A monitoring program with a weekly sampling frequency over a 15-month period indicates that urea concentrations above a certain threshold level may trigger the blooms of Alexandrium catenella in Thau lagoon. However, urea concentrations were also sometimes related to ammonium and dissolved organic nitrogen concentrations, indicating that the role of urea may not be a direct one. An original app...

Urea synthesized commercially and formed naturally as a by-product of cellular metabolism is an important source of nitrogen (N) for primary producers in aquatic ecosystems. Although urea is usually present at ambient concentrations below 1 μM-N, it can contribute 50% or more of the total N used by planktonic communities. Urea may be produced intracellularly via purine catabolism and/or the ure...

Raspberries composed of various varieties, are popular ingredients of daily diet with highly distinguished biological activities. In this study, a comparative investigation was conducted on various chemical potential of methanol extracts from Rubus loganobaccus L. leaf parts cultured in greenhouse and open-field. Biochemical activity of the extracts obtained from the field cul...

in order to study the effects of nitrogen (n), boron (b) and sulfur (s) on yield, yield components, oil and protein content of safflower (carthamus tinctorius l.) an experiment was conducted in research station, college of agriculture, shahid bahonar university of kerman, using a local variety’’ isfahan’’. a randomized complete block design with three replications was used. treatments were all ...

Field and laboratory experiments were designed to determine the differential growth and toxin response to inorganic and organic nitrogen additions in Pseudo-nitzschia spp. Nitrogen enrichments of 50 mM nitrate (KNO3), 10 mM ammonium (NH4Cl), 20 mM urea and a control (no addition) were carried out in separate carboys with seawater collected from the mouth of the San Francisco Bay (Bolinas Bay), ...

Cropland soil is an important source of atmospheric nitric oxide (NO) and ammonia (NH3). Chinese croplands are characterized by intensive management, but limited information is available with regard to NO emissions from croplands in China and NH3 emissions in south China. In this study, a mesocosm experiment was conducted to measure NO and NH3 emissions from a typical vegetable-land soil in the...

the nutritional value of cereal straw can be increased using urea treatments as a source of ammonia. the conventional urea treatment process for cereal straw is a laborious and time-consuming task. it is essential to facilitate or eliminate part of the procedure with the use of machinery. this study examines the mechanical urea treatment of wheat straw and compares chemical components and diges...

abstract to study the effects of different levels of n, mn and zn on yield and quality of pomegranate fruit a factorial experiment based on complete randomized block design with 18 treatments and three replications was conducted in behshahr city, mazandaran province, in 2009.investigated treatments were include: nitrogen, manganese, zinc. fertilizer source for nitrogen was urea and three rates ...

The revolving algal biofilm (RAB) system is a wastewater treatment method that effective at removing nutrients from wastewater, and as result produces algae could be used sustainable fertilizer source. A two-year greenhouse study was conducted to investigate if algae-based fertilizers produced the RAB an turfgrass fertilizer. Fertilizer treatments included pure (PA), + cellulosic filler (Blende...

BACKGROUND: Fertilizer management plays an important role to achieve sustainable agriculture. OBJECTIVES: Current study was conducted to assess response of agrophysiological traits of wheat to apply different level of fertilizer and biologic fertilizer (Phosphorus and Nitrogen). METHODS: This research was carried out via factorial e...