نتایج جستجو برای: nitrate nitrogen content

تعداد نتایج: 546641  

Ahmadvand, Maryam , Hashemi Garmdareh, Seyyed Ebrahim , Soltani, Jaber , Varavipour, Maryam ,

Background: Nitrogen leaching from agricultural lands is a major threat to groundwater and surface waters. This study investigated the relationship between the characteristics of wheat-straw biochar produced at different temperatures and its impact on the uptake of NO3--N. Methods: Three types of biochar were produced from wheat straw at three different pyrolysis temperatures of 300, 400 and 5...

Journal: :Plant physiology 1994
T. K. Raab N. Terry

Sugar beets (Beta vulgaris L. cv F58-554H1) were grown hydroponically in a 16-h light, 8-h dark period at a photosynthetic photon flux density of 0.5 mmol m-2 s-1 for 4 weeks in half-Hoagland culture solution containing only nitrate-nitrogen. Half of the plants were then transferred to half-Hoagland solution with ammonium-nitrogen (7.35mM), while the other half continued on 7.5 mM nitrate. Grow...

2013
J. Bednarz

In Oscillatoria chalybea, as in other cyanobacteria, nitrate reduction depends directly on photosynthetic activity. Hence, nitrate reduction occurs only in the light and appears inhibited when photosynthesis is inhibited by the herbicide DCM U. Growth o f Oscillatoria cells is pos­ sible on a variety o f exogenous nitrogen sources in the medium and appears largely independ­ ent on the type of n...

2013
Javad Sharifi Rad Majid Sharifi Rad Abdolhossein Miri

The effect of different sources of nitrate salts (ammonium nitrate, sodium nitrate and potassium nitrate) on nitrate reductase (NR) activity and nitrate reductase expression in the leaves of Foeniculum vulgare seedlings grown in pots containing perlite. Two week old seedlings were treated with 30, 60 and 120 mM aqueous solution of ammonium nitrate, sodium nitrate or potassium nitrate. After 21 ...

Journal: :Applied and environmental microbiology 2000
P R Girguis R W Lee N Desaulniers J J Childress M Pospesel H Felbeck F Zal

The hydrothermal vent tubeworm Riftia pachyptila lacks a mouth and gut and lives in association with intracellular, sulfide-oxidizing chemoautotrophic bacteria. Growth of this tubeworm requires an exogenous source of nitrogen for biosynthesis, and, as determined in previous studies, environmental ammonia and free amino acids appear to be unlikely sources of nitrogen. Nitrate, however, is presen...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2011
Alex C C Wilson Leonel da S L Sternberg Katherine B Hurley

Plant sap-feeding insects and blood-feeding parasites are frequently depleted in (15)N relative to their diet. Unfortunately, most fluid-feeder/host nitrogen stable-isotope studies simply report stable-isotope signatures, but few attempt to elucidate the mechanism of isotopic trophic depletion. Here we address this deficit by investigating the nitrogen stable-isotope dynamics of a fluid-feeding...

2011
Michael Atkin Samira Daroub

3 Introduction Numerous counties within the State of Florida have proposed restrictions on the sale and application of fertilizer. Fertilizer nitrogen is a pollutant in Florida's shallow groundwater. Excessive nitrate-N in drinking water can cause low oxygen in infant's bloodstream (blue baby syndrome), spontaneous abortions, and non-Hodgkin's lymphoma. Average groundwater background nitrate co...

Objective: An experiment was performed in Ardabil (2012) to investigate the effects of manure consumption in different amounts on reducing nitrogen fertilizer consumption in potato cv. Agria. Methods: This research was conducted in factorial design based on randomized completely blocks design in three replication  in which two manure factors in three levels (control, 30 and 60 tons/h) and nitro...

2002
John A. Berges Diana E. Varela Paul J. Harrison

Although temperature effects on phytoplankton growth and photosynthesis can be clearly demonstrated in the laboratory, their relevance in the field is much harder to establish. Recently, however, it has been recognized that temperature has a significant influence on nitrogen uptake. In particular, temperate marine diatom species may be limited by their ability to acquire nitrate at temperatures...

Deficiency of nitrogen may lead to decrease in yield and yield potential of crop plants. An experiment was done under glasshouse conditions in order to investigate nitrogen levels and salicylic acid interaction on some physiologic traits of borage (Borago officinials L.). In this experiment various levels of nitrogen (including; 27.5, 55, 110, 220 and 330 mg/L from ammonium nitrate) and salicyl...

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