbos, affording more flexibility for fire management than in shrublands associated with winter rainfall.

scholarly journals The effect of four commercial broiler hybrids and the season on occurrence of broiler condemnations in the abattoirs

2020 ◽  
Vol 50 (10) ◽  
Author(s):  
Antonise Mariely Jaguezeski ◽  
Ana Martiele Engelmann ◽  
Ivna Nalério dos Reis Machado ◽  
Beatriz Pavei Bez Batti
Keyword(s):  
Financial Impact ◽  
Welfare Programs ◽  
Conviction Rate ◽  
Commercial Broiler ◽  
Different Seasons ◽  
Time Of Year ◽  
One Year ◽  
The One ◽  
Inspection Service ◽  
Abattoir Data

ABSTRACT: Condemnations in the broilers abattoirs can represent an overview farms health and effectiveness of welfare programs, as well as predisposition between hybrids. The aim of this study was to investigate the prevalence of condemnation among four commercial broiler hybrids and the oscillation of condemnations in different seasons in a poultry abattoir. Data from condemnations of the Federal Inspection Service of a slaughterhouse were analyzed during one year, in which a total of 12.81% of partial condemnations were observed and total condemnations represented 0.41% of slaughtered broiler. There was a difference in total and partial condemnation among the hybrids evaluated, with Hubbard hybrid being the one with the highest number of condemnations (0.67% - 17.71%), followed by Ross 95 (0.42% - 14.21%), Cobb (0.30% - 10.03%); and Cobb Fast (0.26% - 9.29%). The analysis between the seasons showed a higher conviction rate in winter and a lower rate in autumn for both total and partial condemnation. Hubbard had the highest rates and Cobb Fast the lowest for most causes of condemnation. We concluded that the metabolic cause led to higher losses by total condemnation, while contamination or technopathies represented the highest rates in partial losses. The broiler hybrid and the time of year may influence the causes of condemnation in the abattoir. This information should be considered by the abattoir and the farms in sanitary planning, considering the financial impact due to losses by condemnations of carcasses.

scholarly journals Monitoring of fish diseases in the Magadan region

2021 ◽  
Vol 36 ◽  
pp. 07008
Author(s):  
E.A. Vitomskova
Keyword(s):  
Pacific Salmon ◽  
Animal Health ◽  
Natural Populations ◽  
Clinical Signs ◽  
Commercial Fish ◽  
Fish Diseases ◽  
North East ◽  
Comparative Aspect ◽  
Different Seasons

In such a large region as the Far North-East of Russia, there is still no purposeful ichthyopathological study of fish diseases, which has epizootic and epidemiological significance. The material for the study was commercial fish caught in different seasons of 1995-2021. As a result of the research, individuals of natural populations and in aquaculture with clinical signs of infectious and parasitic diseases were found, and cultures of virulent strains of microorganisms were isolated. According to the results of the parasitological study, larvae of nematodes of the family Anisakidae and plerocercoids of cestodes Diphyllobothriidae, which have important epidemiological and epizootic significance, were registered. Based on long-term ichthyopathological studies, a retrospective review of own data was carried out. The analysis of infectious diseases of mature individuals of anadromous Pacific salmon of the genus Oncorhynchus, as well as long-term parasitological monitoring in a comparative aspect of the invasion of commercial fish by helminths dangerous to human and animal health, is presented.

scholarly journals Diversity and distribution of diatoms in Bagmati River, Kathmandu, Nepal

2018 ◽  
Vol 6 ◽  
pp. 6-15
Author(s):  
Shiva Kumar Rai ◽  
Sudip Khadka
Keyword(s):  
Aquatic Macrophytes ◽  
Habitat Diversity ◽  
Diatom Cell ◽  
Different Seasons ◽  
Bagmati River

Diversity and distribution of diatoms in different seasons from different localities and habitats of Bagmati River, Kathmandu was studied. Samples were collected as epilithic forms using a toothbrush, epipelic forms using a dropper, and epiphytic forms by squeezing aquatic macrophytes and were preserved in FAA solution. The dominant diatom taxa of Bagmati river were Achnanthes crenulata, Gomphonema pseudoaugur, Nitzschia linearis, N. palea, Pinnularia cf divergens and Surirella linearis. Out of 48 taxa reported, maximum taxa (87.5%) were found at Mulkharka site whereas taxa were minimum (39.58%) at Pashupati-Guheshwori site. The sizes of diatom cell, from largest to smallest, also followed the same pattern as above. Ten diatom taxa were common in all three sites. Seasonal and habitat diversity of diatom studied in Mulkharka site showed that the maximum number of taxa was reported during summer (92.85%) and least during winter (23.8%), and maximum taxa were found as epilithic (85.71%) followed by epipelic (38.09%) and epiphytic (33.33%).

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