Decision support systems (DSS) have been used to a very limited extent in pond aquaculture. This study documents the development of a DSS (POND) which allows representation of an entire pond aquaculture facility, and provides analysis capabilities in the form of simulation models and an economics package. Simulation tools in...
A recent development in drift-control for agricultural ground sprayers is the
installation of a hood (or shroud) over the boom. Hoods are designed to provide
a protected zone in which droplets can be sprayed and deposited on the target with
limited interference from the wind.
This study compared chemical drift...
Soil solution samplers have certain inadequacies that limit their range of
possible applications. Passive Capillary Samplers (PCAPS), which apply suction to the
soil pore-water via a fiber glass wick, have shown promising results in preliminary
experiments in regard to collection efficiency of water and of bromide tracers. The
objectives of...
Several methods of infering plant water stress for
irrigation scheduling are based upon measurements of the
environment in which the plants grow. These measurements
include parameters such as soil water content, air
temperature, pan evaporation and incident radiation. It is
hypothesized that improved estimates of plant water deficit
can be...
With the expansion of the Tillamook Creamery, in Tillamook Oregon, to double or more
its cheese production, the demand for milk presents an economic opportunity for the member
dairies of the Tillamook County Creamery Association. Before area dairies can expand their
herd size to increase milk production for the creamery,...
Treatment efficiency in a constructed wetland is related in part to the amount of
time that a wastewater remains in the system. Current design methods idealize the system
as a plug flow reactor and use a "residence time" based solely on the volume of the cell
and the flow rate....
Methane is the most abundant organic chemical in the
earth's atmosphere. Its abundance in the atmosphere is
increasing with time and has reached levels not seen in recent
geological history. The methane is produced both naturally, and
anthropogenically. One of the sources of anthropogenic methane
is manure from domesticated animals....
Recent advances in computer technology have made possible the development of expert systems. Expert systems are computer programs that perform at the level of a human expert. Expert systems can help integrate and apply diverse sources of information and expertise to problems of integrated crop management. A prototype Crop Management...
A two year experiment demonstrated electrical energy savings
through evaporator fan cycling in part of a full-sized refrigerated
controlled atmosphere apple storage facility in Yakima, Washington.
Room cooling demand and evaporator fan operation was controlled by
the bulk fruit temperature. Refrigerant temperature was regulated
by a computer controlled ramping sequence...
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...
Dried cattail and bulrush plant pieces in mesh bags were incubated in the
constructed wetland treating Pope & Talbot pulp mill effluent. Two ponds
planted with each species and two depth ranges in each pond were chosen, to
determine decomposition rates. Bags were withdrawn and analyzed at five time
points...
This project explored the feasibility of using fungi in a constructed wetland
for the treatment of pulp mill effluent. The effluent is high in dissolved
lignins (some of which are chlorinated), which have proven very difficult to
degrade biologically. Mindful of work done with the (terrestrial) white rot
fungi, especially...
Small commercial and non-commercial animal enterprises (SCAEs) raise a few
beef cows, horses, pigs, sheep, poultry, and other animals on a few acres. These
enterprises are often located in suburban areas of watersheds and show potential for
degrading water quality through to increased bacterial, nitrogen, and phosphorus
concentrations. SCAEs implement...
Assessment of the environmental impacts of an agricultural production system
requires information on both soil water quality and solute flux. Passive Capillary Samplers
(PCAPS), which sample water from the vadose zone using fiber glass wicks, have shown
potential to provide both flux and solute concentration in unsaturated zone sampling but...
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...