Citation: Atkins JF, Moloney CL, Probyn TA and Bernard S (2016) In situ Measurements and Model Estimates of NO3 and NH4 Uptake by Different Phytoplankton Size Fractions in the Southern Benguela Upwelling System Front. Mar. Sci. 3:194. doi: 10.3389/fmars.2016.00194 In situ Measurements and Model Estimates of NO3 and NH4 Uptake by Different Phytoplankton Size Fractions in the Southern Benguela Up...

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, ...

Adsorption and desorption of phosphorus (P) and nitrogen (N) by stalk residues may influence the concentrations of P and N in runoff. A laboratory study was conducted to measure the effects of P and N constituents in solution on adsorption and desorption of P and N by corn, soybean, and wheat stalk residues. Experimental variables included type of stalk material (corn, soybean, and wheat), inor...

Nitrate transporters (NRTs) play an important role in nitrate absorption and internal distribution plant roots other parts. Experiments were carried out to explore the sequences expression characteristics of NRT genes, their correlation with N uptake flowering Chinese cabbage. We have isolated three BcNRTs (BcNRT1.1, BcNRT1.2, BcNRT2.1) from Spatio-temporal analysis found that BcNRT1.1 BcNRT2.1...

We compared growth kinetics of Prorocentrum donghaiense cultures on different nitrogen (N) compounds including nitrate (NO3-), ammonium (NH4+), urea, glutamic acid (glu), dialanine (diala) and cyanate. P. donghaiense exhibited standard Monod-type growth kinetics over a range of N concentraions (0.5-500 μmol N L-1 for NO3- and NH4+, 0.5-50 μmol N L-1 for urea, 0.5-100 μmol N L-1 for glu and cyan...

Availability and leaching of dissolved inorganic N (DIN = NH4 + NO3) in soil were measured in a periodically flooded forest of the Central Amazon floodplain (v rzea) during one terrestrial phase. Special emphasis was on the effects of a legume and a nonlegume tree species. NH4-N accounted for more than 85% of DIN even at the end of the terrestrial phase although it decreased throughout the expe...

Ammonium (NH4) toxicity is an issue of global ecological and economic importance. In this review, we discuss the major themes of NH4 toxicity, including the occurrence of NH4 in the biosphere, response differences to NH4 nutrition among wild and domesticated species, symptoms and proposed mechanisms underlying toxicity, and means by which it can be alleviated. Where possible, nitrate (NO3) nutr...