Picoplankton populations dominate the planktonic community in surface oligotrophic ocean. Yet, their strategies acquisition and partitioning of organic inorganic sources nitrogen (N) carbon (C) are poorly described. Here, we measured at single-cell level uptake dissolved C (C-fixation), C-leucine, N-leucine, nitrate (NO3?), ammonium (NH4+), N-urea pigmented nonpigmented picoplankton groups six ...

Two successive lettuce crops were grown in spring 2005 in a completely closed hydroponic system. The ratio of ammonium to total nitrogen (Nr) in the fresh nutrient solution (FNS) introduced into the closed system to compensate for plant uptake was 0, 0.1, 0.2 and 0.3 on amolar basis. In allNr treatments, the concentrations of total N, K, Ca, Mg, P, and micronutrients in the FNS were identical, ...

Plants are dependent on exogenous nitrogen (N) supply. Ammonium (NH₄(+)), together with nitrate (NO₃(-)), is one of the main nitrogenous compounds available in the soil. Paradoxically, although NH4 (+) assimilation requires less energy than that of NO₃(-), many plants display toxicity symptoms when grown with NH₄(+) as the sole N source. However, in addition to species-specific ammonium toxicit...

Most of the studies about NH4+ stress mechanism simply address the effects of free NH4+, failing to recognize the changed nitrogen assimilation products. The objective of this study was to elucidate the effects of glutamate on root growth under high ammonium (NH4+) conditions in winter wheat (Triticum aestivum L.). Hydroponic experiments were conducted using two wheat cultivars, AK58 (NH4+-sens...

phytoplankton communities play a significant role in the oceanic biological pump by forming the base of the trophic structure. increase in nutrients loading affects spatial and temporal distribution of phytoplankton. this study examined the phytoplankton community structure and ecological indices in relation to nutrients dynamics in both estuarine and oceanic areas of ramisi-vanga systems along...

The ecological problems caused by dry and wet deposition of atmospheric nitrogen have been widespread concern in the world. In this study, wet and dry atmospheric depositions were monitored in plant growing season in the coastal zone of the Yellow River Delta (YRD) using automatic sampling equipment. The results showed that SO4 (2-) and Na(+) were the predominant anion and cation, respectively,...

The total nitrogen (TN) increases and the water quality deteriorates when a large amount of nitrogen-containing is discharged from farmlands into wetlands. This research on relationship between TN, ammonia (NH4-N), nitrate (NO3-N) concentrations in has certain reference significance for understanding spatial pattern removal Taking Sanhuanpao wetland northeast China as object, 24 sampling plots ...

Free ammonium in industries wastewater could be one of the worst toxic contaminants of aquatic life if diluted in water. Biological nitrogen removal (BNR) is the most common method for removing ammonium and nitrate from wastewater. Attached growth and suspended growth are the main BNR systems. The aim of the present work was to study the treatment of petrochemical wastewater (ammonium and nitra...

Moving bed biofilm reactors (MBBRs) were placed at two wastewater treatment plants, where they constantly fed with effluent and intermittently primary wastewater. Each reactor was subjected to different feast/famine periods flow rates of wastewater, thus the organic nutrient loads (chemical oxygen demand(COD), ammonium(NH4-N)) resulted in feast-famine conditions applied biomass. In batch experi...