نتایج جستجو برای: nh4

تعداد نتایج: 4997  

Journal: :Ecological applications : a publication of the Ecological Society of America 2017
Alexander V Alexiades Alexander S Flecker Clifford E Kraft

Each year, millions of hatchery-raised fish are stocked into streams and rivers worldwide, yet the effects of hatchery-raised fish on stream nutrient cycles have seldom been examined. We quantified the influence of supplemental nonnative fish stocking, a widespread recreational fishery management practice, on in-stream nutrient storage and cycling. We predicted that supplemental, hatchery-raise...

2008
Mark W. Szczerba Dev T. Britto Konstantine D. Balkos

Futile plasma membrane cycling of ammonium (NH4 ) is characteristic of low-affinity NH4 + transport, and has been proposed to be a critical factor in NH4 + toxicity. Using unidirectional flux analysis with the positronemitting tracer N in intact seedlings of barley (Hordeum vulgare L.), it is shown that rapid, futile NH4 + cycling is alleviated by elevated K supply, and that low-affinity NH4 + ...

ژورنال: علوم آب و خاک 2014
جعفری, سیروس, پیشگیر, معصومه,

This study was done to compare K+ and NH4+ fixation in different agricultural systems in Khuzestan province. Soil samples were collected from Shushtar and Abadan. Samples were collected from depths of 0-30 and 30-60 cm in sugarcane, multi cropping, palm and uncultivated land. Then, 0-50-100-200-400-600-800-1000 mg kg-1 K+ or NH4+ concentrations were added to 0.5 gram of clay separated from thes...

2008
PHILIP ROBERTSON

A six-point primary sere developed on sand dunes and a four-point secondary sere developed on old fields were studied to examine the regulation of nitrification in succession. Soils from sites along the seres were incubated in funnel-microlysimeters leached weekly with NH4CI and other nutrient solutions. Nitrate output in soils from the five youngest sites along the primary sere was rapidly sti...

Journal: :علوم باغبانی 0
عبدالرضا سجادی نیا حمید روستا محمد سوری اصغر رحیمی

abstract in this study different proportions of nh4+ and no3- in the growth medium on plant growth were investigated in hydroponic greenhouse experiments. the objectives of these studies were to investigate if ammonium (nh4+) stress in cucumber, a species sensitive to nh4+ toxicity, can be alleviated by matching the nitrogen supply rate to the plant nitrogen demand. ammonium was applied at a re...

2012
Matthias Weil

In comparison with the original determination based on Weissenberg film data [Khan et al. (1970 ▶). Acta Cryst. B26, 1889-1892], the current redetermination of diammonium hydrogenarsenate(V) reveals all atoms with anisotropic displacement parameters and all H atoms localized. This allowed an unambiguous assignment of the hydrogen-bonding pattern, which is similar to that of the isotypic phospha...

Journal: :Journal of experimental botany 2008
Mark W Szczerba Dev T Britto Konstantine D Balkos Herbert J Kronzucker

Futile plasma membrane cycling of ammonium (NH4+) is characteristic of low-affinity NH4+ transport, and has been proposed to be a critical factor in NH4+ toxicity. Using unidirectional flux analysis with the positron-emitting tracer 13N in intact seedlings of barley (Hordeum vulgare L.), it is shown that rapid, futile NH4+ cycling is alleviated by elevated K+ supply, and that low-affinity NH4+ ...

2010
Floor ten Hoopen Tracey Ann Cuin Pai Pedas Josefine N. Hegelund Sergey Shabala Jan K. Schjoerring Thomas P. Jahn

Plants can use ammonium (NH4+) as the sole nitrogen source, but at high NH4+ concentrations in the root medium, particularly in combination with a low availability of K+, plants suffer from NH4+ toxicity. To understand the role of K+ transporters and non-selective cation channels in K+/NH4+ interactions better, growth, NH4+ and K+ accumulation and the specific fluxes of NH4+, K+, and H+ were ex...

2005
Duoying Zhang Fengming Ma Yue Zhao Caifeng Li

Solution culture experiments were carried out to study the kinetics at cotyledon stage (11-day-old) and the effect of different NO3/NH4 on NO3 and NH4 uptake at seedling stage (31-day-old) with two cultivars of sugar beet, including Tianyan7 and Tianyan8. NO3 uptake by sugar beet seedlings at cotyledon stage (11-day-old) reached equilibration after 2 hours of adaptation, and NH4 uptake reached ...

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