scholarly journals Sedimentary Nitrogen Uptake & Assimilation in the Temperate Zooxanthellate Anemone Anthopleura aureoradiata

2021 ◽  
Author(s):  
◽  
Shyam Ravi Morar
Keyword(s):  
Nitrogen Uptake ◽  
Littoral Zone ◽  
Carbon Fixation ◽  
Nitrogen Deficiency ◽  
Dry Weight ◽  
Rocky Intertidal ◽  
Nitrogen Status ◽  
Particulate Nitrogen ◽  
Sediment Treatment ◽  
Algal Symbionts

<p>This study investigated the potential for, and efficiency of, particulate nitrogen uptake from the sediment and subsequent consequences of this on the nutrient status of endosymbiotic dinoflagellates (zooxanthellae) in the temperate zooxanthellate anemone Anthopleura aureoradiata. Sediment was collected from a mudflat and labelled with (15NH4)2SO4 before being provided to A. aureoradiata at low (5 g dry weight) and high sediment (20 g dry weight) loads for 6 hours. While no discernible change in the isotopic content of the sediment could be detected, analysis of the host and algal symbionts revealed that 15N had been taken up. Uptake by the host was similar at both high and low sediment loads, but the algal symbionts acquired more nitrogen at the lower load (1.13 versus 0.93 atom % 15N in the low and high loads, respectively). Evaluation of this particulate nitrogen uptake from the sediment was further examined by measuring the nitrogen status of the zooxanthellae. This was determined by measuring the extent to which ammonium (40 muM NH+4) enhanced the rate of zooxanthellar dark carbon fixation above that seen in filtered seawater (FSW) alone; the enhancement ratio was expressed as [dark NH+4 rate/dark FSW rate]. VD'/VL, a further index of nitrogen status, was also calculated where VD' = [dark NH+4 rate - dark FSW rate] and VL = rate of carbon fixation in the light. When anemones were starved for 2-8 weeks, zooxanthellar nitrogen deficiency became apparent at greater than or equal to 4 weeks, with NH+4/FSW and VD'/VL averaging up to 2.90 and 0.11, respectively. In comparison, when anemones were fed 5 times per week for 8 weeks the addition of ammonium had little effect, indicating nitrogen sufficiency; NH+4/FSW and VD'/VL values were 1.03 and -1.0 x 10-3, respectively. The nitrogen status of zooxanthellae from anemones starved and incubated with and without sediment was examined with no apparent difference between sediment and no sediment treatments; zooxanthellar nitrogen deficiency became apparent at greater than or equal to 4 weeks in both treatments, with NH+4/FSW and VD'/VL averaging up to 3.73 and 0.17 for the sediment treatment and 2.74 and 0.15 for the no sediment treatment, respectively. The nitrogen status of zooxanthellae from anemones found on a mudflat (Pauatahanui Inlet) and a rocky intertidal site (Kau Bay) was different. Zooxanthellae from mudflat anemones were nitrogen sufficient with NH+4/FSW and VD'/VL values averaging up to 1.26 and -6.0 x 10-3, respectively. Nitrogen deficient zooxanthellae were present in anemones from the rocky intertidal. Anemones from tide pools in the upper littoral zone had NH+4/FSW and VD'/VL values of 2.99 and 0.11, respectively, while anemones from the mid littoral zone had NH+4/FSW and VD'/VL of 2.90 and 0.13, respectively; there was no significant difference in nitrogen status between zooxanthellae from high shore tide pool anemones and aerially exposed mid-littoral anemones. These results suggest that while particulate nitrogen can be taken up from the sediment by this species, dissolved inorganic nitrogen such as ammonium in the seawater, and especially the interstitial water surrounding infaunal anemones on mudflats, may be a more important source of nitrogen in the field.</p>

scholarly journals Sedimentary Nitrogen Uptake & Assimilation in the Temperate Zooxanthellate Anemone Anthopleura aureoradiata

2021 ◽  
Author(s):  
◽  
Shyam Ravi Morar
Keyword(s):  
Nitrogen Uptake ◽  
Littoral Zone ◽  
Carbon Fixation ◽  
Nitrogen Deficiency ◽  
Dry Weight ◽  
Rocky Intertidal ◽  
Nitrogen Status ◽  
Particulate Nitrogen ◽  
Sediment Treatment ◽  
Algal Symbionts

