scholarly journals Initial evaluation of nitrogen uptake of Thalassia hemprichii in Nha Trang, Khanh Hoa

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Phan Minh Thu ◽  
Nguyen Minh Hieu ◽  
Hoang Trung Du ◽  
Nguyen Kim Hanh ◽  
Pham Thi Mien ◽  
...  
Keyword(s):  
Water Column ◽  
Nitrogen Uptake ◽  
Uptake Rate ◽  
Laboratory Experiments ◽  
Nitrate Uptake ◽  
Seagrass Beds ◽  
Thalassia Hemprichii ◽  
Maximum Uptake Rate ◽  
Nitrate Uptake Rate ◽  
Leaves And Roots

The uptake rate of nitrate by leaves and roots was simultaneously investigated in the seagrass T. hemprichii collected from Lo river, Nha Trang. The principle of nutrient uptake of seagrass was based on the approaches of the Michaelis-Menten model. The laboratory experiments of nitrate uptake were done the ranges of ambient nitrate concentrations in the separate water column of leaves and roots. The calculated results indicated that the nitrate uptake rate through the leaves was higher than that of the roots. The maximum uptake rate (Vmax) through the leaves and the roots was 1,777.0 mgN/g DW/h and 131.6 mgN/g DW/h, respectively. From these results, the nitrate uptake rate by the seagrass in Lo river was estimated at 52.2 mgNm-2h-1. The value plays an important role in developing and implementing plans for the protection and rehabilitation of seagrass beds in coastal areas.

scholarly journals Removal of Nitrate from Groundwater by Cyanobacteria: Quantitative Assessment of Factors Influencing Nitrate Uptake

2000 ◽  
Vol 66 (1) ◽  
pp. 133-139 ◽  
Author(s):  
Qiang Hu ◽  
Paul Westerhoff ◽  
Wim Vermaas
Keyword(s):  
Uptake Rate ◽  
Large Scale ◽  
Nitrate Uptake ◽  
Nitrate Removal ◽  
Aeration Rate ◽  
Inoculum Size ◽  
Logarithmic Phase ◽  
Batch Mode ◽  
Nitrate Uptake Rate ◽  
Cyanobacteria And Algae

ABSTRACT The feasibility of biologically removing nitrate from groundwater was tested by using cyanobacterial cultures in batch mode under laboratory conditions. Results demonstrated that nitrate-contaminated groundwater, when supplemented with phosphate and some trace elements, can be used as growth medium supporting vigorous growth of several strains of cyanobacteria. As cyanobacteria grew, nitrate was removed from the water. Of three species tested, Synechococcus sp. strain PCC 7942 displayed the highest nitrate uptake rate, but all species showed rapid removal of nitrate from groundwater. The nitrate uptake rate increased proportionally with increasing light intensity up to 100 μmol of photons m−2 s−1, which parallels photosynthetic activity. The nitrate uptake rate was affected by inoculum size (i.e., cell density), fixed-nitrogen level in the cells in the inoculum, and aeration rate, with vigorously aerated, nitrate-sufficient cells in mid-logarithmic phase having the highest long-term nitrate uptake rate. Average nitrate uptake rates up to 0.05 mM NO3 − h−1 could be achieved at a culture optical density at 730 nm of 0.5 to 1.0 over a 2-day culture period. This result compares favorably with those reported for nitrate removal by other cyanobacteria and algae, and therefore effective nitrate removal from groundwater using this organism could be anticipated on large-scale operations.

scholarly journals Kandungan Nitrat dan Fosfat dalam Air Pori Sedimen dan Kolom Air di Daerah Padang Lamun Perairan Pantai Prawean, Bandengan, Jepara

2020 ◽  
Vol 9 (4) ◽  
pp. 464-473
Author(s):  
Eko Wardana Parsaulian Tampubolon ◽  
Ria Azizah Tri Nuraini ◽  
Endang Supriyantini
Keyword(s):  
Water Column ◽  
Pore Water ◽  
Descriptive Analysis ◽  
Nitrate Content ◽  
Seagrass Beds ◽  
Thalassia Hemprichii ◽  
Sediment Pore Water ◽  
Decomposition Of Organic Matter ◽  
Cymodocea Rotundata ◽  
Seagrass Density

