Effects of contrasting climatic conditions and nitrogen (N) deposition levels on streamwater N dynamics are assessed at two small heathland catchments; Dalelva in northern Norway (69oN) and Øygard in southwestern Norway (58oN). The study comprises 11 years of data on climate, hydrology and N inputs/outputs from Dalelva and 8 years of corresponding data from Øygard. Both sites are comparable in ...

We examined the hypothesis that elevated CO2 concentration would increase NO3- absorption and assimilation using intact wheat canopies (Triticum aestivum cv. Veery 10). Nitrate consumption, the sum of plant absorption and nitrogen loss, was continuously monitored for 23 d following germination under two CO2 concentrations (360 and 1000 micromol mol-1 CO2) and two root zone NO3- concentrations (...

The fluxes and transformations of nitrogen (N) were investigated from 1985 through 1987 at the Emerald Lake watershed (ELW), a 120 ha high-elevation catchment located in the southern Sierra Nevada, California, USA. Up to 90% of annual wet deposition of N was stored in the seasonal snowpack; NO3 and NH+ were released from storage in the form of an ionic pulse, where the first fraction of meltwat...

Root development is extremely sensitive to variations in nutrient supply, but the mechanisms are poorly understood. We have investigated the processes by which nitrate (NO3-), depending on its availability and distribution, can have both positive and negative effects on the development and growth of lateral roots. When Arabidopsis roots were exposed to a locally concentrated supply of NO3- ther...

The Catskill Mountains of southeastern New York receive relatively high rates of atmospheric N deposition, and NO3 concentrations in some streams have increased dramatically since the late 1960s. We measured the chemistry of 39 firstand second-order streams with forested watersheds to determine the variability of nitrogen concentrations within the Catskill Mountain area. We found that some stre...

With current agricultural practices the amounts of fertilizer N applied are frequently more than the amounts removed by the crop. Excessive N application may result in short-term accumulation of nitrate nitrogen (NO3-N) in soil, which can easily be leached from the root zone and into the ground water. A management practice suggested for conserving accumulated NO3-N is the application of oily fo...

Effects of contrasting climatic conditions and nitrogen (N) deposition levels on streamwater N dynamics are assessed at two small heathland catchments; Dalelva in northern Norway (69oN) and Øygard in southwestern Norway (58oN). The study comprises 11 years of data on climate, hydrology and N inputs/outputs from Dalelva and 8 years of corresponding data from Øygard. Both sites are comparable in ...

Removal efficiency of COD, NH4-N and PO4-P and NO3-N in five step SBR processes is widely influenced by hydraulic retention time of Anaerobic/Anoxic/Aerobic/Anoxic/Aerobic step of this system where the hydraulic retention time in each step is influence directly on removal efficiency of this system therefore the operator of this system cannot control on this system without experience or a contro...

A sequencing batch reactor (SBR) was operated to develop denitrifying bacteria that had a mean specific denitrification rate of 0.11 g NO3 -N/gVSS/day. Another system (an anaerobic digester) was operated to generate volatile fatty acids (VFAs) with the effluent concentration being measured to be 5655 ± 876 mg/L as acetic acid. Using the denitrifying biomass developed in the SBR and VFAs generat...