The potential for denitrification in marl and peat sediments in the Shark River Slough in the Everglades National Park was determined by the acetylene blockage assay. The influence of nitrate concentration on denitrification rate and N(2)O yield from added nitrate was examined. The effects of added glucose and phosphate and of temperature on the denitrification potential were determined. The se...

mapping of groundwater nitrate can be useful in management of groundwater resources. the objectives of this study were to analyze the spatial variability of nitrate and to map its contamination in the lordegan aquifer and to evaluate the variations in nitrate variability and mapping during a year. then 32 wells were sampled four times during 2010. seasonal nitrate concentrations remained consta...

Elevated atmospheric CO2 concentrations (eCO2) has become the main feature and cause of global change that could affect crop growth in many aspects, including physiological processes morphological development plants nutrient cycling uptake from soil. Studying responses to different nitrogen (N) supply forms under elevated can guide management strategies for agricultural production future climat...

Nitrate and ammonium concentration in wet deposition detrimentally impacted a sensitive pollution indicator species irrespective of the nitrogen dose.

Root development is strongly affected by the plant's nutritional status and the external availability of nutrients. Employing split-root systems, we show here that local ammonium supply to Arabidopsis thaliana plants increases lateral root initiation and higher-order lateral root branching, whereas the elongation of lateral roots is stimulated mainly by nitrate. Ammonium-stimulated lateral root...

In cyanobacteria, the transcriptional activator NtcA is involved in global nitrogen control and, in the absence of ammonium, regulates the expression of genes involved in the assimilation of alternative nitrogen sources. The oceanic picocyanobacterium Synechococcus sp. strain WH 8103 harbors a copy of ntcA, but in the present study, we show that unlike other marine cyanobacteria that have been ...

†Background and Aims One of the most striking attributes of clonal plants is their capacity for physiological integration, which enables movement of essential resources between connected ramets. This study investigated the capacity of physiological integration to buffer differences in resource availability experienced by ramets of the clonal wild strawberry plant, Fragaria vesca. Specifically, ...

Wet deposition of nitrogen (N) occurs in oxidized (nitrate) and reduced (ammonium) forms. Whether one form drives vegetation change more than the other is widely debated, as field evidence has been lacking. We are manipulating N form in wet deposition to an ombrotrophic bog, Whim (Scottish Borders), and here report nine years of results. Ammonium and nitrate were provided in rainwater spray as ...

Greenhouse studies were conducted in 2006 to evaluate the effects of urea ammonium nitrate (UAN) solution on bispyribac and penoxsulam efficacy on barnyardgrass and hemp sesbania. Bispyribac and penoxsulam treatments containing an adjuvant and UAN significantly reduced barnyardgrass biomass over most treatments without UAN. Urea ammonium nitrate did not increase hemp sesbania biomass reduction,...