ABSTRAK : Secara alamiah konsentrasi zat hara dalam perairan bervariasi untuk masing-masing bentuk senyawanya, termasuk nitrat dan fosfat. Lamun berperan penting terhadap sumbangan nutrien di perairan dengan hasil dekomposisi serasah lamun oleh mikroorganisme pengurai. Fungsi sistem lamun terletak pada pemahaman faktor-faktor yang mengatur produksi dan dekomposisi bahan organik serta efisiensi daur nutrisi dalam sistemnya. Penelitian ini bertujuan untuk mengetahui kandungan nitrat dan fosfat air pori sedimen dan kolom air serta mengetahui jenis dan jumlah kerapatan lamun yang terdapat di perairan Pantai Prawean Bandengan Jepara. Metode penelitian ini menggunakan analisis deskriptif. Analisa kandungan nitrat menggunakan metode analisis SNI 06-6989.31-2005 dan fosfat menggunakan metode analisis BP2-MU-A-08. Pengamatan lamun menggunakan transek kuadrat 50x50cm menurut panduan LIPI. Kandungan nitrat air pori sedimen berkisar 1,85 – 2,82 mg/l, tergolong sedang. Sedangkan kandungan nitrat kolom air berkisar 0,63 – 1,09 mg/l, tergolong rendah. Kandungan fosfat pada air pori berkisar 0,09 – 0,15 mg/l, tergolong sangat subur. Sedangkan kandungan fosfat kolom air berkisar 0,02 – 0,04 mg/l, tergolong cukup subur. Jenis lamun yang ditemukan pada lokasi penelitian sebanyak 4 spesies yaitu Enhalus accoroides, Thalassia hemprichii, Cymodocea serullata, dan Cymodocea rotundata. Kerapatan lamun tertinggi di stasiun 2 sebanyak 132 tegakan/m2 (rapat) sedangkan stasiun 1 sebanyak 95 tegakan/m2 (agak rapat) dan stasiun 3 sebanyak 123 tegakan/m2 (agak rapat). Lamun jenis Cymodocea serullata memiliki dominansi tertinggi pada setiap stasiun. ABSTRACT : Naturally the concentration of nutrients in the waters varies for eachthe form of its compounds, including nitrates and phosphates. Seagrass plays an important role in the contribution of nutrients in waters with the result of decomposition of  seagrass litter by decomposing microorganisms. The function of the seagrass system lies in understanding the factors that govern the production and decomposition of organic matter and the efficiency of nutrient cycling in the system. This research aims to determine the content of nitrate and phosphate in sediment pore water and water columns in the seagrass beds of Prawean Coast waters Jepara and determine the type and the amount of seagrass density. This research method uses descriptive analysis. Nitrate content analysis using SNI 06-6989.31-2005 and phosphate analysis using BP2-MU-A-08. Seagrass observations using the Transect squared 50x50cm according to the LIPI guidelines. The content of nitrates sediment pore water in the seagrass beds of Prawean Coast ranges from 1,85 to 2,82 mg/l, while the content of nitrate in water column ranges from 0,63 – 1,09 mg/l. The content of phosphate in pore water ranges from 0,09 – 0,15 mg/l, while the phosphate content of the water column ranges from 0,02 to 0,04 mg/l. Four types of seagrass found were Enhalus accoroides, Thalassia hemprichii, Cymodocea serullata, and Cymodocea rotundata. The highest seagrass density at station 2 was 132 stands/m2, while the station 1 was 95 stands/m2 and station 3 was 123 stands/m2. Seagrass type Cymodocea Serullata has the highest dominance at each station.Kata Kunci :   Nitrat, Fosfat, Air Pori Sedimen, Kolom Air, Lamun.

scholarly journals 293 Genotypic and Temporal Variation in Nitrate Uptake Rate by Kentucky Bluegrass

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 493A-493
Author(s):  
Zhongchun Jiang ◽  
W. Michael Sullivan ◽  
Carl D. Sawyer ◽  
Richard J. Hull
Keyword(s):  
Temporal Variation ◽  
Nutrient Solution ◽  
Uptake Rate ◽  
Nitrate Uptake ◽  
Poa Pratensis ◽  
Tap Water ◽  
Kentucky Bluegrass ◽  
Genotypic Differences ◽  
Half Strength ◽  
Nitrate Uptake Rate

