An increasing nitrogen deposition experiment (2 g N m 2 year 1) was initiated in an alpine meadow on the Qinghai-Tibetan Plateau in May 2007. The greenhouse gases (GHGs), including CO2, CH4 and N2O, was observed in the growing season (from May to September) of 2008 using static chamber and gas chromatography techniques. The CO2 emission and CH4 uptake rate showed a seasonal fluctuation, reachin...

Languishing for many years in the shadow of plant inorganic nitrogen (N) nutrition research, studies of organic N uptake have attracted increased attention during the last decade. The capacity of plants to acquire organic N, demonstrated in laboratory and field settings, has thereby been well established. Even so, the ecological significance of organic N uptake for plant N nutrition is still a ...

We examined the ability of seagrasses to take up dissolved organic nitrogen (DON) with leaves (in situ) and roots (laboratory) in an oligotrophic tropical offshore meadow in Indonesia using 15N-labeled nitrogen (N) substrates. We compared the uptake of urea and amino acids with that of ammonium (NH z4 ) and nitrate (NO { 3 ) and determined uptake kinetics of amino acids for the seagrasses Thala...

Superintendents know that management of putting greens is an art. Greens are often made of high-porosity sand that does not retain water or nutrients very effectively. Also, putting green grasses are cut extremely short, which does not allow a deep root system to develop and take up nutrients from deep in the soil profile. Therefore, putting greens require frequent irrigation and fertilizer app...

[1] Prochlorococcus is ubiquitous in tropical oceans, but its biogeochemical role is not well constrained. For example, cultured Prochlorococcus clones do not grow on NO3 !, but these cultured clones may only represent 10–15% of the natural population variance resulting in a biased biogeochemical role. We report NO3 !, NO2 !, NH4 + and urea uptake rates for flow-cytometrically sorted Sargasso S...

abstract biological and chemical changes in rhizosphere following organic residues as well as manures application are important processes which influence nitrogen mineralization and nutrients bioavailibity in soils. this study was done to evaluation of organic residues effect on growth, nitrogen supply and rhizosphere characteristics of corn and sunflower plants in greenhouse experiment using s...

Green mussels (Perna viridis) can effectively remove nutrients from seawater through their filtration process. This study aims to estimate “net” nutrient removal rate by green mussel through calculation of nutrient uptake and release. Nutrients (carbon, nitrogen and phosphorus) uptake was calculated based on the mussel filtration rate. Nutrient release was evaluated from carbon, nitrogen and ph...