A growth model is developed for coho salmon which accounts for
temperatures and feeding rates typically encountered in fish hatchery
operation. Feeding rates utilized by the model ranged from
maintenance to maximum utilizable rations. The model is derived from
an empirical equation for maximum growth rate, and a theoretical
equation...
Potato ground cover and spectral data were measured
in the Columbia Basin during the 1990 growing season.
Three spectral were correlated with ground cover;
normalized difference, near infrared-red ratio, and the
first derivative of the spectral curve at 750 nm. All
models were statistically significant at the 99% level.
Normalized...
This study investigated the effect of plant surface
area (plant density) on the efficiency of organic carbon
removal in a bench-scale constructed wetland.
Constructed wetlands are commonly assumed to be biofilm
reactors in which organic carbon removal occurs primarily
through sedimentation and aerobic degradation by attached
microbial biofilms. In conventional...
Nitrate contamination in ground and surface waters is of great concern to environmentalists. A two-dimensional model of water and solute movement in soils was used to test the usefulness and relative advantages of a two-dimensional model over a one dimensional model for analysis of deep percolation and nitrate leaching in...
Furrow irrigation is the dominant practice for irrigating row crops in the western Treasure Valley region near Ontario, Oregon. Though improvements have been made in management practices over the years, excessive runoff and deep percolation are still important problems contributing to surface water and groundwater degradation. Field observations were made...
The shallow aquifer in Northeast Malheur County, Oregon is polluted with Nitrates at concentrations exceeding federal drinking water standards. Efforts to solve the groundwater problems in this area have focused on developing farm management practices that will increase groundwater quality while maintaining agricultural production. Furrow irrigation is the dominant practice...
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...
Recycling of water in aquaculture facilities is used to minimize the amount of energy or tempered water required to control water temperatures. The rate of heat exchange between the water and the environment can be an important variable in the design, management, and economic analysis of a recycle system. A...