Recent increases in nitrate concentrations in the Suwannee River and associated springs in northern Florida have raised concerns over the contributions of non-point sources. The Middle Suwannee River Basin (MSRB) is of special concern because of prevalent karst topography, unconfined aquifers and sandy soils which increase vulnerability of the ground water contamination from agricultural operat...

[1] Soil water dynamics and drainage are key abiotic factors controlling losses of atmospherically deposited N in Southern California. In this paper soil N leaching and trace gaseous emissions simulated by the DAYCENT biogeochemical model using its original semi‐dynamic water flow module were compared to that coupled with a finite element transient water flow module (HYDRUS), for two mixed coni...

correlated with human population densities in various watersheds (Peierls et al., 1991; Vitousek et al., 1997). Turfgrass landscapes have the potential for loss of applied N However, the underlying sources of elevated N in waterthrough both runoff and leaching. Lower maintenance alternative vegetation used in mixed-species landscapes may reduce N leaching sheds remain unclear. One possibility i...

Establishing the relationship among the spatial distribution of forest ecosystems, N cycling processes, and N loss following harvesting could enable land managers to anticipate and predict the potential for N loss at the scale of local and regional landscapes. In the Great Lakes region, northern hardwood forests with distinct floristic, edaphic, and physiographic characteristics vary predictabl...

An accurate and management sensitive simulation model for tile-drained Midwestern soils is needed to optimize the use of agricultural management practices (e.g., winter cover crops) to reduce nitrate leaching without adversely affecting corn yield. Our objectives were to enhance the Agricultural Production Systems Simulator (APSIM) for tile drainage, test the modified model for several manageme...

Although short-rotation woody crop biomass production technology has demonstrated a promising potential to supply feedstocks for bioenergy production, the water and nutrient processes in the woody crop planation ecosystem are poorly understood. In this study, a computer model was developed to estimate the dynamics of water and nitrogen (N) species (e.g., NH-N, NO-N, particulate organic N, and s...

Improper use of urea may cause environmental pollution through NH3 volatilization and NO3 (-) leaching from urea. Clinoptilolite zeolite and compost could be used to control N loss from urea by controlling NH4 (+) and NO3 (-) release from urea. Soil incubation and leaching experiments were conducted to determine the effects of clinoptilolite zeolite and compost on controlling NH4 (+) and NO3 (-...

The steady-state First-order Acidity Balance (FAB) model for calculating critical loads of sulphur (S) and nitrogen (N) is applied to 609 Norwegian soft-water lakes to assess the future nitrate (NO3 -) leaching potential under present (1992-96) S and N deposition. The lakes were separated into five groups receiving increasing levels of N deposition (<25, 25-49, 50-74, 75-99 and 100-125 meq m-2 ...

Nitrogen (N) export from soils to streams and groundwater under the intensifying cropping schemes of the Pampas is modest compared to intensively cultivated basins of Europe and North America; however, a slow N enrichment of water resources has been suggested. We (1) analyzed the fate of fertilizer N and (2) evaluated the contribution of fertilizer and soil organic matter (SOM) to N leaching un...