The critical role streamside riparian zones play in mitigating the movement of nitrogen (N) and other elements from terrestrial to aquatic ecosystems could be threatened by residential development in the southern Appalachian Mountains. Many studies have investigated the influence of agriculture on N loading to streams but less is known about the impacts of residential development. Here we consi...

A declining Picea abies (L.) Karst. stand produced as much foliage and branches as a healthy stand but less stemwood at a similar leaf area index and climate. Nutrient analyses revealed that most biomass components at the declining site had lower concentrations of calcium and magnesium, but similar nitrogen and potassium (except for lower potassium in younger needles) and higher phosphorus , ma...

Clear-cutting of forests affects the nitrogen cycle and the nitrogen isotopic composition of bioavailable ammonium and nitrate in the soil. Here, we have used nitrogen isotopic variations of tree-rings in red oak (Quercus rubra) and white oak (Quercus alba) as indicators of changes in the nitrogen cycle on a local scale. The delta15N values of late-wood from trees at two remnant forest stands i...

Concentration together with the stable isotope composition (δ15N) of both ammoniumand nitrate-nitrogen were conducted for sedentary soils under the piscivorous seabird colony developed on Quaternary basaltic ejecta from the Hatana islands, Fiji, south Pacific. Higher inorganic nitrogen content (up to 2,420 mg-N/kg dry soil) was observed for soils under dense forest vegetation, relative to a low...

Field experiment was carried out to study on the spatial and temporal distribution of soil nitrate nitrogen at Ranzhuang water resources experiment station in Hebei piedmont plain from 2011 to 2012. The results show that nitrate nitrogen content varies in sinusoidal curve at shallow tilth soil and shows in “W” shape at deep soil profile during the wheat-maize rotation period. Nitrate nitrogen i...

Nitrogen-nitrate, while being fundamental for crop production, is of particular concern in the agricultural sector, as it can easily leach to water table, worsening groundwater quality. Numerical models and Geographic Information System may support estimation nitrate leaching rates space time, sustainable management practices. In this paper, we present a module simulation processes involved nit...

Monolithic waste materials (e.g. Portland cement treated wastes) in many field scenarios do not remain continuously saturated, but experience intermittent wetting interspersed with periods of storage in an unsaturated environment. During storage, the matrix may loss moisture to the environment, promoting precipitation or redistribution of species. In addition, the matrix may react with the surr...

Land application of animal manure is an important means of utilization of nitrogen and phosphorus. However, the presence of pathogens in manure and their occasional leaching into subsurface water has become a topic of concern during the past few years. This study was undertaken to determine the extent to which Salmonella anatum may leach through tile-drained clay loam soil on which swine manure...