illustrated that return to VRT and the viable range of spatial variability increased for higher corn and nitrogen prices. …

Agricultural nitrogen losses are the major contributor to nitrogen loads in the Mississippi River, and consequently, to … reducing nitrogen losses. Of particular importance was the study's explicit focus on agricultural subsurface (tile) drainage …, which has been identified as the major pathway for agricultural nitrogen losses in the upper Midwest, and the use of …

Agricultural nitrogen is a major contributor to Gulf of Mexico hypoxia, and research has shown that agricultural … subsurface tile drainage is a major carrier of nitrogen from croplands to streams and rivers. This study compares the results of … abating nitrogen under a retired-land minimization policy with those of a new revenue-maximizing policy, paying particular …

. Optimal nitrogen application recommendations are calculated for the linear response plateau and Spillman-Mitscherlich. The … stochastic models lead to smaller recommended levels of nitrogen, but the economic benefits of using fully stochastic crop yield …

This study presents changes in the concentrations of nitrogen and phosphorus in two streams in Western Antarctica … concentrations of the determined forms of N and P between 2001 and 2005. The decrease ranged from 9.3% for reactive phosphorus to 73 ….2% for ammonium-nitrogen. Such inferred declines in N and P concentrations are considered to reflect reduced deposition on …