<p>This study investigated the potential for, and efficiency of, particulate nitrogen uptake from the sediment and subsequent consequences of this on the nutrient status of endosymbiotic dinoflagellates (zooxanthellae) in the temperate zooxanthellate anemone Anthopleura aureoradiata. Sediment was collected from a mudflat and labelled with (15NH4)2SO4 before being provided to A. aureoradiata at low (5 g dry weight) and high sediment (20 g dry weight) loads for 6 hours. While no discernible change in the isotopic content of the sediment could be detected, analysis of the host and algal symbionts revealed that 15N had been taken up. Uptake by the host was similar at both high and low sediment loads, but the algal symbionts acquired more nitrogen at the lower load (1.13 versus 0.93 atom % 15N in the low and high loads, respectively). Evaluation of this particulate nitrogen uptake from the sediment was further examined by measuring the nitrogen status of the zooxanthellae. This was determined by measuring the extent to which ammonium (40 muM NH+4) enhanced the rate of zooxanthellar dark carbon fixation above that seen in filtered seawater (FSW) alone; the enhancement ratio was expressed as [dark NH+4 rate/dark FSW rate]. VD'/VL, a further index of nitrogen status, was also calculated where VD' = [dark NH+4 rate - dark FSW rate] and VL = rate of carbon fixation in the light. When anemones were starved for 2-8 weeks, zooxanthellar nitrogen deficiency became apparent at greater than or equal to 4 weeks, with NH+4/FSW and VD'/VL averaging up to 2.90 and 0.11, respectively. In comparison, when anemones were fed 5 times per week for 8 weeks the addition of ammonium had little effect, indicating nitrogen sufficiency; NH+4/FSW and VD'/VL values were 1.03 and -1.0 x 10-3, respectively. The nitrogen status of zooxanthellae from anemones starved and incubated with and without sediment was examined with no apparent difference between sediment and no sediment treatments; zooxanthellar nitrogen deficiency became apparent at greater than or equal to 4 weeks in both treatments, with NH+4/FSW and VD'/VL averaging up to 3.73 and 0.17 for the sediment treatment and 2.74 and 0.15 for the no sediment treatment, respectively. The nitrogen status of zooxanthellae from anemones found on a mudflat (Pauatahanui Inlet) and a rocky intertidal site (Kau Bay) was different. Zooxanthellae from mudflat anemones were nitrogen sufficient with NH+4/FSW and VD'/VL values averaging up to 1.26 and -6.0 x 10-3, respectively. Nitrogen deficient zooxanthellae were present in anemones from the rocky intertidal. Anemones from tide pools in the upper littoral zone had NH+4/FSW and VD'/VL values of 2.99 and 0.11, respectively, while anemones from the mid littoral zone had NH+4/FSW and VD'/VL of 2.90 and 0.13, respectively; there was no significant difference in nitrogen status between zooxanthellae from high shore tide pool anemones and aerially exposed mid-littoral anemones. These results suggest that while particulate nitrogen can be taken up from the sediment by this species, dissolved inorganic nitrogen such as ammonium in the seawater, and especially the interstitial water surrounding infaunal anemones on mudflats, may be a more important source of nitrogen in the field.</p>

scholarly journals Pengaruh Pupuk Hayati Endofitik Dengan Azolla Pinnata Terhadap Serapan N , N-Total Tanah, Dan Bobot Kering Tanaman Padi (Oryza Sativa L.) Pada Tanah Salin

Agrologia ◽  
2018 ◽  
Vol 6 (2) ◽  
Author(s):  
Alin Kusumah Dewi ◽  
Mieke Rochimi Setiawati
Keyword(s):  
Nitrogen Uptake ◽  
Endophytic Bacteria ◽  
Saline Soil ◽  
Oryza Sativa L ◽  
Block Design ◽  
Nitrogen Deficiency ◽  
Dry Weight ◽  
Biological Properties ◽  
Azolla Pinnata ◽  
Total N

Saline soil contain excessive NaCl content which inhibit plant growth and lead to nitrogen deficiency. Endophytic bacteria live inside the plant tissue and has the ability to fix nitrogen directly from the atmosphere, meanwhile Azolla pinnata can be used as organic ameliorant that able to increase the number of availability nitrogen for plant in soil, and improve the physical, chemical, and biological properties of soil. The aims of this experiment were to find out the treatment that cause highest nitrogen uptake by plant, total-N of soil, and dry weight of rice in saline soil. The experimental design was randomized block design with eight treatments and four repetitions. The results showed that the application of biofertilizer and ameliorant increased nitrogen uptake by plant and dry weight of rice in saline soil, but there was no significant effect on  total-N of soil. This experiment suggested that endophytic bacteria biofertilizer and Azolla pinnata were effective to increase dry weight and nitrogen uptake of rice grown in soil with EC between  2 dS m-1 - 4 dS m-1.

