Dry land agriculture using summer fallow is a common crop production
practice in the Columbia Plateau region of eastern Oregon. Farmed-over level
terraces are used to control surface water runoff and soil erosion. More than
70 percent of the average annual precipitation around Pendleton, Oregon (350 -
400 mm) falls...
Nitrification and denitrification are major biological processes transforming nitrogen (N) in soils to plant available N, highly leachable nitrate (NO₃⁻) and gaseous N oxides. Although many studies in the past have studied N cycling communities, the effect of increased N inputs on ammonia-oxidizer and denitrifier population dynamics is still under...
Soils of 49 agricultural and 2 "native condition" sites in the Lower Umatilla Basin,
Oregon were sampled for nitrate-nitrogen, ammonium-nitrogen, chloride, and pH
beginning in Fall of 1992. Several sites were sampled in Spring and Fall 1993 in order to
indicate movement or loss of residual soil nitrogen over time....
Forest harvest persists as one of the most globally important industries, and crucially provides raw wood products for both building and fuel materials. Mechanistically complex abiotic and biotic processes curb ecosystem recovery following timber harvest and it is of great importance to understand the effects of this practice on biogeochemical...