Turfgrass cultivars that have superior nitrate uptake ability are needed for the protection of ground water from pollution by excess nitrate. Information on temporal variation of nitrate absorption is also needed to enhance the environmental safety of turfgrass N fertilization programs. Our objectives were to evaluate Kentucky bluegrass (Poa pratensis L.) cultivars for their differences in nitrate uptake rate (NUR) and temporal variation in NUR. Six cultivars (Barzan, Blacksburg, Connie, Dawn, Eclipse, and Gnome) were propagated from individual tillers and six plants of each cultivar were generated from one mother plant. Plants were grown in silica sand, mowed weekly, and watered daily with half-strength modified Hoagland's nutrient solution containing 1 mM nitrate. When 5 months old, the plants were excavated, the roots were washed to remove sand, and the plants were transferred to 120-mL black bottles. After 24 hours in tap water, the plants were supplied with half-strength nutrient solution containing 0.5 mM nitrate, and the solutions were replaced daily for 8 days. NURs expressed as micromoles per plant per hour were calculated from solution nitrate depletion data. Significant genotypic differences in NUR were found: `Blacksburg' > `Connie' > `Dawn' > `Barzan' = `Eclipse' > `Gnome'. Significant temporal variation in NUR was also found, with NUR on the second day more than the first day after tap water. A significant interaction was noted between genotype and time. Temporal variation was greatest in `Blacksburg', while none noted in `Connie' and `Eclipse'. In `Barzan' and `Gnome', NUR on the last day was higher than the first day.

Lupinus angustifolius has a plastic uptake response to heterogeneously supplied nitrate while Lupinus pilosus does not

2001 ◽  
Vol 52 (4) ◽  
pp. 505 ◽  
Author(s):  
V. Dunbabin ◽  
Z. Rengel ◽  
A. Diggle
Keyword(s):  
Root System ◽  
Uptake Rate ◽  
Root Length ◽  
Nitrate Uptake ◽  
Lupinus Angustifolius ◽  
Nitrate Losses ◽  
Nitrate Supply ◽  
Nitrate Uptake Rate ◽  
The Difference ◽  
Set Up

Uptake rates calculated from plants uniformly supplied with a nutrient will underestimate uptake under heterogeneous conditions. A split-root nutrient solution experiment was set up to compare the uptake rate of 2 lupin species (Lupinus angustifolius L., L. pilosus Murr.) under conditions of uniform and heterogeneous nitrate supply. Nitrate was supplied uniformly to the root system at 250 M (low), 750 M (high), or 1500 M (high), or in a split low/high or high/low combination between the upper and lower root system. While L. pilosus had a greater total nitrate uptake over the treatment period due to a higher total root length, L. angustifolius had 1.5–2.5 times greater nitrate uptake rate per unit of root length. L. angustifolius also had the capacity to increase the nitrate uptake rate in sections of the root system supplied locally with high nitrate, compared with a root system uniformly supplied with high nitrate. This increased uptake rate under heterogeneous supply enabled the plant to take up 74–94% of the total nitrate taken up when uniformly supplied with high nitrate, while only 58–72% would have been taken up without such a compensation mechanism. L. pilosus did not show this response. The difference between the response of these 2 species suggests that a range of nitrate uptake responses may exist across the lupin germplasm, and that it may be possible to select a lupin species with an enhanced ability to capture nitrate from the profile, thus decreasing nitrate losses from leaching.

scholarly journals A geographical and seasonal comparison of nitrogen uptake by phytoplankton in the Southern Ocean

2014 ◽  
Vol 11 (4) ◽  
pp. 1829-1869
Author(s):  
R. Philibert ◽  
H. Waldron ◽  
D. Clark
Keyword(s):  
Southern Ocean ◽  
Primary Production ◽  
Nitrogen Uptake ◽  
Uptake Rate ◽  
Nitrate Uptake ◽  
Day Length ◽  
Ammonium Uptake ◽  
Ammonium Concentration ◽  
Uptake Rates ◽  
The Impact

