The impact of increasing anthropogenic atmospheric nitrogen deposition on marine biogeochemistry is uncertain. We performed simulations to quantify its effect on nitrogen cycling and marine productivity in a global 3-D ocean biogeochemistry model. Nitrogen fixation provides an efficient feedback by decreasing immediately to deposition, whereas water column denitrification increases more gradual...

.soil microorganisms are important agents in nutrient cycling and energy flow. they are extremely sensitive to environmental changes. soil microbial biomass has been proposed as an index of soil stress and disturbance. the objective of this study was to determine the effects of barley (hordeum vulgare l.) residue amounts, burning, nitrogen fertilizer levels and tillage management on organic car...

the use of nitrogen in nutrient media is essential for growth and helps identify highly productive media for potato (solanum tuberosum l.) micropropagation and adventitious shoot formation. three potato cultivars (agria, marfona and savalan cultivars) were examined for their growth response with medium containing four different levels of kno3 (1, 1.25, 1.5 and 1.75 times as much 1.9 g l-1) and ...

in order to study the effects of different irrigation system and different amounts of nitrogen fertilizer on yield and quality of sugar beet, an experiment was conducted at ekbatan research station, hamedan during 2005-2006 as split plot based on randomized complete block design  with three replications. the main plots were irrigation systems (furrow, sprinkler and drip irrigation) and subplots...

Recent advances in biologically based ecosystem models of the coupled terrestrial, hydrological, carbon, and nutrient cycles have provided new perspectives on the terrestrial biosphere's behavior globally, over a range of time scales. We used the terrestrial ecosystem model Century to examine relationships between carbon, nitrogen, and water dynamics. The model, run to a quasi-steady-state, sho...

in order to study the effects of simultaneous application of znso4 and biological fertilizer, azotobacter chroococcum and azospirillum brasilense, on grain yield and nitrogen uptake efficiency in rapeseed (brassica napus l.), cv. hyola308, a field experiment was conducted as split plot factorial based on randomized complete block design at research field of faculty of agricultural sciences, uni...