scholarly journals Uji Isolat Bakteri Azotobacter Asal Kebun Lidah Buaya dengan Pupuk Urea terhadap Serapan Nitrogen pada Tanaman Kedelai (Glycine Max L.) di Tanah Gambut

2021 ◽  
Vol 2 ◽  
pp. 131-138
Author(s):  
Nandung Erlanda ◽  
Feira B. Arief ◽  
Ismahan Umran ◽  
Sutarman Gafur ◽  
Denah Suswati
Keyword(s):  
Nitrogen Uptake ◽  
Peat Soil ◽  
Aloe Vera ◽  
Dry Weight ◽  
Growth Media ◽  
Chemical Fertilizers ◽  
Urea Fertilizer ◽  
Randomized Design ◽  
The Media ◽  
Soybean Plants

Azotobacter nitrogen-fixing bacteria and urea fertilizer to reduce excessive use of chemical fertilizers. These bacteria can play a role in increasing nitrogen uptake and further growth of soybean plants. This study aimed to obtain growth media for Azotobacter and increase plant and root growth and nitrogen uptake of Biosoy soybean varieties. The research was conducted to help the uptake of n in the soil and reduce the excessive use of chemical fertilizers. The first experiment was carried out by growing bacteria on the media for 120 hours. The second experiment was designed in a completely randomized design that tested two treatments with additional use of urea fertilizer and Azotobacter and no Azotobacter. The results showed that there was no effect of giving Azotobacter from aloe vera gardens, and urea fertilizer showed a significant effect on the observed variables of soil pH in soybean plants on peat soil. In contrast, the variables observed were population, plant height, N content, N-total, plant dry weight, dry weight of plant roots, and N span of soybean plants had no significant effect.

Effect of Nitrogen Nutrition Upon Sugar Content and Dry Weight of Juvenile Lodgepole Pine and White Spruce

1972 ◽  
Vol 2 (4) ◽  
pp. 434-440 ◽  
Author(s):  
Harold M. Etter
Keyword(s):  
Species Interactions ◽  
Nitrogen Nutrition ◽  
Sugar Content ◽  
Nitrogen Deficiency ◽  
Dry Weight ◽  
Nitrogen Level ◽  
Growth Responses ◽  
Free Sugars ◽  
Glucose Levels ◽  
Physiological Processes

A factorial experiment was conducted in which Pinuscontorta var. latifolia and Piceaglauca (Moench) Voss seedlings were grown for 6 weeks under controlled environmental conditions with deficient and normal supplies of nitrate and ammonium. Free sugars (sucrose, fructose and glucose), starch (as glucose) and pectic sugars (galactose, arabinose, mannose and xylose) were quantitated. Effects of nitrogen form and nitrogen level, and their interactions, upon sugar contents and dry weights of the two species were examined. Growth responses to nitrogen occurred mainly in the shoots. For most parameters the two species reacted similarly to changes in nitrogen level and form, although the concentration of individual sugars differed between the species. In the shoots there were level × species interactions in the dry weight and the sum of free sugars plus starch. Plants grown under nitrogen deficiency were characterized by higher starch contents throughout and lower free sugars in the shoots. Supplying nitrate instead of ammonium lowered glucose levels, particularly in the shoots. Pectic sugar contents were unaffected by nitrogen nutrition. These compositional and growth responses to the nutritional regime implied changes in carbohydrate metabolism and physiological processes that are described by the C/N ratio of the plant.

The availability of mineral nitrogen in a wheat soil from southern New South Wales

1962 ◽  
Vol 2 (6) ◽  
pp. 185 ◽  
Author(s):  
RR Storrier
Keyword(s):  
Nitrogen Uptake ◽  
New South ◽  
New South Wales ◽  
Nitrogen Deficiency ◽  
Ammonia Nitrogen ◽  
Mineral Nitrogen ◽  
Wheat Crop ◽  
Wagga Wagga ◽  
Emergence Period ◽  
South Wales

In a red-brown earth soil from Wagga Wagga the fluctuations in the level of mineral nitrogen (ammonia plus nitrate-nitrogen) and its availability to wheat under growing period rainfalls of 6 inches and 16 inches were studied. Ammonia-nitrogen did not exceed 8 lb nitrogen per acre 6 inches but showed statistically significant short term fluctuations. Mineral nitrogen decreased steadily from the 4-5 leaf stage of plant growth, reaching minimum values in the ear-emergence period when a temporary nitrogen deficiency occurred. Following rainfalls of about one inch or more, conditions favoured biological activity and nitrogen was mineralized, absorbed by the crop and/or leached down the profile. In one season a release of mineral nitrogen about two weeks before flowering contributed an estimated 20-30 per cent of the total nitrogen uptake of the crop. Nitrogen uptake by the wheat crop ceased after flowering and subsequent changes in mineral nitrogen level reflect the net result of mineralization and demineralization processes, and nitrogen uptake by weeds, particularly skeleton weed. Absorption of nitrogen from the profile depended upon seasonal conditions, with the surface 18 inches suppling the greater part of the nitrogen absorbed by the crop. This indicates the need to sample regularly to at least a depth of 18 inches, particularly during the period from 4-5 leaf to flowering, when studying the relation between mineral nitrogen and crop growth. The data suggest that the response of wheat, as measured by grain yield and protein content, to the higher levels of mineral nitrogen in the improved soils of southern New South Wales is determined by soil moisture levels, particularly in the post-flowering period.

