Traditionally, livestock operations were small and combined with cropping operations. This allowed farms to be self-sustaining because nutrients were constantly recycled on the farm. Since the Haber-Bosch chemical process was patented, crop farmers turn to industrial fertilizers when soils nutrients are depleted. Animal and plant operations diverged, functionally separated, and...
Mass transfer processes in food systems, such as solute infusion, are poorly understood because of their complex nature. Food systems contain porous matrices and a variety of continuous phases within cellular tissues. Mass transfer processes are generally not pure diffusion: often convection, binding and obstructing diffusion will occur. Monte Carlo...
Improved water use efficiencies in irrigated agriculture are necessary to assist in coping with the accelerating demand and economic competition for the world's fresh water supply and increasing ecological concerns. This will likely rely in part on optimum irrigation, which implies regulated deficit irrigation. While conventional irrigation management is intended...
Often furrow irrigation application efficiencies are low compared to sprinkler systems. The primary goal of furrow irrigation is to infiltrate a relatively uniform target depth of water necessary for the crop, while minimizing the amount of runoff. The concept is difficult because water can infiltrate differently at all locations in...
Using network architecture to describe a biological system is an effective organizational method. The utility of this approach, which generally applies to qualitative models, is enhanced by the addition of quantitative models characterizing the interactions between network nodes. A chromatophore-based signal transduction network is developed, and the highly interconnected major...
Non-dilute salt strength solutions occur in many near surface geologic environments. In order to better understand the occurrence and movement of the water and salt, mathematical models for this non-ideal fluid need to be developed. Initial boundary value problems may then be solved to predict behavior for comparison with observations....
Channel evolution and influences of changing floodplain characteristics, heterogenous bank materials, and altered flow regimes were examined along the Willamette River, a large alluvial river in northwestern Oregon. The Willamette River is composed of a series of geomorphically diverse reaches, which have each evolved uniquely in the century following Euro-American...
The fate of antimicrobials entering the aquatic environment is an increasing concern for researchers and regulators, and recent research has focused on antimicrobial contamination from point sources, such as wastewater treatment facility outfalls. The terraccumulation of antimicrobials and mobility in diffuse pollution pathways should not be overlooked as a contributor...
Increasing costs for wastewater treatment provide incentives to
evaluate system alternatives, especially among small communities with limited
financial resources. Land treatment systems with hybrid poplar tree
plantations are becoming increasingly popular as one such alternative in the
Pacific Northwest.
Land treatment systems are made up of a complex dual system:...
Unpaved roads are sources of chronic sediment in forested watersheds. Bare soil on roads is exposed to erosion from rainfall and runoff Published research on sediment production from forest roads focuses primarily on road characteristics. Since water drives the mechanics of sediment transport, hydrologic variables should correlate with sediment production....