While nitrogen (N) is an essential element for life, human population growth and demands for energy, transportation and food can lead to excess nitrogen in the environment. A modeling framework is described and implemented to promote a more integrated, process-based and systemlevel approach to the estimation of ammonia (NH3) emissions which result from the application of inorganic nitrogen fert...

Technologies and management practices (TMPs) that reduce the application of nitrogen (N) fertilizer while maintaining crop yields can improve N use efficiency (NUE) and are important tools for meeting the dual challenges of increasing food production and reducing N pollution. However, because farmers operate to maximize their profits, incentives to implement TMPs are limited, and TMP implementa...

Further reductions in pollution will require new management approaches based on ecosystem concepts. In this paper we examine three case studies that analyze flows of nutrients in urban ecosystems to identify new approaches for pollution management. An analysis of the food chain for the Twin Cities (Minneapolis-St. Paul, Minnesota, USA) is used to examine generation of nutrient pollution in the ...

Legumes play a crucial role in agricultural and ecosystems based on their ability to convert atmospheric nitrogen gas into plant-available ammonium in symbiosis with soil bacteria commonly called ‘rhizobia’. This nitrogen-fixing ability makes legumes attractive as an agricultural, economical and environmentally friendly crop as their requirement for nitrogen fertilizer is reduced, leading to a ...

We studied nutrient balance in a paddy field that had a recycling irrigation system and evaluated the effect of the irrigation system on nutrient balance during the irrigation period, from April to August 2002. Chemical fertilizer was the main input of phosphorus; the soil absorbed about 56% of it. The amount of nitrogen supplied by the irrigation system was higher than in a representative padd...

Nitrogen (N) fertilizer management in young hardwood plantations is difficult due to our lack of understanding of the site-specific mechanisms that control tree response. Differences in landuse history and soil characteristics can alter the plant response to added N considerably. Foliage biomass, N content, N concentration, resorption, and soil N supply characteristics were measured on two 4 ye...

Objective: An experiment was performed in Ardabil (2012) to investigate the effects of manure consumption in different amounts on reducing nitrogen fertilizer consumption in potato cv. Agria. Methods: This research was conducted in factorial design based on randomized completely blocks design in three replication  in which two manure factors in three levels (control, 30 and 60 tons/h) and nitro...