Inshore–Offshore Sedimentation Differences Resulting from Resuspension in the Eastern Basin of Lake Erie

1982 ◽  
Vol 39 (5) ◽  
pp. 748-759 ◽  
Author(s):  
J. Bloesch
Keyword(s):  
Lake Erie ◽  
Sediment Cores ◽  
Dry Weight ◽  
Sediment Traps ◽  
Particulate Phosphorus ◽  
Particulate Nitrogen ◽  
Eastern Basin ◽  
Fine Grained ◽  
Lake Bottom ◽  
Offshore Station

From June through October 1978 sediment traps were moored at three stations in an inshore–offshore transect in the Eastern Basin of Lake Erie. Settling fluxes measured with the traps exposed close to lake bottom were rather similar at all three stations during summer stratification, averaging 6.1 g∙m−2∙d−1 for dry weight, 293 mg∙m−2∙d−1 for particulate organic carbon (POC), 38 mg∙m−2∙d−1 for particulate nitrogen (PN), and 5.44 mg∙m−2∙d−1 for particulate phosphorus (PP). A comparison of the hypolimnetic traps with the epilimnetic traps at the offshore station indicated that considerable resuspension takes place even in summer. During fall, however, the nearshore sedimentation rates were markedly increased because of storm-induced bottom resuspension. By comparing the trap catches with sediment cores taken at all three stations, a resuspension model for dry weight, POC, and PN was developed. The calculations showed that newly formed organic material is resuspended and redeposited more frequently at nearshore locations than offshore. This repeated nearshore resuspension enhances decomposition of detritus, as shown by low relative phytoplankton activity in the hypolimnetic traps, and results in horizontal transport of fine-grained organic matter in the offshore direction. The significant POC and PN concentration differences found in the inshore–offshore transect of the bottom sediments can be explained by these two processes.Key words: sedimentation, sediment traps, sediment cores, resuspension, inshore–offshore differences

Quantifying Nitrogen Status of Rice Using Low Altitude UAV-Mounted System and Object-Oriented Segmentation Methodology

2009 ◽  
Author(s):  
Jinxia Zhu ◽  
Ke Wang ◽  
Jinsong Deng ◽  
Tom Harmon
Keyword(s):  
Crop Production ◽  
Nitrogen Deficiency ◽  
Object Oriented ◽  
Spatial And Temporal Variation ◽  
Nitrogen Application ◽  
Color Parameter ◽  
Nitrogen Status ◽  
Predictive Tool ◽  
Nutrient Runoff ◽  
Application Rates

Nitrogen deficiency can seriously reduce yield, while over-fertilization can result problems such as excess nutrient runoff and groundwater pollution. Hence, efficient methods for assessing crop nitrogen status are needed to enable more optimal fertilizer management. The ability to quantify the different nitrogen application rates by crops using digital images taken from an unmanned aerial vehicle (UAV) was investigated in comparison with ground-based hyperspectral reflectance and chlorophyll content data from 140 plots on a managed field. This research utilized new UAV system, comprised of remote-controlled helicopter (Hercules II) and digital camera (EOS 30D), was used to characterize spatial and temporal variation in crop production. Digital information was extracted based on an object-oriented segmentation method, and the color parameter was reduced and represented using principal component analysis (PCA). An estimating model was established after analyzing the relationship between the optimal color parameter and ground-based measurements. Model testing demonstrated that unknown samples could be associated with the controlled nitrogen application rates (0, 60, 90, and 120 kg N·hm−2): 91.6% %; N1 (60 kg N·hm−2): 70.83%; N2 (90 kg N·hm−2): 86.7%; N3 (120 kg N·hm−2): 95%. Overall, this result proved to provide a cost-effective and accurate way and the UAV was an exploratory and predictive tool when applied to quantify different status of nitrogen. In addition, it indicated that the application of digital image from UAV to the problem of estimating different nitrogen rates is promising.

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