Soil moisture in a crop's root zone must be regularly
monitored to accurately predict crop water requirements.
Most irrigation scheduling services currently
use the neutron probe to monitor soil moisture. Unfortunately,
there is a degree of variability associated
with use of the neutron probe creating uncertainty in
measurements of soil...
Four years of daily weather observations from Central Tunisia were available for testing the application of the Penman Equation to estimate reference evapotranspiration in the arid climate of Central Tunisia. The data included minimum and maximum temperature, minimum and maximum relative humidity, 24-hour wind run, and lysimeter measurements of reference...
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...