Abstract Critical Zone Observatories (CZOs) have been established initially in natural
environments to monitor CZ processes. A new generation of CZOs has been extended to …

Nitrogen isotope ratios of soil water and ground water nitrate have been used to identify or
implicate sources; however, lack of data on δ15N in thick (> 12 m) vadose zones beneath …

Among the mineral nutrient elements, nitrogen (N) most often limits the growth and yield of
nonleguminous crop plants, which require relatively large quantities of N (from 1.5 to 5% of …

Changes in agricultural management can minimize NO3–N leaching, but then the time
needed to improve ground water quality is uncertain. A study was conducted in two first …

The time it takes for deep percolation water from irrigated fields to reach underlying
groundwater increases with decreasing particle size of the vadose zone material and …

Monitoring groundwater quality and analyzing geochemical processes are very crucial in dry
environments, especially in areas with intense agriculture and inadequate irrigation …

The role of cation exchange in the retardation of am-monium (NH4+) and potassium (K+)
transport in a shallow sand and gravel aquifer was evaluated by use of observed …

Munition residues from waste disposal on ordnance property have resulted in a defined
plume of RDX contaminated groundwater stretching 6.5 km and underlying an area of 6.5 …

The Susquehanna River is a major contributor of nutrients and sediment to Chesapeake
Bay, the most productive estuary in North America. Excessive nitrogen (N) loading to the bay …

Twenty wells were sampled and analyzed for nitrate content and nitrogen isotopes during
late September, 1986. The groundwater nitrate δ 15 N values ranged from+ 6.8 to+ 17.6 …