Abstract. Primary production in the Southern Ocean has been shown to be regulated by light and nutrients (such as silicate and iron) availability. However, the impact of these factors vary seasonally and differ from region to region. The seasonal cycle of primary production in this region is not fully resolved over an annual scale due to the lack of winter in situ measurements. In this study, nitrate and ammonium uptake rates were measured using 15N tracers during a winter cruise in July 2012 and a summer cruise in February/March 2013. In winter, nitrogen uptake rates were measured at 55% and 1% of the surface photosynthetically active radiation (sPAR). The summer uptake rates were measured at 4 light depths corresponding to 55, 30, 10 and 3% sPAR. The integrated nitrate uptake rates during the winter cruise ranged from 0.16–5.20 (average 1.14) mmol N m−2 d−1 while the ammonium uptake rates ranged from 0.6–32.8 (average 6.72) mmol N m−2 d−1. During the summer cruise, the mean integrated nitrate uptake rate was 0.34 mmol N m−2 d−1 with a range between 0.16–0.65 mmol N m−2 d−1. The integrated ammonium uptake rate averaged 5.61 mmol N m−2 d−1 and ranged from 1.44–11.28 mmol N m−2 d−1. The factors controlling primary production in winter and summer were investigated. During the winter cruise, it was found the different nitrogen uptake regimes were not separated by fronts. Light (in terms of day length) and ammonium concentration had the most influence on the nitrogen uptake regime. In the summer, increases in the mixed layer depth (MLD) resulted in increased nitrogen uptake rates. This suggests that the increases in the MLD could be alleviating nutrient limitations experienced by the phytoplankton at the end of summer.

scholarly journals Characterization of Nitrate Uptake by Kentucky Bluegrass at the Whole-plant and Organ Levels

HortScience ◽  
2000 ◽  
Vol 35 (5) ◽  
pp. 829D-829
Author(s):  
Yuexia Wang ◽  
Chhandak Basu ◽  
Zhongchun Jiang ◽  
W. Michael Sullivan
Keyword(s):  
Nutrient Solution ◽  
Uptake Rate ◽  
Nitrate Uptake ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Whole Plant ◽  
Nitrate Uptake Rate ◽  
Nitrate Depletion

It has been suggested that shoot demand for nitrogen controls nitrate uptake in plant roots. In turfgrasses, shoots are partly removed by regular mowing, which may severely alter nitrate uptake ability. However, reported groundwater nitrate concentrations under intensively managed turf are well below the USEPA maximum contaminant limit of 10 mg·L-1 nitrate-N in potable water. We hypothesize that the turfgrass root can also exert significant control over its nitrate uptake ability. The present study was to test this hypothesis by comparing nitrate uptake rates of excised roots and intact, whole plants of six Kentucky bluegrass (Poa pratensis L.) cultivars. Three replications or cultures of each cultivar were grown in sand for 15 months. For whole-plant nitrate uptake, the roots were placed in a flask filled with 200 mL of a nutrient solution containing 0.125 mm nitrate. Nitrate depletion was monitored at 20-minute intervals over an 8-hour period under ≈600 μmol·m-2·s-1 photosynthetic photon flux density. After the whole-plant experiment, the plants were placed in an N-free nutrient solution for 15 hours, and the roots were then excised. The excised roots were placed in a beaker containing 60 mL of the 0.125-mm nitrate nutrient solution and nitrate depletion was monitored at 20-minute intervals over a 6-hour period. Whole-plant nitrate uptake rate differed significantly (P ≤ 0.05) among cultivars and was twice that of excised roots. Excised root nitrate uptake rate exhibited no cultivar difference but was positively and significantly (P ≤ 0.05) correlated with whole-plant nitrate uptake rate. Our results indicate that turfgrass roots exert substantial control over nitrate uptake.

Nitrate Uptake Rate by Soybean and Wheat Plants Determined by External Nitrate Concentration and Shoot-Mediated Demand

1998 ◽  
Vol 159 (2) ◽  
pp. 305-312 ◽  
Author(s):  
Carole H. Saravitz ◽  
Florence Devienne-Barret ◽  
C. David Raper, ◽  
Sylvain Chaillou ◽  
Thierry Lamaze
Keyword(s):  
Uptake Rate ◽  
Nitrate Uptake ◽  
Nitrate Concentration ◽  
Nitrate Uptake Rate
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