A 60-year database of nitrate concentrations from more than 200 wells in and around Phoenix, Arizona, was studied using geographic information system tools. This information, augmented with land-use maps, ground water levels, and well construction details, was used to examine ground water nitrate concentrations and changes in concentration and their relationship to land use, land-use changes, a...

Nitrate contamination of municipal and domestic well water supplies is becoming an increasing problem in many rural and urban areas, raising the cost of providing safe drinking water. The objective of this paper is to describe a marketable permit scheme that can effectively manage nitrate pollution of groundwater supplies for communities in rural areas without hindering agricultural production ...

15N-labeled fertilizer was applied to Sorghum at different rates (0, 100 kg N.ha -1 ) to 1m2 microplots and with two kind of water (well water “WW” and treated wastewater “TWW”) to Sorghum grown in field during 1997 and 1999. Increases in DM production, N uptake and 15 NRF were observed with TWW. About 17% and 36% of the 15Nfertilizer were recovered in the crop with TWW in 1997 and 1999, respec...

Snowmelt dominates the hydrograph of many temperate montane streams, yet little work has characterized how streamwater sources and nitrogen (N) dynamics vary across wildland to urban land use gradients in these watersheds. Across a third-order catchment in Salt Lake City, Utah, we asked where and when groundwater vs shallow surface water inputs controlled stream discharge and N dynamics. Stream...

Nitrogen (N) pollution is emerging as one of the most important environmental issues of the 21st Century, contributing to air and water pollution, climate change, and stratospheric ozone depletion. With agriculture being the dominant source, we tested whether it is possible to reduce agricultural N pollution in a way that benefits the environment, reduces farmers' costs, and increases fertilize...

The disposal of manure on agricultural land has caused water quality concerns in many rural watersheds, sometimes requiring state environmental agencies to conduct total maximum daily load (TMDL) assessments of stream nutrients, such as nitrogen (N) and phosphorus (P). A best management practice (BMP) has been developed in response to a TMDL that mandates a 50% reduction of annual P load to the...

A highly effective biological fertilizer (bio-fertilizer) can be produced cheaply in countries that have a source of a suitable type of zeolitic rock (tuff). Such rocks occur worldwide in areas of past or current volcanism. In the event of explosive volcanic activity huge volumes of silicic glass and other debris are projected into the atmosphere. Reaching high altitude the fine material is sep...